Urinary Polycyclic Aromatic Hydrocarbons Metabolite Levels Research Articles

Seasonal variation in urinary PAH metabolite levels and associations with neonatal birth outcomes.

Previous studies have demonstrated that exposure to polycyclic aromatic hydrocarbons (PAHs) can affect maternal and infant health. However, the conclusions regarding the effects of seasonal PAH exposure on maternal and infant health have been inconsistent. To further elucidate this issue, this study included data from 2282 mother-infant pairs in the Zuni birth cohort. The objective was to investigate the association between maternal late-pregnancy urinary PAH metabolite concentrations and neonatal birth outcomes during the heating and non-heating seasons. The results demonstrated that PAH exposure in Zunyi was primarily dominated by 2-OHNAP and 1-OHNAP and that the concentrations of PAH metabolites were significantly higher during the heating season. Furthermore, PAH metabolite exposure was found to affect neonatal birth weight, birth length, and parity index with seasonal differences. Further dose-effect analyses revealed nonlinear relationships and seasonal differences between PAH metabolites and neonatal birth weight, birth length, and parity index. Bayesian kernel mechanism regression modeling demonstrated that the inverted U-shaped relationship between PAH metabolites and neonatal birth weight and parity index was exclusive to the heating season. Consequently, it can be posited that maternal exposure to PAH metabolites during late pregnancy exerts a detrimental influence on neonatal growth and development, which is further compounded by the use of heating fuels. This highlights the necessity to either control or alter the use of heating fuels during pregnancy.

Investigating industrial PAH air pollution in relation to population exposure in major countries: A scoring approach

Polycyclic aromatic hydrocarbons (PAHs) are common air pollutants worldwide, associated with industrial processes. In the general population, both modeling and field studies revealed a positive correlation between air PAH concentrations and urinary PAH metabolite levels. Many countries lack population urinary data that correspond to local PAH air concentrations. Thus, we proposed a scoring-based approximate approach to investigating that correlation in selected countries, hypothesizing that PAH air concentrations in selected regions could represent the national air quality influenced by industrial emission and further correlate to PAH internal exposure in the general population. This research compiled 85 peer-reviewed journal articles and 9 official monitoring datasets/reports covering 34 countries, 16 of which with both atmospheric PAH data and human biomonitoring data. For the air pollution score (AirS), Egypt had the highest AirS at 0.94 and Pakistan was at the bottom of the score ranking at −1.95, as well as the median in the UK (AirS: 0.50). For the population exposure score (ExpS), China gained the top ExpS at 0.44 and Spain was with the lowest ExpS of −1.52, with the median value in Italy (ExpS: 0.43). Through the correlation analysis, atmospheric PAHs and their corresponding urinary metabolites provided a positive relationship to a diverse extent, indicating that the related urinary metabolites could reflect the population's exposure to specific atmospheric PAHs. The findings also revealed that in the 16 selected countries, AirS indexes were positively correlated with ExpS indexes, implying that higher PAH levels in the air may lead to elevated metabolite urinary levels in general populations. Furthermore, lowering PAH air concentrations could reduce population internal PAH exposure, implying that strict PAH air regulation or emission would reduce health risks for general populations. Notably, this study was an ideal theoretical research based on proposed assumptions to some extent. Further research should focus on understanding exposure pathways, protecting vulnerable populations, and improving the PAH database to optimize PAH pollution control.

Urinary polycyclic aromatic hydrocarbon metabolites are positively related to serum testosterone levels of males and serum estradiol levels of females among U.S. adults.

It has been reported for several years that polycyclic aromatic hydrocarbons (PAHs) could disturb human endocrine function. However, there is still a short of consistent conclusion about the relationship between PAH exposure and levels of sexual hormones. The aim of our study is to explore whether exposure to PAHs and how PAHs affect the levels of serum testosterone (T) and estradiol (E2) in adults, hoping to fulfill the knowledge gap. This study included adults aged 20 and above who participated in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2016. We included 10 PAH metabolites in this study. The levels of urinary PAH metabolites were log-transformed and divided into quartiles. The associations between PAH metabolites and both serum T levels of males and E2 levels of females were investigated using multivariate regression models. We furtherly calculated PAHs scores by sum of ranks across 10 PAHs metabolites, which represented the exposure levels of PAHs mixtures, and the association between PAHs scores and serum T and E2 levels were analyzed. A total of 4,654 subjects were included in this study, including 2,460 males and 2,194 females. After adjusting for confounders, 2-hydroxynapthalene and 3-hydroxyfluorene were positively associated with serum T levels of males (p-value for trend=0.047, and p-value for trend=0.006, respectively), while 1-hydroxyphenanthrene was positively associated with serum E2 levels of females (p-value for trend=0.013). In the adjusted models, no significant association was found between PAHs scores and either T levels of males or E2 levels of females (p-value for trend=0.615, and p-value for trend=0.241, respectively). This study showed urinary 2-hydroxynapthalene and 3-hydroxyfluorene were associated with increased T levels of males, and urinary 1-hydroxyphenanthrene was associated with increased E2 levels of females. The observed association indicated disrupting effects of PAH exposure on reproductive health.

Associations of Bitumen Fumes with Lymphocyte Subsets and Cytokines Expression in the Peripheral Blood of Exposed Workers

The present study aimed to investigate the distribution of lymphocyte subsets and cytokines expression in the peripheral blood of bitumen fumes-exposed workers. In this study, 129 workers from molding and roasting workshops were recruited as the exposed group and 99 office and quality inspection staff were chosen as the control. The polycyclic aromatic hydrocarbons (PAHs) levels of bitumen fumes in individual and fixed-point air samples and the urinary levels of 1-hydroxypyrene (1-OH-P), 1-hydroxynaphthols (1-OH-N) and 2-hydroxynaphthols (2-OH-N) in workers were measured using High Performance Liquid Chromatography. The lymphocyte subsets and serum cytokines concentrations were analyzed by flow cytometry and cytometric bead array, respectively. The median values of PAHs were 0.08 mg/m3 for permissible concentration-time weighted average and 0.12 mg/m3 for permissible concentration-short term exposure (PC-STEL) in molding and roasting workshops, which were higher than that in the control area (< 0.01 mg/m3). Multivariate linear regression models were used to adjust for influential covariates, including age, gender, work age, smoking status, and alcohol consumptions. After adjusting for these covariates, we compared levels of urinary PAHs metabolites, the percentages of lymphocyte subsets, and serum cytokines concentrations between the two groups. The 1-OH-P, 1-OH-N, and 2-OH-N levels in the urine of bitumen fumes exposed workers were significantly higher than that in the controls (P < 0.05). Compared with the control group, the percentage of the natural killer (NK) cell (CD56+ cell) was significantly increased in the exposed group (P < 0.001). There was a significant decrease in the percentages of CD3+ T cell, CD4+ T cell, and CD8+ T cell in the exposed group compared to the control (P < 0.001). The serum levels of interleukin-1β (IL-1β) and IL-6 in bitumen fumes exposed workers were significantly higher than that of the controls (P < 0.05). Moreover, positive correlations were observed between the serum levels of IL-1β, IL-6, and urinary 1-OH-P levels in bitumen fumes-exposed workers, respectively (P < 0.05). There were no significant differences in the serum levels of IL-8, tumor necrosis factor-α (TNF-α), macrophage inflammatory protein-1β (MIP-1β) and monocyte chemotactic protein-1 (MCP-1) between the exposed group and the control group (P > 0.05). Our study suggested that low dose of bitumen fumes exposure could decrease the percentage of T cell, increase the percentage of NK cell and stimulate the release of serum IL-1β and IL-6 in the peripheral blood of exposed workers. The serum levels of IL-1β and IL-6 were positive correlated with the urinary 1-OH-P levels in bitumen fumes exposed workers. These results may inform the search for potential effective biomarkers and provide evidences for early health monitoring in workers occupationally exposed to bitumen fumes.

Proximity to traffic and exposure to polycyclic aromatic hydrocarbons in relation to Attention Deficit Hyperactivity Disorder and conduct disorder in U.S. children.

Traffic related air pollution (TRAP) and its component polycyclic aromatic hydrocarbons (PAHs) may be neurotoxic in children. There is limited research on postnatal exposure to TRAP and PAHs and child neurodevelopment. We linked data from the U.S. NHANES 2001-2004 with the National Highway Planning Network 2005 to examine the proximity to major roads (highway or urban/rural principal arterials), urinary PAH metabolites, and diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) and Conduct Disorder (CD) based on Diagnostic Interview Schedule for Children (C-DISC) in 1253 children aged 8-15 years. We calculated odds ratios (ORs) and 95% Confidence Intervals (CIs) for ADHD and CD by traffic proximity and PAH exposures using logistic regression adjusted for confounders. Higher ADHD prevalence was observed among children living <500m (9.86%) compared to those ≥500m (3.84%) from a major road. Prevalence of children with CD was comparable (<500m: 2.51% and ≥500m: 2.43%). We found little difference in urinary PAH metabolite levels between children living near major roads and those who did not. Children living <500m from a major road had a non-significant OR of 2.06 (95% CI 0.85-5.03) for ADHD diagnosis. Children living on ≥2 major roads within 500m of a highway had a non-significant OR of 2.27 (95% CI 0.71-7.26) for ADHD diagnosis. There was no association between proximity to major roads and CD diagnosis. We found living close to a major road was not associated with increased PAH levels. We did not find statistically significant relation between proximity to a major road or urinary PAH metabolite levels and ADHD or CD diagnosis in this cross-sectional analysis. Prospective studies are needed for the investigation of postnatal TRAP exposure and ADHD and CD diagnosis.

Neurobehavioral performance of PAH exposure in male coal miners in Shanxi, China: a cross-sectional study.

Coal miners are exposed to polycyclic aromatic hydrocarbons (PAHs), a group of neurotoxicants formed and released during incomplete combustion of coal. High levels of anxiety and depression have been reported in coal miners, but little is known about neurobehavioral functions in populations that are occupationally exposed to PAHs. We tested neurobehavioral performance in coal miners and correlated it with levels of urinary markers of PAH exposure. Levels of urinary PAH metabolites were measured in 652 male coal miners as an indicator of exposure. Subjects were divided into a high-exposure group and a low-exposure group based on the median level of total PAH metabolites. A neurobehavioral core test battery and a questionnaire were used to assess neurobehavioral performance and collect demographic information, respectively. The median level of total PAH metabolites in urine was 4.88μmol/mol creatinine. Highly exposed workers exhibited more fatigue-inertia than less-exposed workers (p < 0.05), and had lower scores in forward digit span, digit symbol, and Benton visual retention tests (p < 0.05). Multiple linear regression indicated that age, education, and shift work were significantly correlated with test scores. PAH exposure may be associated with neurobehavioral alterations, which should be monitored in coal miners to prevent neurobehavioral disorders.

Pro-Oxidative and Proinflammatory Effects After Traveling From Los Angeles to Beijing: A Biomarker-Based Natural Experiment.

Exposure to air pollution increases cardiovascular morbidity and mortality. Preventing chronic cardiovascular diseases caused by air pollution relies on detecting the early effects of pollutants on the risk of cardiovascular disease development, which is limited by the lack of sensitive biomarkers. We have previously identified promising biomarkers in experimental animals but comparable evidence in humans is lacking. Air pollution is substantially worse in Beijing than in Los Angeles. We collected urine and blood samples from 26 nonsmoking, healthy adult residents of Los Angeles (mean age, 23.8 years; 14 women) before, during, and after spending 10 weeks in Beijing during the summers of 2014 and 2015. We assessed a panel of circulating biomarkers indicative of lipid peroxidation and inflammation. Personal exposure to polycyclic aromatic hydrocarbons (PAHs), a group of combustion-originated air pollutants, was assessed by urinary PAH metabolite levels. Urinary concentrations of 4 PAH metabolites were 176% (95% CI, 103% to 276%) to 800% (95% CI, 509% to 1780%) greater in Beijing than in Los Angeles. Concentrations of 6 lipid peroxidation biomarkers were also increased in Beijing, among which 5-, 12-, and 15-hydroxyeicosatetraenoic acid and 9- and 13-hydroxyoctadecadienoic acid levels reached statistical significance (false discovery rate <5%), but not 8-isoprostane (20.8%; 95% CI, -5.0% to 53.6%). The antioxidative activities of paraoxonase (-9.8%; 95% CI, -14.0% to -5.3%) and arylesterase (-14.5%; 95% CI, -22.3% to -5.8%) were lower and proinflammatory C-reactive protein (101%; 95% CI, 3.3% to 291%) and fibrinogen (48.3%; 95% CI, 4.9% to 110%) concentrations were higher in Beijing. Changes in all these biomarkers were reversed, at least partially, after study participants returned to Los Angeles. Changes in most outcomes were associated with urinary PAH metabolites (P<0.05). Traveling from a less-polluted to a more-polluted city induces systemic pro-oxidative and proinflammatory effects. Changes in the levels of 5-, 12-, and 15-hydroxyeicosatetraenoic acid and 9- and 13-hydroxyoctadecadienoic acid as well as paraoxonase and arylesterase activities in the blood, in association with exposures to PAH metabolites, might have important implications in preventive medicine as indicators of increased cardiovascular risk caused by air pollution exposure.

Predictors of Urinary Polycyclic Aromatic Hydrocarbon Concentrations: NHANES 2001–2006

Polycyclic aromatic hydrocarbons (PAHs) are hazardous air pollutants formed during incomplete combustion, absorbed through inhalation and ingestion, and metabolized to hydroxylated compounds that can be detected in urine. Biomonitoring data provide a direct way to link human exposure to environmental contaminants. However, these data do not reveal how various exposure routes or media contribute to the body burden of a specific chemical. We evaluated predictors of urinary PAH concentrations in 2001–2006 NHANES participants from reported information on demographic and housing characteristics, reported food intake, and modeled outdoor air pollutant exposures. NHANES participants were linked to their daily PM2.5 exposure estimate and annual air toxics concentrations. Multivariate linear regression models were developed using the Deletion/Substitution/Addition algorithm to predict urinary PAHs. Exposure to air pollution was not associated with levels of urinary PAH metabolites. Current smoking status was the strongest predictor of PAH biomarker concentration and was able to explain 10–47% of the variability of PAH biomarker concentrations. In non-smokers, our prediction models were able to explain only 2–5% of the variability of PAH biomarker concentrations. Overall, our results indicated, with the exception of smoking status, there are not strong demographic, dietary, or environmental predictors of PAH exposure.

Association of PAHs and BTEX exposure with lung function and respiratory symptoms among a nonoccupational population near the coal chemical industry in Northern China

Emissions (particularly aromatic compounds) from coal industries and biomass fuels combustion lead to high health risks for neighboring residents. To investigate the association of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and 1,2-dimethylbenzene (BTEX) exposure with lung function and respiratory symptoms among adults and children near the coal-chemical industry in Northern China, adults and children from a county dotted with coal chemical industry were chosen as subjects for investigation (investigated area, IR). The control group consisted of adults and children from an agricultural county (control area, CR). The environmental and urinary PAH and BTEX levels of adults and children were determined by isotope dilution liquid chromatography coupled with tandem mass spectrometry. The Mann-Whitney U test and multivariate linear regression models were used to analyze the relationship between pollutant exposure and the respiratory system. The results showed that in an ambient environment, levels of PAHs and BTEX in the IR were significantly higher than those in the CR. Particularly, the concentration profiles for air samples were IR > CR and indoor > outdoor. Both for adults and children, the geometric (GM) concentrations of urinary PAHs and BTEX from the IR were significantly higher than those measured in the CR. Additionally, the urinary PAH exposure level profiles of smokers were higher than those of nonsmokers, indicating that indoor air and smoking were both important nonoccupational exposure sources. The decline of the forced expiratory in the first second (FEV1, %) and the forced expiratory middle flow rate (FEF25%) in children were associated with increasing urinary PAH metabolite levels (p < 0.05). The increase in urinary 1-OHN, 3-OHPhe, 4-OHPhe and 1-OHP levels could be linked to a decrease in FEV1 (r = −0.179, p < 0.05) and FEF25% with the coefficient of −0.166, −0.201 and −0.175 (p < 0.05), respectively. Medical examinations and lung function tests indicated that residents in the IR had higher occurrences of chest inflammation or declining lung function than residents in the CR. Moreover, exposure to PAHs and BTEX could decrease child lung function, though decreased lung function was not observed in adults. Both urinary monitoring and lung function data showed that children were more sensitive to PAH and BTEX exposure than adults.

Elevated Exposures to Polycyclic Aromatic Hydrocarbons and Other Organic Mutagens in Ottawa Firefighters Participating in Emergency, On-Shift Fire Suppression.

Occupational exposures to combustion emissions were examined in Ottawa Fire Service (OFS) firefighters. Paired urine and dermal wipe samples (i.e., pre- and post-event) as well as personal air samples and fire event questionnaires were collected from 27 male OFS firefighters. A total of 18 OFS office workers were used as additional controls. Exposures to polycyclic aromatic hydrocarbons (PAHs) and other organic mutagens were assessed by quantification of urinary PAH metabolite levels, levels of PAHs in dermal wipes and personal air samples, and urinary mutagenicity using the Salmonella mutagenicity assay (Ames test). Urinary Clara Cell 16 (CC16) and 15-isoprostane F2t (8-iso-PGF2α) levels were used to assess lung injury and overall oxidative stress, respectively. The results showed significant 2.9- to 5.3-fold increases in average post-event levels of urinary PAH metabolites, depending on the PAH metabolite (p < 0.0001). Average post-event levels of urinary mutagenicity showed a significant, event-related 4.3-fold increase (p < 0.0001). Urinary CC16 and 8-iso-PGF2α did not increase. PAH concentrations in personal air and on skin accounted for 54% of the variation in fold changes of urinary PAH metabolites (p < 0.002). The results indicate that emergency, on-shift fire suppression is associated with significantly elevated exposures to combustion emissions.

Polycyclic aromatic hydrocarbons exposure decreased sperm mitochondrial DNA copy number: A cross-sectional study (MARHCS) in Chongqing, China

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that have adverse effects on the male reproductive function. Many studies have confirmed that PAHs preferentially accumulate in mitochondria DNA relative to nuclear DNA and disrupt mitochondrial functions. However, it is rare whether exposure to PAHs is associated with mitochondrial damage and dysfunction in sperm. To evaluate the effects of PAHs on sperm mitochondria, we measured mitochondrial membrane potential (MMP), mitochondrial DNA copy number (mtDNAcn) and mtDNA integrity in 666 individuals from the Male Reproductive Health in Chongqing College Students (MARHCS) study. PAHs exposure was estimated by measuring eight urinary PAH metabolites (1-OHNap, 2-OHNap, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe, 2-OHFlu and 1-OHPyr). The subjects were divided into low, median and high exposure groups using the tertile levels of urinary PAH metabolites. In univariate analyses, the results showed that increased levels of 2-OHPhe, 3-OHPhe, ∑Phe metabolites and 2-OHFlu were found to be associated with decreased sperm mtDNAcn. After adjusting for potential confounders, significantly negative associations of these metabolites remained (p = 0.039, 0.012, 0.01, 0.035, respectively). Each 1 μg/g creatinine increase in 2-OHPhe, 3-OHPhe, ∑Phe metabolites and 2-OHFlu was associated with a decrease in sperm mtDNAcn of 9.427%, 11.488%, 9.635% and 11.692%, respectively. There were no significant associations between urinary PAH metabolites and sperm MMP or mtDNA integrity. The results indicated that the low exposure levels of PAHs can cause abnormities in sperm mitochondria.

Urinary Polycyclic Aromatic Hydrocarbon Metabolites and Altered Lung Function in Wuhan, China.

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with adverse effects on the respiratory system. However, the association between internal levels of PAH metabolites and lung function levels remains unclear. We investigated the relationships between urinary PAH metabolite concentrations and lung function levels in a general Chinese population. Lung function and 12 urinary PAH metabolites were measured in 2,747 participants from the Wuhan-Zhuhai cohort in China. Associations between urinary PAH metabolites and lung function were analyzed by linear mixed models. We also investigated associations among urinary PAH metabolite concentrations, traffic exposure time, and dietary PAH exposure. We found significant associations between increased levels of urinary PAH metabolites and reduced lung function. Each 1-U increase in log-transformed levels of 2-hydroxynaphthalene, 9-hydroxyfluorene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1-hydroxypyrene, or total urinary PAH metabolites was associated with a 23.79-, 19.36-, 41.76-, 36.87-, 33.47-, 27.37-, 39.53-, 34.35-, 25.03-, or 37.13-ml reduction in FEV1, respectively (all P < 0.05). Each 1-U increase in 2-hydroxynaphthalene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, or total urinary PAH metabolites was associated with a 24.39-, 33.90-, 27.15-, 28.56-, 27.46-, or 27.99-ml reduction in FVC, respectively (all P < 0.05). The total urinary PAH metabolites concentration was positively associated with both traffic exposure time and dietary PAH exposure among nonsmokers. Total and specific urinary PAH metabolites were associated with lung function reduction in a general Chinese population. Further studies are needed to investigate the potential mechanism by which PAHs induces lung function reduction.

Repeatedly high polycyclic aromatic hydrocarbon exposure and cockroach sensitization among inner-city children

BackgroundExposures to traffic-related air pollutants including polycyclic aromatic hydrocarbons (PAH) have been associated with the development and exacerbation of asthma. However, there is limited evidence on whether these pollutants are associated with the development of cockroach sensitization, a strong risk factor for urban asthma. We hypothesized that repeatedly high PAH exposure during childhood would be associated with increased risk of new cockroach sensitization. MethodsAs part of the research being conducted by the Columbia Center for Children’s Environmental Health (CCCEH) birth cohort study in New York, a spot urine sample was collected from children at age 5 years (2003–2008) and again at age 9–10 years (2008–2012; n=248) and analyzed for 10 PAH metabolites. Repeatedly high PAH (High–High) exposure was defined as measures above median for age 5 PAH metabolites at both time points. Child blood samples at age 5 and 9 years were analyzed for total, anti-cockroach, mouse, dust mite, cat and dog IgE. Relative risks (RR) were estimated with multivariable modified Poisson regression. ResultsIndividual PAH metabolite levels, except for 1-naphthol (1-OH-NAP), increased by 10-60% from age 5 to age 9–10. The prevalence of cockroach sensitization increased from 17.6% (33/188) at age 5 to 33.0% (62/188) at 9 years (p=0.001). After controlling for potential covariates including cockroach sensitization at age 5 in regression analyses, positive associations were found between repeatedly high exposure (High–High) to 1-OH-NAP, 3-hydroxyphenanthrene (3-OH-PHEN), or 1-hydroxypyrene (1-OH-PYR) and cockroach sensitization at age 9 (p-values<0.05). Compared to Low–Low exposure, the relative risk (RR) [95% CI] with repeatedly high exposure was 1.83 [1.06–3.17] for 1-OH-NAP, 1.54 [1.06–2.23] for 3-OH-PHEN, and 1.59 [1.04–2.43] for 1-OH-PYR. ConclusionsRepeatedly high levels of urinary PAH metabolites during childhood may increase likelihood of sensitization to cockroach allergen in urban inner-city children at age 9 years.

Effects of profession on urinary PAH metabolite levels in the US population.

Although exposure to polycyclic aromatic hydrocarbons (PAHs) is common in both environmental and occupational settings, few studies have compared PAH exposure among people with different professions. The purpose of this study was to investigate the variations in recent PAH exposure among different occupational groups over time using national representative samples. The study population consisted of 4162 participants from the 2001 to 2008 National Health and Nutrition Examination Survey, who had both urinary PAH metabolites and occupational information. Four corresponding monohydroxy-PAH urine metabolites: naphthalene (NAP), fluorene (FLUO), phenanthrene (PHEN), and pyrene (PYR) among seven broad occupational groups were analyzed using weighted linear regression models, adjusting for creatinine levels, sociodemographic factors, smoking status, and sampling season. The overall geometric mean concentrations of NAP, FLUO, PHEN, and PYR were 6927, 477, 335, and 87 ng/L, respectively. All four PAH metabolites were elevated in the "extractive, construction, and repair (ECR)" group, with 21-42 % higher concentrations than those in the reference group of "management." Similar trends were seen in the "operators, fabricators, and laborers (OFL)" group for FLUO, PHEN, and PYR. In addition, both "service" and "support" groups had elevated FLUO. Significant (p < 0.001) upward temporal trends were seen in NAP and PYR, with an approximately 6-17 % annual increase, and FLUO and PHEN remained relatively stable. Race and socioeconomic status show independent effects on PAH exposure. Heterogeneous distributions of urinary PAH metabolites among people with different job categories exist at the population level. The upward temporal trends in NAP and PYR warrant reduction in PAH exposure, especially among those with OFL and ECR occupations.

Systemic exposure to PAHs and benzene in firefighters suppressing controlled structure fires.

Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters’ bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants.

Biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs) and DNA damage: a cross-sectional pilot study among roofers in South Florida

ObjectiveThe main goal of this pilot study was to assess the technical and logistic feasibility of a future study. The research hypothesis is that occupational exposures to polycyclic aromatic hydrocarbons...

Association between Urinary Polycyclic Aromatic Hydrocarbon Metabolites and Sperm DNA Damage: A Population Study in Chongqing, China

BackgroundPolycyclic aromatic hydrocarbons (PAHs), a class of the most ubiquitous environmental contaminants, may reduce male reproductive functions, but the data from human population studies are very limited.ObjectivesWe designed this study to determine whether environmental exposure to PAHs contributes to the alteration in semen quality, sperm DNA damage, and apoptosis in the general male human population.MethodsWe measured urinary levels of four PAH metabolites and assessed semen quality, sperm apoptotic markers with Annexin V assay, and sperm DNA damage with comet assay in 232 men from Chongqing, China.ResultsWe found that increased urinary 2-hydroxynaphthalene (2-OHNa) levels were associated with increased comet parameters, including the percentage of DNA in the tail (tail%) [β coefficient = 13.26% per log unit 2-OHNa (micrograms per gram creatinine); 95% confidence interval (CI), 7.97–18.55]; tail length (12.25; 95% CI, 0.01–24.52), and tail distribution (7.55; 95% CI, 1.28–18.83). The urinary level of 1-hydroxypyrene was associated only with increased tail% (5.32; 95% CI, 0.47–10.17). Additionally, the increased levels of four urinary PAH metabolites were significantly associated with decreased vital Annexin V negative sperm counts. However, there was no significant association between urinary PAH metabolite levels and human semen parameters or morphology of the sperm samples.ConclusionsOur data indicate that the environmental level of PAH exposure is associated with increased sperm DNA damage but not with semen quality. These findings suggest that exposure to PAHs may disrupt sperm DNA and thereby interfere with human male fertility.