Effect of Urban Traffic, Individual Habits, and Genetic Polymorphisms on Background Urinary 1-Hydroxypyrene Excretion

Stomatal Response of Maize (Zea mays L.) to Crude Oil Contamination in Soils

In this study, maize plant was cultured in soil contaminated with different levels of crude oil. The purpose was to investigate the change of soil properties, leaf physiological and chemical parameters, and phenanthrene content in the leaf. Results showed that soil water content significantly increased when the levels of total petroleum hydrocarbons were 3700–17,800 mg/kg in soil, and soil electrical conductivity significantly increased compared with the control. In maize leaf, stomatal length and density, as well as K and Na contents decreased in contaminated treatments compared with the control. Stomatal length has a significant positive correlation with K content in leaf (r = 0.92, p < 0.01), while stomatal density was negatively correlated to the crude oil level in soil (r = −0.91, p < 0.05). Accumulation of phenanthrene in maize leaf was mainly through the foliar uptake pathway. Phenanthrene concentrations of maize leaf in oil-treated soil were less than that of the control, which exhibited a significant positive relationship with stomatal length (r = 0.98, p < 0.01). This study demonstrated that the stomata structure of maize could be influenced by crude oil and thus possibly controlling the accumulation of polycyclic aromatic hydrocarbons in aerial tissues. Based on these results, controlling stomata movement will be beneficial to phytoremediation of contaminated soil.

Association of active/passive smoking and urinary 1-hydroxypyrene with poor sleep quality: A cross-sectional survey among Chinese male enterprise workers

INTRODUCTION

Tobacco use has been implicated as an important factor for poor sleep quality. However, in most studies, the sleep quality of smokers was only assessed though a self-reported questionnaire, without measuring any internal biomarkers that reflect the levels of tobacco exposure. We examined the association of active and passive smoking with sleep quality, assessed smoking exposure using urinary 1-hydroxypyrene (1-HOP) as an internal biomarker, and further explored the relationship between 1-HOP and sleep quality.

METHODS

A cross-sectional survey was conducted in Liuzhou city, Guangxi, China. A total of 1787 male enterprise workers were enrolled. The smoking attribute data were collected by self-reported questionnaire, and individual sleep quality was evaluated through the Pittsburgh Sleep Quality Index (PSQI). The concentration of urinary 1-HOP was measured by high-performance liquid chromatography.

RESULTS

Compared with non-smoking, active smoking and passive smoking were significantly associated with long sleep latency (odds ratio, OR=1.84, 95% confidence interval, CI=1.28–2.64; 1.45, 1.00–2.11, respectively), short sleep duration (OR=2.72, 95% CI=1.45–5.09; 1.94, 1.01–3.71, respectively), daytime dysfunction (OR=1.54, 95% CI=1.10–2.17; 1.44, 1.02–2.03, respectively), and overall poor sleep quality with PSQI total score >5 (OR=1.41, 95% CI=1.05–1.88; 1.34, 1.00–1.79, respectively). Compared with non-smokers, active smokers had higher urinary 1-OHP concentrations that were significant (p=0.004), while passive smokers had no significant difference in urinary 1-OHP concentration (p=0.344). The high concentration group was significantly associated with daytime dysfunction and overall poor sleep quality with PSQI total score >5 (OR = 1.73, 95% CI=1.06–2.81; 1.76, 1.18–2.63, respectively).

CONCLUSIONS

Both active smoking and passive smoking are risk factors for poor sleep quality among Chinese male enterprise workers. Active smokers had significantly higher levels of urinary 1-OHP than non-smokers, and high concentration of 1-OHP was associated with daytime dysfunction and overall poor sleep quality.

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.

Variations of emission characterization of PAHs emitted from different utility boilers of coal-fired power plants and risk assessment related to atmospheric PAHs

Coal-fired power plants (CFPPs) represent important source of atmospheric PAHs, however, their emission characterization are still largely unknown. In this work, the concentration, distribution and gas-particle partitioning of PM10- and gas-phase PAHs in flue gas emitted from different coal-fired utility boilers were investigated. Moreover, concentration and distribution in airborne PAHs from different functional areas of power plants were studied. People's inhalatory and dermal exposures to airborne PAHs at these sites were estimated and their resultant lung cancer and skin cancer risks were assessed. Results indicated that the boiler capacity and operation conditions have significant effect on PAH concentrations in both PM10 and gas phases due to the variation of combustion efficiency, whereas they take neglected effect on PAH distributions. The wet flue gas desulphurization (WFGD) takes significant effect on the scavenging of PAH in both PM10 and gas phases, higher scavenging efficiency were found for less volatile PAHs. PAH partitioning is dominated by absorption into organic matter and accompanied by adsorption onto PM10 surface. In addition, different partitioning mechanism is observed for individual PAHs, which is assumed arising from their chemical affinity and vapor pressure. Risk assessment indicates that both inhalation and dermal contact greatly contribute to the cancer risk for CFPP workers and nearby residents. People working in workshop are exposed to greater inhalation and dermal exposure risk than people living in nearby vicinity and working office.

Effect of surfactant amendment to PAHs-contaminated soil for phytoremediation by maize (Zea mays L.)

Understanding the uptake of organic pollutants by plants is an important part of the assessment of risks from crops grown on contaminated soils. This study was an investigation of the effects of surfactants added to PAHs-contaminated soil on the uptake and accumulation of PAHs in maize tissues during phytoremediation. The accumulation of phenanthrene (PHE) and pyrene (PYR) by maize plant was not influenced significantly by the surfactant amendment to the soil. The distribution of PHE and PYR in maize tissues was not positively correlated with the corresponding lipid contents. Remarkably, the concentrations of PHE (20.9 ng g(-1)) and PYR (0.9 ng g(-1)) in maize grain were similar to or even much lower than those in some foods. Moreover, surfactants could enhance the removal of pollutants from contaminated soil during phytoremediation, which might be due to surfactant desorption ability and microbial activity in soil. The study suggests that use of maize plant with surfactant is an alternative technology for remediation of PAHs-contaminated soils.

Assessing traffic and polycyclic aromatic hydrocarbon exposure in Montreal, Canada

INTRODUCTION

The 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.

METHODS

A cross-sectional study was conducted in Montreal with 200 volunteers (107 females and 93 males) ages 20 to 53 years. 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 48 h prior to urine collection.

RESULTS

Detection 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 48 h and the two PAH biomarkers. Biomarker levels were related to smoking more than one pack of cigarettes in the previous 48 h, 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).

CONCLUSIONS

Both 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.

Dietary and inhalation exposure to polycyclic aromatic hydrocarbons and urinary excretion of monohydroxy metabolites--a controlled case study in Beijing, China

Daily dietary and inhalation exposures to 16 parent polycyclic aromatic hydrocarbons (PAHs) and urinary excretion of 13 monohydroxy metabolites (OHPAHs) were monitored for 12 non-smoking university students in Beijing, China, during a controlled feeding experiment. The relationship between the urinary excretion of OHPAHs and the uptake of PAHs was investigated. The results suggest severe exposure of the subjects to PAHs via both dietary and inhalation pathways. Large increase of most urinary OHPAHs occurred after the ingestion of lamb kabob. Higher concentrations of OHPAHs were observed for female subjects, with the intakes of parent PAHs lower than those by males, likely due to the gender differences in metabolism. It appears that besides 1-PYR, metabolites of PHE could also be used as biomarkers to indicate the short-term dietary exposure to PAHs and urinary 3-BaA may serve as the biomarker for inhalation intake of high molecular weight PAHs.

Exposure chambers for studying the partitioning of atmospheric PAHs in environmental compartments: validation and calibration using experimental and computational approaches

The environmental partitioning of atmospheric polycyclic aromatic hydrocarbons (PAHs) conditions their entry into food chains and subsequent risks for human health. The need for new experimental exposure devices for elucidating the mechanisms governing ecosystemic PAH transfer motivated the elaboration of an original small-scale exposure chamber (EC). A dual approach pairing experimentation and computational fluid dynamics (CFD) was selected to provide comprehensive validation of this EC as a tool to study the transfer and biological effects of atmospheric PAH pollution in microsystems. Soil samples and passive air samplers (PASs) were exposed to atmospheric pollution by phenanthrene (PHE), a gaseous PAH, for 2 weeks in examples of the EC being tested, set up under different conditions. Dynamic concentrations of atmospheric PHE and its uptake by PASs were simulated with CFD, results showing homogeneous distribution and constant atmospheric PHE concentrations inside the ECs. This work provides insight into the setting of given concentrations and pollution levels when using such ECs. The combination of experimentation and CFD is a successful ECs calibration method that should be developed with other semivolatile organic pollutants, including those that tend to partition in the aerosol phase.

Challenges in tracing the fate and effects of atmospheric polycyclic aromatic hydrocarbon deposition in vascular plants

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that raise environmental concerns because of their toxicity. Their accumulation in vascular plants conditions harmful consequences to human health because of their position in the food chain. Consequently, understanding how atmospheric PAHs are taken up in plant tissues is crucial for risk assessment. In this review we synthesize current knowledge about PAH atmospheric deposition, accumulation in both gymnosperms and angiosperms, mechanisms of transfer, and ecological and physiological effects. PAHs emitted in the atmosphere partition between gas and particulate phases and undergo atmospheric deposition on shoots and soil. Most PAH concentration data from vascular plant leaves suggest that contamination occurs by both direct (air-leaf) and indirect (air-soil-root) pathways. Experimental studies demonstrate that PAHs affect plant growth, interfering with plant carbon allocation and root symbioses. Photosynthesis remains the most studied physiological process affected by PAHs. Among scientific challenges, identifying specific physiological transfer mechanisms and improving the understanding of plant-symbiont interactions in relation to PAH pollution remain pivotal for both fundamental and applied environmental sciences.

The influence of metabolic gene polymorphisms on urinary 1-hydroxypyrene concentration in Thai bus drivers

Polycyclic aromatic hydrocarbons (PAHs) are associated with an increased cancer risk. CYP1A1 and GSTs enzymes are important in metabolism of PAHs. Genetic polymorphisms of these enzymes are responsible for enzyme activity and concentration variation. The objectives of this study were to evaluate association of 1-OHP concentration with genetic polymorphisms of CYP1A1 and GSTs in Thai bus drivers. The results showed that 1-OHP levels in bus drivers were significantly higher than that in the control group. Significant difference in 1-OHP was found between smokers and non-smokers, in only bus drivers. Significantly increasing of 1-OHP levels were observed in bus drivers with CYP1A1 MspI and exon 7 variants. Whereas, bus drivers with GSTP1 Val and GSTM1 null genotypes showed decreasing in excretion of 1-OHP. No association between 1-OHP and polymorphisms of GSTT1 was found. This study indicated that 1-OHP concentrations were associated with exposure to air pollution, cigarette smoking and polymorphisms of CYP1A1, GSTM1 and GSTP1 genes.

Effects of benzo[a]pyrene on autonomic nervous system of coke oven workers

Objectives are to investigate the effects of benzo[a]pyrene (B[a]P) on the autonomic nervous system of coke oven workers. One hundred eighty-four coke oven workers were divided into 3 groups according to their working sites (coke oven bottom group, coke oven side group and coke oven top group), and 93 referents were recruited. B[a]P monitored by air sampling pumps as well as urinary 1-hydroxypyrene (1-OH-Py) was determined by high performance liquid chromatograph with a fluorescence detector (HPLC-FD). The autonomic nervous system (ANS) function was determined by 4 tests: Valsalva Manoeuvre heart rate variation (HR-V), variation of heart rate when breathing deeply (HR-DB), variation of heart rate when instantly standing up (HR-IS, including RR30:15 and RRmax:min) and variation of blood pressure when instantly standing up (BP-IS). The B[a]P mean concentrations in coke oven bottom, coke oven side and coke oven top were 19, 185 and 1,623 ng/m(3), respectively. The levels of urinary 1-OH-Py were markedly higher in the 3 exposed groups than that in the referent group (p<0.01). No significant difference was found in each group between smokers and non-smokers (p>0.05). Compared with referents, HR-V decreased significantly in coke oven workers (p<0.01), representing modulation of parasympathetic nervous function. However, no statistical differences were found in HR-DB, RR30:15, RRmax:min and BP-IS between the exposed groups and the control group (p>0.05). HR-V decreased with the increment of 1-OH-Py (p<0.05), and results of multiple linear stepwise regression demonstrated that external exposure level and duration of education entered the HR-V model; age was a significant factor of HR-DB and RRmax:min, but no variable was involved in RR30:15 and BP-IS regression. Benzo[a]pyrene affects the autonomic nervous function of coke oven workers mainly by down-regulating the parasympathetic nervous function.

Carcinogen DNA adducts and the risk of colon cancer: case-control study

Colorectal cancer represents 8.5% of all tumours at the King Faisal Specialist Hospital & Research Centre. Environmental and dietary carcinogens such as polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) have long been suspected to play a prominent role in colon cancer aetiology. We designed a case-control study to test the hypothesis of whether or not the presence of DNA adducts can play a role in the aetiology of colon cancer. DNA adducts were measured in 24 cancerous and 20 non-cancerous tissue samples of newly diagnosed colon cancer patients by (32)P-post-labelling technique. Normal tissue from 19 hospital patients served as controls. The mean levels of adducts per 10(10) nucleotides in cancerous and non-cancerous tissue were 151.75+/-217.27 and 114.81+/-186.10, respectively; however, only adducts in cancerous tissue were significantly higher than controls (32.78+/-57.51 per 10(10) nucleotides) with p-values of 0.017. No BPDE-DNA adducts were found. No relationship was found between urinary cotinine as a marker of tobacco smoke and 1-hydroxypyrene as an indicator of an individual's internal dose of PAHs and DNA adducts. In a logistic regression model, only adducts in cancerous tissue were associated with the subsequent risk of colon cancer, with an odds ratio of 3.587 (95% confidence interval 0.833-15.448) after adjustment for age and the duration of living in the current region, but of a borderline significance (p=0.086). Although it is difficult to arrive at a definite conclusion from a small dataset, our preliminary results suggest the potential role of DNA adducts in the colon carcinogenesis process. Additional studies with larger sample sizes are needed to confirm our preliminary finding. It is also important to identify the structural characterization of these unknown DNA adducts in order to have a better understanding of whether or not environmental carcinogens play a role in the aetiology of colon cancer.

Urinary 1‐Hydroxypyrene Level Relative to Vehicle Exhaust Exposure Mediated by Metabolic Enzyme Polymorphisms

Polycyclic aromatic hydrocarbons (PAH) are common air pollutants generated from incomplete combustion. The inhalation of exhaust fumes in urban areas has been suggested to be an additional contributing factor. This study investigated the influence of urban traffic exposure, personal lifestyle factors and metabolic enzyme polymorphisms on the urinary 1-hydroxypyrene (1-OHP) level, approximating exposure to PAH. With consents, 95 male taxi drivers exposed to vehicle exhaust in traffic and 75 male office employees received health interviews and provided urine samples. The results showed taxi drivers had higher urinary 1-OHP than the office employees (mean +/- standard deviation were 0.17 +/- 0.10 vs. 0.10 +/- 0.07 mol/mol creatinine, p<0.001). The average urinary 1-OHP level increased from 0.07 micromol/mol creatinine for non-smoking office employees to 0.17 micromol/mol creatinine for those who smoked more than 20 cigarettes daily. The values for taxi drivers with similar smoking statuses were 0.12 and 0.25 micromol/mol creatinine, respectively. Among non-smokers, taxi drivers still had higher 1-OHP level than office employees (0.12 +/- 0.05 vs. 0.07 +/- 0.03 micromol/mol creatinine). The subjects with the m1/m2 or m2/m2 genotype of CYP1A1 MspI or GSTM1 deficiency had significantly higher urinary 1-OHP levels than those with other CYP1A1 MspI and GSTM1 genotypes. Multivariate logistic regression analysis showed that taxi drivers (adjusted odds ratio (OR)=5.1, 95% confidence interval (CI)=1.1-13.6), smokers (OR=5.5, 95% CI=1.6-18.4) and subjects with the m1/m2 or m2/m2 genotype of CYP1A1 MspI (OR=9.7, 95% CI=2.7-35.0) had elevated urinary 1-OHP (greater than the overall median value, 0.11 micromol/mol creatinine). The results of this study suggest smoking contributes to the elevated urinary 1-OHP levels in taxi drivers in addition to taxi driving, and the excess level contributed from traffic exhaust and smoke was regulated by the CYP1A1 MspI genotype. Traffic exhaust exposure, smoking and CYP1A1 MspI genotype contributed to the variation in levels of urinary 1-OHP excretion.