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Road dust resuspension in urban environments can contribute to high human exposure to metal(loid)s, polycyclic aromatic hydrocarbons, and other potentially toxic organic compounds. However, for many regions, information on loadings, emission factors and chemical profiles is lacking to accurately apply emission inventories and source apportionment models. In the present study, PM10 samples were collected with an in situ road dust sampler from eleven representative streets of Bragança, an inland city of the Iberian Peninsula, and were analysed for organic and elemental carbon by a thermal-optical technique, elemental composition by ICP-MS and ICP-OES, and ecotoxicity by a luminescence inhibition bioassay with Allivibrio fischeri. A global emission factor of 5.36 ± 2.35 mg veh−1 km−1 was obtained but in suburban areas the values reached twice the average. Total carbon accounted for 14.9 ± 6.8% of the PM10 mass, while element oxides represented the largest share (28.6 ± 18.7%). Very high enrichments were found for typical traffic-related elements such as Cu, Zn, S, Pb and Ni. The geochemical index Igeo further confirmed that road dust of the study region is extremely contaminated by elements mainly originated from tyre and brake wear. Although the total non-carcinogenic and carcinogenic risks associated with metal exposure were found to be low for both children and adults, the bioluminescence inhibition assay showed (eco)toxic responses for all samples, indicating that road dust resuspension may pose a significant human health and ecological threat. [ABSTRACT FROM AUTHOR]

Plants exposed to abiotic stressors show diverse physiological, biochemical, and molecular responses. Biosynthesis of plant secondary metabolites—including essential oils—is a vital plant defense mechanism. As these bioactive compounds are widely used in the pharmaceutical, cosmetic and food industries, it is essential to understand how their production is affected in various environments. While interaction between specific abiotic stressors such as salt stress has been widely studied, relatively less information is available on how essential oil production is affected by toxic contaminants. Present review intends to give an insight into the possible interaction between chemical stress and essential oil production, with special regard to soil and air pollution. Available studies clearly demonstrate that heavy metal induced stress does affect quantity and quality of EOs produced, however, pattern seems ambiguous as nature of effect depends on the plant taxon and on the EO. Considering mechanisms, genetic studies clearly prove that exposure to heavy metals influences the expression of genes being responsible for EO synthesis. [ABSTRACT FROM AUTHOR]

Atmospheric polycyclic aromatic hydrocarbons (PAHs) have well-known phytotoxicity on higher plants. However, while numerous bioindication studies have been targeted on how different symptoms indicate the deleterious effects of PAHs in the field, laboratory-scale phytotoxicity tests are much rarer. While ecotoxicity tests might rely on the very same end-points as bioindication studies, they have to comply with quality assurance criteria, repeatability being the most important. As such, proper reporting involves the description of the test compound, experimental design and conditions, test organism used, and end-points measured. The recent review intends to give an overview of studies available in the literature complying with these requirements. PAHs occur in the atmosphere both in gaseous form and bound to particles. As plants are exposed to both phases, test protocols available represent different exposure pathways, fumigation chambers vs. direct foliar treatment. Reported studies, therefore, are grouped based on the exposure route they intend to simulate. [ABSTRACT FROM AUTHOR]

Urban gardening has become more and more popular in recent years, as people might prefer to grow their own vegetables from controlled sources. In addition, community building also plays a key role. However, air pollution in settlements is a serious hazard affecting the quality of home-grown vegetables. During the vegetation period, traffic is the main factor generating atmospheric particulate matter. These particles will, in turn, bind to potentially toxic compounds, of which heavy metals and polycyclic aromatic hydrocarbons (PAHs) are the most widely studied and discussed. In addition to their potential toxicity, both groups contain carcinogenic species. Heavy metals, as well as PAHs, are capable of bioaccumulation, depending on the element or compound's characteristics and the vegetable species. Some leafy vegetables can accumulate these toxic materials in significant quantities. As dietary uptake is considered the major exposure route of both heavy metals and PAHs, the consumption of impacted vegetables might even pose human health risks. This recent review summarises available data reported on heavy metal and PAH accumulation in urban environments, specified by vegetable species. Also, the assessment of possible human impact is given. [ABSTRACT FROM AUTHOR]

The airborne transport of bacteria is a well-known phenomenon, making it possible to exchange species between ecosystems, but it also provides a tool for spreading of pathogenic microorganisms. As part of a large-scale study, microbial community of inhalable and respirable fractions (PM1-10) of resuspended dust collected in Budapest (Hungary) has been characterised by culture-independent next generation sequencing (NGS) of variable 16S rRNA gene regions. Apart from common, mostly ubiqituos soil and organic material-dwelling bacteria, exotic airborne species have been identified, such as Variovorax ginsengisoli, previously isolated from Korean ginseng fields or Exiguobacterium sibiricum, isolated from the Siberian permafrost.

Particulate matter (PM) is grouped as coarse, fine, and ultrafine particles (UFPs) with aerodynamic diameters of 2.5 to 10 μm (PM10),

Air pollution in settlements has become a continuously growing problem. Traffic, especially emission of diesel-powered vehicles, poses an important health risk. Emitted particles carry a wide range to potentially toxic chemicals, of them polycyclic aromatic hydrocarbons (PAHs) are the most important group of concern. Despite the risk of air pollution, rural gardens are very popular both for food production and for environmental benefit. On the other hand, several mutagenic and/or carcinogenic PAHs have been detected in leafy vegetables grown in impacted areas. In our study, the No. 227 OECD GUIDELINE FOR THE TESTING OF CHEMICALS: Terrestrial Plant Test: Vegetative Vigor Test was followed to assess foliar uptake of PAHs from aqueous extract of diesel aerosol sample. Significant differences were found in the bioaccumulation capacity of the tested vegetables as well as in their bioaccumulation pattern. In general, most vegetables showed good even strong correlation with individual PAHs of the diesel extract. In consistency with other studies, prevalence of 3- and 4-ring PAHs was experienced. [ABSTRACT FROM AUTHOR]

Air pollution, including PM2.5 concentration in Ulaanbaatar (capital of Mongolia) is a serious matter of concern. As the majority of households use coal in large areas of the city, indoor air quality is also posing a serious risk to human health. This study investigated the concentration of polycyclic aromatic compounds (PAHs) in indoor particulate matter (PM2.5) in 10 non-smoker households. Sampling was conducted in winter of 2018, between 27 January and 09 February. Concentrations of PM2.5 in the indoor air of households ranged between 62.8 and 324.8 µg m−3. Total concentration of PAHs also varied in a relatively wide range, between 46.2 and 175.7 ng m−3. Five-ring PAHs represented a considerably high fraction of total PAHs between 25 and 53%, benzo[b]fluoranthene (BbF) and benzo[a]pyrene (BaP) were the two predominant compounds within five-ring PAHs. Significant correlation was found between indoor and outdoor particulate matter levels in wintertime. Considering individual characteristic PAHs, heavier PAHs homologues (4- to 5-ring and 6-ring PAHs) were detected in all households, which suggested the influence of coal combustion and traffic exhaust. Health risk of children attributed to PAHs inhalation was assessed by taking into account the lifetime-average daily dose (LADD) and corresponding lifetime cancer risk. Lifetime average daily dose for children in only one household were slightly higher than health-based guideline level (1.0 × 10−5), defined by WHO, whereas LADD for adults and children of other households were within acceptable limit. The cancer risks from the exposure of children to air pollutants in all households except HH-3 were found high. In the Vibrio fischeri bioluminescence inhibition assay, according to the toxic unit (TU) values of indoor PM2.5 from ten households, all samples were classified as toxic. [ABSTRACT FROM AUTHOR]