Search

Humans are exposed daily to metallic nanoparticles (Me NPs) from multiple sources which can have both natural and anthropogenic origins. Such exposures take place via different routes including inhalation and skin contact and may result in adverse health effects. The objectives of this thesis were to investigate surface interactions taking place on metallic nanoparticles upon simplified inhalation and how such interactions influence their toxic potency. Except for the particle and surface characteristics, the interface to the cell environment, the extent, speciation of the released metal fraction, and the ability of the particles to form reactive oxygen species (ROS) were investigated as these parameters are known to largely govern the cell toxicity. ROS naturally form in the cells as an essential part of our immune system, but can in excess, result in cell membrane damage and harmful effects. This has been studied using a multianalytical and interdisciplinary approach combining surface and material chemistry with toxicological investigations with the main focus on ROS formation. The study has for example elucidated which reactive oxygen species that are formed due to the presence of metallic NPs, and the underlying mechanisms. The reliability of using different ROS assays, and the possible artifacts induced by metallic NPs, have been investigated. Methods to assess ROS which previously have not been used in the field of nanotoxicology were introduced showing that copper NPs via corrosion reactions produce ROS and Haber Weiss or Fenton-reactions can decompose hydrogen peroxide into the reactive hydroxyl radical. A way to group NPs based on their surface reactions forming ROS was proposed. Other particle- and surface characteristics of metallic NPs of importance for the toxic potency and ability to induce oxidative stress, e.g. adsorption of biomolecules, particle agglomeration, surface composition, and release of metal ions including their speciation., Människor utsätts dagligen för metalliska nanopartiklar från olika källor vilka kan ha både naturligt och antropogent ursprung. Sådan exponering sker via olika exponeringsvägar, till exempel genom inandning och hudkontakt, vilket kan leda till negativa hälsoeffekter. Syftet med denna avhandling var att undersöka vad som sker på ytan av metalliska nanopartiklar vid simulerad inandning och hur detta påverkar deras potentiellt toxiska egenskaper. Partikelytans egenskaper undersöktes då denna yta är i direkt kontakt med den omgivande miljön. Egenskaperna av intresse var främst graden av metallfrisättning, dess kemiska form, samt partiklarnas förmåga att bilda syreradikaler och väteperoxid (ROS). ROS bildas naturligt i cellerna som en viktig del av vårt immunsystem, men kan i överskott resultera i negativa effekter. Studier genomfördes genom att tillämpa ett multianalytiskt och tvärvetenskapligt tillvägagångssätt där yt- och materialkemiska studier kombinerades med toxikologiska undersökningar, med huvudfokus på ROS-bildning. Studierna har bland annat belyst vilka typer av ROS som kan bildas på grund av metalliska NP samt de underliggande mekanismerna. Tillförlitligheten av att använda olika tekniker för ROS-analyser och deras möjliga artefakter inducerade av metalliska NP undersöktes. Metoder för att bedöma ROS som tidigare inte har använts inom nanotoxikologi introducerades vilka möjliggör detektion av specifika syreradikaler. Resultat för Cu NP visade på att både korrosionsreaktioner producerar ROS samt att Haber Weiss- eller Fenton(lika) reaktioner kan sönderdela väteperoxid och bilda den reaktiva hydroxylradikalen. Ett förslag för gruppering av metalliska NP baserat på deras ROS mekanismer föreslås. Studier av andra partikel- och ytegenskaper hos metalliska NP av betydelse för deras möjliga toxicitet omfattar även adsorption av ligander och biomolekyler, grad av partikelagglomeration, yt-sammansättning, metallfrisättning och deras speciering i lösning., QC 2022-11-17

Humans are exposed daily to metallic nanoparticles (Me NPs) from multiple sources which can have both natural and anthropogenic origins. Such exposures take place via different routes including inhalation and skin contact and may result in adverse health effects. The objectives of this thesis were to investigate surface interactions taking place on metallic nanoparticles upon simplified inhalation and how such interactions influence their toxic potency. Except for the particle and surface characteristics, the interface to the cell environment, the extent, speciation of the released metal fraction, and the ability of the particles to form reactive oxygen species (ROS) were investigated as these parameters are known to largely govern the cell toxicity. ROS naturally form in the cells as an essential part of our immune system, but can in excess, result in cell membrane damage and harmful effects. This has been studied using a multianalytical and interdisciplinary approach combining surface and material chemistry with toxicological investigations with the main focus on ROS formation. The study has for example elucidated which reactive oxygen species that are formed due to the presence of metallic NPs, and the underlying mechanisms. The reliability of using different ROS assays, and the possible artifacts induced by metallic NPs, have been investigated. Methods to assess ROS which previously have not been used in the field of nanotoxicology were introduced showing that copper NPs via corrosion reactions produce ROS and Haber Weiss or Fenton-reactions can decompose hydrogen peroxide into the reactive hydroxyl radical. A way to group NPs based on their surface reactions forming ROS was proposed. Other particle- and surface characteristics of metallic NPs of importance for the toxic potency and ability to induce oxidative stress, e.g. adsorption of biomolecules, particle agglomeration, surface composition, and release of metal ions including their speciation., Människor utsätts dagligen för metalliska nanopartiklar från olika källor vilka kan ha både naturligt och antropogent ursprung. Sådan exponering sker via olika exponeringsvägar, till exempel genom inandning och hudkontakt, vilket kan leda till negativa hälsoeffekter. Syftet med denna avhandling var att undersöka vad som sker på ytan av metalliska nanopartiklar vid simulerad inandning och hur detta påverkar deras potentiellt toxiska egenskaper. Partikelytans egenskaper undersöktes då denna yta är i direkt kontakt med den omgivande miljön. Egenskaperna av intresse var främst graden av metallfrisättning, dess kemiska form, samt partiklarnas förmåga att bilda syreradikaler och väteperoxid (ROS). ROS bildas naturligt i cellerna som en viktig del av vårt immunsystem, men kan i överskott resultera i negativa effekter. Studier genomfördes genom att tillämpa ett multianalytiskt och tvärvetenskapligt tillvägagångssätt där yt- och materialkemiska studier kombinerades med toxikologiska undersökningar, med huvudfokus på ROS-bildning. Studierna har bland annat belyst vilka typer av ROS som kan bildas på grund av metalliska NP samt de underliggande mekanismerna. Tillförlitligheten av att använda olika tekniker för ROS-analyser och deras möjliga artefakter inducerade av metalliska NP undersöktes. Metoder för att bedöma ROS som tidigare inte har använts inom nanotoxikologi introducerades vilka möjliggör detektion av specifika syreradikaler. Resultat för Cu NP visade på att både korrosionsreaktioner producerar ROS samt att Haber Weiss- eller Fenton(lika) reaktioner kan sönderdela väteperoxid och bilda den reaktiva hydroxylradikalen. Ett förslag för gruppering av metalliska NP baserat på deras ROS mekanismer föreslås. Studier av andra partikel- och ytegenskaper hos metalliska NP av betydelse för deras möjliga toxicitet omfattar även adsorption av ligander och biomolekyler, grad av partikelagglomeration, yt-sammansättning, metallfrisättning och deras speciering i lösning., QC 2022-11-17

Humans are exposed daily to metallic nanoparticles (Me NPs) from multiple sources which can have both natural and anthropogenic origins. Such exposures take place via different routes including inhalation and skin contact and may result in adverse health effects. The objectives of this thesis were to investigate surface interactions taking place on metallic nanoparticles upon simplified inhalation and how such interactions influence their toxic potency. Except for the particle and surface characteristics, the interface to the cell environment, the extent, speciation of the released metal fraction, and the ability of the particles to form reactive oxygen species (ROS) were investigated as these parameters are known to largely govern the cell toxicity. ROS naturally form in the cells as an essential part of our immune system, but can in excess, result in cell membrane damage and harmful effects. This has been studied using a multianalytical and interdisciplinary approach combining surface and material chemistry with toxicological investigations with the main focus on ROS formation. The study has for example elucidated which reactive oxygen species that are formed due to the presence of metallic NPs, and the underlying mechanisms. The reliability of using different ROS assays, and the possible artifacts induced by metallic NPs, have been investigated. Methods to assess ROS which previously have not been used in the field of nanotoxicology were introduced showing that copper NPs via corrosion reactions produce ROS and Haber Weiss or Fenton-reactions can decompose hydrogen peroxide into the reactive hydroxyl radical. A way to group NPs based on their surface reactions forming ROS was proposed. Other particle- and surface characteristics of metallic NPs of importance for the toxic potency and ability to induce oxidative stress, e.g. adsorption of biomolecules, particle agglomeration, surface composition, and release of metal ions including their speciation., Människor utsätts dagligen för metalliska nanopartiklar från olika källor vilka kan ha både naturligt och antropogent ursprung. Sådan exponering sker via olika exponeringsvägar, till exempel genom inandning och hudkontakt, vilket kan leda till negativa hälsoeffekter. Syftet med denna avhandling var att undersöka vad som sker på ytan av metalliska nanopartiklar vid simulerad inandning och hur detta påverkar deras potentiellt toxiska egenskaper. Partikelytans egenskaper undersöktes då denna yta är i direkt kontakt med den omgivande miljön. Egenskaperna av intresse var främst graden av metallfrisättning, dess kemiska form, samt partiklarnas förmåga att bilda syreradikaler och väteperoxid (ROS). ROS bildas naturligt i cellerna som en viktig del av vårt immunsystem, men kan i överskott resultera i negativa effekter. Studier genomfördes genom att tillämpa ett multianalytiskt och tvärvetenskapligt tillvägagångssätt där yt- och materialkemiska studier kombinerades med toxikologiska undersökningar, med huvudfokus på ROS-bildning. Studierna har bland annat belyst vilka typer av ROS som kan bildas på grund av metalliska NP samt de underliggande mekanismerna. Tillförlitligheten av att använda olika tekniker för ROS-analyser och deras möjliga artefakter inducerade av metalliska NP undersöktes. Metoder för att bedöma ROS som tidigare inte har använts inom nanotoxikologi introducerades vilka möjliggör detektion av specifika syreradikaler. Resultat för Cu NP visade på att både korrosionsreaktioner producerar ROS samt att Haber Weiss- eller Fenton(lika) reaktioner kan sönderdela väteperoxid och bilda den reaktiva hydroxylradikalen. Ett förslag för gruppering av metalliska NP baserat på deras ROS mekanismer föreslås. Studier av andra partikel- och ytegenskaper hos metalliska NP av betydelse för deras möjliga toxicitet omfattar även adsorption av ligander och biomolekyler, grad av partikelagglomeration, yt-sammansättning, metallfrisättning och deras speciering i lösning., QC 2022-11-17

Humans are exposed daily to metallic nanoparticles (Me NPs) from multiple sources which can have both natural and anthropogenic origins. Such exposures take place via different routes including inhalation and skin contact and may result in adverse health effects. The objectives of this thesis were to investigate surface interactions taking place on metallic nanoparticles upon simplified inhalation and how such interactions influence their toxic potency. Except for the particle and surface characteristics, the interface to the cell environment, the extent, speciation of the released metal fraction, and the ability of the particles to form reactive oxygen species (ROS) were investigated as these parameters are known to largely govern the cell toxicity. ROS naturally form in the cells as an essential part of our immune system, but can in excess, result in cell membrane damage and harmful effects. This has been studied using a multianalytical and interdisciplinary approach combining surface and material chemistry with toxicological investigations with the main focus on ROS formation. The study has for example elucidated which reactive oxygen species that are formed due to the presence of metallic NPs, and the underlying mechanisms. The reliability of using different ROS assays, and the possible artifacts induced by metallic NPs, have been investigated. Methods to assess ROS which previously have not been used in the field of nanotoxicology were introduced showing that copper NPs via corrosion reactions produce ROS and Haber Weiss or Fenton-reactions can decompose hydrogen peroxide into the reactive hydroxyl radical. A way to group NPs based on their surface reactions forming ROS was proposed. Other particle- and surface characteristics of metallic NPs of importance for the toxic potency and ability to induce oxidative stress, e.g. adsorption of biomolecules, particle agglomeration, surface composition, and release of metal ions including their speciation., Människor utsätts dagligen för metalliska nanopartiklar från olika källor vilka kan ha både naturligt och antropogent ursprung. Sådan exponering sker via olika exponeringsvägar, till exempel genom inandning och hudkontakt, vilket kan leda till negativa hälsoeffekter. Syftet med denna avhandling var att undersöka vad som sker på ytan av metalliska nanopartiklar vid simulerad inandning och hur detta påverkar deras potentiellt toxiska egenskaper. Partikelytans egenskaper undersöktes då denna yta är i direkt kontakt med den omgivande miljön. Egenskaperna av intresse var främst graden av metallfrisättning, dess kemiska form, samt partiklarnas förmåga att bilda syreradikaler och väteperoxid (ROS). ROS bildas naturligt i cellerna som en viktig del av vårt immunsystem, men kan i överskott resultera i negativa effekter. Studier genomfördes genom att tillämpa ett multianalytiskt och tvärvetenskapligt tillvägagångssätt där yt- och materialkemiska studier kombinerades med toxikologiska undersökningar, med huvudfokus på ROS-bildning. Studierna har bland annat belyst vilka typer av ROS som kan bildas på grund av metalliska NP samt de underliggande mekanismerna. Tillförlitligheten av att använda olika tekniker för ROS-analyser och deras möjliga artefakter inducerade av metalliska NP undersöktes. Metoder för att bedöma ROS som tidigare inte har använts inom nanotoxikologi introducerades vilka möjliggör detektion av specifika syreradikaler. Resultat för Cu NP visade på att både korrosionsreaktioner producerar ROS samt att Haber Weiss- eller Fenton(lika) reaktioner kan sönderdela väteperoxid och bilda den reaktiva hydroxylradikalen. Ett förslag för gruppering av metalliska NP baserat på deras ROS mekanismer föreslås. Studier av andra partikel- och ytegenskaper hos metalliska NP av betydelse för deras möjliga toxicitet omfattar även adsorption av ligander och biomolekyler, grad av partikelagglomeration, yt-sammansättning, metallfrisättning och deras speciering i lösning., QC 2022-11-17

Humans are exposed daily to metallic nanoparticles (Me NPs) from multiple sources which can have both natural and anthropogenic origins. Such exposures take place via different routes including inhalation and skin contact and may result in adverse health effects. The objectives of this thesis were to investigate surface interactions taking place on metallic nanoparticles upon simplified inhalation and how such interactions influence their toxic potency. Except for the particle and surface characteristics, the interface to the cell environment, the extent, speciation of the released metal fraction, and the ability of the particles to form reactive oxygen species (ROS) were investigated as these parameters are known to largely govern the cell toxicity. ROS naturally form in the cells as an essential part of our immune system, but can in excess, result in cell membrane damage and harmful effects. This has been studied using a multianalytical and interdisciplinary approach combining surface and material chemistry with toxicological investigations with the main focus on ROS formation. The study has for example elucidated which reactive oxygen species that are formed due to the presence of metallic NPs, and the underlying mechanisms. The reliability of using different ROS assays, and the possible artifacts induced by metallic NPs, have been investigated. Methods to assess ROS which previously have not been used in the field of nanotoxicology were introduced showing that copper NPs via corrosion reactions produce ROS and Haber Weiss or Fenton-reactions can decompose hydrogen peroxide into the reactive hydroxyl radical. A way to group NPs based on their surface reactions forming ROS was proposed. Other particle- and surface characteristics of metallic NPs of importance for the toxic potency and ability to induce oxidative stress, e.g. adsorption of biomolecules, particle agglomeration, surface composition, and release of metal ions including their speciation., Människor utsätts dagligen för metalliska nanopartiklar från olika källor vilka kan ha både naturligt och antropogent ursprung. Sådan exponering sker via olika exponeringsvägar, till exempel genom inandning och hudkontakt, vilket kan leda till negativa hälsoeffekter. Syftet med denna avhandling var att undersöka vad som sker på ytan av metalliska nanopartiklar vid simulerad inandning och hur detta påverkar deras potentiellt toxiska egenskaper. Partikelytans egenskaper undersöktes då denna yta är i direkt kontakt med den omgivande miljön. Egenskaperna av intresse var främst graden av metallfrisättning, dess kemiska form, samt partiklarnas förmåga att bilda syreradikaler och väteperoxid (ROS). ROS bildas naturligt i cellerna som en viktig del av vårt immunsystem, men kan i överskott resultera i negativa effekter. Studier genomfördes genom att tillämpa ett multianalytiskt och tvärvetenskapligt tillvägagångssätt där yt- och materialkemiska studier kombinerades med toxikologiska undersökningar, med huvudfokus på ROS-bildning. Studierna har bland annat belyst vilka typer av ROS som kan bildas på grund av metalliska NP samt de underliggande mekanismerna. Tillförlitligheten av att använda olika tekniker för ROS-analyser och deras möjliga artefakter inducerade av metalliska NP undersöktes. Metoder för att bedöma ROS som tidigare inte har använts inom nanotoxikologi introducerades vilka möjliggör detektion av specifika syreradikaler. Resultat för Cu NP visade på att både korrosionsreaktioner producerar ROS samt att Haber Weiss- eller Fenton(lika) reaktioner kan sönderdela väteperoxid och bilda den reaktiva hydroxylradikalen. Ett förslag för gruppering av metalliska NP baserat på deras ROS mekanismer föreslås. Studier av andra partikel- och ytegenskaper hos metalliska NP av betydelse för deras möjliga toxicitet omfattar även adsorption av ligander och biomolekyler, grad av partikelagglomeration, yt-sammansättning, metallfrisättning och deras speciering i lösning., QC 2022-11-17

When assessing hazards of metals, alloys, and metal-containing items, the metal release (bioaccessibility) is of high importance. Triggered by increasingly stricter hazard classifications for metals, especially cobalt (Co), and limited knowledge, the aim of this doctoral thesis is to assess correlations between the metal/alloy surface characteristics, corrosion and metal release pattern in different simulated biological fluids relevant to human exposure scenarios (dermal, ingestion and inhalation, Papers I-V). In addition, occupational alloy powders (additive manufacturing, Paper III) and tattoo inks (Paper VI) were assessed in relation to potential health hazards. A reliable and reproducible in-vitro bioaccessibility test methodology was elaborated (Paper I). Generated nickel (Ni) and Co bioaccessibility data correlates with the surface and corrosion properties of the metals/alloys in the synthetic fluids, suggesting that the bioaccessible concentration, rather than bulk content, should be used for hazard assessment of Ni and Co in alloys and metals (Papers I-IV). Metallic Co was homogeneously distributed along with metallic Ni beneath the surface oxide of stainless steel 316L under different exposure conditions (Paper V). Exposure in a phosphate-containing neutral fluid resulted in the precipitation and incorporation of both Co and phosphate in the oxide (Paper V). Reused alloy powder during laser additive manufacturing processes revealed, depending on alloy type, different physicochemical properties including corrosion properties (Paper III). A large majority of the investigated tattoo inks violated existing regulations on labelling and substances of health concern (Paper VI), and Co, Ni, and other impurities were associated with iron-rich pigments. In all, this thesis presents bioaccessibility findings connected to surface characteristics relevant for hazard assessments of alloys and powders, and points towards physicochemical reasons behind the release of certa, Olika hälsorisker som till exempel hudallergi kan uppstå vid exponering för nickel och kobolt. Det är därför viktigt att förstå om olika metalliska föremål, metaller och legeringar kan frisätta dessa element i kontakt med olika kroppsvätskor. I den här doktorsavhandlingen har en metod utvecklats för att bestämma mängder av frisatt nickel och kobolt från massiva ytor och pulver av olika metalliska legeringar och rena metaller på ett jämförbart sätt och för olika exponeringsvägar (hudkontakt, inandning, förtäring). Ett annat mål har varit att undersöka om metaller som kobolt, som ofta endast befinner sig som föroreningar i legeringar, förekommer i ytoxiden eller endast i bulkmaterialet och hur det påverkar frisättningen (kobolt har nyligen omklassificierats då metallen kan orsaka cancer). Studierna har också omfattat samband mellan ytegenskaper och frisättning av metaller från metalliska pulver som används i tillverkningsindustrin och metalliska föroreningar samt undersökt hälsorisker med tatueringsfärger. Resultaten har visat att frisättningen av nickel och kobolt till olika syntetiska kroppsvätskor från metaller och legeringar ofta korrelerar väl med deras yt- och korrosionsegenskaper. Det medför att frisättnings- eller korrosionstester skulle kunna användas för att gruppera olika metaller och legeringar och bedöma deras hälsorisker, i stället för att eventuella risker baseras på legeringarnas bulksammansättningar. Legeringarnas ytoxider har ofta en skild sammansättning och en förmåga att minska frisättning av metaller på ett mycket effektivt sätt. Återanvänt pulver vid additiv tillverkning (3D-printning) kan erhålla ändrade fysikaliska och kemiska egenskaper på grund av exponeringen för laser. Innehållet av nickel, kobolt och kromföroreningar i tatueringsfärger var kopplat till andra metaller, främst järnrik röd pigment. Den här avhandlingen bidrar till att förfina riskbedömningar av metaller, legeringar, och metallinnehållande produkter., QC 2021-11-15

When assessing hazards of metals, alloys, and metal-containing items, the metal release (bioaccessibility) is of high importance. Triggered by increasingly stricter hazard classifications for metals, especially cobalt (Co), and limited knowledge, the aim of this doctoral thesis is to assess correlations between the metal/alloy surface characteristics, corrosion and metal release pattern in different simulated biological fluids relevant to human exposure scenarios (dermal, ingestion and inhalation, Papers I-V). In addition, occupational alloy powders (additive manufacturing, Paper III) and tattoo inks (Paper VI) were assessed in relation to potential health hazards. A reliable and reproducible in-vitro bioaccessibility test methodology was elaborated (Paper I). Generated nickel (Ni) and Co bioaccessibility data correlates with the surface and corrosion properties of the metals/alloys in the synthetic fluids, suggesting that the bioaccessible concentration, rather than bulk content, should be used for hazard assessment of Ni and Co in alloys and metals (Papers I-IV). Metallic Co was homogeneously distributed along with metallic Ni beneath the surface oxide of stainless steel 316L under different exposure conditions (Paper V). Exposure in a phosphate-containing neutral fluid resulted in the precipitation and incorporation of both Co and phosphate in the oxide (Paper V). Reused alloy powder during laser additive manufacturing processes revealed, depending on alloy type, different physicochemical properties including corrosion properties (Paper III). A large majority of the investigated tattoo inks violated existing regulations on labelling and substances of health concern (Paper VI), and Co, Ni, and other impurities were associated with iron-rich pigments. In all, this thesis presents bioaccessibility findings connected to surface characteristics relevant for hazard assessments of alloys and powders, and points towards physicochemical reasons behind the release of certa, Olika hälsorisker som till exempel hudallergi kan uppstå vid exponering för nickel och kobolt. Det är därför viktigt att förstå om olika metalliska föremål, metaller och legeringar kan frisätta dessa element i kontakt med olika kroppsvätskor. I den här doktorsavhandlingen har en metod utvecklats för att bestämma mängder av frisatt nickel och kobolt från massiva ytor och pulver av olika metalliska legeringar och rena metaller på ett jämförbart sätt och för olika exponeringsvägar (hudkontakt, inandning, förtäring). Ett annat mål har varit att undersöka om metaller som kobolt, som ofta endast befinner sig som föroreningar i legeringar, förekommer i ytoxiden eller endast i bulkmaterialet och hur det påverkar frisättningen (kobolt har nyligen omklassificierats då metallen kan orsaka cancer). Studierna har också omfattat samband mellan ytegenskaper och frisättning av metaller från metalliska pulver som används i tillverkningsindustrin och metalliska föroreningar samt undersökt hälsorisker med tatueringsfärger. Resultaten har visat att frisättningen av nickel och kobolt till olika syntetiska kroppsvätskor från metaller och legeringar ofta korrelerar väl med deras yt- och korrosionsegenskaper. Det medför att frisättnings- eller korrosionstester skulle kunna användas för att gruppera olika metaller och legeringar och bedöma deras hälsorisker, i stället för att eventuella risker baseras på legeringarnas bulksammansättningar. Legeringarnas ytoxider har ofta en skild sammansättning och en förmåga att minska frisättning av metaller på ett mycket effektivt sätt. Återanvänt pulver vid additiv tillverkning (3D-printning) kan erhålla ändrade fysikaliska och kemiska egenskaper på grund av exponeringen för laser. Innehållet av nickel, kobolt och kromföroreningar i tatueringsfärger var kopplat till andra metaller, främst järnrik röd pigment. Den här avhandlingen bidrar till att förfina riskbedömningar av metaller, legeringar, och metallinnehållande produkter., QC 2021-11-15

When assessing hazards of metals, alloys, and metal-containing items, the metal release (bioaccessibility) is of high importance. Triggered by increasingly stricter hazard classifications for metals, especially cobalt (Co), and limited knowledge, the aim of this doctoral thesis is to assess correlations between the metal/alloy surface characteristics, corrosion and metal release pattern in different simulated biological fluids relevant to human exposure scenarios (dermal, ingestion and inhalation, Papers I-V). In addition, occupational alloy powders (additive manufacturing, Paper III) and tattoo inks (Paper VI) were assessed in relation to potential health hazards. A reliable and reproducible in-vitro bioaccessibility test methodology was elaborated (Paper I). Generated nickel (Ni) and Co bioaccessibility data correlates with the surface and corrosion properties of the metals/alloys in the synthetic fluids, suggesting that the bioaccessible concentration, rather than bulk content, should be used for hazard assessment of Ni and Co in alloys and metals (Papers I-IV). Metallic Co was homogeneously distributed along with metallic Ni beneath the surface oxide of stainless steel 316L under different exposure conditions (Paper V). Exposure in a phosphate-containing neutral fluid resulted in the precipitation and incorporation of both Co and phosphate in the oxide (Paper V). Reused alloy powder during laser additive manufacturing processes revealed, depending on alloy type, different physicochemical properties including corrosion properties (Paper III). A large majority of the investigated tattoo inks violated existing regulations on labelling and substances of health concern (Paper VI), and Co, Ni, and other impurities were associated with iron-rich pigments. In all, this thesis presents bioaccessibility findings connected to surface characteristics relevant for hazard assessments of alloys and powders, and points towards physicochemical reasons behind the release of certa, Olika hälsorisker som till exempel hudallergi kan uppstå vid exponering för nickel och kobolt. Det är därför viktigt att förstå om olika metalliska föremål, metaller och legeringar kan frisätta dessa element i kontakt med olika kroppsvätskor. I den här doktorsavhandlingen har en metod utvecklats för att bestämma mängder av frisatt nickel och kobolt från massiva ytor och pulver av olika metalliska legeringar och rena metaller på ett jämförbart sätt och för olika exponeringsvägar (hudkontakt, inandning, förtäring). Ett annat mål har varit att undersöka om metaller som kobolt, som ofta endast befinner sig som föroreningar i legeringar, förekommer i ytoxiden eller endast i bulkmaterialet och hur det påverkar frisättningen (kobolt har nyligen omklassificierats då metallen kan orsaka cancer). Studierna har också omfattat samband mellan ytegenskaper och frisättning av metaller från metalliska pulver som används i tillverkningsindustrin och metalliska föroreningar samt undersökt hälsorisker med tatueringsfärger. Resultaten har visat att frisättningen av nickel och kobolt till olika syntetiska kroppsvätskor från metaller och legeringar ofta korrelerar väl med deras yt- och korrosionsegenskaper. Det medför att frisättnings- eller korrosionstester skulle kunna användas för att gruppera olika metaller och legeringar och bedöma deras hälsorisker, i stället för att eventuella risker baseras på legeringarnas bulksammansättningar. Legeringarnas ytoxider har ofta en skild sammansättning och en förmåga att minska frisättning av metaller på ett mycket effektivt sätt. Återanvänt pulver vid additiv tillverkning (3D-printning) kan erhålla ändrade fysikaliska och kemiska egenskaper på grund av exponeringen för laser. Innehållet av nickel, kobolt och kromföroreningar i tatueringsfärger var kopplat till andra metaller, främst järnrik röd pigment. Den här avhandlingen bidrar till att förfina riskbedömningar av metaller, legeringar, och metallinnehållande produkter., QC 2021-11-15

When assessing hazards of metals, alloys, and metal-containing items, the metal release (bioaccessibility) is of high importance. Triggered by increasingly stricter hazard classifications for metals, especially cobalt (Co), and limited knowledge, the aim of this doctoral thesis is to assess correlations between the metal/alloy surface characteristics, corrosion and metal release pattern in different simulated biological fluids relevant to human exposure scenarios (dermal, ingestion and inhalation, Papers I-V). In addition, occupational alloy powders (additive manufacturing, Paper III) and tattoo inks (Paper VI) were assessed in relation to potential health hazards. A reliable and reproducible in-vitro bioaccessibility test methodology was elaborated (Paper I). Generated nickel (Ni) and Co bioaccessibility data correlates with the surface and corrosion properties of the metals/alloys in the synthetic fluids, suggesting that the bioaccessible concentration, rather than bulk content, should be used for hazard assessment of Ni and Co in alloys and metals (Papers I-IV). Metallic Co was homogeneously distributed along with metallic Ni beneath the surface oxide of stainless steel 316L under different exposure conditions (Paper V). Exposure in a phosphate-containing neutral fluid resulted in the precipitation and incorporation of both Co and phosphate in the oxide (Paper V). Reused alloy powder during laser additive manufacturing processes revealed, depending on alloy type, different physicochemical properties including corrosion properties (Paper III). A large majority of the investigated tattoo inks violated existing regulations on labelling and substances of health concern (Paper VI), and Co, Ni, and other impurities were associated with iron-rich pigments. In all, this thesis presents bioaccessibility findings connected to surface characteristics relevant for hazard assessments of alloys and powders, and points towards physicochemical reasons behind the release of certa, Olika hälsorisker som till exempel hudallergi kan uppstå vid exponering för nickel och kobolt. Det är därför viktigt att förstå om olika metalliska föremål, metaller och legeringar kan frisätta dessa element i kontakt med olika kroppsvätskor. I den här doktorsavhandlingen har en metod utvecklats för att bestämma mängder av frisatt nickel och kobolt från massiva ytor och pulver av olika metalliska legeringar och rena metaller på ett jämförbart sätt och för olika exponeringsvägar (hudkontakt, inandning, förtäring). Ett annat mål har varit att undersöka om metaller som kobolt, som ofta endast befinner sig som föroreningar i legeringar, förekommer i ytoxiden eller endast i bulkmaterialet och hur det påverkar frisättningen (kobolt har nyligen omklassificierats då metallen kan orsaka cancer). Studierna har också omfattat samband mellan ytegenskaper och frisättning av metaller från metalliska pulver som används i tillverkningsindustrin och metalliska föroreningar samt undersökt hälsorisker med tatueringsfärger. Resultaten har visat att frisättningen av nickel och kobolt till olika syntetiska kroppsvätskor från metaller och legeringar ofta korrelerar väl med deras yt- och korrosionsegenskaper. Det medför att frisättnings- eller korrosionstester skulle kunna användas för att gruppera olika metaller och legeringar och bedöma deras hälsorisker, i stället för att eventuella risker baseras på legeringarnas bulksammansättningar. Legeringarnas ytoxider har ofta en skild sammansättning och en förmåga att minska frisättning av metaller på ett mycket effektivt sätt. Återanvänt pulver vid additiv tillverkning (3D-printning) kan erhålla ändrade fysikaliska och kemiska egenskaper på grund av exponeringen för laser. Innehållet av nickel, kobolt och kromföroreningar i tatueringsfärger var kopplat till andra metaller, främst järnrik röd pigment. Den här avhandlingen bidrar till att förfina riskbedömningar av metaller, legeringar, och metallinnehållande produkter., QC 2021-11-15

When assessing hazards of metals, alloys, and metal-containing items, the metal release (bioaccessibility) is of high importance. Triggered by increasingly stricter hazard classifications for metals, especially cobalt (Co), and limited knowledge, the aim of this doctoral thesis is to assess correlations between the metal/alloy surface characteristics, corrosion and metal release pattern in different simulated biological fluids relevant to human exposure scenarios (dermal, ingestion and inhalation, Papers I-V). In addition, occupational alloy powders (additive manufacturing, Paper III) and tattoo inks (Paper VI) were assessed in relation to potential health hazards. A reliable and reproducible in-vitro bioaccessibility test methodology was elaborated (Paper I). Generated nickel (Ni) and Co bioaccessibility data correlates with the surface and corrosion properties of the metals/alloys in the synthetic fluids, suggesting that the bioaccessible concentration, rather than bulk content, should be used for hazard assessment of Ni and Co in alloys and metals (Papers I-IV). Metallic Co was homogeneously distributed along with metallic Ni beneath the surface oxide of stainless steel 316L under different exposure conditions (Paper V). Exposure in a phosphate-containing neutral fluid resulted in the precipitation and incorporation of both Co and phosphate in the oxide (Paper V). Reused alloy powder during laser additive manufacturing processes revealed, depending on alloy type, different physicochemical properties including corrosion properties (Paper III). A large majority of the investigated tattoo inks violated existing regulations on labelling and substances of health concern (Paper VI), and Co, Ni, and other impurities were associated with iron-rich pigments. In all, this thesis presents bioaccessibility findings connected to surface characteristics relevant for hazard assessments of alloys and powders, and points towards physicochemical reasons behind the release of certa, Olika hälsorisker som till exempel hudallergi kan uppstå vid exponering för nickel och kobolt. Det är därför viktigt att förstå om olika metalliska föremål, metaller och legeringar kan frisätta dessa element i kontakt med olika kroppsvätskor. I den här doktorsavhandlingen har en metod utvecklats för att bestämma mängder av frisatt nickel och kobolt från massiva ytor och pulver av olika metalliska legeringar och rena metaller på ett jämförbart sätt och för olika exponeringsvägar (hudkontakt, inandning, förtäring). Ett annat mål har varit att undersöka om metaller som kobolt, som ofta endast befinner sig som föroreningar i legeringar, förekommer i ytoxiden eller endast i bulkmaterialet och hur det påverkar frisättningen (kobolt har nyligen omklassificierats då metallen kan orsaka cancer). Studierna har också omfattat samband mellan ytegenskaper och frisättning av metaller från metalliska pulver som används i tillverkningsindustrin och metalliska föroreningar samt undersökt hälsorisker med tatueringsfärger. Resultaten har visat att frisättningen av nickel och kobolt till olika syntetiska kroppsvätskor från metaller och legeringar ofta korrelerar väl med deras yt- och korrosionsegenskaper. Det medför att frisättnings- eller korrosionstester skulle kunna användas för att gruppera olika metaller och legeringar och bedöma deras hälsorisker, i stället för att eventuella risker baseras på legeringarnas bulksammansättningar. Legeringarnas ytoxider har ofta en skild sammansättning och en förmåga att minska frisättning av metaller på ett mycket effektivt sätt. Återanvänt pulver vid additiv tillverkning (3D-printning) kan erhålla ändrade fysikaliska och kemiska egenskaper på grund av exponeringen för laser. Innehållet av nickel, kobolt och kromföroreningar i tatueringsfärger var kopplat till andra metaller, främst järnrik röd pigment. Den här avhandlingen bidrar till att förfina riskbedömningar av metaller, legeringar, och metallinnehållande produkter., QC 2021-11-15

Highly corrosion-resistant alloys are used in sensitive environments such as the human body and food environments. However, even tiny amounts of released metals from these surfaces could potentially cause adverse effects. It is hence important to study the biointerface between corrosion-resistant alloys and protein-rich environments. This licentiate thesis focused on the metal release processes for stainless steels and cobalt-chromium-molybdenum (CoCrMo) alloys in different protein-rich environments. It aimed at investigating the effect of protein displacement (Vroman effect), gamma irradiation, and friction on the metal release processes. Trace metal analysis was the main tool, combined with other solution analytical tools, electrochemical methods, and surface sensitive techniques. The effect of gamma irradiation, of relevance for cancer radiotherapy, on metal release from CoCrMo and stainless steel 316L was investigated in Paper I. The effect was minor, however the released amount of metals increased after irradiation causing an enhanced surface passivation effect. Whether the displacement of surface proteins (Vroman effect) was playing a role on the metal release and corrosion processes of stainless steels 316L and 303, and of CoCrMo, was investigated in Papers II and III. A Vroman effect influencing the metal release could be observed for stainless steel 316L, but not for CoCrMo and stainless steel grade 303. However, the displacement of the smaller protein bovine serum albumin (BSA) from the surface by the larger protein fibrinogen (Fbn) was observed for both stainless steel grades. The Vroman effect also caused a higher corrosion susceptibility of stainless steel 303, probably due to a thicker layer or patches of adsorbed Fbn. Most probably, protein aggregation and precipitation caused an underestimation of the extent of metal release, especially in the case of CoCrMo. Protein aggregation and precipitation were significantly observed in all studies, especially, QC 2020-09-28

Highly corrosion-resistant alloys are used in sensitive environments such as the human body and food environments. However, even tiny amounts of released metals from these surfaces could potentially cause adverse effects. It is hence important to study the biointerface between corrosion-resistant alloys and protein-rich environments. This licentiate thesis focused on the metal release processes for stainless steels and cobalt-chromium-molybdenum (CoCrMo) alloys in different protein-rich environments. It aimed at investigating the effect of protein displacement (Vroman effect), gamma irradiation, and friction on the metal release processes. Trace metal analysis was the main tool, combined with other solution analytical tools, electrochemical methods, and surface sensitive techniques. The effect of gamma irradiation, of relevance for cancer radiotherapy, on metal release from CoCrMo and stainless steel 316L was investigated in Paper I. The effect was minor, however the released amount of metals increased after irradiation causing an enhanced surface passivation effect. Whether the displacement of surface proteins (Vroman effect) was playing a role on the metal release and corrosion processes of stainless steels 316L and 303, and of CoCrMo, was investigated in Papers II and III. A Vroman effect influencing the metal release could be observed for stainless steel 316L, but not for CoCrMo and stainless steel grade 303. However, the displacement of the smaller protein bovine serum albumin (BSA) from the surface by the larger protein fibrinogen (Fbn) was observed for both stainless steel grades. The Vroman effect also caused a higher corrosion susceptibility of stainless steel 303, probably due to a thicker layer or patches of adsorbed Fbn. Most probably, protein aggregation and precipitation caused an underestimation of the extent of metal release, especially in the case of CoCrMo. Protein aggregation and precipitation were significantly observed in all studies, especially, QC 2020-09-28

Highly corrosion-resistant alloys are used in sensitive environments such as the human body and food environments. However, even tiny amounts of released metals from these surfaces could potentially cause adverse effects. It is hence important to study the biointerface between corrosion-resistant alloys and protein-rich environments. This licentiate thesis focused on the metal release processes for stainless steels and cobalt-chromium-molybdenum (CoCrMo) alloys in different protein-rich environments. It aimed at investigating the effect of protein displacement (Vroman effect), gamma irradiation, and friction on the metal release processes. Trace metal analysis was the main tool, combined with other solution analytical tools, electrochemical methods, and surface sensitive techniques. The effect of gamma irradiation, of relevance for cancer radiotherapy, on metal release from CoCrMo and stainless steel 316L was investigated in Paper I. The effect was minor, however the released amount of metals increased after irradiation causing an enhanced surface passivation effect. Whether the displacement of surface proteins (Vroman effect) was playing a role on the metal release and corrosion processes of stainless steels 316L and 303, and of CoCrMo, was investigated in Papers II and III. A Vroman effect influencing the metal release could be observed for stainless steel 316L, but not for CoCrMo and stainless steel grade 303. However, the displacement of the smaller protein bovine serum albumin (BSA) from the surface by the larger protein fibrinogen (Fbn) was observed for both stainless steel grades. The Vroman effect also caused a higher corrosion susceptibility of stainless steel 303, probably due to a thicker layer or patches of adsorbed Fbn. Most probably, protein aggregation and precipitation caused an underestimation of the extent of metal release, especially in the case of CoCrMo. Protein aggregation and precipitation were significantly observed in all studies, especially, QC 2020-09-28

Highly corrosion-resistant alloys are used in sensitive environments such as the human body and food environments. However, even tiny amounts of released metals from these surfaces could potentially cause adverse effects. It is hence important to study the biointerface between corrosion-resistant alloys and protein-rich environments. This licentiate thesis focused on the metal release processes for stainless steels and cobalt-chromium-molybdenum (CoCrMo) alloys in different protein-rich environments. It aimed at investigating the effect of protein displacement (Vroman effect), gamma irradiation, and friction on the metal release processes. Trace metal analysis was the main tool, combined with other solution analytical tools, electrochemical methods, and surface sensitive techniques. The effect of gamma irradiation, of relevance for cancer radiotherapy, on metal release from CoCrMo and stainless steel 316L was investigated in Paper I. The effect was minor, however the released amount of metals increased after irradiation causing an enhanced surface passivation effect. Whether the displacement of surface proteins (Vroman effect) was playing a role on the metal release and corrosion processes of stainless steels 316L and 303, and of CoCrMo, was investigated in Papers II and III. A Vroman effect influencing the metal release could be observed for stainless steel 316L, but not for CoCrMo and stainless steel grade 303. However, the displacement of the smaller protein bovine serum albumin (BSA) from the surface by the larger protein fibrinogen (Fbn) was observed for both stainless steel grades. The Vroman effect also caused a higher corrosion susceptibility of stainless steel 303, probably due to a thicker layer or patches of adsorbed Fbn. Most probably, protein aggregation and precipitation caused an underestimation of the extent of metal release, especially in the case of CoCrMo. Protein aggregation and precipitation were significantly observed in all studies, especially, QC 2020-09-28

Highly corrosion-resistant alloys are used in sensitive environments such as the human body and food environments. However, even tiny amounts of released metals from these surfaces could potentially cause adverse effects. It is hence important to study the biointerface between corrosion-resistant alloys and protein-rich environments. This licentiate thesis focused on the metal release processes for stainless steels and cobalt-chromium-molybdenum (CoCrMo) alloys in different protein-rich environments. It aimed at investigating the effect of protein displacement (Vroman effect), gamma irradiation, and friction on the metal release processes. Trace metal analysis was the main tool, combined with other solution analytical tools, electrochemical methods, and surface sensitive techniques. The effect of gamma irradiation, of relevance for cancer radiotherapy, on metal release from CoCrMo and stainless steel 316L was investigated in Paper I. The effect was minor, however the released amount of metals increased after irradiation causing an enhanced surface passivation effect. Whether the displacement of surface proteins (Vroman effect) was playing a role on the metal release and corrosion processes of stainless steels 316L and 303, and of CoCrMo, was investigated in Papers II and III. A Vroman effect influencing the metal release could be observed for stainless steel 316L, but not for CoCrMo and stainless steel grade 303. However, the displacement of the smaller protein bovine serum albumin (BSA) from the surface by the larger protein fibrinogen (Fbn) was observed for both stainless steel grades. The Vroman effect also caused a higher corrosion susceptibility of stainless steel 303, probably due to a thicker layer or patches of adsorbed Fbn. Most probably, protein aggregation and precipitation caused an underestimation of the extent of metal release, especially in the case of CoCrMo. Protein aggregation and precipitation were significantly observed in all studies, especially, QC 2020-09-28

Highly corrosion-resistant alloys are used in sensitive environments such as the human body and food environments. However, even tiny amounts of released metals from these surfaces could potentially cause adverse effects. It is hence important to study the biointerface between corrosion-resistant alloys and protein-rich environments. This licentiate thesis focused on the metal release processes for stainless steels and cobalt-chromium-molybdenum (CoCrMo) alloys in different protein-rich environments. It aimed at investigating the effect of protein displacement (Vroman effect), gamma irradiation, and friction on the metal release processes. Trace metal analysis was the main tool, combined with other solution analytical tools, electrochemical methods, and surface sensitive techniques. The effect of gamma irradiation, of relevance for cancer radiotherapy, on metal release from CoCrMo and stainless steel 316L was investigated in Paper I. The effect was minor, however the released amount of metals increased after irradiation causing an enhanced surface passivation effect. Whether the displacement of surface proteins (Vroman effect) was playing a role on the metal release and corrosion processes of stainless steels 316L and 303, and of CoCrMo, was investigated in Papers II and III. A Vroman effect influencing the metal release could be observed for stainless steel 316L, but not for CoCrMo and stainless steel grade 303. However, the displacement of the smaller protein bovine serum albumin (BSA) from the surface by the larger protein fibrinogen (Fbn) was observed for both stainless steel grades. The Vroman effect also caused a higher corrosion susceptibility of stainless steel 303, probably due to a thicker layer or patches of adsorbed Fbn. Most probably, protein aggregation and precipitation caused an underestimation of the extent of metal release, especially in the case of CoCrMo. Protein aggregation and precipitation were significantly observed in all studies, especially, QC 2020-09-28

Metallic nanoparticles possess unique properties due to their size and are widely used in e.g. consumer products. From this follows a need to identify and assess potential risks of human and environmental exposure. Their size facilitates uptake in organisms and disruption of various biological processes. Together with a high reactivity, mainly due to their large surface area in solution, they are both commonly used in different applications and of a potential safety concern. Risk assessment requires hence in-depth knowledge on the particle characteristics and their behavior in solution but also how these properties change with time and exposure conditions and whether these characteristics can be linked to toxicity following nanoparticle exposure. This thesis addresses these aspects with a main focus on metal nanoparticles and elaborates on the importance of characterization, how such measurements can be done, and on interactions with surfactants and biomolecules and toxic effects.Silver nanoparticles are, due to their antibacterial properties, often used in sportswear to prevent sweat odor. During laundry they may be dispersed and interact with surfactants of the washing powder, influencing their properties and stability in solution. These aspects are addressed in Papers I, III and V on silver nanoparticles of different size and surface coatings. The stability was shown to depend on the surface charge and the concentration of the surfactant. The stability and extent of silver release were reduced upon sequential exposure, indicating the importance of the particle history on their bioaccessibility, mobility and potential toxicity. A mechanism was proposed for how silver nanoparticles are stabilized in surfactant solutions.Toxic effects of silver nanoparticles of different size and coatings on cultivated lung cells, Paper II, and effects of copper-containing nanoparticles on different blood cells, Paper IV, were studied in vitro. The smallest particles were most cytot, QC 20170111

Metallic nanoparticles possess unique properties due to their size and are widely used in e.g. consumer products. From this follows a need to identify and assess potential risks of human and environmental exposure. Their size facilitates uptake in organisms and disruption of various biological processes. Together with a high reactivity, mainly due to their large surface area in solution, they are both commonly used in different applications and of a potential safety concern. Risk assessment requires hence in-depth knowledge on the particle characteristics and their behavior in solution but also how these properties change with time and exposure conditions and whether these characteristics can be linked to toxicity following nanoparticle exposure. This thesis addresses these aspects with a main focus on metal nanoparticles and elaborates on the importance of characterization, how such measurements can be done, and on interactions with surfactants and biomolecules and toxic effects.Silver nanoparticles are, due to their antibacterial properties, often used in sportswear to prevent sweat odor. During laundry they may be dispersed and interact with surfactants of the washing powder, influencing their properties and stability in solution. These aspects are addressed in Papers I, III and V on silver nanoparticles of different size and surface coatings. The stability was shown to depend on the surface charge and the concentration of the surfactant. The stability and extent of silver release were reduced upon sequential exposure, indicating the importance of the particle history on their bioaccessibility, mobility and potential toxicity. A mechanism was proposed for how silver nanoparticles are stabilized in surfactant solutions.Toxic effects of silver nanoparticles of different size and coatings on cultivated lung cells, Paper II, and effects of copper-containing nanoparticles on different blood cells, Paper IV, were studied in vitro. The smallest particles were most cytot, QC 20170111

Metallic nanoparticles possess unique properties due to their size and are widely used in e.g. consumer products. From this follows a need to identify and assess potential risks of human and environmental exposure. Their size facilitates uptake in organisms and disruption of various biological processes. Together with a high reactivity, mainly due to their large surface area in solution, they are both commonly used in different applications and of a potential safety concern. Risk assessment requires hence in-depth knowledge on the particle characteristics and their behavior in solution but also how these properties change with time and exposure conditions and whether these characteristics can be linked to toxicity following nanoparticle exposure. This thesis addresses these aspects with a main focus on metal nanoparticles and elaborates on the importance of characterization, how such measurements can be done, and on interactions with surfactants and biomolecules and toxic effects.Silver nanoparticles are, due to their antibacterial properties, often used in sportswear to prevent sweat odor. During laundry they may be dispersed and interact with surfactants of the washing powder, influencing their properties and stability in solution. These aspects are addressed in Papers I, III and V on silver nanoparticles of different size and surface coatings. The stability was shown to depend on the surface charge and the concentration of the surfactant. The stability and extent of silver release were reduced upon sequential exposure, indicating the importance of the particle history on their bioaccessibility, mobility and potential toxicity. A mechanism was proposed for how silver nanoparticles are stabilized in surfactant solutions.Toxic effects of silver nanoparticles of different size and coatings on cultivated lung cells, Paper II, and effects of copper-containing nanoparticles on different blood cells, Paper IV, were studied in vitro. The smallest particles were most cytot, QC 20170111

Metallic nanoparticles possess unique properties due to their size and are widely used in e.g. consumer products. From this follows a need to identify and assess potential risks of human and environmental exposure. Their size facilitates uptake in organisms and disruption of various biological processes. Together with a high reactivity, mainly due to their large surface area in solution, they are both commonly used in different applications and of a potential safety concern. Risk assessment requires hence in-depth knowledge on the particle characteristics and their behavior in solution but also how these properties change with time and exposure conditions and whether these characteristics can be linked to toxicity following nanoparticle exposure. This thesis addresses these aspects with a main focus on metal nanoparticles and elaborates on the importance of characterization, how such measurements can be done, and on interactions with surfactants and biomolecules and toxic effects.Silver nanoparticles are, due to their antibacterial properties, often used in sportswear to prevent sweat odor. During laundry they may be dispersed and interact with surfactants of the washing powder, influencing their properties and stability in solution. These aspects are addressed in Papers I, III and V on silver nanoparticles of different size and surface coatings. The stability was shown to depend on the surface charge and the concentration of the surfactant. The stability and extent of silver release were reduced upon sequential exposure, indicating the importance of the particle history on their bioaccessibility, mobility and potential toxicity. A mechanism was proposed for how silver nanoparticles are stabilized in surfactant solutions.Toxic effects of silver nanoparticles of different size and coatings on cultivated lung cells, Paper II, and effects of copper-containing nanoparticles on different blood cells, Paper IV, were studied in vitro. The smallest particles were most cytot, QC 20170111

Metallic nanoparticles possess unique properties due to their size and are widely used in e.g. consumer products. From this follows a need to identify and assess potential risks of human and environmental exposure. Their size facilitates uptake in organisms and disruption of various biological processes. Together with a high reactivity, mainly due to their large surface area in solution, they are both commonly used in different applications and of a potential safety concern. Risk assessment requires hence in-depth knowledge on the particle characteristics and their behavior in solution but also how these properties change with time and exposure conditions and whether these characteristics can be linked to toxicity following nanoparticle exposure. This thesis addresses these aspects with a main focus on metal nanoparticles and elaborates on the importance of characterization, how such measurements can be done, and on interactions with surfactants and biomolecules and toxic effects.Silver nanoparticles are, due to their antibacterial properties, often used in sportswear to prevent sweat odor. During laundry they may be dispersed and interact with surfactants of the washing powder, influencing their properties and stability in solution. These aspects are addressed in Papers I, III and V on silver nanoparticles of different size and surface coatings. The stability was shown to depend on the surface charge and the concentration of the surfactant. The stability and extent of silver release were reduced upon sequential exposure, indicating the importance of the particle history on their bioaccessibility, mobility and potential toxicity. A mechanism was proposed for how silver nanoparticles are stabilized in surfactant solutions.Toxic effects of silver nanoparticles of different size and coatings on cultivated lung cells, Paper II, and effects of copper-containing nanoparticles on different blood cells, Paper IV, were studied in vitro. The smallest particles were most cytot, QC 20170111

Fundamental understanding of atmospheric corrosion mechanisms requires an in-depth understanding on the dynamic interaction between corrosive constituents and metal/alloy surfaces. This doctoral study comprises field and laboratory investigations that assess atmospheric corrosion and metal release processes for two different groups of alloys exposed in chloride-rich environments. These groups comprise two commercial Zn-Al alloy coatings on steel, Galfan™ (Zn5Al) and Galvalume™ (Zn55Al), and four copper-based alloys (Cu4Sn, Cu15Zn, Cu40Zn and Cu5Zn5Al). In-depth laboratory investigations were conducted to assess the role of chloride deposition and alloy microstructure on the initial corrosion mechanisms and subsequent corrosion product formation. Comparisons were made with long-term field exposures at unsheltered marine conditions in Brest, France. A multitude of surface sensitive and non-destructive analytical methods were adopted for detailed in-situ and ex-situ analysis to assess corrosion product evolution scenarios for the Zn-Al and the Cu-based alloys. Scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were employed for morphological investigations and scanning Kelvin probe force microscopy (SKPFM) for nobility distribution measurements and to gain microstructural information. SEM/EDS, infrared reflection-absorption spectroscopy (IRAS), confocal Raman micro-spectroscopy (CRM) and grazing incidence x-ray diffraction (GIXRD) were utilized to gain information on corrosion product formation and possibly their lateral distribution upon field and laboratory exposures. The multi-analytical approach enabled the exploration of the interplay between the microstructure and corrosion initiation and corrosion product evolution. A clear influence of the microstructure on the initial corrosion product formation was preferentially observed in the zinc-rich phase for both the Zn-Al and the Cu-Zn alloys, processes being triggered by microgalvanic effects., Bättre molekylär förståelse för metallers atmosfäriska korrosion kräver en fördjupad kunskap i det dynamiska samspelet mellan atmosfärens korrosiva beståndsdelar och metallytan. Denna doktorsavhandling omfattar laboratorie- och fältundersökningar av korrosions- och metallfrigöringsprocesser av två grupper av legeringar som exponerats i kloridrika atmosfärsmiljöer: två kommersiella Zn-Al beläggningar på stål, Galfan™ (Zn med 5% Al, förkortat Zn5Al) och Galvalume™ (Zn55Al), samt fyra kopparbaserade legeringar (Cu4Sn, Cu15Zn, Cu40Zn och Cu5Zn5Al). Undersökningar har genomförts i renodlade laboratorie-miljöer med för-deponerade NaCl-partiklar i en atmosfär av varierande relativ fuktighet. Syftet har varit att utvärdera betydelsen av kloriders deposition och legeringarnas mikrostruktur på korrosionsmekanismen samt bildandet av korrosionsprodukter. Jämförelser av korrosionsmekanismer har även gjorts efter flerårsexponeringar av samma legeringar i en marin fältmiljö i Brest, Frankrike. Undersökningarna har baserats på ett brett spektrum av analysmetoder för detaljerade studier dels under pågående atmosfärisk korrosion (in-situ), och dels efter avslutad korrosion (ex-situ). Legeringarnas mikrostruktur och tillhörande variation i ädelhet hos olika faser har undersökts med svepelektronmikroskopi och energidispersiv röntgenmikroanalys (SEM/EDS) samt med en variant av atomkraftsmikroskopi (engelska: scanning Kelvin probe force microscopy, SKPFM). Korrosionsprodukternas tillväxt har analyserats in-situ med infraröd reflektions-absorptionsspektroskopi (IRAS), samt morfologi och sammansättning av bildade korrosionsprodukter ex-situ med SEM/EDS, konfokal Raman mikro-spektroskopi (CRM) samt röntgendiffraktion vid strykande ifall (GIXRD). Det multi-analytiska tillvägagångssättet har medfört att det komplexa samspelet mellan de skilda legeringarnas mikrostruktur, korrosionsinitiering och bildandet av korrosionsprodukter kunnat studeras i detalj. En tydlig påverkan av mikrostruktur på, QC 20140915, Autocorr, RFSR-CT-2009-00015 Corrosion of heterogeneous metal-metal assemblies in the automotive industry, Atmospheric corrosion and environmental metal dispersion from outdoor construction materials

Fundamental understanding of atmospheric corrosion mechanisms requires an in-depth understanding on the dynamic interaction between corrosive constituents and metal/alloy surfaces. This doctoral study comprises field and laboratory investigations that assess atmospheric corrosion and metal release processes for two different groups of alloys exposed in chloride-rich environments. These groups comprise two commercial Zn-Al alloy coatings on steel, Galfan™ (Zn5Al) and Galvalume™ (Zn55Al), and four copper-based alloys (Cu4Sn, Cu15Zn, Cu40Zn and Cu5Zn5Al). In-depth laboratory investigations were conducted to assess the role of chloride deposition and alloy microstructure on the initial corrosion mechanisms and subsequent corrosion product formation. Comparisons were made with long-term field exposures at unsheltered marine conditions in Brest, France. A multitude of surface sensitive and non-destructive analytical methods were adopted for detailed in-situ and ex-situ analysis to assess corrosion product evolution scenarios for the Zn-Al and the Cu-based alloys. Scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were employed for morphological investigations and scanning Kelvin probe force microscopy (SKPFM) for nobility distribution measurements and to gain microstructural information. SEM/EDS, infrared reflection-absorption spectroscopy (IRAS), confocal Raman micro-spectroscopy (CRM) and grazing incidence x-ray diffraction (GIXRD) were utilized to gain information on corrosion product formation and possibly their lateral distribution upon field and laboratory exposures. The multi-analytical approach enabled the exploration of the interplay between the microstructure and corrosion initiation and corrosion product evolution. A clear influence of the microstructure on the initial corrosion product formation was preferentially observed in the zinc-rich phase for both the Zn-Al and the Cu-Zn alloys, processes being triggered by microgalvanic effects., Bättre molekylär förståelse för metallers atmosfäriska korrosion kräver en fördjupad kunskap i det dynamiska samspelet mellan atmosfärens korrosiva beståndsdelar och metallytan. Denna doktorsavhandling omfattar laboratorie- och fältundersökningar av korrosions- och metallfrigöringsprocesser av två grupper av legeringar som exponerats i kloridrika atmosfärsmiljöer: två kommersiella Zn-Al beläggningar på stål, Galfan™ (Zn med 5% Al, förkortat Zn5Al) och Galvalume™ (Zn55Al), samt fyra kopparbaserade legeringar (Cu4Sn, Cu15Zn, Cu40Zn och Cu5Zn5Al). Undersökningar har genomförts i renodlade laboratorie-miljöer med för-deponerade NaCl-partiklar i en atmosfär av varierande relativ fuktighet. Syftet har varit att utvärdera betydelsen av kloriders deposition och legeringarnas mikrostruktur på korrosionsmekanismen samt bildandet av korrosionsprodukter. Jämförelser av korrosionsmekanismer har även gjorts efter flerårsexponeringar av samma legeringar i en marin fältmiljö i Brest, Frankrike. Undersökningarna har baserats på ett brett spektrum av analysmetoder för detaljerade studier dels under pågående atmosfärisk korrosion (in-situ), och dels efter avslutad korrosion (ex-situ). Legeringarnas mikrostruktur och tillhörande variation i ädelhet hos olika faser har undersökts med svepelektronmikroskopi och energidispersiv röntgenmikroanalys (SEM/EDS) samt med en variant av atomkraftsmikroskopi (engelska: scanning Kelvin probe force microscopy, SKPFM). Korrosionsprodukternas tillväxt har analyserats in-situ med infraröd reflektions-absorptionsspektroskopi (IRAS), samt morfologi och sammansättning av bildade korrosionsprodukter ex-situ med SEM/EDS, konfokal Raman mikro-spektroskopi (CRM) samt röntgendiffraktion vid strykande ifall (GIXRD). Det multi-analytiska tillvägagångssättet har medfört att det komplexa samspelet mellan de skilda legeringarnas mikrostruktur, korrosionsinitiering och bildandet av korrosionsprodukter kunnat studeras i detalj. En tydlig påverkan av mikrostruktur på, QC 20140915, Autocorr, RFSR-CT-2009-00015 Corrosion of heterogeneous metal-metal assemblies in the automotive industry, Atmospheric corrosion and environmental metal dispersion from outdoor construction materials

Fundamental understanding of atmospheric corrosion mechanisms requires an in-depth understanding on the dynamic interaction between corrosive constituents and metal/alloy surfaces. This doctoral study comprises field and laboratory investigations that assess atmospheric corrosion and metal release processes for two different groups of alloys exposed in chloride-rich environments. These groups comprise two commercial Zn-Al alloy coatings on steel, Galfan™ (Zn5Al) and Galvalume™ (Zn55Al), and four copper-based alloys (Cu4Sn, Cu15Zn, Cu40Zn and Cu5Zn5Al). In-depth laboratory investigations were conducted to assess the role of chloride deposition and alloy microstructure on the initial corrosion mechanisms and subsequent corrosion product formation. Comparisons were made with long-term field exposures at unsheltered marine conditions in Brest, France. A multitude of surface sensitive and non-destructive analytical methods were adopted for detailed in-situ and ex-situ analysis to assess corrosion product evolution scenarios for the Zn-Al and the Cu-based alloys. Scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were employed for morphological investigations and scanning Kelvin probe force microscopy (SKPFM) for nobility distribution measurements and to gain microstructural information. SEM/EDS, infrared reflection-absorption spectroscopy (IRAS), confocal Raman micro-spectroscopy (CRM) and grazing incidence x-ray diffraction (GIXRD) were utilized to gain information on corrosion product formation and possibly their lateral distribution upon field and laboratory exposures. The multi-analytical approach enabled the exploration of the interplay between the microstructure and corrosion initiation and corrosion product evolution. A clear influence of the microstructure on the initial corrosion product formation was preferentially observed in the zinc-rich phase for both the Zn-Al and the Cu-Zn alloys, processes being triggered by microgalvanic effects., Bättre molekylär förståelse för metallers atmosfäriska korrosion kräver en fördjupad kunskap i det dynamiska samspelet mellan atmosfärens korrosiva beståndsdelar och metallytan. Denna doktorsavhandling omfattar laboratorie- och fältundersökningar av korrosions- och metallfrigöringsprocesser av två grupper av legeringar som exponerats i kloridrika atmosfärsmiljöer: två kommersiella Zn-Al beläggningar på stål, Galfan™ (Zn med 5% Al, förkortat Zn5Al) och Galvalume™ (Zn55Al), samt fyra kopparbaserade legeringar (Cu4Sn, Cu15Zn, Cu40Zn och Cu5Zn5Al). Undersökningar har genomförts i renodlade laboratorie-miljöer med för-deponerade NaCl-partiklar i en atmosfär av varierande relativ fuktighet. Syftet har varit att utvärdera betydelsen av kloriders deposition och legeringarnas mikrostruktur på korrosionsmekanismen samt bildandet av korrosionsprodukter. Jämförelser av korrosionsmekanismer har även gjorts efter flerårsexponeringar av samma legeringar i en marin fältmiljö i Brest, Frankrike. Undersökningarna har baserats på ett brett spektrum av analysmetoder för detaljerade studier dels under pågående atmosfärisk korrosion (in-situ), och dels efter avslutad korrosion (ex-situ). Legeringarnas mikrostruktur och tillhörande variation i ädelhet hos olika faser har undersökts med svepelektronmikroskopi och energidispersiv röntgenmikroanalys (SEM/EDS) samt med en variant av atomkraftsmikroskopi (engelska: scanning Kelvin probe force microscopy, SKPFM). Korrosionsprodukternas tillväxt har analyserats in-situ med infraröd reflektions-absorptionsspektroskopi (IRAS), samt morfologi och sammansättning av bildade korrosionsprodukter ex-situ med SEM/EDS, konfokal Raman mikro-spektroskopi (CRM) samt röntgendiffraktion vid strykande ifall (GIXRD). Det multi-analytiska tillvägagångssättet har medfört att det komplexa samspelet mellan de skilda legeringarnas mikrostruktur, korrosionsinitiering och bildandet av korrosionsprodukter kunnat studeras i detalj. En tydlig påverkan av mikrostruktur på, QC 20140915, Autocorr, RFSR-CT-2009-00015 Corrosion of heterogeneous metal-metal assemblies in the automotive industry, Atmospheric corrosion and environmental metal dispersion from outdoor construction materials

Fundamental understanding of atmospheric corrosion mechanisms requires an in-depth understanding on the dynamic interaction between corrosive constituents and metal/alloy surfaces. This doctoral study comprises field and laboratory investigations that assess atmospheric corrosion and metal release processes for two different groups of alloys exposed in chloride-rich environments. These groups comprise two commercial Zn-Al alloy coatings on steel, Galfan™ (Zn5Al) and Galvalume™ (Zn55Al), and four copper-based alloys (Cu4Sn, Cu15Zn, Cu40Zn and Cu5Zn5Al). In-depth laboratory investigations were conducted to assess the role of chloride deposition and alloy microstructure on the initial corrosion mechanisms and subsequent corrosion product formation. Comparisons were made with long-term field exposures at unsheltered marine conditions in Brest, France. A multitude of surface sensitive and non-destructive analytical methods were adopted for detailed in-situ and ex-situ analysis to assess corrosion product evolution scenarios for the Zn-Al and the Cu-based alloys. Scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were employed for morphological investigations and scanning Kelvin probe force microscopy (SKPFM) for nobility distribution measurements and to gain microstructural information. SEM/EDS, infrared reflection-absorption spectroscopy (IRAS), confocal Raman micro-spectroscopy (CRM) and grazing incidence x-ray diffraction (GIXRD) were utilized to gain information on corrosion product formation and possibly their lateral distribution upon field and laboratory exposures. The multi-analytical approach enabled the exploration of the interplay between the microstructure and corrosion initiation and corrosion product evolution. A clear influence of the microstructure on the initial corrosion product formation was preferentially observed in the zinc-rich phase for both the Zn-Al and the Cu-Zn alloys, processes being triggered by microgalvanic effects., Bättre molekylär förståelse för metallers atmosfäriska korrosion kräver en fördjupad kunskap i det dynamiska samspelet mellan atmosfärens korrosiva beståndsdelar och metallytan. Denna doktorsavhandling omfattar laboratorie- och fältundersökningar av korrosions- och metallfrigöringsprocesser av två grupper av legeringar som exponerats i kloridrika atmosfärsmiljöer: två kommersiella Zn-Al beläggningar på stål, Galfan™ (Zn med 5% Al, förkortat Zn5Al) och Galvalume™ (Zn55Al), samt fyra kopparbaserade legeringar (Cu4Sn, Cu15Zn, Cu40Zn och Cu5Zn5Al). Undersökningar har genomförts i renodlade laboratorie-miljöer med för-deponerade NaCl-partiklar i en atmosfär av varierande relativ fuktighet. Syftet har varit att utvärdera betydelsen av kloriders deposition och legeringarnas mikrostruktur på korrosionsmekanismen samt bildandet av korrosionsprodukter. Jämförelser av korrosionsmekanismer har även gjorts efter flerårsexponeringar av samma legeringar i en marin fältmiljö i Brest, Frankrike. Undersökningarna har baserats på ett brett spektrum av analysmetoder för detaljerade studier dels under pågående atmosfärisk korrosion (in-situ), och dels efter avslutad korrosion (ex-situ). Legeringarnas mikrostruktur och tillhörande variation i ädelhet hos olika faser har undersökts med svepelektronmikroskopi och energidispersiv röntgenmikroanalys (SEM/EDS) samt med en variant av atomkraftsmikroskopi (engelska: scanning Kelvin probe force microscopy, SKPFM). Korrosionsprodukternas tillväxt har analyserats in-situ med infraröd reflektions-absorptionsspektroskopi (IRAS), samt morfologi och sammansättning av bildade korrosionsprodukter ex-situ med SEM/EDS, konfokal Raman mikro-spektroskopi (CRM) samt röntgendiffraktion vid strykande ifall (GIXRD). Det multi-analytiska tillvägagångssättet har medfört att det komplexa samspelet mellan de skilda legeringarnas mikrostruktur, korrosionsinitiering och bildandet av korrosionsprodukter kunnat studeras i detalj. En tydlig påverkan av mikrostruktur på, QC 20140915, Autocorr, RFSR-CT-2009-00015 Corrosion of heterogeneous metal-metal assemblies in the automotive industry, Atmospheric corrosion and environmental metal dispersion from outdoor construction materials

Fundamental understanding of atmospheric corrosion mechanisms requires an in-depth understanding on the dynamic interaction between corrosive constituents and metal/alloy surfaces. This doctoral study comprises field and laboratory investigations that assess atmospheric corrosion and metal release processes for two different groups of alloys exposed in chloride-rich environments. These groups comprise two commercial Zn-Al alloy coatings on steel, Galfan™ (Zn5Al) and Galvalume™ (Zn55Al), and four copper-based alloys (Cu4Sn, Cu15Zn, Cu40Zn and Cu5Zn5Al). In-depth laboratory investigations were conducted to assess the role of chloride deposition and alloy microstructure on the initial corrosion mechanisms and subsequent corrosion product formation. Comparisons were made with long-term field exposures at unsheltered marine conditions in Brest, France. A multitude of surface sensitive and non-destructive analytical methods were adopted for detailed in-situ and ex-situ analysis to assess corrosion product evolution scenarios for the Zn-Al and the Cu-based alloys. Scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were employed for morphological investigations and scanning Kelvin probe force microscopy (SKPFM) for nobility distribution measurements and to gain microstructural information. SEM/EDS, infrared reflection-absorption spectroscopy (IRAS), confocal Raman micro-spectroscopy (CRM) and grazing incidence x-ray diffraction (GIXRD) were utilized to gain information on corrosion product formation and possibly their lateral distribution upon field and laboratory exposures. The multi-analytical approach enabled the exploration of the interplay between the microstructure and corrosion initiation and corrosion product evolution. A clear influence of the microstructure on the initial corrosion product formation was preferentially observed in the zinc-rich phase for both the Zn-Al and the Cu-Zn alloys, processes being triggered by microgalvanic effects., Bättre molekylär förståelse för metallers atmosfäriska korrosion kräver en fördjupad kunskap i det dynamiska samspelet mellan atmosfärens korrosiva beståndsdelar och metallytan. Denna doktorsavhandling omfattar laboratorie- och fältundersökningar av korrosions- och metallfrigöringsprocesser av två grupper av legeringar som exponerats i kloridrika atmosfärsmiljöer: två kommersiella Zn-Al beläggningar på stål, Galfan™ (Zn med 5% Al, förkortat Zn5Al) och Galvalume™ (Zn55Al), samt fyra kopparbaserade legeringar (Cu4Sn, Cu15Zn, Cu40Zn och Cu5Zn5Al). Undersökningar har genomförts i renodlade laboratorie-miljöer med för-deponerade NaCl-partiklar i en atmosfär av varierande relativ fuktighet. Syftet har varit att utvärdera betydelsen av kloriders deposition och legeringarnas mikrostruktur på korrosionsmekanismen samt bildandet av korrosionsprodukter. Jämförelser av korrosionsmekanismer har även gjorts efter flerårsexponeringar av samma legeringar i en marin fältmiljö i Brest, Frankrike. Undersökningarna har baserats på ett brett spektrum av analysmetoder för detaljerade studier dels under pågående atmosfärisk korrosion (in-situ), och dels efter avslutad korrosion (ex-situ). Legeringarnas mikrostruktur och tillhörande variation i ädelhet hos olika faser har undersökts med svepelektronmikroskopi och energidispersiv röntgenmikroanalys (SEM/EDS) samt med en variant av atomkraftsmikroskopi (engelska: scanning Kelvin probe force microscopy, SKPFM). Korrosionsprodukternas tillväxt har analyserats in-situ med infraröd reflektions-absorptionsspektroskopi (IRAS), samt morfologi och sammansättning av bildade korrosionsprodukter ex-situ med SEM/EDS, konfokal Raman mikro-spektroskopi (CRM) samt röntgendiffraktion vid strykande ifall (GIXRD). Det multi-analytiska tillvägagångssättet har medfört att det komplexa samspelet mellan de skilda legeringarnas mikrostruktur, korrosionsinitiering och bildandet av korrosionsprodukter kunnat studeras i detalj. En tydlig påverkan av mikrostruktur på, QC 20140915, Autocorr, RFSR-CT-2009-00015 Corrosion of heterogeneous metal-metal assemblies in the automotive industry, Atmospheric corrosion and environmental metal dispersion from outdoor construction materials

This study has been triggered by the fact that stainless steel is being increasingly used in new applications, where possible environmental effects may be a matter of concern. When stainless steel is exposed to a given environment, a key issue is the release of small amounts of the main alloying elements iron, chromium, nickel and molybdenum. Published release rate data of these elements turned out to be sparse. Furthermore, only little was known about the role of different parameters that may affect the release rate, such as degree of alloying, exposure time and surface finish. Hence, the aim of this study was to develop methodological means and to provide accurate metal release rates of alloying constituents from different grades of stainless steels- austenitic, ferritic and duplex- when exposed to selected environments: artificial rain and synthetic body fluids. The results and discussion have been summarised in this thesis by formulating and answering ten questions, all believed to be crucial for the understanding of possible environmental effects of stainless steels. Some common conclusions could be drawn, independent of stainless steel grade and exposure condition. Iron was always preferentially released, and the release rates of chromium, nickel and molybdenum (when measured) were significantly lower than of iron, also when considering the bulk proportion of these elements. The release rate of all elements was initially high and decreased with exposure time, mainly because of an observed enrichment of chromium in the passive film formed. The release rates of iron (2 μgcm-2week-1) and nickel (0.08 μgcm-2week-1) from stainless steel from grades 304 and 316 exposed to artificial rain were much lower than corresponding rates for the pure metals (750 μgcm-2week-1 released Fe and 15 μgcm-2week-1 released Ni), whereas chromium exhibited similar release rates from stainless steel and the pure metal (0.1 μgcm-2week-1). This implies that the common procedure to calcula, QC 20120217

This study has been triggered by the fact that stainless steel is being increasingly used in new applications, where possible environmental effects may be a matter of concern. When stainless steel is exposed to a given environment, a key issue is the release of small amounts of the main alloying elements iron, chromium, nickel and molybdenum. Published release rate data of these elements turned out to be sparse. Furthermore, only little was known about the role of different parameters that may affect the release rate, such as degree of alloying, exposure time and surface finish. Hence, the aim of this study was to develop methodological means and to provide accurate metal release rates of alloying constituents from different grades of stainless steels- austenitic, ferritic and duplex- when exposed to selected environments: artificial rain and synthetic body fluids. The results and discussion have been summarised in this thesis by formulating and answering ten questions, all believed to be crucial for the understanding of possible environmental effects of stainless steels. Some common conclusions could be drawn, independent of stainless steel grade and exposure condition. Iron was always preferentially released, and the release rates of chromium, nickel and molybdenum (when measured) were significantly lower than of iron, also when considering the bulk proportion of these elements. The release rate of all elements was initially high and decreased with exposure time, mainly because of an observed enrichment of chromium in the passive film formed. The release rates of iron (2 μgcm-2week-1) and nickel (0.08 μgcm-2week-1) from stainless steel from grades 304 and 316 exposed to artificial rain were much lower than corresponding rates for the pure metals (750 μgcm-2week-1 released Fe and 15 μgcm-2week-1 released Ni), whereas chromium exhibited similar release rates from stainless steel and the pure metal (0.1 μgcm-2week-1). This implies that the common procedure to calcula, QC 20120217

This study has been triggered by the fact that stainless steel is being increasingly used in new applications, where possible environmental effects may be a matter of concern. When stainless steel is exposed to a given environment, a key issue is the release of small amounts of the main alloying elements iron, chromium, nickel and molybdenum. Published release rate data of these elements turned out to be sparse. Furthermore, only little was known about the role of different parameters that may affect the release rate, such as degree of alloying, exposure time and surface finish. Hence, the aim of this study was to develop methodological means and to provide accurate metal release rates of alloying constituents from different grades of stainless steels- austenitic, ferritic and duplex- when exposed to selected environments: artificial rain and synthetic body fluids. The results and discussion have been summarised in this thesis by formulating and answering ten questions, all believed to be crucial for the understanding of possible environmental effects of stainless steels. Some common conclusions could be drawn, independent of stainless steel grade and exposure condition. Iron was always preferentially released, and the release rates of chromium, nickel and molybdenum (when measured) were significantly lower than of iron, also when considering the bulk proportion of these elements. The release rate of all elements was initially high and decreased with exposure time, mainly because of an observed enrichment of chromium in the passive film formed. The release rates of iron (2 μgcm-2week-1) and nickel (0.08 μgcm-2week-1) from stainless steel from grades 304 and 316 exposed to artificial rain were much lower than corresponding rates for the pure metals (750 μgcm-2week-1 released Fe and 15 μgcm-2week-1 released Ni), whereas chromium exhibited similar release rates from stainless steel and the pure metal (0.1 μgcm-2week-1). This implies that the common procedure to calcula, QC 20120217