HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe.

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe. The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum. Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 µg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population. This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Incorporation of Fast-Elimination Chemicals in Hair Is Governed by Pharmacokinetics-Implications for Exposure Assessment.

Mechanisms governing chemicals' incorporation in hair are incompletely understood, and gaps remain to link the concentration of chemicals in hair to level of exposure and internal dose present in the body. This study assesses the relevance of hair analysis for the biomonitoring of exposure to fast-elimination compounds and investigates the role of pharmacokinetics (PK) in their incorporation in hair. Rats were administered with pesticides, bisphenols, phthalates, and DINCH over 2 months. Hairs were analyzed for 28 chemicals/metabolites to investigate correlations between their concentration in hair and the dose administered to the animals. Urine collected over 24 h after gavage was used to determine chemicals' PK and to investigate their influence on incorporation into hair by means of linear mixed models (LMMs). Eighteen chemicals presented a significant correlation between concentration in hair and level of exposure. In models combining all chemicals, agreement between concentration in hair predicted by LMM and experimental values was moderate (R2 = 0.19) but significantly increased when PK were included in the models (R2 = 0.37), and even more when chemical families were considered separately (e.g., R2 = 0.98 for pesticides). This study shows that pharmacokinetics mediate incorporation of chemicals in hair and suggests the relevance of hair for assessing exposure to fast-elimination chemicals.

Pervasive exposure of wild small mammals to legacy and currently used pesticide mixtures in arable landscapes.

Knowledge gaps regarding the potential role of pesticides in the loss of agricultural biodiversity worldwide and mixture-related issues hamper proper risk assessment of unintentional impacts of pesticides, rendering essential the monitoring of wildlife exposure to these compounds. Free-ranging mammal exposure to legacy (Banned and Restricted: BRPs) and currently used (CUPs) pesticides was investigated, testing the hypotheses of: (1) a background bioaccumulation for BRPs whereas a "hot-spot" pattern for CUPs, (2) different contamination profiles between carnivores and granivores/omnivores, and (3) the role of non-treated areas as refuges towards exposure to CUPs. Apodemus mice (omnivore) and Crocidura shrews (insectivore) were sampled over two French agricultural landscapes (n = 93). The concentrations of 140 parent chemicals and metabolites were screened in hair samples. A total of 112 compounds were detected, showing small mammal exposure to fungicides, herbicides and insecticides with 32 to 65 residues detected per individual (13-26 BRPs and 18-41 CUPs). Detection frequencies exceeded 75% of individuals for 13 BRPs and 25 CUPs. Concentrations above 10 ng/g were quantified for 7 BRPs and 29 CUPs (in 46% and 72% of individuals, respectively), and above 100 ng/g for 10 CUPs (in 22% of individuals). Contamination (number of compounds or concentrations) was overall higher in shrews than rodents and higher in animals captured in hedgerows and cereal crops than in grasslands, but did not differ significantly between conventional and organic farming. A general, ubiquitous contamination by legacy and current pesticides was shown, raising issues about exposure pathways and impacts on ecosystems. We propose a concept referred to as "biowidening", depicting an increase of compound diversity at higher trophic levels. This work suggests that wildlife exposure to pesticide mixtures is a rule rather than an exception, highlighting the need for consideration of the exposome concept and questioning appropriateness of current risk assessment and mitigation processes.

Impact of Protein-Enriched Plant Food Items on the Bioaccessibility and Cellular Uptake of Carotenoids.

Carotenoids are lipophilic pigments which have been associated with a number of health benefits, partly related to antioxidant effects. However, due to their poor solubility during digestion, carotenoid bioavailability is low and variable. In this study, we investigated the effect of frequently consumed proteins on carotenoid bioaccessibility and cellular uptake. Whey protein isolate (WPI), soy protein isolate (SPI), sodium caseinate (SC), gelatin (GEL), turkey and cod, equivalent to 0/10/25/50% of the recommended dietary allowance (RDA, approx. 60g/d), were co-digested gastro-intestinally with carotenoid-rich food matrices (tomato and carrot juice, spinach), and digesta further studied in Caco-2 cell models. Lipid digestion, surface tension and microscopic visualization were also carried out. Co-digested proteins positively influenced the micellization of carotenes (up to 3-fold, depending on type and concentration), especially in the presence of SPI (p < 0.001). An increased cellular uptake was observed for xanthophylls/carotenes (up to 12/33%, p < 0.001), which was stronger for matrices with an initially poor carotenoid micellization (i.e., tomato juice, p < 0.001), similar to what was encountered for bioaccessibility. Turkey and cod had a weaker impact. Significant interactions between carotenoids, lipids and proteins were observed during digestion. Co-digested proteins generally improved lipid digestion in all matrices (p < 0.001), especially for carrot juice, though slight decreases were observed for GEL. Protein impact on the surface tension was limited. In conclusion, proteins generally improved both carotenoid bioaccessibility and cellular uptake, depending on the matrices and carotenoid-type (i.e., carotene vs. xanthophylls), which may be relevant under specific circumstances, such as intake of carotenoid-rich food items low in lipids.

Biomonitoring of fast-elimination endocrine disruptors - Results from a 6-month follow up on human volunteers with repeated urine and hair collection.

BACKGROUND: The assessment of human exposure to fast-elimination endocrine disruptors (ED) such as phthalates, bisphenols or pesticides is usually based on urinary biomarkers. The variability of biomarkers concentration, due to rapid elimination from the body combined with frequent exposure is however pointed out as a major limitation to exposure assessment. Other matrices such as hair, less sensitive to short-term variations in the exposure, have been proposed as possible alternatives. Nevertheless, no study compared the information obtained from hair and urine respectively in a follow-up allowing to assess biomarkers variability over time in these two matrices, and to compare the correlation between them. METHODS: In the present study, hair and urine samples were collected from 16 volunteers over a 6 months follow-up. All in all, 92 hair samples and 805 urines samples were collected and analyzed for the presence of 16 phthalate metabolites, 4 bisphenols and 8 pesticides/metabolites. RESULTS: All the biomarkers analyzed were detected in at least one of the two matrices. 21 biomarkers were more frequently detected in hair, 6 in urine, and 1 was equivalent. Biomarkers intraclass correlation coefficients (ICC) ranged from 0.1 to 0.8 (ten above 0.4) in hair, and from 0.09 to 0.51 in urine (two above 0.4). The concentrations of biomarkers in hair and urine were significantly correlated for only one compound. CONCLUSION: This study highlights the complexity of assessing exposure to fast-elimination ED and suggests considering with caution the specificity of the matrix in data interpretation. The results document the respective advantages and limitations of urine and hair, and provide new insight in the understanding of the information provided by these biological matrices and their relevance for the assessment of human exposure to fast elimination contaminants. CAPSULE: 92 hair and 805 urine samples collected from 16 volunteers over 6 months, tested for phthalate metabolites, bisphenols and pesticides. 19 biomarkers (in hair) and 24 (in urine) were detected in >50% of the samples.

Population-based biomonitoring of exposure to persistent and non-persistent organic pollutants in the Grand Duchy of Luxembourg: Results from hair analysis.

Environmental exposure of humans to pollutants has been associated with adverse health outcomes, but few studies have evaluated the multiple exposure of general populations. In the present study, we used hair analysis to assess the exposure of a general adult population (n = 497) in Luxembourg to 34 persistent and 33 non-persistent organic pollutants from 11 chemical families, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), and pyrethroid pesticides (PYRs). We detected 24 persistent and 29 non-persistent organic pollutants, with 17 pollutants being detected in more than 50% of hair samples. The median concentrations for pollutants detected in 100% of the samples were 0.37 pg/mg for lindane (γ-HCH), 0.15 pg/mg for hexachlorobenzene (HCB), 14.1 pg/mg for p-nitrophenyl (PNP), and 0.10 pg/mg for trifluralin. Each participant in this study had detectable levels of at least 10 of the pollutants analyzed, and 50% of participants had 19 or more, suggesting the simultaneous exposure to numerous different pollutants among our study population. Significant correlations were often found between pollutants from the same family, with the strongest being found between two PYR metabolites, trans/cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-carboxylic acid (Cl2CA) and 3-phenoxybenzoic acid (3-PBA). Results from multiple linear regression analyses showed that sex, age and/or body mass index were significantly associated with 15 out of the 17 frequently detected pollutants. The current study is the first nationwide biomonitoring investigating organic contaminants in the Luxembourg population using hair analysis.

Hair versus urine for the biomonitoring of pesticide exposure: Results from a pilot cohort study on pregnant women.

BACKGROUND/AIM: The quantitative assessment of human exposure to contaminants such as pesticides is a crucial step in the characterization of exposure-associated risk. For this purpose, biomonitoring is often privileged as it presents the advantage of integrating all the possible sources and routes of exposure and of being representative of the internal dose resulting from exposure. Although biological fluids such as urine and blood have been used to date for this purpose, increasing interest has also been observed over the past decade for hair analysis. The present work aimed at comparing the information obtained from the analysis of urine versus hair regarding exposure to pesticides in a pilot cohort of pregnant women. METHODS: In ninety-three pregnant women included in the pilot of the French cohort ELFE, one urine and one hair sample were collected simultaneously from each subject at the maternity. Samples were analyzed using GC-MS/MS analytical methods allowing for the detection of both parent pesticides and metabolites, and designed to be as similar as possible between urine and hair for reliable inter-matrix comparison. Fifty-two biomarkers of exposure were targeted, including parents and metabolites of organochlorines, organophosphates, pyrethroids, carbamates, phenylpyrazoles and other pesticides. RESULTS: The number of different compounds detected ranged from 16 to 27 (median = 22) in hair, and from 3 to 22 (median = 12) in urine. In hair, 24 compounds were found in > 40% of the individuals, whereas only 12 compounds presented the same frequency of detection in urine. Among the chemicals detected in > 80% of both hair and urine samples, only one (pentachlorophenol) showed a signification correlation between hair and urine concentrations. CONCLUSIONS: The present results highlight the multiple exposure of the pregnant women included in this cohort and suggest that hair provides more comprehensive information on pesticide exposure than urine analysis. This study thus supports the relevance of hair analysis in future epidemiological studies investigating association between exposure and adverse health effects.

Human exposure to PCBs, PBDEs and bisphenols revealed by hair analysis: A comparison between two adult female populations in China and France.

Humans are exposed to various anthropogenic chemicals in daily life, including endocrine-disrupting chemicals (EDCs). However, there are limited data on chronic, low-level exposure to such contaminants among the general population. Here hair analysis was used to investigate the occurrence of four polychlorinated biphenyls (PCBs), seven polybrominated diphenyl ethers (PBDEs) and two bisphenols (BPs) in 204 Chinese women living in the urban areas of Baoding and Dalian and 311 pregnant French women. All the PCBs and PBDEs tested here were more frequently detected in the hair samples of the French women than in those of the Chinese women. In both cohorts, PCB 180 and BDE 47 were the dominant PCB and PBDE congener, respectively. PCB 180 was found in 82% of the French women and 44% of the Chinese women, while the corresponding values of BDE 47 were 54% and 11%, respectively. A discriminant analysis further demonstrated the difference in PCBs and PBDEs exposure profile between the two cohorts. These results demonstrate that hair analysis is sufficiently sensitive to detect exposure to these pollutants and highlight differences in exposure between populations even at environmental levels. Although BPA and BPS were found in 100% of the hair samples in both cohorts, the French women had significantly higher levels of BPA and BPS than the Chinese women. The median concentrations of BPA were one order of magnitude higher than BPS in both the Chinese (34.9 versus 2.84 pg/mg) and the French women (118 versus 8.01 pg/mg) respectively. Our results suggest that both French and Chinese populations were extensively exposed to BPA and BPS.

Exposure to multiclass pesticides among female adult population in two Chinese cities revealed by hair analysis.

The high use of pesticides worldwide and the constant exposure of humans to these toxic-by-design chemicals have drawn the attention on the possible consequences on human health. However, information on the exposure of the general population to pesticides remain very limited in most countries, especially in urban areas. In the present work, hair analysis was conducted to investigate the exposure of 204 urban women living in two Chinese cities (Baoding and Dalian) to 110 pesticides and 30 metabolites of the following families: organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, phenylpyrazoles, acid herbicides, urea herbicides and azoles. Results showed that 71 pesticides and 23 metabolites were found in the hair samples, with concentrations ranging up to 1070 pg/mg in hair. In each hair sample, the number of detected chemicals ranged from 25 to 50, demonstrating the cumulative exposure to pesticides among Chinese women in the studied regions. The concentrations of 38 chemicals (e.g., p-nitrophenol, diethyldithiophosphate, λ-cyhalothrin, permethrin, carbendazim and tebuconazole) were significantly different between women in Baoding and Dalian, indicating the regional differences in exposure to pesticide. Using a multiple regression analysis, we found that concentrations of a few dominant pesticides were associated with age, body mass index (BMI), cooking frequency and regions. These results can provide baseline information on exposure of female adult Chinese population to multiple pesticides and support future studies focused on the health effects associated with pesticide exposure.

Multiple pesticides in mothers' hair samples and children's measurements at birth: Results from the French national birth cohort (ELFE).

BACKGROUND: A growing body of studies now suggests that the general population is continuously and ubiquitously exposed to numerous pesticides. However, studies investigating the possible role of environmental exposure to pesticides on fetal growth have focused on a limited set of substances, despite the hundreds of modern pesticides currently available. AIM: To explore the relation between maternal hair concentrations of 64 pesticides and metabolites and their newborns' measurements at birth, with data from the ELFE French nationwide birth cohort. METHODS: We measured 64 compounds (10-100% detection) in bundles of hair 9 cm long collected at birth from 311 women who gave birth in France in 2011. We assessed their associations with birth weight, length, and head circumference, adjusted for potential confounders, and used elastic net regularization to simultaneously select the strongest predictors of measurements at birth. Selected variables were multiply imputed for missing values, and unpenalized estimators were assessed by standard linear regression. RESULTS: We observed statistically significant associations between maternal hair concentrations of seven pesticides or pesticide metabolites and birth measurements (weight: fipronil sulfone; length: TCPy, bitertanol, DEP, and isoproturon; head circumference: tebuconazole and prochloraz). Analyses restricted to boys identified 12 additional compounds: 8 independently associated with birth weight (3Me4NP, DCPMU, DMST, fipronil, mecoprop, propoxur, fenhexamid, and thiabendazole), 2 with birth length (dieldrin and ß-endosulfan), and 6 with head circumference (ß-endosulfan, ß-HCH, fenuron, DCPMU, propoxur, and thiabendazole). CONCLUSION: Our results suggest that prenatal exposure to 19 pesticides or metabolites from various chemical families may influence measurements at birth. As with any exploratory research findings, results should be interpreted cautiously, until they are replicated or verified by further epidemiological or mechanistic studies.

Biomonitoring of children exposure to urban pollution and environmental tobacco smoke with hair analysis - A pilot study on children living in Paris and Yeu Island, France.

The impact of pollution on children's health has been increasingly pointed out in numerous studies which emphasized their increased vulnerability compared to adults. This pilot study investigated the relevance of hair analysis for the assessment of children exposure to pollution and to environmental tobacco smoke (ETS). The methodology based on GC-MS/MS and LC-MS/MS, is the first one to investigate simultaneously parent PAH (n = 15), PAH metabolites (n = 56), nicotine and cotinine in a biological matrix. The method was applied to hair samples collected from 25 children, aged from 2 to 11 years, living in Paris, France, selected as densely populated area with urban pollution including vehicle exhausts, and Yeu Island, a French island in the Atlantic ocean, selected as control area with low population density and no fuel powered vehicles. Nicotine and cotinine were detected in all the samples at concentrations up to 2275 pg/mg and 110 pg/mg respectively, suggesting exposure to ETS in the two areas. 10 parent PAH and 10 metabolites were detected in 100% and in >90% of the samples respectively. Eight of these biomarkers presented a significantly higher concentration in children from Paris than from Yeu Island. The results suggest association between PAH exposure and estimated time of exposure to vehicle exhaust as well as higher exposure to both PAH and ETS in the youngest children. Although these findings need to be confirmed on wider populations, the results obtained in this pilot study strongly support the relevance of hair analysis for the biomonitoring of children exposure to urban pollution and ETS.

Exposure to polycyclic aromatic hydrocarbons in women living in the Chinese cities of BaoDing and Dalian revealed by hair analysis.

Polycyclic aromatic hydrocarbons (PAH) are produced from incomplete combustion of organic matter and released as environmental contaminants from activities such as transports, wood combustion, coal-fired power plants. In numerous urban areas worldwide, the levels of PAH exposure are considered critical regarding public health issues. The possibility to detect PAH and PAH metabolites biologically incorporated in human hair was demonstrated and proposed as biomarkers of exposure. Nevertheless, the possibility to distinguish different levels of exposure between different populations is still needed to validate the relevance of hair analysis in epidemiological studies. In this work, hair samples were collected from 204 women from two cities in China based on one year Air Quality Index history from governmental data (Baoding as polluted city and Dalian less polluted city). 8 out of the 15 parent PAH and 7 out of the 56 metabolites analyzed in this study were detected in all the samples. The highest concentrations in hair were observed for phenanthrene (4.2 to 889 pg/mg) > fluoranthene (1.05 to 204 pg/mg) > pyrene (3.2 to 124 pg/mg) for parent PAH, and for 9-OH-fluorene (0.04 to 1.78 pg/mg) > 2-OH-naphthalene (0.68 to 811 pg/mg) > 1-OH-anthracene (0.24 to 10.9 pg/mg) for metabolites. 14 parent PAH and 15 metabolites presented a significantly higher concentration in the hair samples collected from Baoding, as compared to Dalian. The median concentration of parent PAH was from 1.5 to 2.8 times higher in the hair of the subjects from Baoding than in subjects from Dalian and that of PAH metabolites was from 1 to 2.3 times higher. The study of inter-chemical associations revealed similarities and differences between the two areas, suggesting common and different sources of exposure depending on PAH respectively. The results confirmed the relevance of hair analysis to identify qualitative and quantitative differences in PAH exposure between populations from different areas. This study is the first one to investigate both parent PAH and their metabolites in a biological matrix.

Hair analysis for the biomonitoring of polycyclic aromatic hydrocarbon exposure: comparison with urinary metabolites and DNA adducts in a rat model.

Alongside the analysis of urinary metabolites which are traditional biomarkers of polycyclic aromatic hydrocarbons (PAH) exposure, the possibility of detecting PAH as well as their metabolites in hair has also recently been demonstrated. As the concentration of pollutants detected in hair is not impacted by short-term variations in exposure as can be observed with urine, it accurately represents an individual's average level of exposure, which is the most relevant information when investigating possible linkages with biological effects. In the current study, based on a rat model exposed to a mixture of PAHs for a 90-day period, the linkage between the PAH exposure level and the resulting concentration of their metabolites in hair was then investigated. The linkage between exposure levels and the concentrations of OH-PAH in hair collected at the end of the experiment were compared to those obtained using urinary concentration of OH-PAH collected from the same animals. Linear relationship between levels of exposure and the concentration of OH-PAH in the rats' hair (R2 0.722-0.965, p < 0.001) was observed for 28 OH-PAH out of the 54 investigated. The difference in PAH concentration between the different groups of exposure and the possibility to back determine the animals' level of exposure on the basis of PAH-metabolite concentrations in both hair and urine was also demonstrated. In addition to the strong linear relation observed between the doses of exposure and the levels of concentration of hydroxylated metabolites in hair (p < 0.001), the analysis of a subset of animals demonstrated a linkage between 3-OH-benzo[a]pyrene concentration levels in hair and the levels of B[a]P-DNA adduct formed (p < 0.05), thereby suggesting the potential of their analysis to predict genetic alteration.

Multiple pesticide analysis in hair samples of pregnant French women: Results from the ELFE national birth cohort.

BACKGROUND: A growing body of evidence suggests that prenatal exposure to pesticides might impair fetal development. Nonetheless, knowledge about pesticide exposure of pregnant women, especially in Europe, is largely restricted to a limited panel of molecules. AIM: To characterize the concentration of 140 pesticides and metabolites in hair strands from women in the ELFE French nationwide birth cohort. METHODS: Among cohort members who gave birth in northeastern and southwestern France in 2011, we selected those with a sufficient available mass of hair (n = 311). Bundles of hair 9 cm long were collected at delivery. We screened 111 pesticides and 29 metabolites, including 112 selected a priori based on their reported usage or detection in the French environment. The bundles of hair from 47 women were split into three segments to explore the intraindividual variability of the exposure. Intraclass correlation coefficients (ICCs) were computed for the chemicals with a detection frequency >70%. RESULTS: We detected a median of 43 chemicals per woman (IQR 38-47). Overall, 122 chemicals (>20 chemical families) were detected at least once, including 28 chemicals detected in 70-100% of hair samples. The highest median concentrations were observed for permethrin (median: 37.9 pg/mg of hair), p-nitrophenol (13.2 pg/mg), and pentachlorophenol (10.0 pg/mg). The ICCs for the 28 chemicals studied ranged from 0.59 to 0.94. CONCLUSION: Pregnant women are exposed to multiple pesticides simultaneously from various chemical families, including chemicals suspected to be reproductive toxicants or endocrine disruptors. The ICCs suggest that the intraindividual variability of pesticide concentrations in hair is lower than its interindividual variability.

Identification of new tetrahydroxylated metabolites of Polycyclic Aromatic Hydrocarbons in hair as biomarkers of exposure and signature of DNA adduct levels.

The present study addresses the hypothesis that the concentration of tetrahydroxylated Polycylic Aromatic Hydrocarbons (tetra-OH-PAHs) in hair might be a useful biomarker of human exposure to PAHs, providing quantitative assessment of the internal dose, as well as information on the associated toxicity in relation to individual's specific metabolism. By means of animal models, this work aimed at identifying new tetra-OH-PAHs which can be released from the hydrolysis of DNA-adducts and can also be directly detected in biological matrices usually used in the field of biomonitoring such as hair and urine. Results obtained from a targeted gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) approach, demonstrated the presence of 8 tetrahydroxylated metabolites in DNA and 23 in hairs of rats exposed to mixtures of PAHs, which had never been analyzed before. Ten tetra-OH-PAHs were clearly characterized by using their analytical standards, corresponding to 4 parent PAHs (phenanthrene, chrysene, benz[a]anthracene and benzo[a]pyrene) whereas 13 tetra-OH-PAHs from 3 other parents (anthracene, fluoranthene and benz[k]fluoranthene) were detected but not yet characterized. No tetrahydroxylated metabolite has been clearly identified for naphthalene, fluorene, benzo[b]fluoranthene, benzo[g,h,i]perylene, or dibenzo[a,h]anthracene, which can all potentially form adducts. The relevance of tetra-OH-PAH analysis in hair as biomarkers of PAH exposure was evaluated in a dose-response study conducted on 64 rats (Long Evans females/n = 8 per groups) under repeated exposure (3 times per week) to a mixture of 16 PAHs at low doses (0.01-0.8 mg/kg) for 90 days. Most of the tetra-OH-PAHs targeted in the method were detected in the hairs of the rats, regardless of the dose of exposure. Significant linear relationships (R2 ranging from 0.558 to 0.964, p < 0.001) were observed between the administered dose and the tetra-OH-PAH concentrations in the hairs for 20 out of the 23 metabolites. By widening the range of PAH metabolites used as biomarkers of exposure so as to include the analysis of PAH tetrahydroxylated forms (especially those exhibiting more than 5 aromatic rings), the present methodology will enable multi-exposure assessments which are more accurately representative of actual situations of exposure to PAHs.

Chemical Evaluation of Electronic Cigarettes: Multicomponent Analysis of Liquid Refills and their Corresponding Aerosols.

Electronic cigarette use has raised concern worldwide regarding potential health risks and its position in tobacco cessation strategies. As part of any toxicity assessment, the chemical characterization of e-liquids and their related vapors are among fundamental data to be determined. Considering the lack of available reference methods, we developed and validated several analytical procedures in order to conduct a multicomponent analysis of six e-liquid refills and their resultant vapor emissions (generated by a smoking machine), and compared them with tobacco smoke. We combined several techniques including gas-chromatography, high and ultra-performance liquid chromatography and inductively coupled plasma with mass spectrometry or ultraviolet and flame ionization detection in order to identify the main e-liquid constituents (propylene glycol, glycerol and nicotine), as well as multiple potentially harmful components (trace elements, polycyclic aromatic hydrocarbons (PAHs), pesticides and carbonyl compounds). Regarding propylene glycol, glycerol and nicotine concentrations, the six tested e-liquids comply with the advertised composition and contain only traces of pollutants. Noticeable lower concentrations of trace elements (≤3.4 pg/mL puff), pesticides (

Hair analysis for the biomonitoring of pesticide exposure: comparison with blood and urine in a rat model.

Urine and plasma have been used to date for the biomonitoring of exposure to pollutants and are still the preferred fluids for this purpose; however, these fluids mainly provide information on the short term and may present a high level of variability regarding pesticide concentrations, especially for nonpersistent compounds. Hair analysis may provide information about chronic exposure that is averaged over several months; therefore, this method has been proposed as an alternative to solely relying on these fluids. Although the possibility of detecting pesticides in hair has been demonstrated over the past few years, the unknown linkage between exposure and pesticides concentration in hair has limited the recognition of this matrix as a relevant tool for assessing human exposure. Based on a rat model in which there was controlled exposure to a mixture of pesticides composed of lindane, ß-hexachlorocyclohexane, ß-endosulfan, p,p'-DDT, p,p'-DDE, dieldrin, pentachlorophenol, diazinon, chlorpyrifos, cyhalothrin, permethrin, cypermethrin, propiconazole, fipronil, oxadiazon, diflufenican, trifluralin, carbofuran, and propoxur, the current work demonstrates the association between exposure intensity and resulting pesticide concentration in hair. We also compared the results obtained from a hair analysis to urine and plasma collected from the same rats. Hair, blood, and urine were collected from rats submitted to 90-day exposure by gavage to the aforementioned mixture of common pesticides at different levels. We observed a linear relationship between exposure intensity and the concentration of pesticides in the rats' hair (R Pearson 0.453-0.978, p < 0.01). A comparison with results from urine and plasma samples demonstrated the relevance of hair analysis and, for many chemicals, its superiority over using fluids for differentiating animals from different groups and for re-attributing animals to their correct groups of exposure based on pesticide concentrations in the matrix. Therefore, this study strongly supports hair analysis as a reliable tool to be used during epidemiological studies to investigate exposure-associated adverse health effects.

Analysis of tetrahydroxylated benzo[a]pyrene isomers in hair as biomarkers of exposure to benzo[a]pyrene.

A first gas chromatography-tandem mass spectrometry (GC-MS/MS) method was designed for analysis of four tetrahydroxylated benzo[a]pyrene metabolites (benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, benzo[a]pyrene-r-7,t-8,t-9,t-10-tetrahydrotetrol, benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol, and benzo[a]pyrene-r-7,t-8,c-9,t-10-tetrahydrotetrol) in hair. Hair powder extract was submitted to liquid-solid extraction, followed by C18 solid-phase purification. The analytes were derivatized with use of N-methyl-N-(trimethylsilyl)trifluoroacetamide and then analyzed by GC-MS/MS in negative chemical ionization mode. The calibration curve was linear from the limit of quantification (LOQ) to 20 pg/mg in hair. The coefficient of determination of the calibration curve was more than 0.975 for all the analytes investigated. The LOQs ranged from 0.075 to 0.2 pg/mg in hair. The method was afterward applied to the analysis of hair of 16 rats randomly allocated to experimental groups receiving 16 polycyclic aromatic hydrocarbons solubilized in oil at 0 or 0.8 mg/kg body weight by oral administration three times per week for 90 days. The analysis of monohydroxylated and dihydroxylated benzo[a]pyrenes was conducted in parallel by GC-MS/MS on the same samples. All tetrahydroxylated benzo[a]pyrene isomers were detected in hair samples collected from rats exposed to polycyclic aromatic hydrocarbons. Benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, the most abundant isomer in hair of treated rats, was also the principal isomer released in DNA adduct hydrolysis in humans. Moreover, the benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol concentrations in hair were significantly greater than those of 2-hydroxybenzo[a]pyrene, 1-hydroxybenzo[a]pyrene, 7-hydroxybenzo[a]pyrene, and 4-hydroxybenzo[a]pyrene and similar to those of 9-hydroxybenzo[a]pyrene and 3-hydroxybenzo[a]pyrene. The method was also sufficiently sensitive to monitor environmental levels of exposure because two hair specimens in the eight analyzed from smokers were above the LOQ for benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol and benzo[a]pyrene-r-7,t-8,c-9,t-10-tetrahydrotetrol. This study therefore demonstrated that tetrahydroxylated benzo[a]pyrenes in hair might be a useful biomarker for the assessment of both the general population and occupationally exposed workers.

Multi-residue analysis of organic pollutants in hair and urine for matrices comparison.

Urine being currently the most classically used matrix for the assessment of human exposure to pesticides, a growing interest is yet observed in hair analysis for the detection of organic pollutants. The aim of the present work was to develop and to validate multi-residue analytical methods, as similar as possible, in order to determine pesticides and their metabolites in these two biological matrices despite their different nature. The list of parent compounds and their metabolites investigated here consisted of 56 compounds, including organochlorines, organophosphates, pyrethroids, carbamates, other pesticides and polychlorinated biphenyls (PCBs). Two different approaches were necessary for the analysis of non-polar compounds (mainly parents) on one hand and polar analytes (mainly metabolites) on the other hand. In the final procedure, extraction from hair was carried out with acetonitrile/water after sample decontamination and pulverization. Extract was split into two fractions, which were analyzed directly with solid phase microextraction (SPME) injection for non-polar compounds and after derivatization with liquid injection for polar compounds. In urine, non-polar compounds were analyzed directly using SPME. Polar compounds were analyzed after acidic hydrolysis, liquid-liquid extraction with acetonitrile-cyclohexane-ethyl acetate, derivatization and liquid injection. Analysis was performed with gas chromatography tandem mass spectrometry operating in negative chemical ionization (GC-MS/MS-NCI) for all the compounds (non-polar and polar) in the two matrices. In hair, limits of quantification (LOQ) ranged from 0.02 pg/mg for trifluralin to 5.5 pg/mg for diethylphosphate. In urine, LOQ ranged from 0.4 pg/mL for α-endosulfan to 4 ng/mL for dimethyldithiophosphate. The analysis of samples supplemented with standards and samples collected from an animal previously submitted to chronic exposure to pesticides confirmed that all the compounds were analyzable in both hair and urine. In addition, the levels of sensitivity reached with these methods were quite satisfactory with regard to previously published studies, and also considering the number of compounds investigated.

Tetrahydroxylated-benzo[a]pyrene isomer analysis after hydrolysis of DNA-adducts isolated from rat and human white blood cells.

Since exposure to benzo[a]pyrene is suspected to be associated with several health issues, significant efforts have been made to develop efficient strategies for the assessment of human exposure to this ubiquitous compound. In this context, a method was developed for the analysis of four tetrahydroxylated-benzo[a]pyrene isomers resulting from the hydrolysis of their respective diol-epoxide precursors which are involved in DNA-adduct formation. The analytical sensitivity necessary to reach environmental levels of concentration was obtained by using gas chromatography-tandem mass spectrometry. The recovery determined at the four concentration levels were estimated in average at 83% for benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol(±), 29% for benzo[a]pyrene-r-7,t-8,t-9,t-10-tetrahydrotetrol(±), and 82% for benzo[a]pyrene-r-7,t-8,C-9,c-10-tetrahydrotetrol(±). The coefficient of determination of the calibration curve was above 0.997 for all the analytes investigated and the limit of quantification ranged from 0.5 to 2 adduct/10(8) nucleotides. The precision was between 5.3% and 22.3%. The suitability of the method was firstly evaluated by the analysis of DNA isolated from white blood cells of rats submitted after controlled exposure to benzo[a]pyrene. The four targeted tetra-OH-benzo[a]pyrenes as well as two unknown isomers were detected in all the treated animals. Benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol(±) appeared as the most abundant isomer in both treated and control animals followed by benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol(±). The method was afterwards applied to the analysis of DNA isolated from white blood cells of human volunteers. The results confirmed that this method was sufficiently sensitive to monitor environmental levels of exposure since all the specimens analyzed were above the limit of quantification for benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol(±) and two of them were positive for benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol(±), thereby highlighting interspecies differences in the nature of the tetrahydroxylated-benzo[a]pyrene isomers formed. This study confirms the necessity to focus on all the tetrahydroxylated-benzo[a]pyrene isomers, which could be indicators of benzo[a]pyrene-associated toxicity related to an individual's own metabolism, rather than limit to a single form.