Exposure to polycyclic aromatic hydrocarbons in petrochemical industries by measurement of urinary 1-hydroxypyrene

Association of occupational exposure to polycyclic aromatic hydrocarbons in workers with hypertension from a northeastern Chinese petrochemical industrial area

Elevated urinary polycyclic aromatic hydrocarbon metabolites have been linked to an increased risk of cardiovascular diseases (CVDs). However, for petrochemical workers with potentially high PAH exposure, it remains largely unknown whether the link will be amplified. Thus, this work aimed to investigate 14 urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in 746 petrochemical workers working in a Chinese petrochemical industrial area and their association with the risk of hypertension using the binary logistic regression. Metabolites of naphthalene, fluorene, phenanthrene, and pyrene were frequently detected in the 746 urine samples analyzed (>98%), with Σ₁₀OH-PAH concentration in the range of 0.906-358 ng/mL. 2-hydroxynaphthalene accounted for the largest proportion of ten detected OH-PAHs (60.8% of Σ₁₀OH-PAHs). There were significant correlations between these metabolites and other factors, including gender, age, and body mass index. Diastolic blood pressure, not systolic blood pressure, was significant positively associated with the urinary Σ₁₀OH-PAH concentrations of the petrochemical workers. Elevated urinary 2/3-OH-Flu was significantly associated with an increased risk of hypertension (adjusted odds ratio: 1.96, 95% confidence interval: 1.20-3.18, p = 0.007), suggesting that PAH exposure in petrochemical workers was a driving factor of hypertension. In the stratified analysis, the association was more pronounced in those who were overweight with older age. Although the PAH exposure risk in petrochemical workers based on the estimated daily intakes was relatively low. Given the long-term impact, we call attention to CVDs of petrochemical workers.

Prenatal developmental toxicity studies on fumes from oxidised asphalt (OA) in the rat

The prenatal developmental toxicity of the fumes of oxidised asphalt (OA) was tested by nose-only inhalation in the rat. The test material was generated by collecting fumes from the headspace of storage tanks filled with OA. The composition of these fumes was matched to fumes sampled at a workplace where the same OA was applied in a pour-and-roll operation, representing occupational exposure with high concentrations of fumes to not underestimate the possible hazard. In the main study, dams were exposed to 0, 53, 158 and 536 mg/m³ of fume (as total organic mass), for 6 h/day for 19 days p.c. The maternal NOAEC was 53 mg/m³ (lowest dose tested). In the high-dose group treatment-related effects on body weight gain were seen. In the mid- and high-dose groups treatment-related effects on food consumption, lung weights, and histopathological changes in lungs and the upper respiratory tract were observed. The NOAEC for prenatal developmental toxicity was 536 mg/m³ since no exposure-related effects were found in any of the exposure groups for any of the investigated reproductive endpoints. Furthermore, nose-only exposure to OA fumes in concentrations up to 536 mg/m³ from days 1-19 p.c. did not induce any significant fetal abnormalities.

Levels of 1-hydroxypyrene in urine of people living in an oil producing region of the Andean Amazon (Ecuador and Peru)

PURPOSE

Polycyclic aromatic hydrocarbons (PAHs) are contaminants with carcinogenic effects but little is known about their presence in environments surrounding oil drilling operations and spills or exposure levels in nearby communities. The objective of this study was to characterize PAH levels in people living near oil drilling operations in relation to fish consumption, occupation, source of water and other socio-demographic characteristics.

METHODS

This pilot study examined PAH exposure by measuring 1-hydroxypyrene (1-OHP) in urine samples using high-performance liquid chromatography and fluorescence detection from 75 women and men in the Ecuadorian and Peruvian Amazon living near oil drilling operations and who answered a questionnaire collecting socio-demographic, occupational and dietary information. Data were analyzed using multiple linear regression models.

RESULTS

The mean value of 1-OHP was 0.40 μmol/mol creatinine, 95% CI 0.32-0.46 μmol/mol creatinine. Women who used water from a surface source (for washing clothes or bathing) had almost twice the amount of 1-OHP in their urine (mean 1-OHP = 0.41 μmol/mol creatinine, 95% CI 0.28-0.54 μmol/mol creatinine, n = 23) as women who used water from either a well, a spring or rain (mean 1-OHP = 0.22 μmol/mol creatinine, 95% CI 0.11-0.34 μmol/mol creatinine, n = 6). Men who reported eating a bottom-dwelling species as their most commonly consumed fish (mean 1-OHP = 0.50 μmol/mol creatinine, 95% CI 0.36-0.64 μmol/mol creatinine, n = 31) had twice as much 1-OHP in their urine as men who reported a pelagic fish (mean 1-OHP = 0.25 μmol/mol creatinine, 95% CI 0.15-0.35 μmol/mol creatinine, n = 15), signaling either oral (fish consumption) or dermal (while standing in water fishing benthic species) exposure.

CONCLUSIONS

More contact with surface water and benthic fish may result in higher levels of 1-OHP in human urine among the study population. Reducing the amount of oil and wastes entering the waterways in Andean Amazonia would be one way to reduce exposure.

Early markers of cardiovascular disease are associated with occupational exposure to polycyclic aromatic hydrocarbons

Occupational exposure to soot, rich in polycyclic aromatic hydrocarbons (PAH), has been associated with increased risk of cardiovascular disease (CVD). However, our knowledge about PAH exposure and early markers of CVD remains limited. In this cross-sectional study of 151 chimney sweeps and 152 controls, we investigated occupational exposure to PAH and early markers of CVD. Blood pressure (BP) (chimney sweeps only), urinary PAH metabolites and serum biomarkers were measured (C-reactive protein, homocysteine, gamma-glutamyltransferase, cholesterol, HDL, LDL, and triglycerides). Chimney sweeps had up to 7 times higher concentrations of PAH metabolites in urine than controls (P < 0.001): median concentrations (adjusted for specific gravity) for 1-hydroxypyrene, 2-hydroxyphenanthrene, 3-hydroxybenzo[a]pyrene, and 3-hydroxybenzo[a]anthracene were 0.56 µg/L, 0.78 µg/L, 4.75 ng/L, and 6.28 ng/L, respectively. Compared with controls, chimney sweeps had increased homocysteine, cholesterol, and HDL (β = 3.4 µmol/L, 0.43 mmol/L, and 0.13 mmol/L, respectively, P ≤ 0.003, adjusted for age, BMI, and smoking). In chimney sweeps, PAH metabolites correlated positively with the percentage of soot sweeping (P < 0.001). 2-hydroxyphenanthrene, 3-hydroxybenzo[a]pyrene, and 3-hydroxybenzo[a]anthracene were positively associated with diastolic BP (P < 0.044, adjusted for age, BMI, and smoking). PAH exposure among chimney sweeps resulted in elevated levels of markers for CVD risk. These findings stress the need to reduce occupational exposure to PAH.

Short-term markers of DNA damage among roofers who work with hot asphalt

BACKGROUND

Roofers are at increased risk for various malignancies and their occupational exposures to polycyclic aromatic hydrocarbons (PAHs) have been considered as important risk factors. The overall goal of this project was to investigate the usefulness of phosphorylated histone H2AX (γH2AX) as a short-term biomarker of DNA damage among roofers.

METHODS

Blood, urine, and dermal wipe samples were collected from 20 roofers who work with hot asphalt before and after 6 h of work on Monday and Thursday of the same week (4 sampling periods). Particle-bound and gas-phase PAHs were collected using personal monitors during work hours. γH2AX was quantified in peripheral lymphocytes using flow cytometry and 8-hydroxy-2-deoxyguanosine (8-OHdG) was assessed in urine using ELISA. General linear mixed models were used to evaluate associations between DNA damage and possible predictors (such as sampling period, exposure levels, work- and life-style factors). Differences in mean biomarker and DNA damage levels were tested via ANOVA contrasts.

RESULTS

Exposure measurements did not show an association with any of the urinary biomarkers or the measures of DNA damage. Naphthalene was the most abundant PAH in gas-phase, while benzo(e)pyrene was the most abundant particle-bound PAH. Post-shift levels of γH2AX and 8-OHdG were higher on both study days, when compared to pre-shift levels. Cigarette smoking was a predictor of γH2AX and urinary creatinine was a predictor of urinary 8-OHdG. Between-subject variance to total variance ratio was 35.3 % for γH2ax and 4.8 % for 8-OHdG.

CONCLUSION

γH2AX is a promising biomarker of DNA damage in occupational epidemiology studies. It has a lower within-subject variation than urinary 8-OHdG and can easily be detected in large scale groups. Future studies that explore the kinetics of H2AX phosphorylation in relation to chemical exposures may reveal the transient and persistent nature of this sensitive biomarker of early DNA damage.

Polycyclic Aromatic Hydrocarbons: Part I. Exposure

Polycyclic aromatic hydrocarbons (PAH) comprise the largest class of cancer-causing chemicals and are ranked ninth among chemical compounds threatening to humans. Although interest in PAH has been mainly due to their carcinogenic property, many of these compounds are genotoxic, mutagenic, teratogenic, and carcinogenic. They tend to bioaccumulate in the soft tissues of living organisms. Interestingly, many are not directly carcinogenic, but act like synergists. PAH carcinogenicity is related to their ability to bind DNA thereby causing a series of disruptive effects that can result in tumor initiation. Thus, any structural attribute or modification of a PAH molecule that enhances DNA cross linking can cause carcinogenicity. In part I, we review exposure to these dangerous chemicals across a spectrum of use in the community and industry.

Effect of exposure to a mixture of organic solvents on hearing thresholds in petrochemical industry workers

INTRODUCTION

Hearing loss is one of the most common occupational diseases. In most workplaces, workers are exposed to noise and solvents simultaneously, so the potential risk of hearing loss due to solvents may be attributed to noise. In this study we aimed to assess the effect of exposure to mixed aromatic solvents on hearing in the absence of exposure to hazardous noise.

MATERIALS AND METHODS

In a cross-sectional study, 99 workers from the petrochemical industry with exposure to a mixture of organic solvents whose noise exposure was lower than 85 dBA were compared with 100 un-exposed controls. After measuring sound pressure level and mean concentration of each solvent in the workplace, pure-tone-audiometry was performed and the two groups were compared in terms of high-frequency and low-frequency hearing loss. T-tests and Chi-square tests were used to compare the two groups.

RESULTS

The mean hearing threshold at all frequencies among petrochemical workers was normal (below 25 dB). We did not observe any significant association between solvent exposure and high-frequency or low-frequency hearing loss.

CONCLUSION

This study showed that temporary exposure (less than 4 years) to a mixture of organic solvents, without exposure to noise, does not affect workers' hearing threshold in audiometry tests.

Limitations and plausibility of the Pliocene lignite hypothesis in explaining the etiology of Balkan endemic nephropathy

BACKGROUND

Balkan endemic nephropathy (BEN) is a chronic, tubulointerstitial renal disease often accompanied by urothelial cancer that has a lethality of nearly 100%.

INTRODUCTION

One of the many factors that have been proposed to play an etiological role in BEN is exposure to organic compounds from Pliocene lignite coal deposits via the drinking water in endemic areas.

OBJECTIVES

The objective of this study was to systematically evaluate the role of the tenets of the Pliocene lignite hypothesis in the etiology of BEN in order to provide an improved understanding of the hypothesis for colleagues and patients alike.

METHODS

A comprehensive compilation of the possible limitations of the hypothesis, with each limitation addressed in turn is presented.

RESULTS

The Pliocene lignite hypothesis can best account for, is consistent with, or has the potential to explain the evidence associated with the myriad of factors related to BEN.

CONCLUSIONS

Residents of endemic areas are exposed to complex mixtures containing hundreds of organic compounds at varying doses and their potentially more toxic (including nephrotoxic) and/or carcinogenic metabolites; however, a multifactorial etiology of BEN appears most likely.

Biological monitoring of environmental exposure to polycyclic aromatic hydrocarbons in subjects living in the area of recycling electronic garbage, in Southern China

The study was undertaken to evaluate the environmental exposure to polycyclic aromatic hydrocarbons in subjects living in the area of recycling electronic garbage in Southern China and research the influence of environment smoke tobacco (EST) to people through active and passive smoking. Urinary concentrations of 2-hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene were determined in 141 randomly selected voluntary residents aged 13 to 81 years in two polycyclic aromatic hydrocarbon (PAH)-exposed groups, two control groups, and an EST research group. The concentrations of 2-hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene in PAH-exposed groups are significantly higher (p<0.05) than those of control groups. Mean value of 1-hydroxypyrene in the residents living in the area of recycling electronic garbage (1.1 μmol/mol creatinine) is a little higher than those of iron foundry workers, automobile repair workers, and firefighters. Mean value of 2-hydroxynaphthalene (11.3 μmol/mol creatinine) is much higher than that of shipyard and aircraft maintenance and much lower than some occupational exposure, such as coking batteries, sorting department, and distillation department in coking plant. Some metabolites of PAHs (PAHm) are significantly elevated through active and passive smoking, while the influence of EST to other PAHm is not statistically significant. 2-Hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene in the urine of smokers are, respectively, 3.9, 1.9, 1.4, and 1.9 times to those of nonsmokers. In nonsmokers, passive smokers excreted 1.1, 1.5, 1.9, and 1.5 times of 2-hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene compared to nonpassive smokers.

Urinary 1-hydroxypyrene as a biomarker of exposure to polycyclic aromatic hydrocarbons: biological monitoring strategies and methodology for determining biological exposure indices for various work environments

This article reviews the published studies on urinary 1-hydroxypyrene (1-OHP) as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs) in work environments. Sampling and analysis strategies as well as a methodology for determining biological exposure indices (BEIs) of 1-OHP in urine for different work environments are proposed for the biological monitoring of occupational exposure to PAHs. Owing to the kinetics of absorption of pyrene by different exposure routes and excretion of 1-OHP in urine, in general, 1-OHP urinary excretion levels increase during the course of a workday, reaching maximum values 3-9 h after the end of work. When the contribution of dermal exposure is important, post-shift 1-OHP excretion can however be lower than pre-shift levels in the case where a worker has been exposed occupationally to PAHs on the day prior to sampling. In addition, 1-OHP excretion levels in either pre-shift, post-shift or evening samples increase during the course of a work-week, levelling off after three consecutive days of work. Consequently, ideally, for a first characterization of a work environment and for an indication of the major exposure route, considering a 5-day work-week (Monday to Friday), the best sampling strategy would be to collect all micturitions over 24 h starting on Monday morning. Alternatively, collection of pre-shift, post-shift and evening urine samples on the first day of the work-week and at the end of the work-week is recommended. For routine monitoring, pre-shift samples on Monday and post-shift samples on Friday should be collected when pulmonary exposure is the main route of exposure. On the other hand, pre-shift samples on Monday and Friday should be collected when the contribution of skin uptake is important. The difference between beginning and end of work-week excretion will give an indication of the average exposure over the workweek. Pre-shift samples on the first day of the work-week will indicate background values, and, hence, reflect general environment exposure and body burden of pyrene and/or its metabolites. On the other hand, since PAH profile can vary substantially in different work sites, a single BEI cannot apply to all workplaces. A simple equation was therefore developed to establish BEIs for workers exposed to PAHs in different work environments by using a BEI already established for a given work environment and by introducing a correction factor corresponding to the ratio of the airborne concentration of the sum of benzo(a)pyrene (BaP) equivalent to that of pyrene. The sum of BaP equivalent concentrations represents the sum of carcinogenic PAH concentrations expressed as BaP using toxic equivalent factors. Based on a previously estimated BEI of 2.3 μmol 1-OHP mol(-1) creatinine for coke-oven workers, BEIs of 4.4, 8.0 and 9.8 μmol 1-OHP mol(-1) creatinine were respectively calculated for vertical pin Söderberg workers, anode workers and pre-bake workers of aluminium plants and a BEI of 1.2 μmol 1-OHP mol(-1) creatinine was estimated for iron foundry workers. This approach will allow the potential risk of cancer in individuals occupationally exposed to PAHs to be assessed better.

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

Background

Data 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.

Methods

1-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).

Results

According 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.

Conclusion

This 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.

Malondialdehyde-deoxyguanosine and bulky DNA adducts in schoolchildren resident in the proximity of the Sarroch industrial estate on Sardinia Island, Italy

Air quality is a primary environmental concern in highly industrialised areas, with potential health effects in children residing nearby. The Sarroch industrial estate in Cagliari province, Sardinia Island, Italy, hosts the world's largest power plant and the second largest European oil refinery and petrochemical park. This industrial estate produces a complex mixture of air pollutants, including benzene, heavy metals and polycyclic aromatic hydrocarbons. Thus, we conducted a cross-sectional study to evaluate the prevalence of malondialdehyde-deoxyguanosine adducts in the nasal epithelium of 75 representative children, aged 6-14 years, attending primary and secondary schools in Sarroch in comparison with 73 rural controls. Additionally, the levels of bulky DNA adducts were analysed in a subset of 62 study children. DNA damage was measured by (32)P-postlabelling methodologies. The air concentrations of benzene and ethyl benzene were measured in the school gardens of Sarroch and a rural village by diffusive samplers. Outdoor measurements were also performed in other Sarroch areas and in the proximity of the industrial estate. The outdoor levels of benzene and ethyl benzene were significantly higher in the school gardens of Sarroch than in the rural village. Higher concentrations were also found in other Sarroch areas and in the vicinity of the industrial park. The mean levels of malondialdehyde-deoxyguanosine adducts per 10(8) normal nucleotides ± standard error (SE) were 74.6±9.1 and 34.1±4.4 in the children from Sarroch and the rural village, respectively. The mean ratio was 2.53, 95% confidence interval (CI): 1.71-2.89, P < 0.001, versus rural controls. Similarly, the levels of bulky DNA adducts per 10(8) normal nucleotides ± SE were 2.9±0.4 and 1.6±0.2 in the schoolchildren from Sarroch and the rural village, respectively. The means ratio was 1.90, 95% CI: 1.25-2.89, P = 0.003 versus rural controls. Our study indicates that children residing near the industrial estate have a significant increment of DNA damage.

Excretion profiles and half-lives of ten urinary polycyclic aromatic hydrocarbon metabolites after dietary exposure

Human exposure to polycyclic aromatic hydrocarbons (PAHs) can be assessed by biomonitoring of their urinary monohydroxylated metabolites (OH-PAHs). Limited information exists on the human pharmacokinetics of OH-PAHs. This study aimed to investigate the excretion half-life of 1-hydroxypyrene (1-PYR), the most used biomarker for PAH exposure, and 9 other OH-PAHs following a dietary exposure in 9 nonsmoking volunteers with no occupational exposure to PAHs. Each person avoided food with known high PAH-content during the study period, except for a high PAH-containing lunch (barbecued chicken) on the first day. Individual urine samples (n = 217) were collected from 15 h before to 60 h following the dietary exposure. Levels of all OH-PAHs in all subjects increased rapidly by 9-141-fold after the exposure, followed by a decrease consistent with first-order kinetics, and returned to background levels 24-48 h after the exposure. The average time to reach maximal concentration ranged from 3.1 h (1-naphthol) to 5.5 h (1-PYR). Creatinine-adjusted urine concentrations for each metabolite were analyzed using a nonlinear mixed effects model including a term to estimate background exposure. The background-adjusted half-life estimate was 3.9 h for 1-PYR and ranged 2.5-6.1 h for the other 9 OH-PAHs, which in general, were shorter than those previously reported. The maximum concentrations after barbecued chicken consumption were comparable to the levels found in reported occupational settings with known high PAH exposures. It is essential to consider the relatively short half-life, the timing of samples relative to exposures, and the effect of diet when conducting PAH exposure biomonitoring studies.

Exposure and kinetics of polycyclic aromatic hydrocarbons (PAHs) in cigarette smokers

Our study objectives were (1) to investigate the selectivity of polycyclic aromatic hydrocarbon (PAH) metabolites for tobacco smoke exposure and (2) to determine half-lives of PAH metabolites in smokers. There were 622 participants from the United States (US) and Poland, and of these, 70% were smokers. All subjects provided spot urine samples, and 125 smokers provided blood samples. Urinary PAH metabolite half-lives were determined in 8 smokers. In controlled hospital studies of 18 smokers, the associations between various measures of nicotine intake and urinary excretion of PAH metabolites were investigated. Plasma nicotine was measured by GC. LC-MS/MS was used to measure the plasma levels of cotinine and trans-3'-hydroxycotinine, and urine levels of nicotine and its metabolites, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and PAH metabolites (2-naphthol, 1-, 2-, and 3-hydroxyfluorenes, 1-, 2-, 3-, and 4-hydroxyphenanthrenes, and 1-hydroxypyrene). Regardless of smoking status, PAH metabolite excretion was higher in Polish subjects than in US subjects (p-values <0.001). 1-Hydroxyfluorene exhibited the greatest difference between smokers and nonsmokers, with a 5-fold difference in Polish subjects and a 25-fold difference in US subjects, followed by 3- and 2-hydroxyfluorenes, 2-naphthol, and 1-hydroxypyrene. The differences for hydroxyphenanthrenes were small or nonsignificant. 1-Hydroxyfluorene had the highest correlation with urine nicotine equivalents (r = 0.77) and urine NNAL (r = 0.64). While the half-lives of PAH metabolites were <10 h in smokers, 1-hydroxyfluorene had the largest ratio of initial to terminal urine concentration (58.4 ± 38.6, mean ± SD) after smoking. Receiver Operating Characteristic (ROC) analysis of PAHs among Polish and US subjects further showed that hydroxyfluorenes are most highly discriminative of smokers from nonsmokers followed by 2-naphthol and 1-hydroxypyrene. In conclusion, hydroxyfluorenes, particularly 1-hydroxyfluorene, and 2-naphthol are more selective of tobacco smoke than 1-hydroxypyrene and hydroxyphenanthrenes. Characterization of hydroxyfluorene and 2-naphthol metabolites in urine may improve the characterization of PAHs from tobacco smoke and related disease risks among smokers and nonsmokers.

Whole genome expression in peripheral-blood samples of workers professionally exposed to polycyclic aromatic hydrocarbons

This study aims to examine global gene expression profiles before and after the work-shift among coke-oven workers (COWs). COWs work six consecutive days and then take two days off. Two blood and urine samples in each worker were collected before starting to work after two days off and end-of-shift in the sixth day of work in 2009. Altered gene expressions (ratio of gene expression levels between end-of-shift and preshift work) were performed by a Human OneArray expression system which probes ~30,000-transcription expression profiling of human genes. Sixteen workers, all men, were enrolled in this study. Median urinary 1-hydroxypyrene (1OHP) levels (μmol/mol creatinine) in end-of-shift work were significantly higher than those in preshift work (2.58 vs 0.29, p = 0.0002). Among the 20,341 genes which passed experimental quality control, 26 gene expression changes, 7 positive and 19 negative, were highly correlated with across-the-shift urinary 1OHP levels (end-of-shift-preshift 1OHP) (p-value <0.001). The high and low exposure groups of across-the-shift urinary 1OHP levels dichotomized in ~2.00 μmol/mol creatinine were able to be distinguished by these 26 genes. Some of them are known to be involved in apoptosis, chromosome stability/DNA repair, cell cycle control/tumor suppressor, cell adhesion, development/spermatogenesis, immune function, and neuronal cell function. These findings in COWs will be an ideal model to study the relationship of PAH exposure with acute changes of gene expressions.

Assessment of non-occupational exposure to polycyclic aromatic hydrocarbons through personal air sampling and urinary biomonitoring

Non-occupational inhalation and ingestion exposure to polycyclic aromatic hydrocarbons (PAHs) has been studied in 8 non-smoking volunteers through personal air sampling and urinary biomonitoring. The study period was divided into 4 segments (2 days/segment), including weekdays with regular commute and weekends with limited traffic related exposures; each segment had a high or low PAH diet. Personal air samples were collected continuously from the subjects while at home, at work, and while commuting to and from work. All urine excretions were collected as individual samples during the study. In personal air samples, 28 PAHs were measured, and in urine samples 9 mono-hydroxylated metabolites (OH-PAHs) from 4 parent PAHs (naphthalene, fluorene, phenanthrene and pyrene) were measured. Naphthalene was found at higher concentrations in air samples collected at the subjects' residences, whereas PAHs with four or more aromatic rings were found at higher levels in samples taken while commuting. Urinary OH-PAH biomarker levels increased following reported high inhalation and/or dietary exposure. On days with a low PAH diet, the total amount of inhaled naphthalene during each 24-hour period was well correlated with the amount of excreted naphthols, as was, to a lesser extent, fluorene with its urinary metabolites. During days with a high dietary intake, only naphthalene was significantly correlated with its excreted metabolite. These findings suggest that this group of non-occupational subjects were exposed to naphthalene primarily through indoor air inhalation, and exposed to other PAHs such as pyrene mainly through ingestion.

EROD activity in peripheral blood lymphocytes and 1-hydroxypyrene in urine and milk as biomarkers of PAH exposure in dairy ruminants

Presently, few biomarker-based approaches are available for the evaluation of environmental exposure to persistent organic pollutants in dairy ruminants. In this study, goats (Capra hircus) were orally administered a mixture of pyrene, phenanthrene, and benzo[a]pyrene daily over a 40-d period (1 or 50 mg/d). Milk and urine 1-hydroxypyrene levels, ethoxyresorufin-O-deethylase (EROD) activity in peripheral blood lymphocytes (PBL) as well as urinary levels of 2- and 3-hydroxyphenanthrene were determined at 10-d intervals. 1-Hydroxypyrene excretion in milk and urine significantly increased and then achieved a plateau at 10 d. Transfer rates of 1-hydroxypyrene were calculated to be approximately 0.5 and 25% in milk and urine, respectively. Concentrations in milk and urine were proportional to the ingested doses. These results demonstrate that 1-hydroxypyrene in milk or urine may be used as a biomarker for evaluating the exposure of dairy ruminants to polycyclic aromatic hydrocarbons (PAHs) over an extended exposure period. Constitutive EROD activity in lymphocytes was 0.5 ± 0.3 pmol resorufin/min/mg protein, and was significantly induced over the entire exposure time, before stabilizing after 40 d at 6.30 ± 1.3 and 18.89 ± 1.12 pmol resorufin/min/mg protein for 1 mg/d and 50 mg/d doses, respectively. Induction kinetics were calculated using a logistic-like model and approximate dose-response curves were designed. We therefore propose EROD activity in PBL as a relevant, convenient, and noninvasive biomarker of subchronic exposure of dairy ruminants to CYP450 inducing PAH.

Variability of urinary concentrations of polycyclic aromatic hydrocarbon metabolite in general population and comparison of spot, first-morning, and 24-h void sampling

Urinary mono-hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) are commonly used in biomonitoring to assess exposure to polycyclic aromatic hydrocarbons (PAHs). Similar to other biologically non-persistent chemicals, OH-PAHs have relatively short biological half-lives (4.4-35 h). Little information is available on their variability in urinary concentrations over time in non-occupationally exposed subjects. This study was designed to (i) examine the variability of nine urinary OH-PAH metabolite concentrations over time and (ii) calculate sample size requirements for future epidemiological studies on the basis of spot urine, first-morning void, and 24-h void sampling. Individual urine samples (n=427) were collected during 1 week from 8 non-occupationally exposed adults. We recorded the time and volume of each urine excretion, dietary details, and driving activities of the participants. Within subjects, the coefficients of variation (CVs) for the wet-weight concentration of OH-PAHs in all samples ranged from 45% to 297%; creatinine adjustment reduced the CV to 19-288% (P<0.001; paired t-test). The simulated 24-h void concentrations were the least variable measure, with CVs ranging from 13% to 182% for the 9 OH-PAHs. Within-day variability contributed on average 84%, and between-day variability accounted for 16% of the total variance of 1-hydroxypyrene (1-PYR). Intraclass correlation coefficients of 1-PYR levels were 0.55 for spot urine samples, 0.65 [corrected] for first-morning voids, and 0.77 [corrected] for 24-h voids, indicating a high degree of correlation between urine measurements collected from the same subject over time. Sample size calculations were performed to estimate the number of subjects required for detecting differences in the geometric mean at a statistical power of 80% for spot urine, first-morning, and 24-h void sampling. These data will aid in the design of future studies of PAHs and possibly other biologically non-persistent chemicals and in the interpretation of their analytical results.

Amounts and proportion of administered pyrene dose excreted as urinary 1-hydroxypyrene after dietary exposure to polycyclic aromatic hydrocarbons

Although urinary 1-hydroxypyrene (1-OHP) is the most relevant parameter for assessing exposure to polycyclic aromatic hydrocarbons, the inability to further elucidate the intra- and inter-individual variability, specificity and kinetics makes it difficult to enhance its value as an exposure predictor. Therefore, this human control study examined the excretion kinetics of urinary 1-OHP after consuming barbecued meat. Two feeding experiments were conducted, with doses of 15 and 30 g of barbecued meat per kg of body weight for experiments 1 and 2, respectively. All voided urine was collected for 7 days and analyzed for 1-OHP. In both experiments, the amounts of urinary 1-OHP excreted was significantly increased (P < 0.05) at 12 h post exposure but not at 12-24 h post exposure. Mean percentages of administered pyrene doses excreted as urinary 1-OHP at 0-12 h and 12-24 h post exposure were 3.80 and 0.61% in experiment 1 and 1.66 and 0.38% in experiment 2. Excretion ratio was inversely related to dose. A pattern of diurnal fluctuation (P < 0.05) in 1-OHP excretions was also identified. That is, 1-OHP excretions were smaller in the first half of the day (~0:00-12:00) than in the last half of the day (~12:00-24:00). This study demonstrated that, even at large dietary doses, most of the total urinary excretion of 1-OHP occurs within 12 h. Thus, subjects of occupational or environmental studies need only recall their diets for the current or previous day to diminish the influence from dietary pyrene.

Malondialdehyde-deoxyguanosine adducts among workers of a Thai industrial estate and nearby residents

BACKGROUND

Humans living near industrial point emissions can experience high levels of exposures to air pollutants. Map Ta Phut Industrial Estate in Thailand is the location of the largest steel, oil refinery, and petrochemical factory complexes in Southeast Asia. Air pollution is an important source of oxidative stress and reactive oxygen species, which interact with DNA and lipids, leading to oxidative damage and lipid peroxidation, respectively.

OBJECTIVE

We measured the levels of malondialdehyde-deoxyguanosine (dG) adducts, a biomarker of oxidative stress and lipid peroxidation, in petrochemical workers, nearby residents, and subjects living in a control district without proximity to industrial sources.

DESIGN

We conducted a cross-sectional study to compare the prevalence of malondialdehyde-dG adducts in groups of subjects experiencing various degrees of air pollution.

RESULTS

The multivariate regression analysis shows that the adduct levels were associated with occupational and environmental exposures to air pollution. The highest adduct level was observed in the steel factory workers. In addition, the formation of DNA damage tended to be associated with tobacco smoking, but without reaching statistical significance. A nonsignificant increase in DNA adducts was observed after 4-6 years of employment among the petrochemical complexes.

CONCLUSIONS

Air pollution emitted from the Map Ta Phut Industrial Estate complexes was associated with increased adduct levels in petrochemical workers and nearby residents. Considering the mutagenic potential of DNA lesions in the carcinogenic process, we recommend measures aimed at reducing the levels of air pollution.

Biological markers of carcinogenic exposure in the aluminum smelter industry--a systematic review

Exposure monitoring programs have been used in the aluminum smelter industry for decades to decrease the risk of cancer from exposure to polycyclic aromatic hydrocarbons (PAHs). Biological monitoring of PAHs incorporates all routes of exposure. Measuring postshift urinary 1-hydroxypyrene (1OHP), a metabolite of pyrene, determines worker's daily PAH exposures, while measuring DNA adducts reflect chronic exposures to PAHs. We reviewed the scientific literature to identify changes over time in (1) 1OHP levels, (2) DNA adduct levels, and (3) other contributing factors associated with 1OHP and DNA adduct levels in the aluminum smelter industry. No trends were observed in 1OHP and DNA adduct levels. This could be due to variable selection of study populations and poorly identified job tasks that prevent comparison of jobs across plants and times, unassessed worker exposure variability, and the impact of cumulative exposures. Thus, it cannot be demonstrated that the use of biological monitoring to estimate PAH exposures has brought about an exposure reduction in the industry. Future studies should be aimed at follow-up in workplaces where dermal and inhalation exposure interventions have been employed. Inconsistent findings were also observed in the analysis of CYP1A1, GSTM1, and GSTP1 polymorphisms and their effect on biomarker levels.

3-Hydroxybenzo(a)pyrene as a biomarker of dermal exposure to benzo(a)pyrene

The aim of this study was to determine the percutaneous absorption flux of BaP (20 microg/cm(2) in ethanol) and the usefulness of urinary 3-OHBaP as a bio-indicator of dermal exposure to BaP. The percutaneous absorbed dose and absorption flux were estimated by comparison with intravenous administration of BaP (0.01 and 0.05 mg/kg in Cremophor) as reference way. A percutaneous absorption flux of 0.37 microg/cm(2)/h was determined by killing groups of rats, following exposure time of 4.5 and 24 h. [(14)C] skin content was 3.1 microg/cm(2), after 24 h exposure to BaP. Total urinary 3-OHBaP accounted for 0.4% of the real absorbed dose, which was fourfold higher than the percentage of an intravenous dose excreted as 3-OHBaP. This finding reveals that percutaneous absorption of BaP, based on the ratio of urinary excretion of 3-OHBaP following percutaneous exposure compared to percutaneous absorption following intravenous administration of BaP, is overestimated in the rat. In vitro, BaP was intensively metabolised by rat skin. Unchanged BaP and 3-OHBaP in receptor fluid accounted for 50 and 30% of the total radioactivity. This percutaneous first past effect of BaP in rats could, in part, explain the higher urinary excretion ratio of 3-OHBaP compared to the value based on intravenous administration of BaP. Conversely, BaP was largely lower metabolised as 3-OHBaP during percutaneous absorption by humans, so BaP absorption flux should be overestimated to a lesser extent in humans than in rats.

Association of aryl hydrocarbon receptor gene polymorphisms and urinary 1-hydroxypyrene in polycyclic aromatic hydrocarbon-exposed workers

Polycyclic aromatic hydrocarbons (PAH) in coke oven emissions could cause lung cancer in human. Individual's genotype of the metabolic enzymes and early biological changes were known to be associated with the susceptibility of cancer development. Knowledge of metabolic gene polymorphisms, which affect on the urinary 1-hydroxypyrene (1-OHP), could benefit us in understanding the interindividual difference in the mechanism of PAH-induced carcinogenesis. In this study, we investigated the association of aryl hydrocarbon receptor (AhR) gene polymorphisms and urinary 1-OHP. One hundred forty-seven workers exposed to PAH and 69 nonexposure workers were recruited. Seven tagging single nucleotide polymorphisms in AhR gene were selected by pariwise r(2) method and minor allele frequency cutoff of 0.05 from Chinese genotype data in HapMap project. These seven tagging single nucleotide polymorphisms were genotyped by PCR-based methods. Multivariate analysis of covariance revealed that the levels of 1-OHP in PAH-exposed workers carrying genotype CT were lower than workers carrying wild genotype TT at loci rs10250822 and rs2282885 of AhR gene (P = 0.032 and 0.044, respectively). In PAH-exposed workers, the urinary 1-OHP levels showed a linear correlation (P(trend) = 0.041) with the genotypes at locus rs2282885, especially in low and moderate exposure groups. In contrast, no significant association was found between urinary 1-OHP level and AhR genotypes among nonexposed workers. Our findings indicated that polymorphisms of AhR gene were associated with the level of 1-OHP among PAH-exposed workers, suggesting that AhR-mediated signaling might contribute to individual susceptibility to PAH exposure.

Role of biomarkers in monitoring exposures to chemicals: present position, future prospects

Biomarkers are becoming increasingly important in toxicology and human health. Many research groups are carrying out studies to develop biomarkers of exposure to chemicals and apply these for human monitoring. There is considerable interest in the use and application of biomarkers to identify the nature and amounts of chemical exposures in occupational and environmental situations. Major research goals are to develop and validate biomarkers that reflect specific exposures and permit the prediction of the risk of disease in individuals and groups. One important objective is to prevent human cancer. This review presents a commentary and consensus views about the major developments on biomarkers for monitoring human exposure to chemicals. A particular emphasis is on monitoring exposures to carcinogens. Significant developments in the areas of new and existing biomarkers, analytical methodologies, validation studies and field trials together with auditing and quality assessment of data are discussed. New developments in the relatively young field of toxicogenomics possibly leading to the identification of individual susceptibility to both cancer and non-cancer endpoints are also considered. The construction and development of reliable databases that integrate information from genomic and proteomic research programmes should offer a promising future for the application of these technologies in the prediction of risks and prevention of diseases related to chemical exposures. Currently adducts of chemicals with macromolecules are important and useful biomarkers especially for certain individual chemicals where there are incidences of occupational exposure. For monitoring exposure to genotoxic compounds protein adducts, such as those formed with haemoglobin, are considered effective biomarkers for determining individual exposure doses of reactive chemicals. For other organic chemicals, the excreted urinary metabolites can also give a useful and complementary indication of exposure for acute exposures. These methods have revealed 'backgrounds' in people not knowingly exposed to chemicals and the sources and significance of these need to be determined, particularly in the context of their contribution to background health risks.

1-Hydroxypyrene concentrations in first morning voids and 24-h composite urine: intra- and inter-individual comparisons

Urinary 1-hydroxypyrene (1-OHP) has been suggested as an exposure biomarker for polycyclic aromatic hydrocarbons (PAHs). However, it remains unknown whether a first morning urine sample can be used to reflect average exposure. In this paper, we examine intra-individual differences and inter-individual associations between first morning voids and 24-h composite urine samples. The analysis was performed using data collected from 100 adults who had a wide range of PAH exposure due to differences in their occupation, e.g., coke oven workers vs. non-coke oven workers. For each subject, all the urine voids within each of two 24-h measurement periods were collected. Results showed a significant (40% to 62%) intra-individual difference between first morning voids and 24-h urinary 1-OHP concentrations (in ng/ml urine). Creatinine adjustments of 1-OHP concentrations (in micromol/mol urinary creatinine) reduced the intra-individual difference by approximately 10%. Across all the subjects, a high overall correlation (r=0.76) was observed between first morning and 24-h average 1-OHP concentrations. Work environment and sampling season were found to significantly affect the relationship between first morning and 24-h 1-OHP concentrations. An increase of 1 ng/ml of first morning urinary 1-OHP predicted an increase of 0.5 and 0.25 ng/ml of 24-h urinary 1-OHP for coke oven workers and non-coke oven workers, respectively. Data collected in a winter season showed a higher correlation between first morning and 24-h concentrations than data collected in a fall season. Creatinine adjustments did not significantly improve overall correlations between first morning void and 24-h measurements, but increased total variances for 24-h urines explained by first morning urines in coke workers.

1-Hydroxypyrene in milk and urine as a bioindicator of polycyclic aromatic hydrocarbon exposure of ruminants

Urinary 1-hydroxypyrene (1-OH-pyrene) is now largely considered to be a valuable biomarker of exposure of man and animals to pyrene and other polycyclic aromatic hydrocarbons (PAHs). However, from a practical and agronomic standpoint, the question remains whether such biomarking capability still holds when 1-OH-pyrene is analyzed in milk produced by ruminants. To assess this hypothesis, four goats were daily submitted to three different amounts of pyrene oral ingestion, together with phenanthrene and benzo(a)pyrene (1, 7, and 49 mg/day during 1 week each). An HPLC-fluorometric analysis of 1-OH-pyrene in milk revealed a perfect correlation between pyrene doses and 1-OH-pyrene detected in milk, thus fully confirming the biomarking capability of 1-OH-pyrene and providing information on its transfer coefficient toward milk. Transfer equations such as the ones found in the present study could be used as a valuable and practical risk assessment tool in (i) the accurate monitoring of exposure of ruminants to pyrene and (ii) the evaluation of occupational and environmental exposure of ruminants to PAH mixtures.

DNA adduct formation among workers in a Thai industrial estate and nearby residents

The genotoxic effects of air pollutant exposures have been studied in people living and working in Map Ta Phut, Rayong province, Thailand, a site where is located the Map Ta Phut Industrial Estate (MIE) one of the largest steel, refinery and petrochemical complex in the South-Eastern Asia. This was done by the conduction of a transversal study aimed to compare the prevalence of bulky DNA adducts in groups of subjects experiencing various degree of air pollution. DNA adduct analysis was performed in the leukocytes of 201 volunteers by the (32)P-postlabelling assay: 79 were workers in the MIE complex, including 24 refinery workers, 40 steel workers and 15 tinplate workers, 72 were people residing downwind in the MIE area and 50 were residents in a control district of the same Rayong province but without industrial exposures. The groups of workers were analyzed separately to evaluate if DNA adduct formation differs by the type of industry. The levels of bulky DNA adducts were 1.17+/-0.17 (SE) adducts/10(8) nucleotides in refinery workers, 1.19+/-0.19 (SE) in steel workers, 0.87+/-0.17 (SE) in tinplate workers, 0.85+/-0.07 (SE) in MIE residents and 0.53+/-0.05 (SE) in district controls. No effects of smoking habits on DNA adducts was found. The multivariate regression analysis shows that the levels of DNA adducts were significantly increased among the individuals living near the MIE industrial complex in respect to those resident in a control district (p<0.05). In the groups of occupationally exposed workers, the highest levels of DNA adducts were found among the workers experiencing an occupational exposure to polycyclic aromatic hydrocarbons, e.g. the steel factory and refinery workers. When we have evaluated if the levels of DNA adducts of the PAH exposed workers were different from those of the MIE residents, a statistical significantly difference was found (p<0.05). Our present study indicates that people living near point sources of industrial air pollution can experiment an excess of DNA adduct formation. The emissions from the MIE complex are the main source of air pollution in this area and can be the cause of such increment in the levels of DNA damage.

Associations Between Exposure to Polycyclic Aromatic Hydrocarbons and Temporal Change of Urinary 1-Hydroxypyrene Levels in Taiwanese Coke-Oven Workers

OBJECTIVES

Our aim is to analyze the association between polycyclic aromatic hydrocarbon (PAH) exposure and the temporal change of urinary 1-hydroxypyrene (1-OHP).

METHODS

Two personal air samples, eight spot urine samples, and questionnaires were used to collect PAH exposure, urinary 1-OHP, demographic data, and environmental pollutants.

RESULTS

Topside-oven workers had significantly higher levels of PAH exposure and 1-OHP than side-oven workers. Urinary 1-OHP was a biomarker for PAH exposure. In topside-oven workers, the trend of 1-OHP increased sharply and reached the top in the sixth day after work and declined dramatically on days off. In side-oven workers, such a trend was not found, and those who smoked showed a slight increase in urinary 1-OHP levels on days off.

CONCLUSIONS

We suggest that the pattern of temporal change of urinary 1-OHP levels is different between topside-oven and side-oven workers.

Multipathway polycyclic aromatic hydrocarbon and pyrene exposure among children living in Campania (Italy)

Multipathway exposure to polycyclic aromatic hydrocarbons (PAHs) and Pyrene (Py) was studied among children ages 7-9 living in two areas of the Campania Region (South-Italy) classified as urban and rural. During five consecutive days PAHs and Py were detected in air samples from outdoors, indoors (school and home), individuals at inhalatory levels, and in food and beverages (defined as food) consumed daily by each child. 1-hydroxypyrene (1-OHP) was detected in children's urine. Gender, weight and height of each subject were recorded, and the personal Body Mass Index (BMI) calculated. The type of home heating, the presence of smokers and the number of cigarettes smoked at home was determined. Total PAH and Py median concentrations in outdoor air from urban areas were 1.70 ng m(-3) and 0.19 ng m(-3), respectively while in rural areas they were 1.10 ng m(-3) and 0.14 ng m(-3). Indoor air total PAH and Py median concentrations were 2.50 ng m(-3) and 0.15 ng m(-3), respectively for urban areas, and 4.10 ng m(-3) and 0.15 ng m(-3) for rural areas. In food the total PAH and Py median levels were 10.44 and 0.81 microg kg(-1) in urban areas and 18.90 and 0.90 microg kg(-1) in rural areas. The median urinary levels of 1-OHP for urban and rural children were 0.07 and 0.06 micromol/mol creat., respectively. From these data, food appears to be the most relevant source of exposure to PAHs and Py. The Py intake from single (food or air) or total (food and air) pathways did not significantly correlate with the urinary 1-OHP excreted daily for each child during all 5 days of observation.

Sperm DNA damage correlates with polycyclic aromatic hydrocarbons biomarker in coke-oven workers

OBJECTIVES

The aim was to determine whether occupational exposure to polycyclic aromatic hydrocarbons (PAHs) in men has adverse effect on semen quality.

METHODS

Forty-eight coke-oven workers, including 16 topside-oven (TO) workers and 32 sideoven (SO) workers, were studied. Ambient PAHs exposure, urinary 1-hydroxypyrene (1-OHP) levels, and parameters of semen quality were determined.

RESULTS

TO workers had significantly higher ambient PAHs exposure (3,436.1+/-3,411.0 vs. 1,123.1+/-1,829.3 ng/m3, P < 0.01), urinary 1-OHP levels (207.8+/-176.4 vs. 54.0+/-44.8 microg/g, P < 0.001), frequency of oligospermia (18.8 vs. 0%, P < 0.05), and morphological abnormality in sperm (32.3 vs. 14.6%, P < 0.01) than SO workers. Among cigarette smokers, TO workers had significantly higher rates of DNA denaturation in spermatozoa (alphaT) and percentage of sperm with increased DNA denaturation (COMP alphaT) levels than SO workers (246.2+/-49.5 vs. 198.1+/-30.3 for alphaT; 34.8+/-14.4 vs. 19.3+/-13.9% for COMP alphaT, P < 0.05). There was a positive correlation between urinary 1-OHP and alphaT, COMP alphaT, and abnormal sperm morphology and a tenfold increase in urinary 1-OHP associated with a 2.35-fold increase in alphaT, as well as a 1.07-fold increase in percentage of sperm with abnormal morphology.

CONCLUSIONS

A potential risk of sperm dysfunction should be considered for workers occupationally exposed to high levels of PAHs. Cigarette smoking may aggravate this risk. Urinary 1-OHP can be used as a biomarker predicting sperm dysfunction.

Urinary metal and polycyclic aromatic hydrocarbon biomarkers in boilermakers exposed to metal fume and residual oil fly ash

BACKGROUND

Boilermakers are occupationally exposed to known carcinogens.

METHODS

The association of urinary 1-hydroxy-pyrene (1-OHP), a biomarker of polycyclic aromatic hydrocarbon (PAH) exposure, with biomarkers of metal exposure (vanadium, chromium, manganese, nickel, copper, and lead) in boilermakers exposed to metal fume from welding and dust particulates from residual oil fly ash (ROFA) was examined. A repeated measures cohort study was conducted during the overhaul of an oil-fired boiler. Twice-daily urine samples were obtained for 5 days and analyzed for cotinine, 1-OHP, and metals. Generalized estimating equations (GEE) were used to model the multivariate relationship of 1-OHP to the explanatory variables.

RESULTS

Metal and 1-OHP levels were determined for 165 urine samples from 20 boilermakers and these levels increased during the workweek. However, the 1-OHP level was not significantly associated with any individual metal level at any time point.

CONCLUSION

This suggests that boilermakers were occupationally exposed to PAH and metals, but 1-OHP as a PAH biomarker was unable to serve as a surrogate marker of metal exposure for the metals measured in this study.

Biological monitoring of exposure: trends and key developments

The concept of biological monitoring (BM) has gained the special interest of individual scientists and international organizations. Today, when analytical problems have almost ceased due to new laboratory techniques and quality assurance systems, the methods for interpretation of results have become the most important issue. There are important discrepancies regarding the role of biological monitoring of occupational exposure between Europe and the United States. BM has been an important tool of medical health surveillance in the European countries. In the United States it belongs rather to the field of occupational hygiene. It seems that both the approaches can be accepted. More attention should be paid to the development of the truly health-based biomarkers of exposure based on the dose-effect and dose-response relationships. New areas of application of BM of occupational exposure include determination of DNA and protein adducts, unchanged volatile organic compounds in urine, monitoring of exposure to pesticides, antineoplastic drugs, hard metals, and polycyclic aromatic hydrocarbons. In the general environment BM is the most valuable tool for acquiring knowledge of current levels of internal exposure to xenobiotics, identifying the hot spots and developments in trends of exposure. BM can provide policy makers with more accurate information on the control measures undertaken. At present, the main areas include heavy metals, persistent organic pollutants and pesticides. BM of chemical exposure has become increasingly important in the assessment of the health risk in occupational and environmental medicine. Therefore it would be worthwhile to include BM in the curricula for the training of occupational hygienists.

Comparison of 1-hydroxypyrene exposure in the US population with that in occupational exposure studies

Urine samples collected in 1999 and 2000 as part of the National Health and Nutrition Examination Survey (NHANES) were analyzed for 14 monohydroxy polycyclic aromatic hydrocarbons (PAHs), and, for the first time, reference range values were calculated for these metabolites in the US population. Pyrene is a major component of most PAH mixtures and often is used as a surrogate for total PAH exposure. We detected 1-hydroxypyrene (1-OHpyrene), a metabolite of pyrene, in more than 99% of the samples. The overall geometric mean concentration for 1-OHpyrene in the USA was 79.8 ng/l, with a 95% confidence interval (CI) of 69.0-92.2 ng/l. The overall geometric mean creatinine-adjusted urinary 1-OHpyrene levels in the USA was 74.2 ng/g creatinine (0.039 micromol/mol), with a 95% CI of 64.1-85.9 ng/g creatinine (0.034-0.046 micromol/mol). There were no statistically significant differences among age, gender, or race/ethnicity groups. Adult smokers in the USA have urinary 1-OHpyrene levels three times higher than those of non-smokers. This difference was statistically significant. In this paper, we compare the reference range of urinary 1-OHpyrene levels with levels reported from various occupations by other researchers.

Lack of modulating influence of GSTM1 and GSTT1 polymorphisms on urinary biomonitoring markers in coke-oven workers

BACKGROUND

Coke-oven workers (COWs) are occupationally exposed to high concentrations of polycyclic aromatic hydrocarbons (PAHs). Urinary 8-hydroxy-2-deoxyguanosine (8-OH-dG) and 1-hydroxypyrene (1-OHP) are biological markers of oxidative DNA damage and PAHs metabolism, respectively. In this study, we investigated whether polymorphisms of glutathione S-transferase (GSTM1 and GSTT1) can modulate the relationship between urinary 8-OH-dG and 1-OHP concentrations among the COWs.

METHODS

This was a cross-sectional study. Between February and November of 2001, 53 topside-oven and 130 side-oven workers with the presence of GSTM1 and GSTT1 genotypes were investigated.

RESULTS

Urinary 1-OHP and 8-OH-dG concentrations (mean +/- SD) in the topside-oven workers with the presence of GSTM1 were 107.2 +/- 107.9 and 15.3 +/- 9.7 ng/ml, respectively, which were not significantly different from those in the absence of GSTM1 (84.1 +/- 104.5 and 12.8 +/- 14.1 ng/ml). The similar insignificant results were also noted in the sideoven workers. For GSTT1 polymorphism, the results remained insignificant. In contrast, individual excretion of urinary 8-OH-dG and 1-OHP concentrations were still highly correlated (Spearman correlation coefficients: r = 0.43, P < 0.0001, n = 183).

CONCLUSIONS

GST may not play a role in the regulation of metabolism of urinary biological markers in COWs.

Naphthalene and its biomarkers as measures of occupational exposure to polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAH) include compounds with two or more fused benzene rings, many of which are carcinogens. Industrial sources produce hundreds of PAH, notably in the coke- and aluminium-producing industries. Because PAH are distributed at varying levels between gaseous and particulate phases, exposure assessment has been problematic. Here, we recommend that occupational exposures to naphthalene be considered as a potential surrogate for occupational PAH exposure for three reasons. Naphthalene is usually the most abundant PAH in a given workplace; naphthalene is present almost entirely in the gaseous phase and is, therefore, easily measured; and naphthalene offers several useful biomarkers, including the urinary metabolites 1- and 2-hydroxynaphthalene. These biomarkers can be used to evaluate total-body exposure to PAH, in much the same way that 1-hydroxypyrene has been applied. Using data from published sources, we show that log-transformed airborne levels of naphthalene are highly correlated with those of total PAH (minus naphthalene) in several industries (creosote impregnation: Pearson r= 0.815, coke production: r= 0.917, iron foundry: r= 0.854, aluminium production: r= 0.933). Furthermore, the slopes of the log-log regressions are close to one indicating that naphthalene levels are proportional to those of total PAH in those industries. We also demonstrate that log-transformed urinary levels of the hydroxynaphthalenes are highly correlated with those of 1-hydroxypyrene among coke oven workers and controls (r= 0.857 and 0.876), again with slopes of log-log regressions close to one. These results support the conjecture that naphthalene is a useful metric for occupational PAH exposure. Since naphthalene has also been shown to be a respiratory carcinogen in several animal studies, it is also argued that naphthalene exposures should be monitored per se in industries with high levels of PAH.

Urinary excretion of 8-hydroxy-2-deoxyguanosine and 1-hydroxypyrene in coke-oven workers

Coke-oven workers (COWs) are occupationally exposed to high concentrations of polycyclic aromatic hydrocarbons (PAH). Urinary 8-hydroxy-2-deoxyguanosine (8-OH-dG) and 1-hydroxypyrene (1-OHP) are biological markers of oxidative DNA damage and PAH metabolism, respectively. We investigated the relationship between urinary 8-OH-dG and 1-OHP in 217 Taiwanese COWs, 55 topside-oven, and 162 sideoven workers. For topside-oven workers, mean 8-OH-dG and 1-OHP concentrations (ng/ml +/- SD) were 13.8 +/- 12.0 and 93.5 +/- 104.4, respectively. These levels were significantly higher than those for sideoven workers: 10.2 +/- 7.9 ng/ml (P = 0.04) and 19.8 +/- 28.6 ng/ml (P < 0.001), respectively. Individual urinary 8-OH-dG concentrations were directly correlated with urinary 1-OHP concentrations: the higher the 1-OHP level, the higher the 8-OH-dG level (Spearman correlation coefficients: r = 0.43, P < 0.0001, n = 217). Multiple regression analysis indicated that a 10-fold increase in 1-OHP was associated with a 1.91-fold increase in 8-OH-dG. Compared to no vitamin intake, intake of at least one multiple vitamin pill per week reduced 8-OH-dG excretion (P = 0.02). Our findings suggest that urinary 1-OHP and 8-OH-dG reflect occupational PAH exposure and oxidative DNA damage in COWs. In addition, multiple vitamins may reduce oxidative stress caused by PAH exposure.

1-hydroxypyrene as a biomarker of occupational exposure to polycyclic aromatic hydrocarbons (PAH) in boilermakers

A repeated measures short-term prospective study was performed in boilermakers to determine occupational polycyclic aromatic hydrocarbon (PAH) exposure using the biomarker, 1-hydroxypyrene (1-OHP). Two work sites were studied; an apprentice school (metal fume exposure) and a boiler overhaul (residual oil fly ash [ROFA] and metal fume exposure). Pre- and postshift urine samples (n = 241; 41 male subjects) were analyzed for cotinine and 1-OHP. Descriptive statistics and generalized estimating equations were calculated. At the apprentice school cross-shift 1-OHP levels did not significantly differ. At the overhaul 1-OHP levels increased during the week in smokers and nonsmokers; in nonsmokers the 1-OHP level increased significantly postshift compared to preshift. In conclusion this study suggests that boilermakers exposed to occupational particulates are exposed to PAH. The urinary 1-OHP level may be a useful biomarker of PAH exposure in boilermakers exposed to ROFA, particularly in nonsmokers.