PAH Exposure Research Articles

Predictors of environmental exposure to polycyclic aromatic hydrocarbons among pregnant women — Prospective cohort study in Poland

The aim of the study was to characterize the PAH exposure level based on 1-hydroxypyrene (1-HP) in urine of Polish pregnant women and to assess the relationship between PAH and factors such as smoking, environmental tobacco smoke exposure, place of residence, heating and cooking method. The study population included in this analysis consisted of 449 pregnant women who had been the subjects of the prospective Polish Mother and Child Cohort study performed in 8 regions of Poland. The women were interviewed three times during pregnancy (once in each trimester). 1-HP concentration in urine was chosen as the biomarker of exposure to PAH. The urine sample was analysed using high performance liquid chromatography (HPLC). The active and passive smoking exposure was verified by saliva cotinine, analysed by high performance liquid chromatography coupled with tandem mass spectrometry (LC-MSMS) and isotope dilution method. 1-HP concentration in urine ranged from 0.02 to 10.2 μg/g creatinine with the geometric mean (GM) 0.4 μg/g creatinine. The significantly higher concentration of urinary 1-HP in pregnant women was observed for summer collection (GM ratio: 1.1; p = 0.01), among smokers (GM ratio: 1.7; p < 0.001) and for the women living in big cities (GM ratio: 1.3; p = 0.001). The significantly higher concentration of urinary 1-HP in pregnant women was observed for summer collection, among smokers and those living in big cities.

Biomarkers of oxidative stress and its association with the urinary reducing capacity in bus maintenance workers

BackgroundExposure to particles (PM) induces adverse health effects (cancer, cardiovascular and pulmonary diseases). A key-role in these adverse effects seems to be played by oxidative stress, which is an excess of reactive oxygen species relative to the amount of reducing species (including antioxidants), the first line of defense against reactive oxygen species. The aim of this study was to document the oxidative stress caused by exposure to respirable particles in vivo, and to test whether exposed workers presented changes in their urinary levels for reducing species.MethodsBus depot workers (n = 32) exposed to particles and pollutants (respirable PM4, organic and elemental carbon, particulate metal content, polycyclic aromatic hydrocarbons, NOx, O3) were surveyed over two consecutive days. We collected urine samples before and after each shift, and quantified an oxidative stress biomarker (8-hydroxy-2'-deoxyguanosine), the reducing capacity and a biomarker of PAH exposure (1-hydroxypyrene). We used a linear mixed model to test for associations between the oxidative stress status of the workers and their particle exposure as well as with their urinary level of reducing species.ResultsWorkers were exposed to low levels of respirable PM4 (range 25-71 μg/m3). However, urinary levels of 8-hydroxy-2'-deoxyguanosine increased significantly within each shift and between both days for non-smokers. The between-day increase was significantly correlated (p < 0.001) with the concentrations of organic carbon, NOx, and the particulate copper content. The within-shift increase in 8OHdG was highly correlated to an increase of the urinary reducing capacity (Spearman ρ = 0.59, p < 0.0001).ConclusionsThese findings confirm that exposure to components associated to respirable particulate matter causes a systemic oxidative stress, as measured with the urinary 8OHdG. The strong association observed between urinary 8OHdG with the reducing capacity is suggestive of protective or other mechanisms, including circadian effects. Additional investigations should be performed to understand these observations.

Abstract B32: Levels of metabolites of naphthalene in urine predict translocations in peripheral blood lymphocytes in children

Abstract Chromosomal aberrations (CAs) and translocations (TRNS) (subtype of CAs) are a validated biomarker of increased cancer risk in adults. Prenatal exposure to semi-volatile air PAH predicts levels of stable CAs in neonatal (cord) blood. Urinary levels of 1 and 2 naphthol, metabolites of naphthalene, an IARC class2b possible carcinogen, appear elevated in the CCCEH birth cohort. We hypothesize that concurrent exposure to naphthalene is associated with development of CAs and TRNS in children. Whole blood from 113 five year old children (68 girls) participating in the CCCEH birth cohort composed of Dominican (DomAm) (N=66) and African-Americans (AfrAm) (N=47) was processed fresh for Whole Chromosome Paint (WCP)-Fluorescent In Situ Hybridization using WCP for chromosomes 1-6. 400 Cell Equivalents [CE]) were scored for each child. TRNS were scored in accordance with the PAINT convention and frequencies were expressed per 100 CE. Levels of PAH metabolites were measured using MSGC in spot urine samples (Sjodin laboratory, CDC) collected concurrently and adjusted for urine specific gravity (SG). We examined predictors of presence of CA's or TRNS. For predicting frequency of CA and TRNS, mean ratios were derived for doubling of naphthol levels using negative binomial models. Results: 35 children had CA's and 20 had TRNS. Geometric means among AfrAm were 3490.2 for 1naphthol, and 3005.1 for 2naphthol, and 3336.4 and 5256.6 for 1 &amp; 2naphthol in DomAm children. Levels of 1&amp; 2 napthol did not vary with presence of a smoker in the child's home. 2naphthol (but not 1napthol) was higher in girls (p= 0.08) and in DomAm (p=0.01). After adjusting for gender and ethnicity, presence of both CA's and TRNS was predicted by increasing levels of 1- and 2- naphthol: OR for presence of CA's with increasing 1naphthol: (1.23; 95%CI:1.01, 1.48); and with 2napthol (1.19; 0.90, 1.56), but the effect was significantly higher in DomAms for both 1naphthol (1.63;1.21, 2.19) &amp; 2naphthol (1.44; 1.02, 2.04). For TRNS, the OR was 1.55 (1.11,2.17) for 1naphthol, and 1.92 (1.20-3.08) for 2naphthol. Frequency of CA's was predicted by 1naph (MR1.38; 1.10, 1.72) in DomAm but not in AfrAm (RR0.90; 0.65, 1.25). The association between naphthols and frequency of TRNS did not differ by ethnicity. To examine possible dose-response, levels of 2naphthol were grouped into tertiles using the lowest tertile as the referent group. After adjusting for gender/ethnicity, the proportion with TRNS present increased with increasing 2naphthol (though trend p = 0.09). Children with 2napthol in the highest tertile were significantly more likely to have translocations (OR 4.29; 95% CI: 1.11-16.55) when compared with children in the lowest tertile. Similarly, children with increasing 2-naphthol levels had increasing frequency of TRNS though the overall trend was not significant: mean TRNS frequencies for children in the highest tertile of exposure had a ratio of 3.23; (95%CI: 0.85-12.50) compared with those in the lowest tertile. The effect of increasing naphthol on aberrations or translocations was not dominated by any one chromosome, in contrast to our findings in newborns and prenatal air-PAH. Together these findings support our earlier findings that PAH exposure is associated with formation of TRNS, and suggests a dose response pattern with exposure to naphthalene, and an ethnic difference in susceptibility to formation of CAs. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B32.

Gene biomarkers in diatom Thalassiosira pseudonana exposed to polycyclic aromatic hydrocarbons from contaminated marine surface sediments

Marine diatoms have a key role in the global carbon fixation and therefore in the ecosystem. We used Thalassiosira pseudonana as a model organism to assess the effects of exposure to environmental pollutants at the gene expression level. Diatoms were exposed to polycyclic aromatic hydrocarbons mixture (PAH) from surface sediments collected at a highly PAH contaminated area of the Mediterranean Sea (Genoa, Italy), due to intense industrial and harbor activities. The gene expression data for exposure to the sediment-derived PAH mixture was compared with gene expression data for in vitro exposure to specific polycyclic aromatic hydrocarbons. The data shows that genes involved in stress response, silica uptake, and metabolism were regulated both upon exposure to the sediment-derived PAH mixture and to the single component. Complementary monitoring of silica in the diatom cultures provide further evidence of a reduced cellular uptake of silica as an end-point for benzo[a]pyrene exposure that could be linked with the reduced gene and protein expression of the silicon transporter protein. However some genes showed differences in regulation indicating that mixtures of structurally related chemical compounds can elicit a slightly different gene expression response compared to that of a single component. The paper provides indications on the specific pathways affected by PAH exposure and shows that selected genes (silicon transporter, and silaffin 3) involved in silica uptake and metabolism could be suitable molecular biomarkers of exposure to PAHs.

Interactions between Exposure to Environmental Polycyclic Aromatic Hydrocarbons and DNA Repair Gene Polymorphisms on Bulky DNA Adducts in Human Sperm

BackgroundNucleotide excision repair (NER) and base excision repair (BER) are the primary mechanisms for repair of bulky adducts caused by chemical agents, such as PAHs. It is expected that polymorphisms in NER or BER genes may modulate individual susceptibility to PAHs exposure. Here, we evaluate the effects of PAHs exposure and polymorphisms in NER and BER pathway, alone or combined, on polycyclic aromatic hydrocarbon-DNA (PAH–DNA) adducts in human sperm.Methodology/Principal FindingsSperm PAH-DNA adducts were measured by immunofluorescent assay using flow cytometry in a sample of 465 infertile adults. Polymorphisms of XPA, XPD, ERCC1, XPF, and XRCC1 were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. The PAHs exposure was detected as urinary 1-hydroxypyrene (1-OHP) levels. In multivariate models adjusted for potential confounders, we observed that XRCC1 5′pUTR -T/C, Arg194Trp, Arg399Gln polymorphisms were associated with increased sperm adduct levels. Furthermore, the stratified analysis indicated that adverse effects of XRCC1 Arg194Trp, Arg399Gln polymorphisms on PAH-DNA adducts were detected only in the high PAHs exposure group.Conclusions/SignificanceThese findings provided the first evidence that polymorphisms of XRCC1 may modify sperm PAH-DNA adduct levels and may be useful biomarkers to identify individuals susceptible to DNA damage resulting from PAHs exposure.

Relationship between urinary 1-hydroxypyrene level and peripheral blood lymphocyte chromosomal damage among coke oven workers

To investigate the relationship between the urinary 1-hydroxypyrene level and cytokinesis-block micronucleus in peripheral blood lymphocyte in coke oven workers. One hundred and fifty-eight workers from a coke plant and 158 referents without occupational PAHs exposure were recruited in this study. Urnary level of 1-hydroxypyrene was measured by alkaline hydrolysis combined with high performance liquid chromatography as an internal exposure dose, and the chromosomal damage of peripheral blood lymphocyte were evaluated with cytokinesis-block micronucleus (CBMN) method. Personal information including occupational history, age, sex, smoking and alcohol drinking, was collected by questionnaire. The lymphocyte chromosomal damage level expressed as frequency of CBMN in coke oven workers was significantly higher than that of controls (3.32 ± 2.90 vs 0.57 ± 0.88, P < 0.01) after adjusting for sex, age, smoking and alcohol drinking, and correlation between urinary 1-hydroxypyrene concentrations and frequency of CBMN was found (Spearman Partial correlation coefficient = 0.28, P < 0.05) in coke oven workers. Three hundreds and sixteen subjects were divided into three groups by their urine 1-hydroxypyrene level (expressed as 0.11 ∼ 0.70, 0.71 ∼ 4.09 and 4.10 ∼ 24.74 µmol/mol Cr). After adjusting for age, sex, smoking and alcohol drinking by multiple nonparametric analysis of covariance, the frequency of CBMN in the groups of 0.71 ∼ 4.09 and 4.10 ∼ 24.74 µmol/mol C were 1.89 ± 2.37 and 3.29 ± 2.36, significantly higher than that in the group of 0 ∼ 0.70 µmol/mol Cr (0.56 ± 0.89). Under present PAHs exposure levels, the Cytokinesis-block micronucleus test could detect PAHs-induced genotoxicity in coke oven workers.

Environmental and biological monitoring of exposures to PAHs and ETS in the general population

The objective of this study was to analyse environmental tobacco smoke (ETS) and PAH metabolites in urine samples of non-occupationally exposed non-smoker adult subjects and to establish relationships between airborne exposures and urinary concentrations in order to (a) assess the suitability of the studied metabolites as biomarkers of PAH and ETS, (b) study the use of 3-ethenypyridine as ETS tracer and (c) link ETS scenarios with exposures to carcinogenic PAH and VOC. Urine samples from 100 subjects were collected and concentrations of monophenolic metabolites of naphthalene, fluorene, phenanthrene, and pyrene and the nicotine metabolites cotinine and trans-3′-hydroxycotinine were measured using liquid chromatography–tandem mass spectrometry (LC-MS/MS) to assess PAH and ETS exposures. Airborne exposures were measured using personal exposure samplers and analysed using GC–MS. These included 1,3-butadiene (BUT), 3-ethenylpyridine (3-EP) (a tobacco-specific tracer derived from nicotine pyrolysis) and PAHs. ETS was reported by the subjects in 30-min time–activity questionnaires and specific comments were collected in an ETS questionnaire each time ETS exposure occurred. The values of 3-EP (> 0.25 μg/m 3 for ETS) were used to confirm the ETS exposure status of the subject. Concentrations as geometric mean, GM, and standard deviation (GSD) of personal exposures were 0.16 (5.50) μg/m 3 for 3-EP, 0.22 (4.28) μg/m 3 for BUT and 0.09 (3.03) ng/m 3 for benzo(a)pyrene. Concentrations of urinary metabolites were 0.44 (1.70) ng/mL for 1-hydroxypyrene and 0.88 (5.28) ng/mL for cotinine. Concentrations of urinary metabolites of nicotine were lower than in most previous studies, suggesting very low exposures in the ETS-exposed group. Nonetheless, concentrations were higher in the ETS population for cotinine, trans-3′hydroxycotinine, 3-EP, BUT and most high molecular weight PAH, whilst 2-hydroxyphenanthrene, 3 + 4-hydroxyphenanthrene and 1-hydroxyphenanthrene were only higher in the high-ETS subpopulation. There were not many significant correlations between either personal exposures to PAH and their urinary metabolites, or of the latter with ETS markers. However, it was found that the urinary log cotinine concentration showed significant correlation with log concentrations of 3-EP ( R = 0.75), BUT ( R = 0.47), and high molecular weight PAHs (MW > 200), especially chrysene ( R = 0.55) at the p = 0.01 level. On the other hand, low correlation was observed between the PAH metabolite 2-naphthol and the parent PAH, gas-phase naphthalene. These results suggest that (1) ETS is a significant source of inhalation exposure to the carcinogen 1,3-butadiene and high molecular weight PAHs, many of which are carcinogenic, and (2) that for lower molecular weight PAHs such as naphthalene, exposure by routes other than inhalation predominate, since metabolite levels correlated poorly with personal exposure air sampling.

Toxicokinetic considerations in using a suite of markers to better understand occupational health risk from PAH exposure

Triclosan (TCS) and propylparaben (PPB) are antimicrobials widely used. They present many similarities in their applications and also in their human and environmental health risks. In order to investigate the mechanisms of toxic action and the efflux pumps involved in their detoxication, we used a strategy with batteries of Schizosaccharomyces pombe yeast strains, either defective in cell signalling, in detoxification pumps, or in cell surveillance mechanisms. Yeast were exposed up to 20 h in solid medium or in liquid medium in 96-well plates. The mechanisms of action investigated were spindle defects (mph1), stress (pmk1), DNA interference (rad3) or diverse effects (MDR-sup). The efflux pumps investigated were Bfr1, Pmd1, Mfs1 and Caf5 or the Pap1 transcription factor. Here we show that TCS was 75 times more toxic than PPB in the wild type fission yeast. More oxidative stress and less protection by exclusion pumps were observed for TCS than for PPB. The cytotoxicity produced by TCS decreased from bfr1> mfs1> pmd1 > pap1 and caf5A deficient strains. In contrast, cytotoxic concentrations of PPB caused only a mild stress. The protection provided for PPB by the transporters was more marked than for TCS, decreasing from Pmd1, Caf5, Mfs1 and Bfr1. Furthermore, microtubule and DNA interferences were revealed for PPB, according to the cytotoxicity of mph1 and rad3 defective cells, respectively. As both compounds present complex adverse effects at concentrations close to exposure, and their combination clearly causes a strong potentiation, more exhaustive controls and regulations in their use should be considered.

Breast Cancer and Urinary Biomarkers of Polycyclic Aromatic Hydrocarbon and Oxidative Stress in the Shanghai Women's Health Study

Polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress from such and other exposures have been associated with breast cancer in some studies. To further evaluate the role of PAH metabolites and oxidative stress on the development of breast cancer, we conducted a nested case-control study in the Shanghai Women's Health Study. We measured urinary 1-hydroxypyrene and 2-naphthol as PAH metabolites and urinary levels of 8-hydroxy-2'-deoxyguanosine and malondialdehyde as oxidative stress biomarkers in 327 breast cancer cases and 654 controls in the Shanghai Women's Health Study. Information on demographic characteristics, past medical history, lifestyles, history of menstruation, pregnancy history, eating and drinking habit, history of residence, employment history, family history, husband's information, and physical activity were collected by a self-administered questionnaire. The mean age was 52.3 in breast cancer cases (n = 354) and 52.5 in controls (n = 708). Age at menarche (P = 0.04), months of breast-feeding the first baby (P = 0.05), and grade of education (P(trend) < 0.01) were significantly different between cases and controls. No association was observed for PAH metabolites and the oxidative stress biomarkers of urinary malondialdehyde and 8-hydroxy-2'-deoxyguanosine and risk of breast cancer. This nested case-control study provides no evidence of association between PAH exposure and oxidative stress and risk of breast cancer in Shanghai women.

Fluorescence Spectroelectrochemical Sensor for 1-Hydroxypyrene, a Biomarker for PAH Exposure

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Biomarkers of PAHs exposure in crabs Ucides cordatus: Laboratory assay and field study

Pyrene metabolites in urine and micronucleus in haemocytes of crabs (Ucides cordatus) were tested as biomarkers of exposure to oil derived PAHs in mangrove sediments. The goal was to verify how well pyrene metabolites in urine represent levels of oil contamination in mangroves and whether the micronuclei assay indicates exposure. For this, bioassays were performed using crabs from clean and contaminated areas, and field studies were conducted in four mangroves. Results of the bioassay show that U. cordatus assimilates, metabolises, and excretes pyrene in urine as pyrene-1-glucoside, pyrene-sulphate and pyrene-conjugate. OH-pyrene-sulphate was the major metabolite produced/excreted over 120 h of observation by crabs from the clean mangrove. The production/excretion of pyrene-1-glucoside in this case increased linearly with time at a rate of 2.3 x 10(-10)mol L(-1)day(-1). The number of micronuclei in haemocytes also increased with the time after pyrene inoculation, indicating that exposure to pyrene triggers genotoxic and mutagenic response. In crabs from a heavily oil-contaminated mangrove pyrene-1-glucoside was the major metabolite, an indication that production/excretion of a certain metabolite varies depending on adaptation of the animal to the environment. A highly significant correlation was found between the concentration of pyrene metabolites in urine of field crabs expressed as OH-pyrene equivalents and the sum of 38 PAHs determined in hepatopancreas/sediments (r=0.825, n=23, p<0.05). The response of these crabs to the micronuclei assay was not significantly related to concentration of individual or total PAHs. Nevertheless, metabolite results prove U. cordatus as excellent bioindicator for evaluating environmental quality in mangrove areas as related to PAHs and oil contamination.

Workplace Environment and Personal Exposure of PM and PAHs to Workers in Natural Rubber Sheet Factories Contaminated by Wood Burning Smoke

The workplace environment in factories producing ribbed smoked sheet rubber (RSS), the interiors which are heavily contaminated by wood burning smoke, was evaluated with a focus on the concentration of suspended particulates and particle-bound PAHs as well as workers' exposure in the breathing zone during the period January, 2006-February, 2008 in Thailand. Seasonal changes in particulate and PAH concentrations are discussed in relation to the amount of RSS produced, wind direction, ventilation type and the geometry of the factory building. The concentration of particulate matter in the workplace was shown to increase nearly linearly with RSS production while being influenced by the wind direction to the open sides of the building and wind speed. Particulate concentrations in the workplace and in the worker’s breathing zone were lower than those for other common occupational exposure limits. However, rather high PAH concentrations of 97.4 ± 129 ng/m^3 and 142 ± 184 ng/m^3 were found in the workplace and in the breathing zone, respectively. BaPTEQ concentrations in the workplace ranging from 21.4 to 91.0 ng/m^3 were similar to those in a sinter plant. The workers' exposure to PAHs was similar to that in a sinter plant, a metal recycling plant, a paving bitumen manufacturing plant and a carbon black manufacturing plant. The mass fraction of PAHs in particles in the RSS factory was as high as 0.30 BaP(subscript TEQ) ng/μg, much higher than that in a carbon black plant (0.004–0.01 BaP(subscript TEQ) ng/μg). The results reported herein suggest that the workers in the RSS factory have a somewhat high health risk from exposure to PAHs. Natural ventilation by the addition of roof turbines was insufficient in terms of reducing PAHs levels in the workplace although a roof ridge vent was functional and had a positive effect.

Functional immune response in Pecten maximus: Combined effects of a pathogen-associated molecular pattern and PAH exposure

Pathogen-associated molecular patterns (PAMPs) enable recognition of structures present in microorganisms such as lipopolysaccharides (LPS). LPS are an essential constituent of the outer membrane of Gram-negative bacteria, stimulating the innate immune system of invertebrates. Here, LPS from Escherichia coli (055:B5) were used to investigate the functional immune response of Pecten maximus after stimulation with a PAMP and to determine the combined effect of a phenanthrene exposure and LPS challenge. Organisms were exposed to 200 μg l −1 phenanthrene and after 7 d were injected with either physiological saline (injection controls) or LPS solution, and returned to their respective exposure tanks. Haemolymph was sampled from the scallops 48 h post-injection and immune function was assessed using a combination of cellular biological responses. The LPS challenge significantly altered the immune response in P. maximus with increased cell counts and phagocytic activity. An immunosuppressive effect of phenanthrene was also observed in this study; however, exposure to phenanthrene did not significantly impair the organism's ability to respond to a PAMP challenge. The overall level of phagocytosis and cytotoxic capability following the LPS challenge was lower in phenanthrene exposed scallops and may have consequences for disease resistance in this commercially-exploited species.

Benzo( a)pyrene induced glycine N-methyltransferase messenger RNA expression in Fundulus heteroclitus embryos

Glycine N-methyltransferase (GNMT) is a mediator in the methionine and folate cycles, and is responsible for the transfer of a methyl group from S-adenosylmethionine (SAM) to glycine forming S-adenosylhomocysteine (SAH) and sarcosine. All the known DNA methyltransferases use SAM as a methyl donor thus, GNMT is critically involved in regulation of DNA methylation. Altered GNMT activities have been associated with liver pathologies including hepatocellular carcinoma. The homotetramer form of GNMT is enzymatically active, but the homodimeric form has been suggested as the 4S PAH-binding protein which may mediate CYP1A expression. To further understand the role of GNMT in benzo( a)pyrene (BaP)-related toxicity, full length Fundulus heteroclitus GNMT cDNA was cloned from adult liver. The open reading frame (ORF) of GNMT is 888 base pairs long and encodes a deduced protein of 295 amino acids which has 74% identity with human GNMT. Expression of GNMT mRNA was determined by quantitative RT-PCR. In unfertilized, 2 days postfertilization (dpf), and 3 dpf embryos GNMT was constitutively higher than in 4, 7, 10 or 14 dpf embryos. Embryos were also exposed to waterborne BaP at 10 and 100 μg L −1, and by 10 dpf the higher BaP dose caused increased expression of GNMT mRNA. These results suggest that PAH exposure may alter expression of an important physiological methylation mediator. Future work will be necessary to determine enzyme level effects of BaP exposure as well.

A historical perspective on the “fish tumors or other deformities” beneficial use impairment at Great Lakes Areas of Concern

The Great Lakes Water Quality Agreement defines Areas of Concern as geographic areas that fail to meet the general or specific objectives of the agreement where such failure has caused or is likely to cause impairment of beneficial use of the area's ability to support aquatic life. One of the beneficial use impairments, fish tumors or other deformities, is defined by the International Joint Commission to occur when the incidence rate of fish tumors and other deformities exceeds rates at unimpacted or control sites, or when survey data confirm the presence of neoplastic or preneoplastic liver tumors in bullhead or suckers. Brown bullhead, a benthic species with a limited home range, have frequently been used as indicator species in U.S. Areas of Concern. While there is strong field evidence for an association between PAH exposure and hepatic neoplasia in brown bullhead, laboratory investigations would strengthen the association. There is less evidence linking specific classes of chemicals in the environment to orocutaneous neoplasia in brown bullhead. Studies on orocutaneous neoplasia of brown bullhead should focus on assessing the presence or absence of viruses and on epidermal exposure to specific chemicals and chemical mixtures. Lastly, the effects of covariates such as length, age, and gender on the prevalence of liver and skin neoplasms should be investigated. This paper reviews the state of science on the fish tumors or other deformities beneficial use impairment. Subsequent papers address specific issues related to this impairment and provide recommendations for standardized criteria.

PAHs: Choi et al. Respond

PAHs: Choi et al. Respond

Determinants of urinary 1-hydroxypyrene glucuronide in South Korean children

This study was conducted to investigate the dominant sources of the urinary pyrene metabolite, 1-hydroxypyrene glucuronide (1-OHPG), in South Korean children. Urine samples were collected from 102 non-smoking children (aged 10-14). Urinary 1-OHPG was assayed by synchronous fluorescence spectroscopy, following immuno-affinity purification using monoclonal antibody 8E11. Urinary cotinine, a metabolite of nicotine, was measured by GC/MS. Information on environmental tobacco smoke (ETS) exposure, diet, fuel type for heating home, and other possible sources of PAH exposure was collected by self-administered questionnaires. Mean (+/-SE) 1-OHPG levels were 1.64 (+/-0.06) ng/ml (range 0.04-3.27 ng/ml). Two multiple linear regression analyses (differing in how ETS was approximated: by parental smoking or urinary cotinine) revealed a positive association between urinary 1-OHPG levels and parental smoking at home (P = 0.007), log urinary cotinine (P = 0.165), frequent grilled (shell)fish consumption (P = 0.061), and living in a commercial/other zone (P = 0.007) versus a residential or industrial zone. No consistent associations were found between 1-OHPG and the child's sex, grilled meat consumption, or fuels used to heat the home. These results support that ETS, frequent grilled fish consumption, and the ambient environment are important predictors of urinary 1-OHPG levels in South Korean children.

THE SIGNIFICANCE OF POLYCYCLIC AROMATIC HYDROCARBONS AS ENVIRONMENTAL CARCINOGENS. 35 YEARS RESEARCH ON PAH—A RETROSPECTIVE

In vivo studies with laboratory animals as well as in vitro studies with bacteria and mammalian cell cultures have demonstrated that the mutagenic and/or carcinogenic properties of numerous PAHs require metabolic transformation. Metabolism of PAHs has been explored in vitro using cellular microsomal fractions, mammalian cell cultures and later genetically engineered cells expressing cytochromes P450 from several species including humans. Balancing the carcinogenic potential of some environmental matrices (vehicle exhaust, condensate of hard coal combustion effluents, cigarette smoke condensate, used motor oil) after separation into sub-fractions evidenced that the carcinogenic effect may be attributed almost exclusively to PAH. Mixtures of well-known carcinogenic PAH in concentrations as present in these matrices, however, did not explain the total biological effect. Thus, it had been speculated that either very potent unknown carcinogens are still hidden in the PAH fraction, or that synergistic effects (enzyme induction) play a significant role. In parallel to these carcinogenicity studies, the metabolism of various PAHs has been investigated in rat liver microsomes from untreated animals as well as from animals pre-treated with inducers of cytochrome P450. It was found that even non-carcinogenic PAHs possess a significant inducing potential. Moreover, in several mammals a highly species-specific metabolism of PAH could be observed allowing a critical view to the extrapolation from animal experiments to the human situation. This was further confirmed by experiments with mammalian cell cultures including human ones as well as by metabolic studies with genetically engineered Chinese hamster V79 cells singularly expressing various cytochrome P450 enzymes from a number of different species (human, rat, mouse, fish). With these cell lines metabolic studies were carried out with a larger number of PAHs as substrates including phenanthrene, pyrene, chrysene, benzo[a]anthracene, benzo[c]phenanthrene, benzo[a]pyrene, dibenzo[a,l]pyrene, and benzo[c]chrysene. Based on the metabolism results, analytical methods have been developed to determine urinary biomarkers of human PAH exposure. Human biomonitoring studies have been performed with different occupationally exposed individuals as well as within smokers and non-smokers of the general population. Endogenous PAH exposure levels and changes in the urinary excreted metabolic profile depending on exposure level have been determined.

Micronuclei Related toAnti–B[a]PDE-DNA Adduct in Peripheral Blood Lymphocytes of Heavily Polycyclic Aromatic Hydrocarbon–Exposed Nonsmoking Coke-Oven Workers and Controls

Micronuclei (MN) frequency associated to biologically effective dose of polycyclic aromatic hydrocarbons [PAH; anti-benzo[a]pyrene diolepoxide (B[a]PDE)-DNA] within the same subjects' peripheral blood lymphocytes (PBL) was evaluated. Study subjects were nonsmoking male Polish coke-oven workers (n=49) and matched controls (n=45) verified for PAH exposure by urinary 1-pyrenol. We found that coke-oven workers, heavily exposed to PAHs (80% workers exceeded the urinary 1-pyrenol biological exposure index value), presented significantly higher MN frequency in PBLs than controls (P<0.01). Substantial difference was also found for adduct levels in PBLs (P<0.01). Increase in MN levels was significantly related to anti-B[a]PDE-DNA formation, key adduct of the ultimate carcinogenic metabolite of B[a]P (n=94; r=0.47; P<0.001). The dose-response relationship was improved when subjects with adduct levels above the 3rd tertile (>or=4.35 adducts/10(8) nucleotides) were excluded (n=61; r=0.69; P<0.001). Saturation of adduct/MN formation at high levels may disturb the underlying relationship. Linear multiple regression analysis, without subjects of 3rd tertile adduct level (n=61), revealed that adduct formation (t=4.61; P<0.001), but not 1-pyrenol, was the significant determinant in increasing MN. In conclusion, the increase in MN frequency is mainly related to the specific anti-B[a]PDE-DNA formation within PBLs of the same subject. Our results substantiate, with the use of an early indicator of biological effect as well, that workers are at higher cancer risk than controls.

Plankton stress responses from PAH exposure and nutrient enrichment

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 363:121-130 (2008) - DOI: https://doi.org/10.3354/meps07470 Plankton stress responses from PAH exposure and nutrient enrichment M. Hjorth1,2,*, V. E. Forbes2, I. Dahllöf1 1Department of Marine Ecology, National Environmental Research Institute, University of Aarhus, Frederiksborgvej 399, 4000 Roskilde, Denmark 2Department of Environmental, Social and Spatial Change, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark *Email: moh@dmu.dk ABSTRACT: The hypothesis that the nature and force of PAH stress responses from plankton systems are coupled to the nutrient status of that system was tested in a mesocosm experiment. Four treatments were applied consisting of control (Cn), pyrene exposed (Py), nutrient spiked (Nu), and nutrient spiked and pyrene exposed (NuPy) groups in replicate bags (n = 3) representing plankton communities including bacteria, phytoplankton and zooplankton. Regardless of nutrient status, all the Py mesocosms were affected directly with decreases in chlorophyll a concentrations to 20% of control values on Day 1. Primary production was also significantly lower (<50%) than Cn communities in both Py and NuPy communities after the first pyrene exposure. Indirect effects were observed as increased bacterial activity due to nutrient release from algal death, thereby channelling growth to another trophic level. With time the plankton system became top-down controlled, dominated by zooplankton, which was also the trophic group experiencing the longest lasting effect on structure. The occurrence of late effects in the zooplankton communities were seen in all treatments, but the magnitude of the effects was dependent on the nutrient status, most probably because of a larger trophic transfer of the contaminant. To improve our understanding of contaminant effects on food webs in natural communities, it is imperative that interactions between trophic levels in relation to abiotic factors are investigated. KEY WORDS: Plankton · PAH · Food web · Stress · Function · Nutrient status · Marine · Mesocosm Full text in pdf format PreviousNextCite this article as: Hjorth M, Forbes VE, Dahllöf I (2008) Plankton stress responses from PAH exposure and nutrient enrichment. Mar Ecol Prog Ser 363:121-130. https://doi.org/10.3354/meps07470 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 363. Online publication date: July 15, 2008 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2008 Inter-Research.