PAH Exposure Research Articles

Assessment of heavy metal and PAH exposure in largemouth bass (Micropterus salmoides) in the Reedy River watershed, South Carolina, USA: A multi‐season assessment of metallothionein and bile fluorescence

Biomarkers can be used as tools to help determine ecological exposure in watershed assessments. In the present study, metallothionein and fixed wavelength bile fluorescence for two-, four-, and five-ring hydrocarbons were used as biomarkers of exposure in largemouth bass (Micropterus salmoides) in the Reedy River watershed located in South Carolina, USA. Fish were sampled from three impoundments and a reference site over three seasons in the same year. Biomarker endpoints were compared to chemical concentrations at each site during each season. Results indicated that despite elevated concentrations of hydrocarbons being present in sediments, the hydrocarbons did not appear to be bioavailable based on bile fluorescence analysis. Bile fluorescence analysis also indicated that the hydrocarbons detected in this watershed were likely of petrogenic origin. Significantly elevated sediment concentrations of Cd, Cr, Cu, Pb, Ni, Ag, Zn, and metallothionein were found in one impoundment, Lake Conestee, compared with the reference site, indicating both the presence and bioavailability of these metals. Seasonal variability of bile fluorescence was limited; however, metallothionein showed elevated concentrations in the spring and summer compared with fall.

Ecological Risk Assessment of Poly Aromatic Hydrocarbons in the North Port, Malaysia

Sediment samples collected from the West Port, West Coastal water of Malaysia, were analyzed by GC-MS in order to determine the degree of hydrocarbon contamination, and identify the sources of poly aromatic hydrocarbon and PAHs. Concentrations of PAHs in the port sediments ranged from 98.28 to 3630.22 µg/kg dw. The highest concentration was observed in stations which is closed to the coastline, this locations affected by intensive shipping activities and industrial inputs and they were dominated by the high molecular weight PAHs (4-6- rings). Source identification showed that PAHs originated mostly from the pyrogenic source either from the combustion of fossil fuels, grass, wood and coal (majority of the samples) or from petroleum combustion (Port area). Regarding to risk index (HQ) estimation, only stations 13 (close to container terminal in West Port) is moderately polluted and the rest of stations were in rare or slight adverse biological effects with the PAHs exposure in surface sediment, suggesting PAHs are not considered as contaminants of concern in the West Port.

Third-hand tobacco smoke: Significant vector for PAH exposure or non-issue?

Third-hand tobacco smoke: Significant vector for PAH exposure or non-issue?

What to do with NOECS/NOELS-prohibition or innovation?

This study attempted to be as realistic as possible when evaluating third-hand PAH residues resulting from 1 cigarette. Smokers were not asked to change their smoking habits, except to continuously hold the cigarette in 1 hand during the entire duration of the cigarette’s burning. Hand size (that is, the adsorptive surface area), duration of smoking, and environmental conditions such as wind, temperature, and humidity, in addition to other factors, may potentially influence PAH concentration. We conducted our third-hand smoke studies outdoors under environmental conditions, and therefore hypothesize that a similar study conducted in the more stable conditions of an indoor environment may reveal higher levels of contaminant residues on surfaces and smokers’ bodies. Moir et al. (2008) quantified PAH concentrations in second-hand tobacco smoke, defined as environmental tobacco smoke that is inhaled involuntarily or passively by someone who is not smoking. Using their study and our data set, we carried out a ‘‘back of the envelope’’ calculation to estimate the percentage of sidestream smoke (i.e., secondhand smoke) that becomes third-hand smoke. We conclude that the PAH inventory on 1 hand of a smoker represents 0.1% to 6% of that emitted from sidestream smoke. Third-hand PAH residues on a smoker’s hand represent only a fraction of the total PAH reservoir for a smoker (compared to residues on all exposed skin and clothing). We have begun to quantify this load of chemicals as the first step in assessing the potential for smokers to act as vectors for impairment of indoor air quality. To completely capture the health risk posed by third-hand smoke, further studies from our research group and others need to address the off-gassing or desorption potential of these compounds and more fully evaluate the significance of third-hand smoke residues in impairing indoor air quality and/or increasing PAH exposure to subpopulations such as children. A thorough ranking of the importance of this exposure route compared to other exposures modes (e.g., release of PAHs from cooking methods such as open fires, incense burning, indoor tobacco smoking, etc.) also remain to be quantified.

Differential gene expression responses of zebrafish to PAH exposure during embryogenesis

Differential gene expression responses of zebrafish to PAH exposure during embryogenesis

Magnetic Solid Phase Extraction Followed by High Performance Liquid Chromatography for Determination of Urinary 1-Hydroxypyrene

A method was established for the determination of urinary pyrene metabolite 1-hydroxypyrene (1-OHP) by the combination of magnetic solid-phase extraction (MSPE) and liquid chromatography-fluorescence detection. Good extraction efficiency was obtained by optimizing the extraction conditions. A 2-mL aliquot of urine sample was diluted to 4 mL with sodium acetate (pH 4.5, 0.1 M) followed by enzymatic hydrolysis. The hydrolyzed sample was further diluted to 10 mL with sodium acetate (pH 5.0, 0.1 M) and then extracted by MSPE using n-octadecylphosphonic acid modified magnetic mesoporous nanoparticles (OPA/MMNPs, 50 mg). The extraction time and desorption time were 1 min and 3 min, respectively, with methanol as the desorption solvent. Desorption solution was evaporated to dryness under a mild nitrogen stream at 35 °C, and then dissolved in mobile phase for HPLC separation. The linearity range of the detection method was 0.01-1.0 μg L−1 with a correlation coefficient of 0.9996. The limit of detection was 0.001 μg L−1. The intra- and inter-day precisions (RSDs) were less than 9.7% (n = 5) and 12.9% (n = 3), respectively, which indicated this method has a satisfying reproducibility. The proposed method was further successfully applied to the determination of 1-OHP concentration in urine samples by normalizing to urinary creatinine. Collectively, the rapid, convenient and cost-effective method developed in current study offers a potential application to evaluate the human body PAHs exposure by determination of urinary 1-OHP.

Fractional exhaled nitric oxide in healthy non‐asthmatic 7‐year olds and prenatal exposure to polycyclic aromatic hydrocarbons: Nested regression analysis

The main goal of the study was to assess possible association between transplacental exposure to genotoxic PAH compounds assessed by the cord blood PAH-DNA adducts and fractional exhaled nitric oxide (FeNO) measured in healthy non-asthmatic children at the age of 7 years. The subjects included the subsample of 89 children who took part in the ongoing population based birth cohort study in Krakow and attended FeNO testing. The effect of transplacental PAH exposure was adjusted for potential confounders, such as maternal allergy and children's specific atopy to common domestic allergens. FeNO values were significantly elevated in children with higher prenatal PAH exposure (gmean = 7.7 ppb; 95% CI: 5.8-10.2 ppb) compared with those at low exposure level (gmean = 3.8 ppb; 95% CI: 2.3-6.3) (P = 0.011). Children with maternal allergy had also significantly higher mean FeNO values (gmean = 13.7 ppb, 95% CI: 8.8-21.4 ppb) compared with the subjects whose mothers denied allergy (gmean = 5.6 ppb, 95% CI: 4.3-7.3 ppb) (P = 0.012). Similarly, FeNO values in atopic children were higher (gmean = 11.2 ppb; 95% CI: 3.8-32.8 ppb) than in non-atopic individuals (gmean = 6.0 ppb; 95% CI: 4.7-7.7 ppb, P = 0.079). The results of the nested multivariable linear regression analysis showed that both maternal allergy and sensitization of children to domestic aeroallergens jointly explained 10.4% of FeNO variance, however, the additional 10.9% was determined by prenatal PAH exposure. FeNO is more than a marker useful for screening atopy or symptomatic bronchial inflammation and may also be a proxy for cytokine deregulation and "allergic response" phenotype possibly established in fetal period due to transplacental PAH exposure. Preliminary results of our study should encourage more studies on intrauterine PAH exposure and later respiratory symptoms.

Personal Exposure to PM2.5 and Urinary Hydroxy-PAH Levels in Bus Drivers Exposed to Traffic Exhaust, in Trujillo, Peru

Public transport vehicle drivers, especially in highly polluted or trafficked areas, are exposed to high levels of air pollutants. In this study, we assessed the influence of traffic on levels of hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) in commercial bus drivers in Trujillo, Peru, by measuring the within-shift changes in the urinary whole weight and creatinine-corrected concentrations of the PAH metabolites. We measured personal PM2.5 as a proxy of exposure to traffic emission. Urine samples were collected daily from two bus drivers and three minivan drivers in Trujillo, pre-, mid-, post-work shift and on days when the drivers were off work (total n = 144). Ten OH-PAH metabolites were measured in the urine samples. Drivers were also monitored for exposure to PM2.5 (n = 41). Daily work shift (mean = 13.1 ± 1.3 hr) integrated PM2.5 was measured in the breathing zones of the drivers for an average of 10.5 days per driver. The differences across shift in OH-PAH concentrations were not statistically significant except for urinary 2-hydroxyfluorene (2-FLU) (p = 0.04) and 4-hydroxyphenanthrene (4-PHE) (p = 0.01) and creatinine-corrected 4-hydroxyphenanthrene (p = 0.01). Correlation between pairs of hydroxy-PAHs (ρ = 0.50 to 0.93) were highest for mid-shift samples. Concentrations of PM2.5 (geometric mean = 64 μg/m3; 95% confidence limits = 52 μg/m3, 78 μg/m3) is similar to those measured in many other studies of traffic exposure. There was significant change across work shift for concentrations of only two of the OH-PAHs (2-FLU and 4-PHE). Results indicate that the drivers may have had limited time for clearance of PAH exposure from the body between work shifts. Comparisons of the concentrations of creatinine-corrected hydroxy-PAH to those reported in other studies indicate that exposure of public transport drivers to PAH could be similar. By following the subjects over multiple days, this study gives an indication of appropriate exposure situations for the use of hydroxy-PAHs and will be beneficial in designing future occupational studies of PAH exposure.

A Perspective on the Toxicity of Low Concentrations of Petroleum-Derived Polycyclic Aromatic Hydrocarbons to Early Life Stages of Herring and Salmon

ABSTRACT This article presents a critical review of two groups of studies that reported adverse effects to salmon and herring eggs and fry from exposure to 1 μg/L or less of aqueous total polycyclic aromatic hydrocarbons (TPAH), as weathered oil, and a more toxic aqueous extract of “very weathered oil.” Exposure media were prepared by continuously flowing water up through vertical columns containing gravel oiled at different concentrations of Prudhoe Bay crude oil. Uncontrolled variables associated with the use of the oiled gravel columns included time- and treatment-dependent variations in the PAH concentration and composition in the exposure water, unexplored toxicity from other oil constituents/degradation products, potential toxicity from bacterial and fungal activity, oil droplets as a potential contaminant source, inherent differences between control and exposed embryo populations, and water flow rate differences. Based on a review of the evidence from published project reports, peer-reviewed publications, chemistry data in a public database, and unpublished reports and laboratory records, the reviewed studies did not establish consistent dose (concentration) response or causality and thus do not demonstrate that dissolved PAH alone from the weathered oil resulted in the claimed effects on fish embryos at low μg/L TPAH concentrations. Accordingly, these studies should not be relied on for management decision-making, when assessing the risk of very low–level PAH exposures to early life stages of fish.

Coal-tar pavement sealants might substantially increase children's PAH exposures

Coal-tar pavement sealants might substantially increase children's PAH exposures

Simultaneous determination of nicotine and PAH metabolites in human hair specimen: A potential methodology to assess tobacco smoke contribution in PAH exposure

The present methodology was developed to simultaneously assess chronic exposure to PAHs and to tobacco from the analysis of one hair specimen per examined individual. The method is a two step extraction of twelve mono-hydroxy-PAHs and of nicotine, and their separate analysis by optimized methods using gas chromatography–negative chemical ionization-mass spectrometry. After method validation and assessment of the hair decontamination procedure, 105 hair specimens from smokers and non-smokers were analyzed. All the hair samples tested positive for nicotine. Median concentration was 10.7ng/mg for smokers and 0.5ng/mg for non-smokers. 70% of the samples tested positive for OH-PAHs. The most common one was 2-naphthol (61%) and its concentration was significantly higher in smokers than in non-smokers (median: 111 vs 70pmol/g, p=0.006). 2-OH-benzo(c)phenanthrene and 6-OH-chrysene were only detected once in a non-smoker's hair. The concentration of the sum of all PAH-metabolites ranged from 24 to 67190pmol/g (median: 118pmol/g). Only six samples tested positive for more than two different metabolites. The simultaneous detection of nicotine and OH-PAHs in hair is possible and provides reliable results. This represents a useful tool for the accurate biomonitoring of chronic exposure to PAH and correct identification of the sources of exposure.

The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure

We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p = 0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+−) genotypes were associated with a decrease in urine naphthalene level (p < 0.0001). The NKA show great promise as biomarkers for dermal exposure to naphthalene. Further studies are warranted to characterize the relationship between NKA, other exposure biomarkers, and/or biomarkers of biological effects due to naphthalene and/or PAH exposure.

EFFECT OF POLY-AROMATIC HYDROCARBONS ON CARDIOVASCULAR AND OXIDATIVE STRESS MARKERS IN ELDERLY KOREANS

Background and Aims: Some researches have shown the effect of PAHs exposure on cardiovascular and oxidative stress markers in occupational settings. We aimed to evaluate this relationship among elderly in community exposure levels in a panel study. Methods: Repeated measurements of blood pressure, SDNN, urinary 1-hydroxypyrene, 2-naphthol and malondealdehyde(MDA) were taken from 509 Korean individuals over 60 years old residing in Seongbuk-gu, Seoul, from August 2008 to August 2010. Mixed model analysis was used to investigate the relationship between log-transformed urinary 1-hydroxypyrene, 2-naphthol levels with systolic and diastolic blood pressure, SDNN, urinary MDA levels. Selected adjustment variables were age, sex, body mass index and cotinine levels (model 1) or all the variables in model 1 plus temperature, humidity and amount of sunshine in Seongbuk area on the day each subject visited for measurements. Results: Mean values of log-transformed 1-hydroxypyrene and 2-naphthol levels were -2.315±1.2674µg/g crt and 1.817±1.1266 µg/g crt, and mean levels of systolic and diastolic blood pressure were 127.8±16.47mmHg and 71.9±100.04mmHg. Mean SDNN was 3.2±0.54ms2, and mean urinary MDA level was 0.47±0.492µg/g crt. Significant associations were found between urinary 1-hydroxypyrene levels with systolic blood pressure(model 1: estimate=0.8207, p-value=0.0011; model 2: estimate=0.5373, p-value=0.0313), diastolic blood pressure(model 1: estimate=0.8345, p-value&lt;0.0001; model 2: estimate=0.6262, p-value&lt;0.0001), SDNN(model 1: estimate=-0.7302, p-value=0.033; model 2: estimate=-0.749, p-value=0.0304) and MDA levels(model 1: estimate=0.0535, p-value&lt;0.0001; model 2: estimate=0.05249, p-value&lt;0.0001). Urinary 2-naphthol also showed significant associations with systolic blood pressure(model 1: estimate=0.7677, p-value=0.0133; model 2: estimate=0.5938, p-value=0.0513), diastolic blood pressure(model 1: estimate=0.5167, p-value=0.0072; model 2: estimate=0.3989, p-value=0.0337) and MDA levels(model 1: estimate=0.07543, p-value&lt;0.001; model 2: estimate=0.07555, p-value&lt;0.001), but not with SDNN(model 1: estimate=0.2096, p-value=0.6167; model 2: estimate=0.1972, p-value=0.6389). Conclusions: Urinary 1-hydroxypyrene and 2-naphthol levels are significantly associated with cardiovascular and oxidative stress markers, systolic and diastolic blood pressures, SDNN and urinary MDA levels in elderly Koreans.

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.

Repeated measurements for assessment of urinary 2-naphthol levels in individuals exposed to polycyclic aromatic hydrocarbons

A repeated measurement cohort study was conducted to determine whether 2-napthol can be a suitable biomarker for evaluating the magnitude of exposure to PAHs from coke oven emissions. Time-course patterns of urinary 2-naphthol levels in coke-oven workers were examined. Also, the correlation between urinary 2-naphthol levels and PAHs from personal breathing zone samples was analyzed while examining and adjusting possible confounding factors, such as smoking alcohol consumption, and age of human subjects. A total of 8 spot urine samples were collected from each high-exposure group (topside-oven workers, n = 17) and low-exposure group (side-oven workers, n = 25) during the whole working cycle, which consists of six consecutive working days followed by 2 days off. Personal breathing zone samples were collected to quantify PAH intake. A questionnaire was distributed and collected from each worker for assessment of demographic parameters. Our results confirmed that the topside-oven area contained significantly higher PAH levels than the side-oven area. Urinary 2-naphthol levels correlated with the levels of PAH species, including pyrene, benzo[k]fluoranthene, benezo[g,h,i]pyrene, naphthalene, phenanthrene, anthracene, indeno[1,2,3-cd]pyrene, benzo[k]fluoranthene, and total PAHs. During the working cycle, urinary 2-naphthol levels remained stable at around 46–97 ng/mg creatinine during the working days and dramatically increased during the off days. After stratification of data based on smoking status, smokers had significantly higher urinary 2-naphthol levels than non-smokers, and 2-naphthol levels positively correlated with smoking status. Coke-oven emissions are a source of exposure to naphthalene. Also, smoking is a significant source of exposure to naphthalene and served as a confounder factor. Due to its abundance, positive association with total PAHs and certain carcinogenic PAH compounds, and slower elimination kinetics, urinary 2-naphthol may have the potential to serve as a biomarker for PAH exposure, when smoking status is carefully adjusted.

The effects of intramuscular and intraperitoneal injections of benzo[ a]pyrene on selected biomarkers in Clarias gariepinus

This study investigated the dose-dependent and time-course effects of intramuscular (i.m.) and intraperitoneal (i.p.) injection of benzo[ a]pyrene (BaP) on the biomarkers EROD activity, GST activity, concentrations of BaP metabolites in bile, and visceral fat deposits (Lipid Somatic Index, LSI) in African catfish ( Clarias gariepinus). Intraperitoneal injection resulted in 4.5 times higher accumulation of total selected biliary FACs than i.m. injection. Hepatic GST activities were inhibited by BaP via both injection methods. Dose–response relationships between BaP injection and both biliary FAC concentrations and hepatic GST activities were linear in the i.p. injected group but nonlinear in the i.m. injected fish. Hepatic EROD activity and LSI were not significantly affected by BaP exposure by either injection route. We conclude that i.p. is a more effective route of exposure than i.m. for future ecotoxicological studies of PAH exposure in C. gariepinus.

1-OH-Pyrene and 3-OH-Phenanthrene in Urine Show Good Relationship with their Parent Polycyclic Aromatic Hydrocarbons in Muscle in Dairy Cattle

The toxicities of phenanthrene (PH) and pyrene (PY) are less than benzo (a) pyrene (BaP) , but both compounds are found in higher concentrations in the air, feed, and food. Most PAHs are metabolized to hydroxylated compounds by the hepatic cytochrome P450 monooxigenases system. Metabolites are excreted into urine and feces. We determined concentrations of PH, PY and BaP in muscle and hydroxylated metabolites, 3-OH-PH, 1-OH-PY, and 3-OH-BaP, respectively, in urine from dairy cattle (n = 24) . We also evaluated the relationship between parent compounds in muscle and their metabolites in urine. Concentrations of PH and PY in muscle ranged from 0.7~4.8 ng/g (1.8 ± 1.7) and 0.4~4.1 ng/g (1.2 ± 1.2) , respectively. Concentrations of 3-OH-PH and 1-OH-PY in urine ranged from 0.1~5.9 ng/ml (2.9 ± 3.7) and 0.5~3.6 ng/ml (1.9 ± 2.3) , respectively. Correlation coefficient for PY concentration in muscle versus 1-OH-PY in urine was 0.657 and for PH concentration in muscle versus 3-OH-PH in urine was 0.579.Coefficient determination for PY and PH concentrations in muscle was 0.886 and for 1-OH-PY and 3-OHPH in urine was 0.834. This study suggests that 1-OH-PY and 3-OH-PH could be used as biomarkers for PAHs exposure in dairy cattle.

Assessments of PAHs Exposure and Health Effects for Foundryʼs Workers

Assessments of PAHs Exposure and Health Effects for Foundryʼs Workers

Inflammation, Oxidative Stress, and PAHs Exposure Biomarkers in Children With Atopic Dermatitis

Inflammation, Oxidative Stress, and PAHs Exposure Biomarkers in Children With Atopic Dermatitis

Exposures and Potential Risks in the Neighborhoods of 5 Different Restaurants Emitting Particulate Polycyclic Aromatic Hydrocarbons

PP-30-096 Background/Aims: Cooking is a very important air pollutant source in urban areas. Especially in oriental countries, multifarious cooking practices may result in significant emission of particulate pollutants such as particulate polycyclic aromatic hydrocarbons (pPAHs), some of which are probable carcinogens. Most restaurants in Taiwan do not equip with emission control devices. Emission of cooking fume results in constant pollutant exposure of neighbors in densely populated urban areas. Methods: This work assessed pPAH levels in the breathing zones of neighborhood residents close to the exhaust outlets of 5 restaurants with different cooking practices, namely, an international fried chicken franchise, a local fried chicken store, a Chinese mom-and-pop place, a Cantonese-style barbeque restaurant, and a Korean barbeque store. A high-volume sampler was used to collect samples under 2 conditions, with or without the operation of the control devices. In all, 21 species of PAH were analyzed with LC/MS/MS. Results: Preliminary results showed that the concentrations of total PAHs were 1.1–2.5 ng/m3 and 1.1–14.8 ng/m3 with and without the control devises, respectively. For the international fried chicken franchise and the local fried chicken store, it was obvious that the control devices did not reduce PAH levels. As for the Cantonese-style barbeque restaurant, the control device can reduce the end-of-pipe PAH level down to 16%. Without the control device, the Cantonese-style barbeque restaurant had the highest PAH level near their exhaust outlet, ie, 14.8 ng/m3. Based on benzo[a]pyrene toxic equivalent factors, PAH exposure levels are in the range of 0.01–0.8 ng-TEQ/m3. The potential health risks of neighbors of such exposure were one order of magnitude higher than risks from pPAH exposure during commuting. Conclusion: Current control devices had no effects to reduce pPAH levels from fried chickens. In addition, the resulting health risks with/without control devices were all higher than those from traffic emission. Cooking emission deserved more attentions in researches and regulations.