Urinary 1-OHP Research Articles

Commuting behaviors and exposure to air pollution in Montreal, Canada

BackgroundVehicular traffic is a major source of outdoor air pollution in urban areas, and studies have shown that air pollution is worse during hours of commuting to and from work and school. However, it is unclear to what extent different commuting behaviors are a source of air pollution compared to non-commuters, and if air pollution exposure actually differs by the mode of commuting. This study aimed to examine the relationships between commuting behaviors and air pollution exposure levels measured by urinary 1-OHP (1-hydroxypyrene), a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs). MethodsA cross-sectional study of 174 volunteers living in Montreal, 92 females and 82 males, aged 20 to 53years was conducted in 2011. Each participant completed a questionnaire regarding demographic factors, commuting behaviors, home and workplace addresses, and potential sources of PAH exposure, and provided a complete first morning void urine sample for 1-OHP analysis. Multivariable general linear regression models were used to examine the relationships between different types of commuting and urinary 1-OHP levels. ResultsCompared to non-commuters, commuters traveling by foot or bicycle and by car or truck had a significantly higher urinary 1-OHP concentration in urine (p=0.01 for foot or bicycle vs. non-commuters; p=0.02 for car or truck vs. non-commuters); those traveling with public transportation and combinations of two or more types of modes tended to have an increased 1-OHP level in urine (p=0.06 for public transportation vs. non-commuters; p=0.05 for commuters with combinations of two or more types of modes vs. non-commuters). No significant difference in urinary 1-OHP variation was found by mode of commuting. ConclusionThis preliminary study suggests that despite the mode of commuting, all types of commuting during rush hours increase exposure to air pollution as measured by a sensitive PAH metabolite biomarker, and mode of commuting did not explain exposure variation.

A study of the status of exposure to polycyclic aromatic hydrocarbons (PAHs) in relation to its metabolites among workers in a Korean chemical factory.

The study was conducted to evaluate the status of worker exposure to polycyclic aromatic hydrocarbons (PAHs) through the measurement of urinary metabolites such as 1-hydroxypyrene (OHP) and 2-naphthol. A survey using a questionnaire involving 326 workers with measurement of urinary metabolites of 1-OHP and 2-naphthol was conducted. The differences in urinary 1-OHP and 2-naphthol concentrations, and changes in work, smoking habits and lifestyle were analyzed. The number of male subjects was 314 (96.3%), the largest age group was the fifth decade (170 cases, 52.1%). The urinary 1-OHP and 2-naphthol concentrations were significantly higher in the production workers. The urinary 1-OHP and 2-naphthol concentrations were significantly higher in smokers. In a multiple regression model, log (1-OHP) increased in smokers and production workers, while log (2-naphthol) only increased in smokers. Our results suggest that workers in this factory were exposed to PAHs from non-occupational as well as occupational sources. The occupational exposure to PAHs can be reduced through the improvement of the process, but the exposure due to smoking can be prevented only by giving up smoking.

Assessment of the levels of urinary 1-hydroxypyrene and air polycyclic aromatic hydrocarbon in PM2.5 for adult exposure to the petrochemical complex emissions

The relationship between external exposure and internal doses of polycyclic aromatic hydrocarbons (PAHs) has not been established for people living in industrial areas. This study was carried out to estimate the relationship between particle-phase PAH exposure and urinary 1-hydroxypyrene (1-OHP) levels among the adults living near a large petrochemical complex in Mailiao, Taiwan. We measured urinary 1-OHP in 781 residents above 35 years old and PM2.5 PAHs within a 20-km radius downwind from the petrochemical complex. Urinary 1-OHP was analyzed by high performance liquid chromatography, while 16 ambient particle-phase PAHs were measured by gas chromatography mass spectrometry. External exposures to individual PAHs at each study subject′s address were estimated by kriging interpolation from air sampling results and regressed against the subjects′ urinary 1-OHP levels, adjusting for confounding factors. The study population′s urinary 1-OHP levels ranged from 0.001 to 3.005μmol/mol-creatinine with significantly higher levels for females, grilled food consumers, and residents living close to roads. All 16 particle-phase PAHs were present in the study area with total PAH concentrations ranging from 0.111 to 1.982ng/m3. The spatial distribution of 4- and 5-ring PAHs identified high-concentration hotspots close to the complex in Mailiao. The multiple regression models showed that the adults′ urinary 1-OHP levels were significantly correlated with 5 out of the 16 PAHs, including benzo[a]anthracene, benzo[k]fluoranthene, fluoranthene, pyrene, and dibenzo[a,h]anthracene; a 0.01ng/m3 increase in the concentration of these 5 PAHs at the study subjects′ addresses was associated with a 20% elevation in urinary 1-OHP levels (μg/g-creatinine). Emissions from a petrochemical complex can elevate particle-phase PAH concentrations in surrounding areas and increase the urinary 1-OHP levels of adults living nearby.

Association of Urinary 1-OHP Concentration with Childhood Asthma

Background: Polycyclic aromatic hydrocarbons (PAHs) are known for their carcinogenic, mutagenic, and teratogenic properties. However, little is known about the effect of PAH on the development of asthma in children. Aims: To address the effect of PAH exposure on the development of sensitization and asthma by objective urine biomarker (1-OHP) at different ages. Methods: A total of 453 children from the Taiwan Childhood Environment and Allergic diseases Study (TCEAS) cohort with urine samples were recruited. Urine 1-OHP levels at age 3 and 6, as an indicator of exposure, were measured by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). At age 3 and 6, information on serum IgE levels and the development of asthma was collected. The association between 1-OHP levels at different stages and IgE levels and asthma was evaluated by multivariate linear regression and logistic regression. Results: The geometric mean levels of 1-OHP at age 3 were higher than those at age 6 (5.71 vs 4.74µg/g creatinine). 1-OHP levels at age 3 positively correlated with serum IgE levels (per ln-unit: ß=55.81 KU/l, p=0.04). Interestingly, analyses stratified by gender revealed that 1-OHP levels positively correlated with IgE only in girls (per ln-unit: ß=131.63 KU/l, p=0.02). Urine 1-OHP levels at age 3 significantly associated with asthma at age 3 and age 6 with OR(95% CI) of 3.18(1.87-5.42) and 2.54(1.45-4.44) for the highest tertile compared with lowest tertile. However, 1-OHP levels at age 6 did not reach statistical significance. Conclusions: Exposure to PAH at young age is associated with the development of sensitization and asthma in children.

Using urinary 1-hydroxypyrene concentrations to evaluate polycyclic aromatic hydrocarbon exposure in women using biomass combustion as main energy source

Context: The use of solid fuels for cooking and heating is likely to be the largest source of indoor air pollution on a global scale. Objective: The aim of this study was to investigate the urinary excretion of 1-hydroxypyrene (1-OHP) in women living in a rural community, where biomass combustion is used as main energy source during a working day. Materials and methods: The study was performed on urine samples collected in 2012, of 30 healthy women who were residents of a rural community in San Luis Potosi, Mexico. Urine was collected from each woman at three time points (morning, post-lunch and evening) during a working day. The analysis of urinary 1-OHP was performed using high-performance liquid chromatography (HPLC). Also, a health-risk assessment was conducted. Results: The highest levels of 1-OHP in this study were found in the samples taken in the evening (geometric mean ± SD; 0.36 ± 0.13 µg/g creatinine). However, no significant differences among 1-OHP concentrations in the evening and post-lunch samples (0.27 ± 0.10 µg/g creatinine; 0.58 ± 0.67 µg/L) were observed. But, the 1-OHP levels (0.17 ± 0.13 µg/g creatinine; 0.19 ± 0.21 µg/L) found in samples collected in the morning were significantly lower than the 1-OHP levels found in samples collected during post-lunch and evening time. Discussion and conclusion: The data shown in this study demonstrated an increment in the exposure levels to PAHs in women across the shift. However, no health risk was found in this study.

Urinary 1-hydroxypyrene is associated with oxidative stress and inflammatory biomarkers in acute Myocardial Infarction.

Several studies have associated exposure to environmental pollutants, especially polycyclic aromatic hydrocarbons (PAHs), with the development of cardiovascular diseases. Considering that 1-hydroxypyrene (1-OHP) is the major biomarker of exposure to pyrenes, the purpose of this study was to evaluate the potential association between 1-OHP and oxidative stress/inflammatory biomarkers in patients who had suffered an acute myocardial infarction (AMI). After adopting the exclusion criteria, 58 post-infarction patients and 41 controls were sub-divided into smokers and non-smokers. Urinary 1-OHP, hematological and biochemical parameters, oxidative stress biomarkers (MDA, SOD, CAT, GPx and exogenous antioxidants) and the inflammatory biomarker (hs-CRP) were analyzed. 1-OHP levels were increased in post-infarct patients compared to controls (p < 0.05) and were correlated to MDA (r = 0.426, p < 0.01), CAT (r = 0.474, p < 0.001) and β-carotene (r = −0.309; p < 0.05) in non-smokers. Furthermore, post-infarction patients had elevated hs-CRP, MDA, CAT and GPx levels compared to controls for both smokers and non-smokers. Besides, β-carotene levels and SOD activity were decreased in post-infarction patients. In summary, our findings indicate that the exposure to pyrenes was associated to lipid damage and alterations of endogenous and exogenous antioxidants, demonstrating that PAHs contribute to oxidative stress and are associated to acute myocardial infarction.

Electrospun polystyrene/oxidized carbon nanotubes film as both sorbent for thin film microextraction and matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

In the current study, polystyrene/oxidized carbon nanotubes (PS/OCNTs) film was prepared and applied as both an adsorbent of thin film microextraction (TFME) and matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF–MS) for the first time. The uniform size of PS/OCNTs film with OCNTs evenly and firmly immobilized in PS was obtained by electrospinning. And a novel TFME device was developed using the prepared PS/OCNTs film to enrich benzo[a]pyrene (BaP) from water, and also BaP and 1-hydroxypyrene (1-OHP) from urine sample. Then the extracted analytes on the PS/OCNTs film were directly applied to MALDI–MS analysis with PS/OCNTs film as the MALDI matrix. Our results show that PS/OCNTs film is a good TFME adsorbent toward the analytes and an excellent matrix for the sensitive determination of BaP and 1-OHP using MALDI–TOF–MS. The employment of PS/OCNTs as the matrix for MALDI can effectively avoid the large variation of signal intensity normally resulting from heterogeneous distribution of the adsorbed analyte on matrix layer, which therefore significantly improve spot-to-spot reproducibility. The introduction of PS in the film can prevent OCNTs from flying out of MALDI plate to damage the equipment. In addition, PS/OCNTs film also largely extended the duration of ion signal of target analyte compared to OCNTs matrix. The developed method was further successfully used to quantitatively determine BaP in environmental water and 1-OHP in urine samples. The results show that BaP and 1-OHP could be easily detected at concentrations of 50pgmL−1 and 500pgmL−1, respectively, indicating the high detection sensitivity of this method. For BaP analysis, the linear range was 0.1–20ngmL−1 with a correlation coefficient of 0.9970 and the recoveries were in the range of 81.3 to 123.4% with the RSD≤8.5% (n=3); for urinary 1-OHP analysis, the linear range was 0.5–20ngmL−1 with a correlation coefficient of 0.9937 and the recoveries were in the range of 79.2 to 103.4% with the RSD≤7.6% (n=3). Taken together, the developed method provides a simple, rapid, cost-effective and high-throughput approach for the analysis of BaP in environmental water and endogenous 1-OHP in urine samples.

Urinary 1‐hydroxypyrene and 8‐hydroxydeoxyguanosine Levels among Coke‐oven Workers for 2 Consecutive Days

This study evaluated the levels of exposure to polycyclic aromatic hydrocarbons (PAHs) and their relationship with oxidative DNA damage among Vietnamese coke-oven workers. We collected urine from 36 coke-oven workers (exposed group) at the beginning and end of the shift on 2 consecutive days. We also collected urine from 78 medical staff (control group). Information was collected by questionnaire about smoking status, drinking habit, and working position. Urinary 1-hydroxypyrene (1-OHP) and 8-hydroxydeoxyguanosine (8-OH-dG) were measured using HPLC. All statistical analyses were performed with SPSS version 19. Urinary 1-OHP was significantly higher in the coke-oven workers than in the control group (p<0.05). Top-oven workers had the highest levels of internal exposure to PAHs, followed by side-oven and then bottom-oven workers (5.41, 4.41 and 1.35 ng/mg creatinine, respectively, at the end of the shift on day 2). Urinary 8-OH-dG was significantly higher in top- and side-oven workers at the end of the shift on day 2 (4.63 and 5.88 ng/mg creatinine, respectively) than in the control group (3.85 ng/mg creatinine). Based on a multi-regression analysis, smoking status had a significant effect on urinary 8-OH-dG (p=0.049). Urinary 1-OHP tended to have a positive correlation with urinary 8-OH-dG (p=0.070). Vietnamese coke-oven workers were exposed to PAHs during their work shift. Urinary 1-OHP exceeded the recommended limit, and elevated oxidative DNA damage occurred in top- and side-oven workers on the second day of work. A tendency for positive correlation was found between urinary 1-OHP and urinary 8-OH-dG.

Urinary 1-hydroxypyrene levels in workers exposed to polycyclic aromatic hydrocarbon from rubber wood burning.

BackgroundUrinary 1-hydroxypyrene (1-OHP) was selected as a biomarker of polycyclic aromatic hydrocarbons (PAHs) to explore the accumulation level in the bodies of workers at rubber smoke sheet factories in southern Thailand.MethodsSpot urine samples were taken from four groups of workers from June 2006 to November 2007. The nonexposure or control groups included habitual cigarette smokers and nonsmokers. The other two groups were workers exposed to particle-bound PAHs from rubber wood smoke and they were nonsmokers. All spot urine samples were analyzed for 1-OHP and creatinine levels.ResultsThe mean ± standard deviation urinary 1-OHP in the control group of habitual smokers and the nonsmokers was 0.24 ± 0.16 μmol/mol creatinine and not-detected to 0.14 μmol/mol creatinine, respectively. In the workers, the 1-OHP levels on workdays had no significant difference from the 1-OHP levels on the days off. The yearly average 1-OHP level was 0.76 ± 0.41 μmol/mol creatinine whereas the average 1-OHP level during 10 consecutive workdays was 1.06 ± 0.29 μmol/mol creatinine (p > 0.05).ConclusionThe urinary 1-OHP levels of workers exposed to PAHs were high. The accumulation of 1-OHP in the body was not clear although the workers had long working hours with few days off during their working experience. Therefore, a regular day off schedule and rotation shift work during high productive RSS should be set for RSS workers.

Polycyclic aromatic hydrocarbons exposure in residents living near a cement factory with kilns

This study was performed to investigate polycyclic aromatic hydrocarbons (PAHs) exposure in the area around a cement factory with kilns using waste, including refuse plastic fuel. Atmospheric total suspended particulates (TSPs) for each of an exposed area and a non-exposed area were collected. Similarly, urine samples were collected from 330 subjects in the exposed area and 126 subjects in the non-exposed area. Gas chromatography with mass spectrometry was used to analyze PAHs in the collected TSP samples and the PAH metabolites, urinary 2-naphthol (2-NAP) and 1-hydroxypyrene (1-OHP), of the residents. The concentrations of urinary 2-NAP and 1-OHP were adjusted by creatinine concentrations. The atmospheric concentrations of PAHs, including naphthalene and pyrene, were higher in the exposed area than those in the non-exposed area. The geometric means (GMs) of the urinary 2-NAP concentrations in the exposed and non-exposed groups without work experience were 4.06 and 1.55μg/g creatinine, respectively. The GMs of the urinary 1-OHP concentrations were 0.26 and 0.14μg/g creatinine, respectively. The results showed that the concentrations of PAH metabolites were significantly higher in the exposed group than those in the non-exposed group (p<0.001). Multiple linear regression analysis with the log-transformed urinary 2-NAP and 1-OHP concentrations and other variables indicated a strong correlation of residence in the exposed area and smoking with an increase in the urinary 2-NAP and 1-OHP concentrations. In addition to the known risk factors, this study indicated that living near a cement factory with kilns is also a risk factor for PAH exposure.

Lymphocyte oxidative stress/genotoxic effects are related to serum IgG and IgA levels in coke oven workers.

We investigated oxidative stress/genotoxic effects levels, immunoglobulin levels, polycyclic aromatic hydrocarbons (PAHs) levels exposed in 126 coke oven workers and in 78 control subjects, and evaluated the association between oxidative stress/genotoxic effects levels and immunoglobulin levels. Significant differences were observed in biomarkers, including 1-hydroxypyrene levels, employment time, percentages of alcohol drinkers, MDA, 8-OHdG levels, CTL levels and CTM, MN, CA frequency, and IgG, IgA levels between the control and exposed groups. Slightly higher 1-OHP levels in smoking users were observed. For the dose-response relationship of IgG, IgA, IgM, and IgE by 1-OHP, each one percentage increase in urinary 1-OHP generates a 0.109%, 0.472%, 0.051%, and 0.067% decrease in control group and generates a 0.312%, 0.538%, 0.062%, and 0.071% decrease in exposed group, respectively. Except for age, alcohol and smoking status, IgM, and IgE, a significant correlation in urinary 1-OHP and other biomarkers in the total population was observed. Additionally, a significant negative correlation in genotoxic/oxidative damage biomarkers of MDA, 8-OH-dG, CTL levels, and immunoglobins of IgG and IgA levels, especially in coke oven workers, was found. These data suggest that oxidative stress/DNA damage induced by PAHs may play a role in toxic responses for PAHs in immunological functions.

Urinary 1-Hydroxypyrene Levels among Office Workers Living in Industrial Areas

We examined exposure to polycyclic aromatic hydrocarbons (PAHs) among non-smoking office workers in 2 countries living in the vicinity of a coke-oven factory by measuring their levels of urinary 1-OHP, a known metabolite of PAHs. Subjects included 10 non-smoking office workers in Kitakyushu city (Japan) and 20 workers in Thai Nguyen city (Vietnam). Measurement was optimized by using the high-performance liquid chromatography (HPLC) method developed by Jongeneelen et al. This method required only a small amount of urine and had a short incubation time, and its detection limit was very low (0.00448 ng/ml), which was practical and highly sensitive.The median urinary 1-OHP concentration in the Vietnamese subjects (0.417 ng/mg creatinine) was six times as high as that in the Japanese subjects (0.069 ng/mg creatinine) (P < 0.001). However, both concentrations were significantly below the guideline level, below which there is no genotoxic effect, implying a low probability of any adverse health effects.Our measurements from both countries showed higher urinary 1-OHP concentrations than in previous studies from locations without factories, indicating that ambient air pollution from industrial emissions is an important source of PAH exposure. Finally, the urinary 1-OHP concentrations did not correlate with gender or lifestyle factors.

Blood pressure changes and polycyclic aromatic hydrocarbons in outdoor workers.

Everyday outdoor workers are exposed to chemicals including the polycyclic aromatic hydrocarbons (PAHs). The aim of the study is to evaluate the relationship between hydroxypyrene and blood pressure in outdoor workers. 374 subjects of both sexes entered the study. We evaluated the assay of urinary hydroxypyrene (1-HOP); their blood pressure (BP) was measured in upright position and in the supine position and the correlation between the levels of 1-HOP and BP was assessed using Pearson test and linear multiple regression. The results obtained show that in the total sample the levels of urinary 1-OHP are negatively associated with systolic and diastolic BP in supine position and in upright position. The significance is maintained despite the stratification of the sample according to age; in non-smokers we found a negative relationship between 1-OHP and differential blood pressure, both systolic and diastolic. The results of the study suggest that occupational exposure to PAHs may be able to significantly influence the blood pressure probably acting on the autonomic nervous system.

Assessing traffic and polycyclic aromatic hydrocarbon exposure in Montreal, Canada

IntroductionThe International Agency for Research on Cancer classifies specific polycyclic aromatic hydrocarbons (PAHs) as probable carcinogens. This study compares two PAH biomarkers and their relationship with geographic information system (GIS) based traffic density (a proxy of PAH exposure), and explores the determinants of the PAH biomarkers. MethodsA cross-sectional study was conducted in Montreal with 200 volunteers (107 females and 93 males) ages 20 to 53years. Data were collected by questionnaire, urine samples were used for biomarker analysis, and innovative GIS-based time- and distance-weighted traffic densities (TDWTD) were calculated for all locations of participants during the 48h prior to urine collection. ResultsDetection rates of the two biomarkers were greater than 95%. Female participants had higher 1-OHP and 1-OHPG levels than males, and no relationship was detected between TDWTD in 48h and the two PAH biomarkers. Biomarker levels were related to smoking more than one pack of cigarettes in the previous 48h, and among non-smokers, barbecued meat consumption increased the level of urinary 1-OHP (exp β: 1.45, 95% CI: 1.07 to 1.98). ConclusionsBoth 1-OHP and 1-OHPG can be used to assess the relatively low PAH levels to which the general population is exposed. With the exception of smoking, the impact of PAH exposure factors on the biomarkers is relatively small in this study population.

An analysis study of the exposure factors from an environmental hazardous material (1-hydroxyperene)

BACKGROUND Polycyclic aromatic hydrocarbons (PAHs) are composed more than two benzene rings that are formed by incomplete combustion of organic materials or the process of high-pressure. PAHs has potential carcinogenic and/or mutagenic properties. 1-Hydroxypyrene, the metabolite of pyrene, is used to assess the exposure of polycyclic aromatic hydrocarbons (PAHs). AIMS In this study, we analyzed the PAHs exposure levels of Korean adults participating to “Korean National Environmental Health Survey”, using the urinary 1-OHP levels as a biomarker for PAHs, and evaluated the exposure factors that closely associated with the level of urinary 1-OHP. METHODS We used log transformed urinary 1-OHP (log(1-OHP)) value as a dependent variable for analysis of the association with exposure factors. Multiple linear regression and logistic regression model were used to evaluate the relationship between log(1-OHP) and exposure factors. RESULTS In a multiple analysis, we observed that 1-OHP was significantly associated with variables including age group, education, smoke, drink, heating source, distance from the road, and charcoal grilled or roasted meet consumption. Results from multiple logistic regression analysis, we observed significant finding with variables including gender(male OR:1.53 (95% CI:1.02,2.31), education (above college OR:0.32 (95% CI:0.18,0.54) and smoke (current smoker OR:17.73 (95% CI:11.02,28.51). We evaluated the association between traffic related air pollution factors (use of public transportation, type of transportation and distance from the road) and log(1-OHP), however, only distance from the road was significantly associated with log(1-OHP) CONCLUSIONS The analysis shows that the factors, such as smoking habit, gender and charcoal grilled or roasted food consumption are significantly associated with log(1-OHP). These results may provide a supportive evidence of the finding from previous studies. These analysis results can be used as reference for policy making for reducing environmental hazardous materials.

224 Exposure to polycyclic aromatic hydrocarbons and sperm quality of coke-oven workers

ObjectivesThe study aimed to assess whether exposure to polycyclic aromatic hydrocarbons (PAHs) alter sperm quality of coke-oven workers.MethodsPersonal breathing zone, urine, and semen samples were collected from nonsmoking workers at...

95 Exposure to polycyclic aromatic hydrocarbons and sperm DNA integrity of coke oven workers

The objective of this study was to examine sperm DNA integrity of coke-oven workers in relation to exposure to PAHs from coke processing. A total of 72 human subjects participated...

Biomarkers of occupational exposure to air pollution, inflammation and oxidative damage in taxi drivers

Exposure to environmental pollutants has been recognised as a risk factor for cardiovascular events. 1-hydroxypyrene (1-OHP) is a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs) from traffic-related air pollution. Experimental studies indicate that PAH exposure could be associated with inflammation and atherogenesis. Thus, the purpose of this study was to evaluate whether the biomarker of PAH exposure is associated with biomarkers of inflammation and oxidative stress and if these effects modulate the risk of developing cardiovascular diseases in workers exposed to air pollution. This study included 60 subjects, comprising 39 taxi drivers and 21 non-occupationally exposed persons. Environmental PM2.5 and benzo[a]pyrene (BaP) levels, in addition to biomarkers of exposure and oxidative damage, were determined. Inflammatory cytokines (IL-1β, IL-6, IL-10, TNF-α, IFN-γ and hs-CRP) and serum levels of oxidised LDL (ox-LDL), auto-antibodies (ox-LDL-Ab) and homocysteine (Hcy) were also evaluated. PM2.5 and BaP exhibited averages of 12.4±6.9μgm−3 and 1.0±0.6ngm−3, respectively. Urinary 1-OHP levels were increased in taxi drivers compared to the non-occupationally exposed subjects (p<0.05) and were positively correlated with pro-inflammatory cytokines and negatively correlated with antioxidants. Furthermore, taxi drivers had elevated pro-inflammatory cytokines, biomarkers of oxidative damage, and ox-LDL, ox-LDL-Ab and Hcy levels, although antioxidant enzymes were decreased compared to the non-occupationally exposed subjects (p<0.05). In summary, our findings indicate that taxi drivers showed major exposure to pollutants, such as PAHs, in relation to non-occupationally exposed subjects. This finding was associated with higher inflammatory biomarkers and Hcy, which represent important predictors for cardiovascular events. These data suggest a contribution of PAHs to cardiovascular diseases upon occupational exposure.

High human exposure to pyrene (polycyclic aromatic hydrocarbon) in Kinshasa, a capital of the Democratic Republic of Congo

BackgroundData on human exposure to chemicals in Africa are scarce. A biomonitoring study was conducted in a representative sample of the population in Kinshasa (Democratic Republic of Congo) to document exposure to polycyclic aromatics hydrocarbons.Methods1-hydroxypyrene (1-OHP) was measured by HPLC fluorescence in spot urine samples from 220 individuals (50.5% women), aged 6–70 years living in the urban area and from 50 additional subjects from the sub-rural area of Kinshasa. Data were compiled as geometric means and selected percentiles, expressed without (μg/L) or with creatinine adjustment (μg/g cr). Multiple regression analyses were applied to factors (creatinine, grilled meat habits and smoking habits) influencing 1-OHP (stepwise procedure, criteria: probability F to enter ≤ 0.05 and probability F to remove ≥ 0.10).ResultsAccording to the regression models, creatinine, grilled meat habits and smoking habits contribute to explain 45% of the variation in population’s urinary 1-OHP by the environmental exposure. Overall, living in urban area of Kinshasa was associated with increased levels of 1-OHP in urine as compared to a population living in the sub-rural area [GM: 1.8 μg/L (n = 220) versus 1.4 μg/L (n = 50), p < 0.01] as well as compared to the reference values from databases involving American or German populations.ConclusionThis study reveals the high pyrene (PAH) exposure of the Kinshasa population. However, more work, with a rigorous design in the exposed population (monitoring of air concentrations and identifying other sources of pyrene –PAH exposure), is needed to establish further documentation.

Epigenetic markers of exposure to polycyclic aromatic hydrocarbons in Mexican brickmakers: A pilot study

A pilot cross-sectional study was carried out in a group of 39 male brick manufacturers in San Luis Potosi, Mexico to identify epigenetic biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs). A questionnaire was used to compile the smoking and drinking habits, clinical history, working time, and socioeconomic characteristics of the participants. 1-Hydroxypyrene (1-OHP) levels were measured from urine samples using high-performance liquid chromatography, and genomic DNA was isolated from blood samples for methylation analysis using pyrosequencing. The mean 1-OHP level was 0.18μgg−1 creatinine (range 0.023–1.11), which was below the expected occupational exposure level. After adjusting for potential confounders, the 1-OHP urine concentration was negatively associated with DNA methylation of the interleukin 12 (β=−1.57; 95% CI: −2.9 to −0.23; p=0.02) and p53 gene promoters (β=−2.7; 95% CI: −5.46–0.06; p=0.055). Suggestive negative associations were also found for the TNF-α gene (β=−3.9; 95% CI:−8.28–0.48; p=0.08) and Alu sequences (β=−0.55; 95% CI:−1.25–0.16; p=0.12). Although the individual exposures to PAHs as estimated by urinary 1-OHP concentrations were low, changes in specific and global DNA methylation were observed.