Search

Thirdhand smoke (THS) is the persistent and toxic residue from tobacco smoke in indoor environments. A comprehensive understanding of the chemical constituents of THS is necessary to assess the risks of long-term exposure and to establish reliable THS tracers. The objective of this study was to investigate compounds associated with THS through nontargeted analysis (NTA) of settled house dust samples from smokers' and non-smokers' homes, using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS). Compounds that were either only present in dust from smokers' homes or that had significantly larger abundance than in non-smokers' homes were termed qualified compounds. We identified 140 qualified compounds, and of these, 42 compounds were tentatively identified by searching matching mass spectra in NIST electron impact (EI) mass spectral library including 20 compounds confirmed with their authentic standards. Among the 42 compounds, 26 compounds were statistically more abundant (p

Indoor house dust is considered an important human exposure route to polybrominated diphenyl ethers (PBDEs), which has raised concern about their environmental persistence and toxicity properties. In this study, eight PBDEs (BDE-28, -47, -99, -100, -153, -154, -183, and -209) were determined in house dust from two cities with different socio-demographic characteristics from Brazil, examining possible relationships with factors that potentially influence contamination (population density, economic activities, presence of electronic equipment, and so on) and also estimating the risk of human exposure through oral ingestion and dermal contact. The Σ8PBDE concentration in Sorocaba city ranged between 380 and 4269 ng/g dw, while in Itapetininga city ranged from 106 to 1000 ng/g dw. In both regions, BDE-209 was the most abundantly found congener, followed by BDE-99. House dust from Sorocaba presented significantly greater concentrations of BDE-183 and BDE-209 than Itapetininga. Regarding risk exposure assessment, the estimated daily intake (EDI) of PBDEs was much lower than their respective reference doses (RfDs) in all pathways estimated (non-dietary ingestion and dermal contact). This study provided valuable data to improve the knowledge about the presence and exposure to PBDEs in Brazilian house dust in comparison to other developing countries and the need to control environmental pollution and protect human health. [ABSTRACT FROM AUTHOR]

A couple of air quality (AQ) parameters were monitored with two types of low-cost sensors (LCSs) before, during and after the garden fence rebuilding of a dwelling house, located at the junction of a main road and a side street in a suburban area of Budapest, Hungary. The AQ variables, recorded concurrently indoors and outdoors, were particulate matter (PM1, PM2.5, PM10) and some gaseous trace pollutants, such as CO2, formaldehyde (HCHO) and volatile organic compounds (VOCs). Medium-size aerosol (PM2.5-1), coarse particulate (PM10-2.5) and indoor-to-outdoor (I/O) ratios were calculated. The I/O ratios showed that indoor fine and medium-size PM was mostly of outdoor origin; its increased levels were observed during the renovation. The related pollution events were characterized by peaks as high as 100, 95 and 37 µg/m3 for PM1, PM2.5-1 and PM10-2.5, respectively. Besides the renovation, some indoor sources (e.g., gas-stove cooking) also contributed to the in-house PM1, PM2.5-1 and PM10-2.5 levels, which peaked as high as 160, 255 and 220 µg/m3, respectively. In addition, these sources enhanced the indoor levels of CO2, HCHO and, rarely, VOCs. Increased and highly fluctuating VOC levels were observed in the outdoor air (average: 0.012 mg/m3), mainly due to the use of paints and thinners during the reconstruction, though the use of a nearby wood stove for heating was an occasional contributing factor. The acquired results show the influence of the fence renovation-related activities on the indoor air quality in terms of aerosols and gaseous components, though to a low extent. The utilization of high-resolution LCS-assisted monitoring of gases and PMx helped to reveal the changes in several AQ parameters and to assign some dominant emission sources. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the presence of a variety of heavy metals in the household dust of residents in Irbid, Jordan. Seventy samples of household dust were taken from various parts of the city, digested, and analyzed using flame atomic absorption spectroscopy (FAAS) for the presence of Pb, Cd, Cu, Zn, Co, Ni, Cr, Fe, and Mn. The geometric mean concentrations were 83.4, 2.1, 531.7, 94.8, 36.2, 16.1, 126.4, 141.3, and 9278 mg/kg for Pb, Cd, Zn, Cu, Cr, Co, Ni, Mn, and Fe, respectively. Calculations were done to determine enrichment factors about the abundance of heavy metals in the ear th's crust. According to the findings, Cd and Ni are extremely enriched in the dust samples taken from indoor environments, whereas Pb, Cu, and Zn are only moderately so. The incorporation of dust from both indoor and outdoor sources into the environment of the house is thought to be the cause of the enrichment of certain elements. Calculations, based on a factor analysis, revealed that the outdoor dust from a variety of sources, which is typically brought inside by foot traffic, has a significant impact on the quality of the indoor environment. [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs) are a group of compounds that, due to their applications, are considered mainly indoor contaminants. To obtain the first information about the presence of PBDEs in Serbia, dust samples (n = 50) were collected in settlements in the northern Serbian province of Vojvodina. The selected/target congeners (BDE-28, 47, 99, 100, 153, 154, and 183) were extracted from house dust by microwave-assisted extraction technique, and purified extracts were analyzed on a dual-column gas chromatograph with micro-electron capture detectors. A wide range of ΣPBDEs was detected (0.295 to 394 ng g−1 dust), which reflects large differences in contamination among the examined homes. For the majority of samples (72%), ΣPBDEs were lower than 5 ng g−1 indicating that people living in Vojvodina province are exposed to low concentrations of PBDEs present in their households. Based on principal component analysis (PCA), balcony areas and age of the house positively correlate with the PBDE congeners with higher detection frequencies (≥ 50%), namely, with BDE-99, BDE-153, and BDE-183. Statistically significant positive correlation (p < 0.01) was obtained for BDE-99 and the number of household's members. Estimated daily intakes (EDItot) were calculated for ingestion and dermal absorption of dust for two age groups—adults and toddlers. These are the first data on PBDE status in the area of the Western Balkan, and the health risk assessment indicates that PBDE levels obtained in household dust do not pose a risk for human health. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are used primarily as flame retardants and plasticizers. Previously, we reported that adrenal cells are important targets of individual OPEs. However, real-life exposures are to complex mixtures of these chemicals. To address this, we exposed H295R human adrenal cells to varying dilutions (1/1000K to 1/3K) of a Canadian household dust–based OPE mixture for 48 hours and evaluated effects on phenotypic, lipidomic, and functional parameters. Using a high-content screening approach, we assessed phenotypic markers at mixture concentrations at which there was greater than 70% cell survival; the most striking effect of the OPE mixture was a 2.5-fold increase in the total area of lipid droplets. We then determined the response of specific lipid species to OPE exposures with novel, nontargeted lipidomic analysis of isolated lipid droplets. These data revealed that house dust OPEs induced concentration-dependent alterations in the composition of lipid droplets, particularly affecting the triglyceride, diglyceride, phosphatidylcholine, and cholesterol ester subclasses. The steroid-producing function of adrenal cells in the presence or absence of a steroidogenic stimulus, forskolin, was determined. While the production of 17β-estradiol remained unaffected, a slight decrease in testosterone production was observed after stimulation. Conversely, a 2-fold increase in both basal and stimulated cortisol and aldosterone production was observed. Thus, exposure to a house dust–based mixture of OPEs exerts endocrine-disrupting effects on adrenal cells, highlighting the importance of assessing the effects of environmentally relevant mixtures. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are widely used in industry and have been linked to various adverse health effects. Communities adjacent to sites where PFAS are manufactured, stored, or used may be at elevated risk. In these impacted communities, significant exposure often occurs through contaminated drinking water, yet less is known about the role of other pathways such as residential exposure through house dust. We analyzed a paired serum and house dust dataset from the Agency for Toxic Substances and Disease Registry’s PFAS Exposure Assessments, which sampled eight United States communities with a history of drinking water contamination due to aqueous film forming foam (AFFF) use at nearby military bases. We found that serum PFAS levels of residents were significantly positively associated with the dust PFAS levels in their homes, for three of seven PFAS analyzed, when accounting for site and participant age. We also found that increased dust PFAS levels were associated with a shift in the relative abundance of PFAS in serum towards those chemicals not strongly linked to AFFF contamination, which may suggest household sources. Additionally, we analyzed participant responses to exposure questionnaires to identify factors associated with dust PFAS levels. Dust PFAS levels for some analytes were significantly elevated in households where participants were older and had lived at the home longer, cleaned less frequently, used stain resistant products, and had carpeted living rooms. Our results suggest that residential exposure to PFAS via dust or other indoor pathways may contribute to overall exposure and body burden, even in communities impacted by AFFF contamination of drinking water, and the magnitude of this exposure may also be influenced by demographic, behavioral, and housing factors.

Per- and polyfluoroalkyl substances (PFAS) are regularly found in soils and dusts, both of which can be consumed by children at relatively high amounts. However, there is little data available to model the bioaccessibility of PFAS in soils and dusts when consumed or to describe how the physiochemical properties of PFAS and soils/dusts might affect bioaccessibility of these chemicals. Because bioaccessibility is an important consideration in estimating absorbed dose for exposure and risk assessments, in the current study, in vitro assays were used to determine bioaccessibility of 14 PFAS in 33 sets of soils and dusts. Bioaccessibility assays were conducted with and without a sink, which was used to account for the removal of PFAS due to their movement across the human intestine. Multiple linear regression with backward elimination showed that a segmented model using PFAS chain length, number of branches, and percent total organic carbon explained 78.0%–88.9% of the variability in PFAS bioaccessibility. In general, PFAS had significantly greater bioaccessibility in soils relative to dusts and the addition of a sink increased bioaccessibility in the test system by as much as 10.8% for soils and 20.3% for dusts. The results from this study indicate that PFAS bioaccessibility in soils and dusts can be predicted using a limited set of physical chemical characteristics and could be used to inform risk assessment models. [ABSTRACT FROM AUTHOR]

The objective of this study was to measure the concentrations of selected heavy metals (Pb, Cd, Zn, Cu, Fe, Cr, Co, Ni, and Mn) in house dust collected during the summer and winter seasons from Mafraq and Irbid cities, Jordan. The average concentrations (±SD) of the metals were found to be 66.8 (±22.4), 10.8 (±3.75), 366 (±108), 81.6 (±43.9), 7586 (±4304), and 37.2 (±15.4) mg/kg, for Pb, Cd, Zn, Cu, Fe, and Cr, respectively, in the summer season. The average concentrations (±SD) of the metals were found to be 92.8 (±65.5), 5.10 (±4.75), 305 (±160), 144 (±163), 5385 (±3812), 27.1 (±15.1), 18.7 (±3.70), 42.2 (±15.1), and 139 (±69.2) mg/kg, for Pb, Cd, Zn, Cu, Fe, Cr, Co, Ni, and Mn, respectively, in the winter season. The influence of different heating systems on the concertation of heavy metal was examined by comparing the results obtained in both summer and winter seasons. The concentrations of the metals in this study were compared with those reported by other researchers around the world. This study shows that the significant accumulation of heavy metals in house dust should be considered a serious risk to the health of residents in Mafraq and Irbid cities.

Upholstered furniture has been a major source of chemical flame retardant (FR) exposures in US homes since the 1970s. FRs are a large group of chemicals, many of which are associated with adverse health effects, including cancer, reproductive toxicity, and neurotoxicity. California homes have some of the highest dust concentrations of FRs, due to Technical Bulletin 117 (TB117), California's outdated flammability standard for furniture foam that was generally followed across the US and Canada. In 2014, this standard was updated to a smolder standard for furniture fabric called TB117-2013, and it is no longer reliant on FRs. This update provided an opportunity to measure differences in FR dust levels in California homes before and after residents replaced older upholstered furniture, or its foam, with products that met the new standard and were expected to be FR-free. We collected dust from homes of participants who had plans to replace older upholstered furniture, or furniture foam, with FR-free options. We returned for follow-up dust collection six, 12, and 18 months following replacement. Concentrations of three polybrominated diphenyl ethers (PBDEs) (BDE-47, BDE-99, BDE-100), three chlorinated organophosphate ester FRs (tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), and tris(1,3-dichloroisopropyl) phosphate (TDCIPP)), and one aryl organophosphate ester FR triphenyl phosphate (TPHP), were widely detected in participant homes. All measured FRs decreased in nearly all homes after the older upholstered furniture was replaced. The decreases in FRs were significant in both homes that replaced entire pieces of furniture and those that replaced only the furniture foam. This study demonstrates that replacing older upholstered furniture or foam significantly reduces concentrations of a range of FRs in the home. Foam replacement offers a potentially more economic alternative that produces a lower volume of waste.

Phthalates are widely used as plasticizer and associated with various health issues. Recently, non-phthalate plasticizers are replacing phthalates; however, the exposure to these substances and the risk in Japan is unclear. In this study, we assessed the concentrations of phthalates, non-phthalate plasticizers, and phthalate degradation products in house dust and determined their respective exposure risks via oral and dermal routes. Twelve phthalates, seven non-phthalate plasticizers, and two degradation products were determined in the house dust obtained from 100 Japanese homes. The median concentration of di(2-ethylhexyl) phthalate (DEHP), accounting for 85 % of the total concentration of phthalates and non-phthalate plasticizers detected in this study, was 2.1 × 103 μg/g of dust. Apart from DEHP, diisononyl phthalate (DINP) and di(2-ethylhexyl) terephthalate (DEHT) were the most abundant in the house dust, accounting for 6.2 % (median: 1.7 × 102 μg/g of dust) and 6.1 % (median: 1.7 × 102 μg/g of dust) of the total concentrations, respectively. DEHP and DEHT concentrations in house dust were higher in apartment and small houses (floor area: ≤30 m2 or 31–60 m2 for DEHP and 31–60 m2 for DEHT) than in detached and large houses (floor area: ≥121 m2). Conversely, di-n-butyl phthalate (DnBP) concentrations were significantly higher in detached and large houses (floor area: ≥121 m2) than in apartment and small houses (floor area: ≤30 m2). The total hazard quotient (HQ), using the maximum concentration in house dust, revealed that oral and dermal exposure to house dust was 1.3 × 10-6–0.11 for adults (all substances) and 1.6 × 10-5–2.2 × 10-2 for preschool children (except for DnBP and DEHP), suggesting no risk. The HQs for DnBP and DEHP exposure via house dust for preschool children using the maximum values were 0.46 and 1.2, and 6.0 × 10-3 and 0.18 using the median values, indicating that risk of DEHP exposure should be exhaustively determined by considering other exposure routes that were not evaluated in this study, such as diet.

The innovative product of 'Perilis Trading Ltd. 'BED Pro-biotic' is a probiotic neutralizer of mites and allergens in household dust. This product was tested for an inhibitory effect on the presence of mites of the species Dermatophagoides pteronyssinus in house dust. The data presented is a representative sample of 4 households and one office. The allergen DERPI is the major antigen produced by the house mite D. pteronyssinus, which is routinely found in house dust. The test for the presence of the allergen DERPI in the monitored premises was carried out before cleaning. After sampling, 'BED Pro-biotic' was administered and sampled again at 5-daily intervals before cleaning for one month. The product was applied according to the manufacturer's instructions. Antigen extraction was performed according to published protocols in the scientific literature, and antigen was detected with a specific immunoassay ELISA for the DERPI antigen. The result obtained showed that the product effectively reduces and eliminates the presence of D. pteronyssinus mites, which are common in Europe. [ABSTRACT FROM AUTHOR]

People living in industrialized countries spend most of the time indoors. Therefore, a significant factor for the intake of pollutants by humans can be indoor contaminants like house dust (HD). The two main migration pathways of inorganic contaminants into buildings are the transport of soil and road dust (RD) adhering to footwear and atmospheric particulate matter sedimented inside the building. Additional sources of contaminants can come from activities carried out within the buildings. Some results are available from studies where samples of RD and HD were collected simultaneously. These results are compared with data from two studies where RD and HD samples were collected in the same area in Austria in Spring 2016. Since these samples were analysed by size fractions size dependent concentration ratios can be calculated for various elements. This information provides additional insight on the sources of specific elements.

IntroductionEnvironmental exposure to lead (Pb) and cadmium (Cd) are risk factors for adverse health outcomes in children and adults. This study examined whether thirdhand smoke residue contributes to Pb and Cd in settled house dust.MethodsParticipants were 60 multiunit housing residents in San Diego, California. All had indoor smoking bans during the study period, and 55 were nonsmokers. Wipe samples from different surfaces and vacuum floor dust samples were analyzed for nicotine, a marker of thirdhand smoke, and for Pb and Cd using liquid chromatography-triple quadrupole mass spectrometry and inductively coupled plasma-mass spectrometry, respectively.ResultsExamined in each sample type separately, Pb and Cd loadings were significantly correlated (r = 0.73, vacuum floor dust; 0.52, floor wipes; 0.72, window sill/trough wipes; all p  0.30). Nicotine loading in dust was significantly correlated with Pb and Cd loading in dust (r = 0.49 for Pb; r = 0.39 for Cd, all p

In past 50 years, with migration of human population from rural to urban areas, both industrialization and urbanization bring with air pollutions problems and consequently cause to increase respiratory and other corresponding diseases. Since people, especially those living in urban areas, spend more than 90% of their time indoors, recently indoor air quality has been paid attention as well as ambient air quality. In the current study, the indoor and outdoor dusts of 80 houses in Kocaeli were simultaneously collected in February and March in 2016. The 16 Polyaromatic Hydrocarbons (PAHs), 14 Polybrominated diphenyl ethers (PBDEs) and 15 Polychlorinated biphenyls (PCBs) were detected. Indoor to Outdoor (I/O) ratio for PAHs (ranging from 1.1 to 3.2) were not detected as high as PBDEs (range from 1.9 to 7.2) and PCBs (ranging from 1.8 to 7.9). The I/O ration for PBDEs and PCBs were comparable. Larger than one of I/O ratios in such a city with high loading of industrial and traffic and these ratios reached to 8 for PBDEs and PCBs indicated the importance of indoor air quality. Therefore certain precautions to regulate indoor air quality should be considered. [ABSTRACT FROM AUTHOR]

The Lavreotiki-Lavrion area, situated in the south-eastern tip of mainland Hellas, has one of the longest mining, ore beneficiation and smelting legacies worldwide. With a history of over 5000 years of argentiferous Pb–Zn ore exploitation, Lavrion is a place that shaped human civilisation by being a major wealth producing centre of the ancient world but also represents one of the few significant industrial developments of the modern Hellenic Republic, since the second part of the 19th century. The long history of mining, ore beneficiation and smelting activities produced a vast amount of potentially toxic wastes. In the post-mining era of Lavrion, during the 1980's, cross-sectional epidemiological studies diagnosed a severe problem of blood-Pb poisoning in primary school-age children and highlighted the seriousness of environmental contamination on the health of the local population. The first part of this review deals with the contamination problem in the area with respect to Pb, and discusses the results of detailed geochemical and epidemiological studies, based on the source-pathway-receptor model. The second part of the review presents the holistic evaluation of the contamination hazard, the assessment of health-related risk to residents, and the socio-economical impact of the proposed remediation plan to the local community. The case of Lavrion-Lavreotiki area is a worldwide reference example of the environmental, economical, societal and health-related implications that the thousand-years long legacy of mineral resources exploitation has left behind. [ABSTRACT FROM AUTHOR]

People living in industrialized countries spend most of the time indoors. Therefore, a significant factor for the intake of pollutants by humans can be indoor contaminants like house dust (HD). The two main migration pathways of inorganic contaminants into buildings are the transport of soil and road dust (RD) adhering to footwear and atmospheric particulate matter sedimented inside the building. Additional sources of contaminants can come from activities carried out within the buildings. Some results are available from studies where samples of RD and HD were collected simultaneously. These results are compared with data from two studies where RD and HD samples were collected in the same area in Austria in Spring 2016. Since these samples were analysed by size fractions size dependent concentration ratios can be calculated for various elements. This information provides additional insight on the sources of specific elements. [ABSTRACT FROM AUTHOR]

We previously demonstrated that indoor house dust extracts could induce adipogenesis in pre-adipocytes, suggesting a potential role for indoor contaminant mixtures in metabolic health. Herein, we investigated the potential role of thyroid receptor beta (TRβ) antagonism in adipogenic effects (dust-induced triglyceride accumulation and pre-adipocyte proliferation) following exposure to environmental mixtures (indoor house dust extracts). Concentrations of specific flame retardants were measured in extracts, and metabolic health information was collected from residents (n = 137). 90% of dust extracts exhibited significant adipogenic activity, >60% via triglyceride accumulation, and >70% via pre-adipocyte proliferation. Triglyceride accumulation was positively correlated with concentrations of each of twelve flame retardants, despite most being independently inactive; this suggests a putative role for co-exposures or mixtures. We further reported a positive correlation between dust-induced triglyceride accumulation and serum thyroid stimulating hormone concentrations, negative correlations with serum free triiodothyronine and thyroxine concentrations, and a positive and significant association between dust-induced triglyceride accumulation and residents' body mass index (BMI). We hypothesized that inhibition of TR antagonism might counteract these effects, and both addition of a TR agonist and siRNA knock-down of TR resulted in decreased dust-induced triglyceride accumulation in a subset of samples, bolstering this as a contributory mechanism. These results highlight a contributory role of environmental TR antagonism as a putative factor in metabolic health, suggesting that further research should evaluate this mechanism and determine whether in vitro adipogenic activity could have utility as a biomarker for metabolic health in residents.

One of the impacts of the COVID-19 pandemic is leading people remain at homes longer than ever. Considering the elongation of the time people spend indoors, the potential health risks caused by contaminants including heavy metals in indoor environments have become even more critical. The purpose of this study was to evaluate the levels and sources of heavy metals in indoor dust, to assess the exposure to heavy metals via indoor dust, and to estimate the associated health risk. The highest median value was measured for Zn (263 μg g−1), while the lowest median concentration value was observed for Cd (0.348 μg g−1). The levels of elements measured in the current study were found to be within the ranges reported in the other parts of the world, mostly close to the lower end of the range. House characteristics such as proximity to the main street, presence of pets, number of occupants, and age of the building were the house characteristics influencing the observed higher concentrations of certain heavy metals in houses. Enrichment factor values range between 1.79 (Cr) and 20.4 (Zn) with an average EF value of 8.80 ± 6.80 representing that the targeted elements are enriched (EF>2) in indoor dust in Ankara. Positive matrix factorization results showed that the heavy metals in the house dust in the study area are mainly contributed from sources namely outdoor dust, carpets/furniture, solders, wall paint/coal combustion, and cigarette smoke. Carcinogenic and non-carcinogenic risk values from heavy metals did not exceed the safe limits recommended by EPA. The highest carcinogenic risk level was caused by Cr. The risk through ingestion was higher than inhalation, and the risk levels were higher for children than for adults. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has caused a decrease in outdoor activities, but an increase in indoor ones. This change in the intensity of land use has caused changes in pollution patterns. Urban dust contaminated with heavy metals can be a risk to the human population. Therefore, the objective of this work was to evaluate the pollution caused by heavy metals in urban dust indoors and outdoors due to changes in land use during the pandemic. Sampling was carried out by the Gomez Palacio citizens. The total number of urban dust samples was 330, 50% indoor samples and 50% outdoor sample. The elements studied were Ca, Cu, Fe, K, Mn, Ni, Pb, Rb, Sr, Ti, Y, Zn, and Zr. The heavy metals were measured through a portable XRF; the contamination factor and the load pollution index were used to assess the pollution level. The human health risk was evaluated with the USEPA methodology. Cu, Pb, and Zn presented higher concentrations indoors than outdoors, probably due to domestic factors, such as the age of the houses and the paint on the walls. Zn presented the highest pollution level among all the metals, outdoors and indoors; spatially, the sites sampled in the northwest, close to agricultural areas, presented the highest Zn pollution. Pb had a moderate pollution level in most of the samples (60%), but some samples showed a high Pb pollution. The health risk was considered within the acceptable levels for Cu, Fe, Ni, Pb, Zn. However, Mn deserves attention because the average of the samples slightly exceeded the USEPA safety limits for children. Children are at higher risk compared to adults. Indoor environments need to be better analyzed because they were shown to represent a higher risk to the population than outdoor ones due to heavy metal pollution by Zn, Cu, and Pb. The pandemic impacted land use intensity; this study reports an apparent effect of the pandemic on the amount and type of heavy metals indoors and outdoors. [ABSTRACT FROM AUTHOR]

Simple Summary: We focused on the actual exposure to OHC in serum from pet cats kept in Thailand, and on cat food and house dust as expected sources of contamination. The Thai cat sera had significantly higher levels of PBDEs than other contaminants. Especially, decabromodiphenyl ether (BDE-209) is a major contaminant of OHCs in dry cat food and house dust, which was estimated to be a source of exposure for Thai pet cats. On the other hand, the level of contamination by PCBs was lower than in other countries. Analysis of pet foods suggested that BDE-209 in pet cat serum was attributable to the consumption of dry cat food. On the other hand, house dust also contained high concentrations of BDE-209. Thus, high levels of BDE-209 in pet cat sera can be attributed to the consumption of dry cat food and house dust. In this study, we analyzed serum samples of pet cats from Thailand and estimated the contribution to organohalogen compounds (OHCs) exposure through cat food and house dust intake. BDE-209 was predominant in cat sera and accounted for 76% of all polybrominated diphenyl ethers (PBDEs). Decabromodiphenyl ether (BDE-209) is a major contaminant in dry cat food and house dust, which has been estimated to be a source of exposure for Thai pet cats. BDE-209 is a major contaminant of OHCs in dry cat food and house dust, which was estimated to be a source of exposure for Thai pet cats. On the other hand, the level of contamination by PCBs was lower than in other countries. Analysis of pet foods suggested that BDE-209 in pet cat serum was attributable to the consumption of dry cat food. On the other hand, house dust also contained high concentrations of BDE-209. Thus, high levels of BDE-209 in pet cat sera can be attributed to the consumption of dry cat food and house dust. These results suggest that pet cats are routinely exposed to non-negligible levels of OHCs. [ABSTRACT FROM AUTHOR]

Interior dust lead loadings on floors and windowsills are reliable predictors of a child's blood lead level and an important predictor in "clearance testing" of residences. The portable X-ray fluorescence device is an alternate technique that can provide fast, accurate, and precise results regarding the presence of dust lead hazards in residences. In this paper, we tested the comparability of the portable X-ray fluorescence device against Inductively Coupled Plasma Mass Spectrometry, using the newer lead hazard standards for dust wipe samples. Dust wipe samples (n = 109) collected from floors and interior windowsills of 13 homes were tested by means of a portable X-ray fluorescence device and subsequently analyzed for lead using Inductively Coupled Plasma Mass Spectrometry. Considering Inductively Coupled Plasma Mass Spectrometry as the "gold standard," the portable X-ray fluorescence device produced an average false negative rate of 27.3% at the new dust lead hazard standards of 10 μg/ft2 for floors, and 100 μg/ft2 for windowsills. There were no false positive results from the portable X-ray fluorescence device at the new dust lead hazard standards. A Bland Altman analysis showed that 96.3% of the data points were within the lower and upper acceptable limits of agreement. The results of the study suggested that the portable X-ray fluorescence device has a good agreement with the Inductively Coupled Plasma Mass Spectrometry method at lower lead concentrations and is appropriate for measuring lead concentrations in field dust wipe samples from homes where lead concentrations are in a lower range. [ABSTRACT FROM AUTHOR]

As a sink and a source of chemicals, house dust represents a relevant medium to assess indoor exposure to metal(loid)s via incidental ingestion or inhalation. However, nationally representative indoor data are scarce. Results from the Canadian House Dust Study (CHDS, 2007–2010; n = 1025) provide nationally representative mean, median and 95th percentile concentrations for 38 elements in typical urban house dust, along with their gastric bioaccessibility. Total concentrations (median/95th percentile) of carcinogenic metal(loid)s in Canadian house dust (μg g−1) are as follows: As (9.0/40), Be (0.4/0.9), Cd (3.5/17), Co (5.6/19), Cr (99/214), Ni (62/322) and Pb (100/760). Total As and Pb concentrations in house dust exceed residential soil guidelines for the protection of human health in about one-third of Canadian homes. Percent bioaccessibilities (median) are: Cd (65%) > Pb (63%) > Be ∼ Ni (36%) > Co (35%) > As (20%) > Cr (15%). Lead, Cd and Co concentrations are significantly greater in older houses (< 1976). Data from two pilot studies (n = 66 + 51) further demonstrate the distinct geochemistry of house dust compared to soils, notably enrichment of carcinogenic metal(loid)s and their increased bioaccessibility. These results provide essential baseline values to refine risk assessment and inform on health risk at contaminated sites. [Display omitted] • Canadian house dust total/bioaccessible concentrations are reported for 38 elements. • Carcinogenic metal(loid)s co-occur in 94% of the 1025 house dust samples. • Total As and Pb concentrations exceed soil health guidelines in 33% Canadian homes. • Median bioaccessibility is high for Pb and Cd (> 60%) but low for As and Cr (≤ 20%). • Nationally representative baseline values help refine health risk assessment. [ABSTRACT FROM AUTHOR]

Analyses of air and house dust have shown that pollution of the indoor environment with microplastics could pose a fundamental hygienic problem. Indoor microplastics can result from abrasion, microplastic beads are frequently added to household products and microplastic granules can be found in artificial turf for sports activities and in synthetic admixtures in equestrian hall litter. In this context, the question arose as to what extent particulate emissions of thermoplastic materials from 3D printing should be at least partially classified as microplastics or nanoplastics. The discussion about textiles as a possible source of indoor microplastics has also been intensified. This Minireview gives an overview of the current exposure of residents to microplastics. Trends can be identified from the results and preventive measures can be derived if necessary. It is recommended that microplastics and their additives be given greater consideration in indoor environmental surveys in the future. [ABSTRACT FROM AUTHOR]

Analyses of air and house dust have shown that pollution of the indoor environment with microplastics could pose a fundamental hygienic problem. Indoor microplastics can result from abrasion, microplastic beads are frequently added to household products and microplastic granules can be found in artificial turf for sports activities and in synthetic admixtures in equestrian hall litter. In this context, the question arose as to what extent particulate emissions of thermoplastic materials from 3D printing should be at least partially classified as microplastics or nanoplastics. The discussion about textiles as a possible source of indoor microplastics has also been intensified. This Minireview gives an overview of the current exposure of residents to microplastics. Trends can be identified from the results and preventive measures can be derived if necessary. It is recommended that microplastics and their additives be given greater consideration in indoor environmental surveys in the future. [ABSTRACT FROM AUTHOR]

An integrated study on the levels of 7 polybrominated diphenyl ethers (PBDEs) in house dust and breast milk samples from women (N = 30) living in these households was conducted. ∑PBDEs ranged from -1 dust (median 4.9 ng g -1 dust), and from 0.16 to 6.3 ng g -1 lipid weight (lw) (median 0.49 ng g -1 lw), in house dust and breast milk samples, respectively. Statistically significant correlations were observed between the mass fractions of BDE-153 from breast milk, and BDE-47, BDE-99 and BDE-100 from house dust, congeners that all originate from the "penta" formulation, indicating its dominance as PBDE exposure source in the examined household dusts. The number of electronic and electrical devices, and age of the building were positive, and the number of upholstered furniture and household area were negative predictors of PBDE dust levels. Mothers age was negative predictor of the PBDE levels in breast milk, possibly due to dilution of PBDEs in total body fat accumulated over the years. The results of health risk assessment suggest that detected PBDE levels don't pose non-carcinogenic risk to the study population., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: European chemicals management aims to protect human health and the environment from legacy and emerging contaminants. The plasticizer market changed in response to the restriction of low molecular weight (LMW) phthalate plasticizers such as Di (2-ethylhexyl) phthalate (DEHP) due to their hazardous properties. We investigated patterns and trends of 19 regulated and emerging plasticizers in house dust from German homes and in suspended particulate matter (SPM) from major German rivers. The samples were used from the mid-2000s and late 2010s from two governmental long-term monitoring programs in Germany. Results: While the sum of the respective plasticizer levels hardly changed over the study period, we observed a significant decrease of LMW phthalates in both house dust (2003/06, 80% of the ∑plasticizer concentration; 2014/17, 31%) and SPM (2005, 48%; 2017, 28%). This was accompanied by their substitution with high molecular weight (HMW) phthalates and non-phthalates. HMW phthalates increased from 19% of the ∑plasticizer concentration to 46% between the mid-2000s and the late 2010s in house dust, and from 50% to 63% in SPM samples. Diisononyl phthalate (DINP) replaced DEHP as the dominant plasticizer in both compartments. A significant tenfold increase (p < 0.05) was observed in SPM samples for Di (2-propylheptyl) phthalate (DPHP) (1–13%), compared to low levels in house dust (2014/17, 1%). Non-phthalates increased to 23% of the ∑plasticizer concentration in house dust but only to 9% in SPM (mid-2000s: house dust, < 1%; SPM, 1.5%). In recent house dust samples, Di (2-ethylhexyl) terephthalate (DEHT) had the third highest concentration of all plasticizers and contributed 18% to the total load, whereas Tris (2-ethylhexyl) trimellitate (TOTM) was one of the major non-phthalates in SPM samples. Conclusions: Unlike in the indoor environment, the substitution of LMW phthalates in the aquatic environment was characterized by a significant shift towards plasticizers with potentially hazardous properties. DPHP and TOTM were identified by European chemical regulation as potentially endocrine disrupting compounds and persistent, bioaccumulative and toxic compounds. Our data document the need for integrated chemicals management to safeguard the transition to a non-toxic environment. [ABSTRACT FROM AUTHOR]

Copyright of Revue Francaise d'Allergologie is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polyurethane foam (PUF) in upholstered furniture frequently is treated with flame retardant chemicals (FRs) to reduce its flammability and adhere to rigorous flammability standards. For decades, a commercial mixture of polybrominated diphenyl ethers (PBDEs) called PentaBDE was commonly applied to foam to fulfill these regulations; however, concerns over toxicity, bioaccumulation, and persistence led to a global phase-out in the mid-2000s. Although PentaBDE is still detected in older furniture, other FR compounds such as tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and Firemaster® 550 (FM550) have been increasingly used as replacements. While biomonitoring studies suggest exposure is widespread, the primary sources of exposure are not clearly known. Here, we investigated the relationships between specific FR applications in furniture foam and human exposure. Paired samples of furniture foam, house dust and serum samples were collected from a cohort in North Carolina, USA and analyzed for FRs typically used in PUF. In general, the presence of a specific FR in the sofa of a home was associated with an increase in the concentration of that FR in house dust. For example, the presence of PentaBDE in sofas was associated with significantly higher levels of BDE-47, a major component of PentaBDE, in house dust (10β=6.4, p

Per- and polyfluoroalkyl substances (PFAS) are widely used in industry and have been linked to various adverse health effects. Communities adjacent to sites where PFAS are manufactured, stored, or used may be at elevated risk. In these impacted communities, significant exposure often occurs through contaminated drinking water, yet less is known about the role of other pathways such as residential exposure through house dust. We analyzed a paired serum and house dust dataset from the Agency for Toxic Substances and Disease Registry's PFAS Exposure Assessments, which sampled eight United States communities with a history of drinking water contamination due to aqueous film forming foam (AFFF) use at nearby military bases. We found that serum PFAS levels of residents were significantly positively associated with the dust PFAS levels in their homes, for three of seven PFAS analyzed, when accounting for site and participant age. We also found that increased dust PFAS levels were associated with a shift in the relative abundance of PFAS in serum towards those chemicals not strongly linked to AFFF contamination, which may suggest household sources. Additionally, we analyzed participant responses to exposure questionnaires to identify factors associated with dust PFAS levels. Dust PFAS levels for some analytes were significantly elevated in households where participants were older and had lived at the home longer, cleaned less frequently, used stain resistant products, and had carpeted living rooms. Our results suggest that residential exposure to PFAS via dust or other indoor pathways may contribute to overall exposure and body burden, even in communities impacted by AFFF contamination of drinking water, and the magnitude of this exposure may also be influenced by demographic, behavioral, and housing factors. [ABSTRACT FROM AUTHOR]

This study investigated the occurrence of 19 aryl phosphates and mixed alkyl-aryl phosphates in dust samples (n = 144) collected under the Canadian House Dust Study (CHDS). The predominant target analytes, detected in 100 % of the samples, were isodecyl diphenyl phosphate (IDDPP), cresyl diphenyl phosphate (CDPP), and isopropylated triaryl phosphates (ITPs), with median concentrations of 1225 (248–17850) ng/g, 91 (14–57700) ng/g, and 805 (203–152000) ng/g, respectively. ITPs included isopropylphenyl diphenyl phosphate (IPPDPP), bis(isopropylphenyl) phenyl phosphate (BIPPPP), and tris(isopropylphenyl) phosphate (TIPPP). Strong correlations were found among IPPDPP, BIPPPP, and TIPPP, suggesting that there might be various consumer and building products containing mixtures of these substances. Bisphenol A bis(diphenyl phosphate) (BPA-DP) and resorcinol bis(diphenyl phosphate) (RBDP) were detected in 69 % and 78 % of samples, with relatively low median concentrations of 30 (max: 818) ng/g and 14 (max: 307) ng/g, respectively. Since the usage of OPEs as flame retardants has increased over the past decade, the current levels of OPEs in Canadian house dust could be higher than those reported in this study, where the samples were collected in 2007–2010. Further monitoring of OPEs in various environmental and biological matrices is recommended.

Exposure to biocontaminants, such as dust mites, animal dander, bacteria, and mold, is associated with a range of health effects. This study identified household characteristics associated with indoor biocontaminant loadings in four Canadian cities. Floor dust was collected in 290 Canadian homes in Edmonton, Halifax, Montreal, and Windsor. The dust samples were analyzed for house dust mite allergens (Der f 1 and Der p 1), cat allergen (Fel d 1), cockroach allergen (Bla g 1), beta‐(1,3)‐D‐glucan, and endotoxin. Household information was obtained through questionnaires and home inspections. We performed univariate and multivariate analyses to identify household determinants of biocontaminant loadings and mold odor presence. We observed large regional variations for all biocontaminants, except for cockroach allergen. The ranges of the contaminants measured in loadings and concentrations were similar to that of previous Canadian studies. Household characteristics including presence of carpeting, low floor cleaning frequency, older home age, presence of pets, and indoor relative humidity above 45% were positively associated with the presence of multiple indoor biocontaminants. High floor cleaning frequency and use of dehumidifiers were negatively associated with the presence of multiple indoor biocontaminants. Mold odor was positively associated with older home age, past water damage, and visible mold growth. [ABSTRACT FROM AUTHOR]

Abstract Background From early life, children are exposed to a multitude of environmental exposures, which may be of crucial importance for healthy development. Here, the environmental microbiota may be of particular interest as it represents the interface between environmental factors and the child. As infants in modern societies spend a considerable amount of time indoors, we hypothesize that the indoor bed dust microbiota might be an important factor for the child and for the early colonization of the airway microbiome. To explore this hypothesis, we analyzed the influence of environmental exposures on 577 dust samples from the beds of infants together with 542 airway samples from the Copenhagen Prospective Studies on Asthma in Childhood2010 cohort. Results Both bacterial and fungal community was profiled from the bed dust. Bacterial and fungal diversity in the bed dust was positively correlated with each other. Bacterial bed dust microbiota was influenced by multiple environmental factors, such as type of home (house or apartment), living environment (rural or urban), sex of siblings, and presence of pets (cat and/or dog), whereas fungal bed dust microbiota was majorly influenced by the type of home (house or apartment) and sampling season. We further observed minor correlation between bed dust and airway microbiota compositions among infants. We also analyzed the transfer of microbiota from bed dust to the airway, but we did not find evidence of transfer of individual taxa. Conclusions Current study explores the influence of environmental factors on bed dust microbiota (both bacterial and fungal) and its correlation with airway microbiota (bacterial) in early life using high-throughput sequencing. Our findings demonstrate that bed dust microbiota is influenced by multiple environmental exposures and could represent an interface between environment and child. Video Abstract

Abstract Background Endotoxin is ubiquitous in the environment, but its clustering with indoor allergens is not well characterized. This study examined the clustering patterns of endotoxin with allergens in house dust and their association with asthma outcomes. Methods We analyzed data from 6963 participants of the 2005–2006 National Health and Nutrition Examination Survey. House dust sampled from bedroom floor and bedding was evaluated for endotoxin and allergens from fungi, cockroach, dog, cat, mites, and rodents. Two-step cluster analysis and logistic regressions were performed to identify the clustering patterns and their associations with current asthma and wheeze in the past 12 months, adjusting for covariates. Results Of the homes, 17.8% had low endotoxin and allergen levels in house dust (Cluster 1). High endotoxin level clustered with Alternaria and pet allergens in the homes of participants with a high socioeconomic status who own pets (Cluster 2) (48.9%). High endotoxin clustered with Aspergillus, dust mites, cockroach, and rodent allergens in the homes of participants with low socioeconomic status (Cluster 3) (33.3%). Compared to Cluster 1, Cluster 2 was associated with higher asthma prevalence (OR 1.42, 95% CI: 1.06–1.91) and wheeze (OR 1.32, 95% CI: 1.07–1.63). Cluster 3 was positively associated with wheeze only in participants sensitized to inhalant allergens (OR 1.42, 95% CI: 1.06–1.91) or exposed to tobacco smoke (OR 1.72, 95% CI: 1.15–2.60). Conclusions The clustering of endotoxin with allergens in dust from homes with pets or of people with low socioeconomic status is associated with asthma and wheeze.

Abstract Background Lead is a toxic metal abundant in the environment. Consumption of food contaminated at low levels of lead, especially by small children and pregnant women, raises a health concern. Methods Duplicated food portions and drinking water were collected over 3 days from 88 children and 87 pregnant women in Shimotsuke, Tochigi, Japan. Participants were recruited in this study between January 2014 and October 2015. Dust was also collected from their homes. Lead concentrations were measured and consequent oral lead exposure levels were estimated for this population at high risk to environmental toxicants. Lead concentrations of peripheral and cord blood, taken from children and pregnant women, and were also analyzed. Results Lead concentrations in food, drinking water, and house dust were low in general. Oral lead exposure to lead was higher for children (Mean ± SEM; 5.21 ± 0.30 μg/kg BW/week) than in pregnant women (1.47 ± 0.13 μg/kg BW/week). Food and house dust were main sources of lead contamination, but the contribution of house dust widely varied. Means ± SEM of peripheral and cord blood lead concentrations were 0.69 ± 0.04 μg/dL and 0.54 ± 0.05 μg/dL, respectively for pregnant women and 1.30 ± 0.07 μg/dL (peripheral only) in children. We detect no correlation between smoking situations and blood lead concentration in pregnant women. Conclusion We conclude that oral lead exposure levels for Japanese children and pregnant women were generally low, with higher concentrations and exposure for children than for pregnant women. More efforts are necessary to clarify the sources of lead contamination and reduce lead exposure of the population at high risk even in Japan.

Indoor dust has been used as a proxy for estimating human indoor pollutant exposure risks, yet source identification remains challenging. This study tentatively investigated whether quantitative fatty acid signature analysis (QFASA) of dust, could be applied to indicate sources and their respective contributions for a major class of indoor organic pollutants organophosphate flame retardants (OPFRs). We observed significant correlations between OPFR concentrations and lipid content (p

In this study, we analyzed serum samples of pet cats from Thailand and estimated the contribution to organohalogen compounds (OHCs) exposure through cat food and house dust intake. BDE-209 was predominant in cat sera and accounted for 76% of all polybrominated diphenyl ethers (PBDEs). Decabromodiphenyl ether (BDE-209) is a major contaminant in dry cat food and house dust, which has been estimated to be a source of exposure for Thai pet cats. BDE-209 is a major contaminant of OHCs in dry cat food and house dust, which was estimated to be a source of exposure for Thai pet cats. On the other hand, the level of contamination by PCBs was lower than in other countries. Analysis of pet foods suggested that BDE-209 in pet cat serum was attributable to the consumption of dry cat food. On the other hand, house dust also contained high concentrations of BDE-209. Thus, high levels of BDE-209 in pet cat sera can be attributed to the consumption of dry cat food and house dust. These results suggest that pet cats are routinely exposed to non-negligible levels of OHCs.

The COVID-19 pandemic has caused a decrease in outdoor activities, but an increase in indoor ones. This change in the intensity of land use has caused changes in pollution patterns. Urban dust contaminated with heavy metals can be a risk to the human population. Therefore, the objective of this work was to evaluate the pollution caused by heavy metals in urban dust indoors and outdoors due to changes in land use during the pandemic. Sampling was carried out by the Gomez Palacio citizens. The total number of urban dust samples was 330, 50% indoor samples and 50% outdoor sample. The elements studied were Ca, Cu, Fe, K, Mn, Ni, Pb, Rb, Sr, Ti, Y, Zn, and Zr. The heavy metals were measured through a portable XRF; the contamination factor and the load pollution index were used to assess the pollution level. The human health risk was evaluated with the USEPA methodology. Cu, Pb, and Zn presented higher concentrations indoors than outdoors, probably due to domestic factors, such as the age of the houses and the paint on the walls. Zn presented the highest pollution level among all the metals, outdoors and indoors; spatially, the sites sampled in the northwest, close to agricultural areas, presented the highest Zn pollution. Pb had a moderate pollution level in most of the samples (60%), but some samples showed a high Pb pollution. The health risk was considered within the acceptable levels for Cu, Fe, Ni, Pb, Zn. However, Mn deserves attention because the average of the samples slightly exceeded the USEPA safety limits for children. Children are at higher risk compared to adults. Indoor environments need to be better analyzed because they were shown to represent a higher risk to the population than outdoor ones due to heavy metal pollution by Zn, Cu, and Pb. The pandemic impacted land use intensity; this study reports an apparent effect of the pandemic on the amount and type of heavy metals indoors and outdoors.

Residential lead (Pb) exposure is of critical concern to families globally as Pb promotes severe neurological effects in children, especially those less than 5 years old, and no blood lead level is deemed safe by the US Center for Disease Control. House dust and soils are commonly thought to be important sources of Pb exposure. Probing the relationship between house dust and soil Pb is critical to understanding residential exposure, as Pb bioavailability is highly influenced by Pb sources and/or species. We investigated paired house dust and soil collected from homes built before 1978 to determine Pb speciation, source, and bioaccessibility with the primary goal of assessing chemical factors driving Pb exposure in residential media. House dust was predominately found to contain (hydro)cerussite (i.e., Pb (hydroxy)carbonate) phases commonly used in Pb-based paint that, in-turn, promoted elevated bioaccessibility (>60%). Pb X-ray absorption spectroscopy, μ-XRF mapping, and Pb isotope ratio analysis for house dust and soils support house dust Pb as chemically unique compared to exterior soils, although paint Pb is expected to be a major source for both. Soil pedogenesis and increased protection from environmental conditions (e.g., weathering) in households is expected to greatly impact Pb phase differences between house dust and soils, subsequently dictating differences in Pb exposure.

The study of the fungal community composition in house dust is useful to assess the accumulative exposure to fungi in indoor environments. The objective of this research was to characterize the fungal diversity of house dust and its association with the environmental conditions of bedrooms. For this, the dust was collected from 41 bedrooms of children between the ages of 8 and 9 with a family history of asthma, residents of Havana, Cuba. The fungal content of each sample was determined by two methods: plate culture with malt extract agar and by direct microscopy. An ecological analysis was carried out from the fungal diversity detected. To describe the factors associated with the fungi detected, bivariate logistic regression was used. Through direct microscopy, between 10 and 2311 fragments of hyphae and spores corresponding mainly to Cladosporium, Coprinus, Curvularia, Aspergillus/Penicillium, Xylariaceae, and Periconia were identified. Through the culture, 0–208 CFU were quantified, where Aspergillus, Cladosporium, and Penicillium predominated. The culturability evidenced the differences between the quantification determined by both methods. A positive relationship was found between the type of cleaning of the furniture, the presence of trees in front of the bedroom, indoor relative humidity, indoor temperature, the presence of air conditioning, and natural ventilation with specific spore types and genera. The use of two different identification methods allowed to detect a greater fungal diversity in the residences evaluated. Monitoring the exposure to these fungal allergens in childhood can help to prevent sensitization in the allergic child, the development of asthma, and other respiratory diseases. [ABSTRACT FROM AUTHOR]

Background: Leprosy is a chronic infectious disease caused by Mycobacterium leprae and persists as a serious public health problem in Brazil. This microorganism is inculturable, making it difficult to diagnose and elucidate details of its transmission chain. Thus, this study aimed to analyze the dynamics of environmental transmission of M. leprae in a case–control study in the city of Mossoró, Brazil. Methods and results: Data of clinical, epidemiological, bacilloscopic, and serological evaluation of 22 newly diagnosed patients were compared, with molecular results of detection of specific genome regions RLEP and 16S rRNA of M. leprae in samples of the nasal swab, saliva, and house dust of these individuals and their controls (44 household contacts and 44 peridomiciliar contacts). The rapid serological tests evaluated, ML flow (IgM ND-O-BSA) and OrangeLife® (IgM and IgG anti NDO-LID 1) showed similar results, with greater positivity among paucibacillaries by OrangeLife® (54.5%). Positivity for nasal swab and saliva in multibacillary patients with RLEP primer was 16.7% and 33.3%, respectively. There was no detection of bacterial DNA in house dust or among paucibacillaries. The OrangeLife® test indicated that the lower the amount of windows, the more transmission in the house (3.79 more chances). Having a history of leprosy cases in the family increased the risk by 2.89 times, and being over 60 years of age gave 3.6 times more chances of acquiring the disease. PCR positivity was higher among all clinical samples using the M. leprae RLEP region than 16S rRNA. Conclusions: In this study, the serological and PCR analysis were capable of detecting M. leprae DNA in clinical samples but not in the environmental samples. Close monitoring of patients and household contacts appears an effective measure to reduce the transmission of leprosy in endemic areas. [ABSTRACT FROM AUTHOR]

This study investigated the occurrence, distribution of several additive brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and some novel brominated flame retardants (NBFRs) in urban indoor dust collected from ten inner districts of Hanoi, Vietnam to assess the contamination status, emission sources, as well as their associated human exposure through indoor dust ingestion and health risks. Total concentrations of PBDEs and NBFRs in indoor dust samples ranged from 43 to 480 ng g−1 (median 170 ng g−1) and from 56 to 2200 ng g−1 (median 180 ng g−1), respectively. The most abundant PBDE congener in these dust samples was BDE-209 with concentrations ranging from 29 to 360 ng g−1, accounting for 62.6–86.5% of total PBDE levels. Among the NBFRs analyzed, decabromodiphenyl ethane (DBDPE) was the predominant compound with a mean contribution of 98.6% total NBFR amounts. Significant concentrations of DBDPE were detected in all dust samples (median 180 ng g−1, range 54–2200 ng g−1), due to DBDPE as a substitute for deca-BDE. Other NBFRs such as 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), pentabromoethylbenzene (PBEB) and 2,2',4,4',5,5'-hexabromobiphenyl (BB-153) were found at very low levels. Based on the measured BFR concentrations, daily intake doses (IDs) of PBDEs and NBFRs via dust ingestion at exposure scenarios using the median and 95th percentile levels for both adults and children were calculated for risk assessment. The results showed that the daily exposure doses via dust ingestion of all compounds, even in the high-exposure scenarios were also lower than their reference dose (RfD) values. The lifetime cancer risks (LTCR) were much lower than the threshold level (10−6), which indicated the acceptable health risks resulting from indoor BFRs exposure for urban residents in Hanoi. [ABSTRACT FROM AUTHOR]

BackgroundHumans are exposed to persistent organic pollutants (POPs) through various routes, including consumption of contaminated food and accidental ingestion of settled dust.ObjectivesWe aimed to identify key routes of exposure to organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in California women of reproductive age.MethodsBlood was collected from 48 mothers participating in the California Childhood Leukemia Study from 2006 to 2007 and analyzed for POPs using gas chromatography-mass spectrometry. Multivariable linear regression models of natural-log transformed serum concentrations were used to identify determinants of exposure from available questionnaire information on dietary habits, reproductive history, and demographic characteristics, as well as vacuum cleaner dust-POP levels.ResultsAfter adjusting for blood lipid levels, age, body mass index, cumulative lactation, and sampling date, serum concentrations of multiple major PCBs were positively associated with fish consumption, but not dust-PCB levels. After adjusting for blood lipid levels, Hispanic ethnicity, country of origin, and household annual income, serum concentrations of multiple major PBDEs were positively associated with dust-PBDE levels.ConclusionsOur findings suggest that the relative contribution of specific exposure routes to total POP intake varies by chemical class, with dust being a relatively important source of PBDEs and diet being a relatively important source of PCBs.

Upholstered furniture has been a major source of chemical flame retardant (FR) exposures in US homes since the 1970s. FRs are a large group of chemicals, many of which are associated with adverse health effects, including cancer, reproductive toxicity, and neurotoxicity. California homes have some of the highest dust concentrations of FRs, due to Technical Bulletin 117 (TB117), California’s outdated flammability standard for furniture foam that was generally followed across the US and Canada. In 2014, this standard was updated to a smolder standard for furniture fabric called TB117-2013, and it is no longer reliant on FRs. This update provided an opportunity to measure differences in FR dust levels in California homes before and after residents replaced older upholstered furniture, or its foam, with products that met the new standard and were expected to be FR-free. We collected dust from homes of participants who had plans to replace older upholstered furniture, or furniture foam, with FR-free options. We returned for follow-up dust collection six, 12, and 18 months following replacement. Concentrations of three polybrominated diphenyl ethers (PBDEs) (BDE-47, BDE-99, BDE-100), three chlorinated organophosphate ester FRs (tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), and tris(1,3-dichloroisopropyl) phosphate (TDCIPP)), and one aryl organophosphate ester FR triphenyl phosphate (TPHP), were widely detected in participant homes. All measured FRs decreased in nearly all homes after the older upholstered furniture was replaced. The decreases in FRs were significant in both homes that replaced entire pieces of furniture and those that replaced only the furniture foam. This study demonstrates that replacing older upholstered furniture or foam significantly reduces concentrations of a range of FRs in the home. Foam replacement offers a potentially more economic alternative that produces a lower volume of waste.

IntroductionManganese (Mn) is an essential nutrient, but at high exposure levels Mn is a neurotoxicant. The fungicides maneb and mancozeb are approximately 21% Mn by weight and more than 150,000 kg are applied each year to crops in the Salinas Valley, California. It is not clear, however, whether agricultural use of these fungicides increases Mn levels in homes.Materials and methodsWe collected house dust samples from 378 residences enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study with a second sample collected approximately nine months later from 90 of the residences. House dust samples were analyzed for Mn using inductively coupled plasma optical emission spectroscopy. Information from interviews, home inspections, and pesticide use reports was used to identify potential predictors of Mn dust concentrations and loadings.ResultsMn was detectable in all dust samples. The median Mn concentration was 171 μg/g and median Mn loading was 1,910 μg/m(2) at first visit. In multivariable models, Mn dust concentrations and loadings increased with the number of farmworkers in the home and the amount of agricultural Mn fungicides applied within three kilometers of the residence during the month prior to dust sample collection. Dust concentrations of Mn and other metals (lead, cadmium and chromium) were higher in residences located in the southern Salinas Valley compared those located in other areas of the Salinas Valley. Dust loadings of Mn and other metals were also higher in residences located on Antioch Loam soil than other soil types, and in homes with poor or average housekeeping practices.ConclusionsAgricultural use of Mn containing fungicides was associated with Mn dust concentrations and loadings in nearby residences and farmworker homes. Housekeeping practices and soil type at residence were also important factors related to dust metal concentrations and loadings.

Background: Environmental exposures are involved in the pathogenesis of the allergic phenotype and in determining which individual triggers a person becomes sensitized to. Atopic dermatitis (AD) may modulate these effects through increased penetration through the skin modifying the immune system and AD may be triggered or intensified by environmental exposures. These exposures and immune‐modulating factors may differ in urban and rural environments. Objectives: To compare house dust composition in urban and rural settings and correlate them with AD outcomes. Methods: Dust samples were collected from the beds of 156 children aged 6 months to 3 years. 42% of participants had atopic dermatitis. Samples were analyzed for bacterial endotoxin, fungal (β‐1,3‐glucan) levels, and house dust mite, cockroach, dog, cat, mouse, and peanut allergen. Exposures were compared in urban and rural environments and in participants with and without AD. Results: Endotoxin but not fungal β‐glucan exposure is higher in the environment of healthy controls than children with AD in both urban and rural settings. House dust mite allergen exposure is high in urban and rural settings with Dermatophagoides detected in 100% of samples. Cat and dog allergen exposure mirrors pet ownership patterns which differ slightly between groups and environments. Mouse allergen exposure is higher in urban homes. Conclusion: Environmental endotoxin may be protective against AD in both urban and rural settings. There are marked differences in allergen exposure in urban and rural settings, but these are unlikely to be important protective or risk factors. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that a child's risk of developing atopic disease is impacted by both genetic and environmental factors. Because small children spend the majority of their time in their homes, exposure to microbial factors in their home environment may be protective or risk factors for development of atopic diseases, such as atopic dermatitis. Methods: Dust samples from the homes of 86 Black South African children 12 to 36 months old were collected for analysis of the bacterial microbiome. This case‐control study design included children with and without atopic dermatitis from rural and urban environments. Results: Significant differences in bacterial composition and diversity were found when comparing children with and without atopic dermatitis. Furthermore, house dust microbiota was significantly different in rural and urban areas. Differences were best accounted for by higher relative abundance of Ruminococcaceae, Lachnospiraceae, and Bacteroidaceae families in rural compared with urban houses. Levels of Ruminococcaceae were also found to be significantly depleted in the house dust of rural children with atopic dermatitis as compared to control children. Conclusions: House dust composition may be an important risk factor for the development of atopic disease, and this association may be driven in part by the gut microbiome. Low levels of the Ruminococcaceae family from Clostridia class in particular may explain the association between urban living and atopy. However, further research is needed to elucidate these links. [ABSTRACT FROM AUTHOR]

In winter and summer of 2016 and 2017, airborne fungi and house dust were collected in indoors of the village Gunja, which had been flooded, and the control village Gornji Stupnik (Croatia) in order to explore variations of fungal indoor levels, particularly Aspergilli section Nidulantes series Versicolores, as well as fungal metabolites in dust. Levels of airborne Aspergilli (Versicolores) were three times as high in winter and summer in Gunja than in the control village, while dustborne isolates were equally present in both locations. Sequencing of the calmodulin gene region revealed that among Aspergilli (Versicolores), A. jensenii and A. creber were dominant and together with A. puulaauensis, A. tennesseensis and A. venenatus produced sterigmatocystin and 5‐methoxysterigmatocystin (HPLC coupled with mass spectrometry); A. amoenus, A. fructus, A. griseoaurantiacus, A. pepii, and A. protuberus produced sterigmatocystin but not 5‐methoxysterigmatocystin; A. sydowii did not produce any of these toxins. A total of 75 metabolites related to Penicillium (29), Aspergillus (22), Fusarium (10), Alternaria (5), Stachybotrys (2), and other fungi (7) were detected in dust by liquid chromatography‐tandem mass spectrometry. The majority of metabolites including sterigmatocystin and 5‐methoxysterigmatocystin exhibited a higher prevalence in winter in Gunja. [ABSTRACT FROM AUTHOR]