Biomarkers of polycyclic aromatic hydrocarbon (PAH)-associated hemolytic anemia in oiled wildlife

Polycyclic aromatic hydrocarbons (PAHs) in crude oil cause a range of adverse effects in oiled seabirds, one of the most common being hemolytic anemia via oxidative attack of erythrocytes by PAH metabolites resulting in hemoglobin leakage and formation of Heinz bodies. In such cases, haptoglobin and ferritin are up-regulated to sequester free Hb and iron in the circulation. We investigated these plasma proteins as biomarkers of PAH-induced Heinz body hemolytic anemia in oiled seabirds. Concentration ranges of PAHs, HAP and FT in plasma samples were 10-184 ng/ml, 0-2.6 mg/ml and 0-7.6 ng/ml, respectively. Dose-response relationships between plasma PAH exposure and haptoglobin and ferritin (FT) were investigated, and evidence of erythrocyte Heinz body formation studied in 50 oiled common guillemots stranded on the Norfolk Wash coast (East England). Haptoglobin was negatively correlated, and FT was positively correlated with PAH exposure. Heinz bodies were also observed confirming the toxic mechanism causing hemolytic anemia and counts were positively correlated with exposure. Our results support the application of these complementary biomarkers to assess hemolytic effects of oiling in wildlife biomonitoring, which also discriminate the influence of hemolytic versus inflammatory effects in oiled guillemots.     

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure and child behavior at age 6-7 years

Background: Airborne polycyclic aromatic hydrocarbons (PAH) are widespread urban air pollutants from fossil fuel burning and other combustion sources. We previously reported that a broad spectrum of combustion-related DNA adducts in cord blood was associated with attention problems at 6–7 years of age in the Columbia Center for Children’s Environmental Health (CCCEH) longitudinal cohort study.Objectives: We evaluated the relationship between behavioral problems and two different measures of prenatal exposure—both specific to PAH—in the same cohort.Methods: Children of nonsmoking African-American and Dominican women in New York City (NYC) were followed from in utero to 6–7 years. Prenatal PAH exposure was estimated by personal air monitoring of the mothers during pregnancy as well as by the measurement of DNA adducts specific to benzo[a]pyrene (BaP), a representative PAH, in maternal and cord blood. At 6–7 years of age, child behavior was assessed using the Child Behavior Checklist (CBCL) (n = 253). Generalized linear models were used to test the association between prenatal PAH exposure and behavioral outcomes.Results: In multivariate analyses, high prenatal PAH exposure, whether characterized by personal air monitoring (greater than the median of 2.27 ng/m³) or maternal and cord adducts (detectable or higher), was positively associated with symptoms of Anxious/Depressed and Attention Problems (p ≤ 0.05).Conclusion: These results provide additional evidence that environmental levels of PAH encountered in NYC air can adversely affect child behavior.     

Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil

The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.     

Spatial covariation of microbial community composition and polycyclic aromatic hydrocarbon concentration in a creosote-polluted soil

Little is known about the spatial connection between soil microbial community composition and polycyclic aromatic hydrocarbon (PAH) concentration. A spatially explicit survey at a creosote-contaminated site demonstrated that microbial biomass (total concentration of phospholipid fatty acids [PLFAs]) and microbial community composition (PLFA fingerprints) were spatially autocorrelated, mostly within a distance of 25 m, and covaried with PAH concentrations. The concentration of PLFAs indicative of gram-negative bacteria (16:1omega7c, 16:1omega7t, 18:1omega7, cy17:0, and cy19:0) increased in the PAH hot spots, whereas PLFAs representing fungi and gram-positive bacteria (including actinomycetes) were negatively correlated to PAH concentrations. Most PLFAs were spatially autocorrelated, with distances varying between 4 and 25 m. Those PLFAs that increased in PAH-contaminated soil had autocorrelation ranges between 4 and 16 m, whereas the fungal indicator PLFA 18:2omega6,9 had the largest autocorrelation range (25 m). Bacterial strains isolated using a spray-plate technique and with the same PLFA composition as that in contaminated soil samples were capable of degrading phenanthrene, fluoranthene, and pyrene, indicating that the main PAH degraders could be isolated.     

Aryl hydrocarbon receptor ligand activity of polycyclic aromatic ketones and polycyclic aromatic quinones

Polycyclic aromatic ketones (PAKs) and polycyclic aromatic quinones (PAQs) are oxygenated polycyclic aromatic hydrocarbons (PAHs), and reports about the aryl hydrocarbon receptor (AhR) ligand activities of these compounds are few. In this study, activation of AhR by 41 polycyclic aromatic compounds (PACs), focusing especially on PAKs and PAQs, was determined by measuring beta-galactosidase activity from a reporter plasmid in yeast engineered to express human AhR and the AhR nuclear translocator proteins and by measuring luciferase activity from mouse hepatoma (H1L1) cells (chemical-activated luciferase expression [CALUX] assay). The PACs used in these experiments included 11 PAKs, seven PAQs, and 21 PAHs. In this study, the PAKs 11H-benzo[a]fluoren-11-one (B[a]FO), 11H-benzo[b]fluoren-11-one (B[b]FO) and 7H-benzo[c]fluoren-7-one and the PAQs 5,12-naphthacenequinone, 1,4-chrysenequinone, and 7,12-benz[a]anthracenequinone showed high AhR activities in H1L1 cells, although these values were not as high as that for benzo[a]pyrene (B[a]P). These PAKs and PAQs showed significantly stronger activities in yeast cells relative to B[a]P. It was predicted that PAKs such as B[a]FO and B[b]FO occupied 0.06% to 1.3% of the total induction equivalents, and each contribution matched the contribution of PAHs such as B[a]P, chrysene, and benz[a]anthracene in gasoline exhaust particulates and airborne particulates using data of CALUX assay.     

Polycyclic aromatic hydrocarbon (PAH) exposure and DNA adduct semi-quantitation in archived human tissues

Polycyclic aromatic hydrocarbons (PAHs) are combustion products of organic materials, mixtures of which contain multiple known and probable human carcinogens. PAHs occur in indoor and outdoor air, as well as in char-broiled meats and fish. Human exposure to PAHs occurs by inhalation, ingestion and topical absorption, and subsequently formed metabolites are either rendered hydrophilic and excreted, or bioactivated and bound to cellular macromolecules. The formation of PAH-DNA adducts (DNA binding products), considered a necessary step in PAH-initiated carcinogenesis, has been widely studied in experimental models and has been documented in human tissues. This review describes immunohistochemistry (IHC) studies, which reveal localization of PAH-DNA adducts in human tissues, and semi-quantify PAH-DNA adduct levels using the Automated Cellular Imaging System (ACIS). These studies have shown that PAH-DNA adducts concentrate in: basal and supra-basal epithelium of the esophagus, cervix and vulva; glandular epithelium of the prostate; and cytotrophoblast cells and syncitiotrophoblast knots of the placenta. The IHC photomicrographs reveal the ubiquitous nature of PAH-DNA adduct formation in human tissues as well as PAH-DNA adduct accumulation in specific, vulnerable, cell types. This semi-quantative method for PAH-DNA adduct measurement could potentially see widespread use in molecular epidemiology studies.     

Polycyclic aromatic hydrocarbon (PAH) residues on skin in relation to air levels among roofers

To assess the utility of skin wipes as an index of exposure to polycyclic aromatic hydrocarbons (PAHs), simultaneous skin wipe and breathing zone air samples were obtained for 10 roofers. Samples were obtained during removal of an old coal-tar pitch roof and application of a new asphalt roof. Skin wipes were obtained immediately before and after the workshift. Anthracene was present in air but not skin samples. In air samples, the relative concentrations of seven PAHs were fluoranthene greater than pyrene greater than benzanthracene greater than benzo[a]pyrene greater than benzo[b]fluoranthene greater than benzo[ghi]perylene greater than benzo[k]fluoranthene. A similar pattern, or rank concentration, was observed in matching skin wipe samples. The amount (ng) of PAH (either total or individual compounds) found in skin wipes taken after the workday was significantly correlated with that in air samples (micrograms/m3, time-weighted average) for 8 of the 9 cases with air and skin samples taken the same day (r = 0.99 for total PAH). Skin wipe PAH residues were not significantly correlated with air samples taken 4 d earlier. These findings suggest that skin wipes can provide a useful measure of exposure to PAH.     

Determination of urinary metabolites of polycyclic aromatic hydrocarbons (PAH) for the risk assessment of PAH-exposed workers

A method for the simultaneous determination of urinary phenanthrene, fluoranthene, pyrene, chrysene and benzo[a]pyrene metabolites has been developed for individual risk assessment at polycyclic aromatic hydrocarbon (PAH)-burdened workplaces. The concentration of urinary metabolites as a measure for individual PAH exposure takes account not only of PAH masses resorbed by the respiratory tract but also those incorporated percutaneously. The method allows the determination of 25 different components with a low margin of error; the individual metabolite profiles thereby allow conclusions on the individual characteristics of PAH-oxidizing enzymes (monooxygenases). The coefficients of variation are lower than 10%. After enzymatic treatment of the urine with glucuronidase and arylsulfatase one part of the benzene or toluene extract is treated with diazomethane to convert phenols into methylethers, while another part is used to convert dihydrodiols into phenols. After further purification the metabolites are determined by means of a combination of gas chromatography and mass spectrometry. The PAH exposure of coke plant workers during several consecutive days resulted in fairly constant individual urinary metabolite profiles which, however, exhibited significant inter-individual variability. This held true also for Wistar rats exposed to tar pitch aerosol on 5 days during a period of 10 days. It was also demonstrated that in the case of coke plant workers there is a correlation between inhaled PAH and metabolites excreted. Mass relationships between inhaled PAH and metabolites excreted were found to differ from one individual to another. Received: 10 October 1995 / Accepted: 26 February 1996     

大气中16种多环芳烃化合物高效液相色谱法测定

目的建立一种用高效液相色谱法同时测定大气中16种多环芳烃化合物的方法。方法用粉尘采样器、聚四氟乙烯滤膜和高分子多孔微球管采集大气中多环芳烃化合物,滤膜用乙腈：甲醇(60∶40)为溶剂,超声波提取多环芳烃化合物；吸收管用乙腈：甲醇(60∶40)、二氯甲烷洗脱,洗脱液经真空干燥后用乙腈：甲醇(60∶40)定容。用乙腈和水作为流动相,进行反相高效液相色谱梯度淋洗分离,程序波长荧光检测器检测。结果16种多环芳烃化合物测定的相对标准偏差为1．1%～5．6%,方法检测限为2．14×10~(-4)～4．3233×10~(-2)μg/ml,回收率为83．6%～98%,均符合方法学要求。结论该方法具有快速简便、准确灵敏、重现性好等优点,能全面真实地反映大气中多环芳烃化合物浓度。     

食品中多环芳烃污染状况分析

目的:了解鞍山市民日常饮食中多环芳烃(PAHs)的污染情况。方法:采集东北地区100名受试者24 h食物样品,采用HPLC可编程序荧光检测法,对14种PAHs进行定量分析。结果:14种PAHs中2~4环化合物暴露量大,最高可达数十μg/d。男性对强致癌性BaP暴露为1μg/d,是文献报导的近5倍,普遍高于女性。结论:从显著相关水平可以看出饮食暴露PAHs中各化合物是有一定相关性的,说明我国食品卫生标准中仅规定BaP一项也是合理的。     

Production of polycyclic aromatic hydrocarbon metabolites from a peroxynitrite/iron(III) porphyrin biomimetic model and their mutagenicities

Some polycyclic aromatic hydrocarbons (PAHs) are typical promutagens that require metabolic activation to exhibit their mutagenicities and carcinogenicities. The metabolites of three PAHs, pyrene (PY), fluoranthene (FLU), and benzo[a]pyrene (BaP), produced from the peroxynitrite/T(p-Cl)PPFeCl(peroxynitrite/(chloride)iron(III)tetrakis(p-chlorophenyl)porphyrin) system, have been identified with high-performance liquid chromatography coupled with electron spray ionization tandem mass spectrometry. The results demonstrated that three major metabolites were the quinone group, OH group, and nitro group. In the Ames test, all three PAH metabolites became mutagenic without using the enzymatic activating system, whereas their parents did not show positive results. Cell transformation assay indicated that 1,3-nitro-BaP and BaP metabolites produced from this biomimetic system have more serious effects in inducing cancer than the BaP parent.     

Polycyclic aromatic hydrocarbon (PAH) contamination in San Francisco Bay: a 10-year retrospective of monitoring in an urbanized estuary

Polycyclic aromatic hydrocarbons (PAH) are widespread contaminants in the San Francisco Bay. Several exceedances of water quality criteria raise the possibility that PAH may be impacting aquatic biota. The Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) has collected annual monitoring data on PAH in the Bay since 1993. Analysis of Bay water, sediment, and mussel SigmaPAH concentration data showed that there were very few significant (P < 0.05) increasing or decreasing temporal trends in SigmaPAH concentrations in the Bay during the period of 1993-2001. Wet and dry season input of PAH did not show any major influence on water SigmaPAH concentrations over the same period. Based on their relative contribution to the estimated total maximum PAH loading (10,700 kg/yr) into the Bay, the PAH loading pathways are ranked as storm water runoff ( approximately 51%) >tributary inflow ( approximately 28%) >wastewater treatment plant effluent ( approximately 10%) >atmospheric deposition ( approximately 8%) >dredged material disposal ( approximately 2%). The PAH sediment quality threshold of 1000 ng/g, which has been previously suggested by NOAA to protect estuarine fish such as English sole against adverse health effects, was frequently exceeded at individual monitoring stations (11 of the 26 stations exceeded the threshold over 50% of the time). Modeling results have shown that the predominant loss pathway for PAH is degradation in sediments, and unless external loading levels of PAH are controlled, the Bay is not expected to recover rapidly.     

Genotoxic risk assessment in white blood cells of occupationally exposed workers before and after alteration of the polycyclic aromatic hydrocarbon (PAH) profile in the production material: comparison with PAH air and urinary metabolite levels

Objective: Workers in various industries can be exposed to polycyclic aromatic hydrocarbons (PAHs). The relationship between biomarkers of genotoxic risk, PAH compounds in air (ambient monitoring) and PAH metabolites in urine (internal exposure) were studied in 17 workers exposed to PAHs in a fireproof-material producing plant before and 3 months after the PAH profile was altered in the binding pitch. Methods: Two biomarkers of exposure, specific DNA adducts of (±)-r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE) and non-specific DNA adduct of 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodGuo) were determined in white blood cells (WBCs). In addition, DNA strand breaks were analysed in lymphocytes by single-cell gel electrophoresis in a genotoxic risk assessment. Sixteen PAH compounds in air were determined by personal air sampling, and hydroxylated metabolites of phenanthrene, pyrene and naphthalene were determined in urine. Results: After substitution of the binding pitch the concentrations of benzo[a]pyrene in air decreased (P<0.01). No changes could be observed for pyrene, while levels of phenanthrene (P=0.0013) and naphthalene (P=0.0346) in air increased. Consequently, median DNA adduct rates of anti-BPDE decreased after alteration of the production material (from 0.9 to <0.5 adducts/10⁸ nucleotides). No changes in the excretion of 1-hydroxypyrene in urine could be determined, whereas increased levels of 1-, 2+9-, 3- and 4-hydroxyphenanthrene (P<0.0001) and 1-naphthol and 2-naphthol (P=0.0072) were found in urine. In addition, a statistically significant increase in DNA strand break frequencies (P<0.01) and elevated 8-oxodGuo adduct levels (P=0.7819, not statistically significant) were found in the WBCs of exposed workers 3 months after the PAH profile in the binding pitch had been altered. Conclusion: The results presented here show that the increased concentration of naphthalene and/or phenanthrene in the air at the work place could induce the formation of DNA strand breaks and alkali-labile sites in WBCs of exposed workers.     

Drosophila melanogaster p-glycoprotein: a membrane detoxification system toward polycyclic aromatic hydrocarbon pollutants

Polycyclic aromatic hydrocarbons (PAHs) are well-known ubiquitous environmental contaminants. Permeability glycoprotein (P-gp) is a transmembrane detoxification efflux pump transporting various lipophilic xenobiotics, such as PAHs, out of the cells. The existence of a P-gp detoxification system inducible by PAHs was investigated in Drosophila melanogaster. Western blot experiments showed that D. melanogaster expressed a 140-kDa P-gp in S12 cells, embryos, and adult flies. Permeability glycoprotein was expressed in adult flies in the head, abdomen, and thorax and sublocalized in the sexual and olfactory organs. Flow cytometry experiments using Drosophila S12 cells in the presence of PAHs and target P-gp drug compounds revealed that Drosophila P-gp acted as an efflux detoxification pump. In Drosophila exposed to benzo[a]pyrene or to ambient air polluted by higher or lower PAH concentrations, P-gp expression was clearly showed a dose-dependent increase response. The P-gp induction was detected both in adult flies and in different fly parts, such as the head, thorax, and antennae. Drosophila P-gp acts as a membrane barrier against PAH pollutants.     

An experimental design approach for optimizing polycyclic aromatic hydrocarbon analysis in contaminated soil by pyrolyser-gas chromatography-mass spectrometry

Pyrolyser-gas chromatography-mass spectrometry was used to analyze polycyclic aromatic hydrocarbons in contaminated soil without preliminary extraction. Experimental research methodology was used to obtain optimal performance of the system. After determination of the main factors (desorption time, Curie point temperature, carrier gas flow), modeling was done using a Box-Behnken matrix. Study of the response surface led to factor values that optimize the experimental response and achieve better chromatographic results.     

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.     

Physicochemical characterization of coke-plant soil for the assessment of polycyclic aromatic hydrocarbon availability and the feasibility of phytoremediation

Coke oven site soil was characterized to assess the particle association and availability of polycyclic aromatic hydrocarbons (PAHs). We identified various carbonaceous materials including coal, coke, pitch, and tar decanter sludge. Most of the PAHs were associated with the polymeric matrix of tar sludge or hard pitch as discrete particles, coatings on soil mineral particles, or complex aggregates. The PAH availability from these particles was very low due to hindered diffusive release from solid tar or pitch with apparent diffusivities of 6 x 10(-15) for phenanthrene, 3 x 10(-15) for pyrene, and 1 x 10(-15) cm2/s for benzo[a]pyrene. Significant concentrations of PAHs were observed in the interior of solid tar aggregates with up to 40,000 mg/kg total PAHs. The release of PAHs from the interior of such particles requires diffusion over a substantial distance, and semipermeable membrane device tests confirmed a very limited availability of PAHs. These findings explain the results from three years of phytoremediation of the site soil, for which no significant changes in the total PAH concentrations were observed in the test plot samples. The observed low bioavailability of PAHs probably inhibited PAH phytoremediation, as diffusion-limited mass transfer would limit the release of PAHs to the aqueous phase.