Dietary Polycyclic Aromatic Hydrocarbons Exposure Research Articles

Environmental and dietary exposure to 24 polycyclic aromatic hydrocarbons in a typical Chinese coking plant

Polycyclic aromatic hydrocarbons (PAHs), known for their health risks, are prevalent in the environment, with the coking industry being a major source of their emissions. To bridge the knowledge gap concerning the relationship between environmental and dietary PAH exposure, we explore this complex interplay by investigating the dietary exposure characteristics of 24 PAHs within a typical Chinese coking plant and their association with environmental pollution. Our research revealed Nap and Fle as primary dietary contaminants, emphasizing the significant influence of soil and atmospheric pollution on PAH exposure. We subjected our data to non-metric multidimensional scaling (NMDS), Spearman correlation analysis, Lasso regression, and Weighted Quantile Sum (WQS) regression to delve into this multifaceted phenomenon. NMDS reveals that dietary PAH exposure, especially within the high molecular weight (HMW) group, is common both within and around the coking plant. This suggests that meals prepared within the plant may be contaminated, posing health risks to coking plant workers. Furthermore, our assessment of dietary exposure risk highlights Nap and Fle as the primary dietary contaminants, with BaP and DahA raising concerns due to their higher carcinogenic potential. Our findings indicate that dietary exposure often exceeds acceptable limits, particularly for coking plant workers. Correlation analyses uncover the dominant roles of soil and atmospheric pollution in shaping dietary PAH exposure. Soil contamination significantly impacts specific PAHs, while atmospheric pollution contributes to others. Additionally, WQS regression emphasizes the substantial influence of soil and drinking water on dietary PAHs. In summary, our study sheds light on the dietary exposure characteristics of PAHs in a typical Chinese coking plant and their intricate interplay with environmental factors. These findings underscore the need for comprehensive strategies to mitigate PAH exposure so as to safeguard both human health and the environment in affected regions.

Occurrence and exposure evaluation of polycyclic aromatic hydrocarbons in tea samples consumed in Beijing-Tianjin-Hebei regions of China

In this study, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were investigated in a total of 129 tea samples marketed in Beijing-Tianjin-Hebei (BTH) regions of China. The total concentrations of 16 PAHs (Σ16 PAHs) varied from 16.6 to 781.6 μg/kg with a mean value of 211.7 μg/kg. Tea samples were contaminated mainly with low molecular weight PAH compounds. During tea infusion, 4.9–9.3% of the Σ16 PAHs contained in different types of tea samples were released into the liquor. The dietary exposure of PAHs and risk assessments of adults in BTH region were then performed by calculating estimated daily intake (EDI), margin of exposure approach (MOE) and incremental lifetime cancer risk (ILCR). Compared to semi-fermented or unfermented tea samples, EDIs of PAHs in fullyfermented tea displayed the highest exposure risk. The MOEs results in all six types tea for local population are at safe range (MOE ≥ 10,000). These ILCR values indicated there is significant potential of carcinogenic risk related to tea consumption, but no significant cancer risk.

Distribution and health risk assessment on dietary exposure of PAHs in vegetables and fruits of Asir, Saudi Arabia

GC/MS/MS was used to examine quantities, sources, and hazards of polycyclic aromatic hydrocarbons (PAHs) in vegetable, leafy vegetables and fruit samples collected from Asir (Saudi Arabia). PAHs were varied from 10.11 to 604.43 (average 147.04), 38.35–798.21 (average 261.30), and 10.32–204.85 (average 90.65) ng/g, respectively. The order of ∑FPAH (fossil fuel PAHs) was Coriander > Eggplant > Grape, with 763.31, 575.93, and 204.85 ng/g, respectively. However, the order of ∑CARC (carcinogenic PAHs) was Carrot > Pear > Dill with 404.73, 35.91, and 34.01 ng/g, respectively. In addition, the order of ∑COMB (combustion PAHs) was cauliflower > lettuce > banana, with 42.31, 69.62, and 11.61 ng/g, respectively. Generally, the order of different PAH categories was ∑FPAHs > ∑CARC > ∑COMB. The hazard index (HI) for phenanthrene, Pyrene, fluoranthene, and anthracene was 10.73, 2.25, 1.65, and 1.13, respectively, indicating undesirable consequences. Phenanthrene recorded HQ > 1, indicating a probable deleterious effect, and other PAHs recorded HQ of about one, indicating that no harmful health effects from them. The diagnostic ratio of PAHs in fruits and vegetables indicated pyrolytic and petrogenic origins, via incomplete combustion of organic components. Finally, PAHs recorded in our samples were slightly greater than other regions of Saudi Arabia and that recorded in Asian and African countries.

Dietary exposure and risk assessment of European Union priority (EU 15+1) polycyclic aromatic hydrocarbons from milks and milk powders in China

Dairy products, characterized by rich nutrition and unique flavor, occupy an increasing share of the human diet with the development of higher living standards. However, trace hazardous contaminants in dairy products, such as polycyclic aromatic hydrocarbons (PAH), are arousing public concern. In this study, we investigated 82 milks and milk powders from Shanghai markets for the occurrence of 20 PAH, including 16 European Union priority (EU 15+1) PAH and 4 derivatives. Furthermore, we carried out a risk assessment of dietary exposure of PAHs from dairy products based on detection results and data on body weight and dietary intake obtained from questionnaires. Two assessment methods were used in this study: the incremental lifetime cancer risk (ILCR) and margin of exposure (MOE) methods. The ILCR of all age groups was 10-6 to 10-4, indicating a potential but acceptable carcinogenic risk. The MOE of the 4 groups (divided by age and sex) was >104, indicating no significant carcinogenic risk of PAH exposure from dairy products. In both methods, children had the highest risk because of their greater consumption of dairy products, followed by seniors, young adults, and middle-aged adults. Results of this study provide reference data on the exposure level and health risk of PAHs from dairy product intake.

Determination of polycyclic aromatic hydrocarbons in commercial olive oils by HPLC/GC/MS – Occurrence, composition and sources

Polycyclic aromatic hydrocarbons (PAHs) are a large class of organic compounds produced from incomplete combustion. Many PAHs are mutagenic and some are carcinogenic and pose a health risk to humans. Dietary intake of PAHs is a major route of exposure, where fats and edible oils are important contributors to overall dietary PAH exposure. Composed of hundreds of individual compounds as a complex mixture, only 16 PAHs are typically monitored in food and the environment. In this present study we analyzed 16 commercial olive oil samples from different countries of origin and type (virgin or refined oil) for their content of 45 PAHs using a high-performance liquid chromatograph coupled to a gas chromatograph with a mass spectrometric detector. The content of the 45 PAHs varied between 9.17 and 94.7 μg/kg (median: 30.1 μg/kg) in the different olive oil samples. Only one sample didn't meet the regulatory threshold levels for PAHs. The compositional profile of PAHs across the olive oil samples showed a high abundance of PAHs of lower molecular weights, and a large contribution of alkylated PAHs regardless of olive oil type. Direct contact with diesel exhaust emissions from mechanical harvesters has previously shown to affect PAH levels in olive oils. Using diagnostic PAH ratios, biomass/coal combustion and/or petroleum/fossil fuel combustion were indicated as important sources. Source apportionment by Positive Matrix Factorization revealed diesel exhaust emission and biomass combustion as the two major sources of PAHs followed by traffic emissions. This suggests that air quality may have a considerable impact on pollution levels in olive oils and thus indirectly affect dietary exposure.

Analytical chemistry, formation, mitigation, and risk assessment of polycyclic aromatic hydrocarbons: From food processing to in vivo metabolic transformation.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the air, oils, water, and food products we encounter every day. Among these exposures, food consumption is a major route of PAH exposure for nonsmokers. The PAH dietary exposure levels vary among different countries; however, many studies have shown PAH exposure to be highly concerning to human health. The levels of PAH contamination in food are mainly influenced by processing procedures and cooking methods, and they could be attenuated by modifying cooking procedures and adding antioxidant-rich marinades. Several PAHs have toxic, mutagenic, and carcinogenic properties. The PAH benzo[a]pyrene (BaP) is particularly regarded as carcinogenic. There are three major metabolism pathways for PAHs, and the final products can bind to DNA, thus exerting mutagenic effects. Biological monitoring through the use of biomarkers is necessary for comprehensive and accurate risk assessments of human PAH exposure. It is important to reduce dietary PAH exposure and to implement reasonable and effective risk management strategies to reduce PAH levels in food to improve public health.

Dietary exposure and cancer risk assessment of the Pakistani population exposed to polycyclic aromatic hydrocarbons

The sixteen-priority polycyclic aromatic hydrocarbons (PAHs) were determined in twenty-one groceries from six food groups consumed by the Pakistani population. The highest concentration of the total PAHs was found in fish (243 ng g−1), while the lowest concentration was determined in rice (53 ng g−1). The total B[a]Peq dietary exposure for the male group followed an increasing order of children (865.5 ng day−1) < adolescents (2301 ng day−1) < seniors (2864 ng day−1) < adults (3004 ng day−1), whereas the similar order was also observed for the female group. The male group showed 1–8.5% (mean 5.5%) of higher exposure amount compared to the female group. Among all food categories, wheat (43%) and milk (34%) contributed the greatest while rice (1%) and egg (1%) contributed the smallest to the total dietary exposure of PAHs. The incremental lifetime cancer risk (ILCR) values for the adults and children revealed a potential cancer risk to the both male and female groups. Whereas at the 95th percentiles, the ILCR values for all age and gender groups exceeded the limit (>10−5), demonstrating a high potential cancer risk in the Pakistani population. The sensitivity analysis found that the daily dietary intake, exposure duration and the cancer slope factor were the most influential variables contributed to the total variance of risk.

Estimation of the dietary exposure of polycyclic aromatic hydrocarbons in Syria and their health risks assessment

In this work, the exposure of people, through their diet, to polycyclic aromatic hydrocarbons (PAHs) has been assessed for the urban, rural, and general populations in Syria. The food categories consumed have been divided into major groups, and the health risk assessment on dietary exposure of PAHs determined in each food category. For this purpose, two approaches were used: incremental lifetime cancer risk (ILCR) and margin of exposure approach (MOE). The results showed that each of the following food categories: oils and fats, meat and meat products, vegetables, and cereals dominantly contribute in the dietary exposure of PAHs. Also their MOE values are the lowest. Additionally, they have higher ILCR values. Therefore, these groups are a main risk source to health. On the other hand, the dietary exposure of PAHs in each of urban, rural and general populations was of low health concern, whereas their ILCR values reached to 10E-05 in total food categories, nevertheless it remains lower than serious risk level (ILCR&gt;10E-04). This work is the first study that is dealing with dietary exposure of PAHs and their health risk assessment in Syria.

Occurrence of polycyclic aromatic hydrocarbons in youtiao and exposure assessment from Shandong Province, China

This study analyzed 15 polycyclic aromatic hydrocarbons (PAHs) in 170 youtiao (Chinese dough sticks) samples collected from Shandong Province of China, which were determined using high performance liquid chromatography-fluorescence detection (HPLC-FLD). The results indicated that the incidence rate of PAHs compounds was 89.4% and the mean concentration of 15 PAHs was 65.8 μg/kg. Naphthalene (Nap) was detected with the highest concentration and the largest incidence rate. One sample exceeded the maximum level of 1 μg/kg for the carcinogenic benzo(a)pyrene (BaP) in cereals and cereal-based products set by European Union (EU), while 47 samples exceeded the maximum level of 1 μg/kg for PAH4 set by EU. The dietary exposure of PAHs and the potential human health risk assessment were assessed using estimated daily intake (EDI), target hazard quotient (THQ), and the incremental lifetime cancer risk (ILCR). EDI values were below the intake range reviewed by the European Food Safety Authority (EFSA) for each class of contaminant. The THQ values were below the safe standard of 1, thus the risk to develop chronic systemic effects due to individual PAH was low. The ILCR results for children, adolescents, adults, and seniors were all lower than the priority level (1 × 10−4), implying no significant cancer risk related to youtiao consumption for local population. Further data are still needed for proper management of the risks associated with PAHs in youtiao samples.

Distribution of polycyclic aromatic hydrocarbons (PAHs) in commonly consumed seafood from coastal areas of Bangladesh and associated human health implications.

Levels, distribution, possible sources and potential risks of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated comprehensively in frequently consumed seafood species collected from the coastal areas of Bangladesh. Samples were collected in winter and summer, 2015. The total concentration of PAHs (∑PAHs) in the examined seafood was 184.5-2806.6ng/g wet weight (ww) in winter and 117.9-4216.8ng/g ww in summer, respectively. The levels of ∑PAHs were comparable to or higher than those reported from other coastal areas. Seasonal variation was not significant for the majority of the monitored PAHs. Spatial distribution revealed that the seafood collected from areas with recent urbanization and industrialization (Chittagong, Cox's Bazar and Sundarbans) was more contaminated with PAHs than those from the unindustrialized area (Meghna Estuary). Low-molecular-weight isomers dominated the PAH composition. Molecular ratios suggested the abundance of mixed sources of PAHs in the Bangladeshi coastal areas with a slight imposition toward the petrogenic origin. A preliminary evaluation of human health risk indicated that the dietary PAH exposure from consumption of Bangladeshi seafood would certainly induce adverse health effects. This finding suggests the need to enhance risk management regarding seafood consumption through public advisory in Bangladesh.

Transcriptional changes in innate immunity genes in head kidneys from Aeromonas salmonicida-challenged rainbow trout fed a mixture of polycyclic aromatic hydrocarbons

We previously observed that exposure to a complex mixture of high molecular weight polycyclic aromatic hydrocarbons (PAHs) increased sensitivity of rainbow trout (Oncorhynchus mykiss) to subsequent challenge with Aeromonas salmonicida, the causative agent of furunculosis. In this study, we evaluate potential mechanisms associated with disease susceptibility from combined environmental factors of dietary PAH exposure and pathogen challenge. Rainbow trout were fed a mixture of ten high molecular weight PAHs at an environmentally relevant concentration (7.82μg PAH mixture/g fish/day) or control diet for 50 days. After 50 days of PAH exposure, fish were challenged with either Aeromonas salmonicida at a lethal concentration 30 (LC30) or growth media without the pathogen (mock challenge). Head kidneys were collected 2, 4, 10 and 20 days after challenge and gene expression (q<0.05) was evaluated among treatments. In animals fed the PAH contaminated diet, we observed down-regulation of expression for innate immune system genes in pathways (p<0.05) for the terminal steps of the complement cascade (complement component C6) and other bacteriolytic processes (lysozyme type II) potentially underlying increased disease susceptibility after pathogen challenge. Increased expression of genes associated with hemorrhage/tissue remodeling/inflammation pathways (p<0.05) was likely related to more severe head kidney damage due to infection in PAH-fed compared to control-fed fish. This study is the first to evaluate transcriptional signatures associated with the impact of chronic exposure to an environmentally relevant mixture of PAHs in disease susceptibility and immunity.

Urinary Polycyclic Aromatic Hydrocarbon Metabolites and Altered Lung Function in Wuhan, China.

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with adverse effects on the respiratory system. However, the association between internal levels of PAH metabolites and lung function levels remains unclear. We investigated the relationships between urinary PAH metabolite concentrations and lung function levels in a general Chinese population. Lung function and 12 urinary PAH metabolites were measured in 2,747 participants from the Wuhan-Zhuhai cohort in China. Associations between urinary PAH metabolites and lung function were analyzed by linear mixed models. We also investigated associations among urinary PAH metabolite concentrations, traffic exposure time, and dietary PAH exposure. We found significant associations between increased levels of urinary PAH metabolites and reduced lung function. Each 1-U increase in log-transformed levels of 2-hydroxynaphthalene, 9-hydroxyfluorene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1-hydroxypyrene, or total urinary PAH metabolites was associated with a 23.79-, 19.36-, 41.76-, 36.87-, 33.47-, 27.37-, 39.53-, 34.35-, 25.03-, or 37.13-ml reduction in FEV1, respectively (all P < 0.05). Each 1-U increase in 2-hydroxynaphthalene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, or total urinary PAH metabolites was associated with a 24.39-, 33.90-, 27.15-, 28.56-, 27.46-, or 27.99-ml reduction in FVC, respectively (all P < 0.05). The total urinary PAH metabolites concentration was positively associated with both traffic exposure time and dietary PAH exposure among nonsmokers. Total and specific urinary PAH metabolites were associated with lung function reduction in a general Chinese population. Further studies are needed to investigate the potential mechanism by which PAHs induces lung function reduction.

Risk of human exposure to polycyclic aromatic hydrocarbons: A case study in Beijing, China

Polycyclic aromatic hydrocarbons (PAHs) can cause adverse effects on human health. The relative contributions of their two major intake routes (diet and inhalation) to population PAH exposure are still unclear. We modeled the contributions of diet and inhalation to the overall PAH exposure of the population of Beijing in China, and assessed their human incremental lifetime cancer risks (ILCR) using a Mont Carlo simulation approach. The results showed that diet accounted for about 85% of low-molecular-weight PAH (L-PAH) exposure, while inhalation accounted for approximately 57% of high-molecular-weight PAH (H-PAH) exposure of the Beijing population. Meat and cereals were the main contributors to dietary PAH exposure. Both gaseous- and particulate-phase PAHs contributed to L-PAH exposure through inhalation, whereas exposure to H-PAHs was mostly from the particulate-phase. To reduce the cancer incidence of the Beijing population, more attention should be given to inhaled particulate-phase PAHs with considerable carcinogenic potential.

Polycyclic aromatic hydrocarbons (PAHs) in Crassostrea rhizophorae and Cathorops spixii from the Caroni Swamp, Trinidad, West Indies.

Dietary exposure to polycyclic aromatic hydrocarbons (PAHs) may pose serious threats to human health. However, within the Caribbean, quantitative assessments regarding the risks associated with dietary PAH exposure remain sparse. This study investigated PAH presence in edible biota from the Caroni Swamp and quantitatively assessed the potential health threat to human consumers. Mangrove oysters (Crassostrea rhizophorae) and Madamango sea catfish (Cathorops spixii) collected from seven sites in the Caroni Swamp were analysed for 16 priority PAHs. Total PAH levels ranged from 109 ± 18.4 to 362 ± 63.0 ng/g dry wt. in Crassostrea rhizophorae and 7.5 ± 0.9 to 43.5 ± 25.5 ng/g dry wt. in Cathorops spixii (average ± standard deviation). Benzo[a]pyrene levels in Crassostrea rhizophorae at all sites exceeded international guidelines from British Colombia (Canada) and the European Union (EU). Incremental lifetime cancer risk (ILCR) values based on the ingestion of Crassostrea rhizophorae ranged from 8.4 × 10(-6) to 1.6 × 10(-5) and slightly exceeded the commonly used 1 × 10(-6) acceptable level of risk. Information from this study is important in understanding the potential health risks posed by PAHs, it is critical towards the protection of public health, and it serves as a useful baseline for comparison with future work.

Reduction of Carcinogenic Polycyclic Aromatic Hydrocarbons in Meat by Sugar-Smoking and Dietary Exposure Assessment in Taiwan

Polycyclic aromatic hydrocarbons (PAHs) represent an important pollutant in foods and/or the environment. This study aimed to determine the PAH contents in sugar-smoked meat by employing a quick, easy, cheap, effective, rugged, safe (QuEChERS) method combined with a GC-MS technique and assess the dietary exposure of PAHs in Taiwan. Results showed that the longer the sugar-smoking duration, the more the total PAH formation. By sugar-smoking for 6 min, the total PAH contents generated in red meat (33.9 ± 3.1-125.5 ± 9.2 ppb) were higher than in poultry meat (19.1 ± 2.0-28.2 ± 1.2 ppb) and seafood (9.1 ± 1.4-31.8 ± 1.8 ppb), with lamb steak containing the largest amount of total PAHs. Most importantly, the highly carcinogenic benzo[a]pyrene remained undetected in all of the sugar-smoked meat samples. In addition, the cancer risk due to dietary PAH exposure based on total intake of meat in Taiwan was <2 × 10(-7). This outcome demonstrates that sugar-smoking can be adopted to replace the traditional smoking process with wood as smoke source.

Immunomodulation in eastern oysters, Crassostrea virginica, exposed to a PAH-contaminated, microphytobenthic diatom

The trophic transfer of sediment-associated pollutants is a growing concern in shellfish harvesting areas. Previous studies have examined the role of phytoplankton in the transport of organic contaminants to bivalve species, but little information on microphytobenthic communities and their role as contaminant vectors exists. Polycyclic aromatic hydrocarbons (PAHs) are organic compounds formed during natural and industrial processes; they are termed “persistent organic pollutants” because they are only slowly degraded by natural processes. This study examined the transfer of PAH compounds (naphthalene, pyrene, and benzo(a)pyrene) by a microphytobenthic diatom to the eastern oyster, a commercially important shellfish species, to determine if dietary accumulation is a route of contaminant exposure capable of inducing physiological responses. PAH compounds were adsorbed to a diatom culture (Nitzschia brevirostris) in a range of concentrations (5, 125, 625, and 1000μgL−1), and eastern oysters were exposed experimentally to the contaminated diatom cultures to assess possible effects upon oyster hemocytes and selected immune-defense functions. A preliminary experiment was designed to identify individual effects of several PAH compounds (naphthalene, pyrene, and benzo(a)pyrene) on hemocyte viability and phagocytic activity. Results from this experiment revealed that the most-toxic compound, benzo(a)pyrene, at the highest concentration, stimulated an increase in agranular hemocyte counts. A follow-up study examined the effects of benzo(a)pyrene on hemocyte viability, adhesion, phagocytosis, and reactive oxygen species (ROS). These studies showed the ability of this benthic diatom to transport PAHs to the eastern oyster and to cause immunomodulation. Hemocyte responses to dietary PAH exposure included an increase in circulating hemocytes and increased production of reactive oxygen species by these cells.

Health risk assessment on dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in Taiyuan, China

Twenty-five kinds of seven categories of foods were sampled in December 2008 and the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined. The highest level of total PAHs was detected in pork (195.30 ng/g) whereas the lowest concentration was found in milk (8.73 ng/g). The median values of B[a]P equivalent (B[a]P eq) daily exposure doses for children, adolescents, adults and seniors of male were estimated to be 392.42, 511.01, 571.56 and 532.56 ng/d, respectively, whereas those for the above population groups of female were found to be 355.16, 440.51, 487.64 and 444.85 ng/d, respectively. The incremental lifetime cancer risk (ILCR) values at the 22.1th, 26.1th, 12.7th, 24.9th, 22.7th, 27.0th, 12.9th, and 25.5th percentiles for male children, male adolescents, male adults, male seniors, female children, female adolescents, female adults and female seniors, respectively, were larger than 10 − 6 , indicating high potential carcinogenic risk, and were larger than 10 − 4 at the 74.5th, 78.7th, 60.6th, 77.4th, 75.3th, 79.5th, 60.8th and 77.9th percentiles for the above groups, respectively, which implied significant cancer risk. Sensitivity analysis found that the two variables of oral cancer slope factor of benzo( a) pyrene (SF) and the daily dietary PAH exposure level (ED) had the greater impact than that of body weight (BW) on the ILCR.

Smoking during pregnancy is associated with higher dietary intake of polycyclic aromatic hydrocarbons and poor diet quality

To estimate the dietary intake of total polycyclic aromatic hydrocarbons (PAH) and benzo(a)pyrene (BaP), and to characterise factors associated with higher intake during pregnancy. Recent studies suggest that prenatal exposure to PAH is associated with adverse reproductive outcomes. Other than tobacco smoke and occupational exposures, diet is the main source of human PAH exposure. Prospective birth cohort study. Dietary exposure to total PAH and BaP was calculated combining food consumption data and estimated PAH concentrations in foods. One-way ANOVA was used to assess differences in intake among non-smokers, passive or active smokers. Linear regression was used to assess factors related to higher intake, and associations between dietary PAH and birth weight. Sabadell, Spain, 2004-2006. Women (n 657) recruited during the first trimester of pregnancy. The mean dietary intake of BaP and total PAH was significantly higher among active (0·199 and 10·207 μg/d, respectively) and passive smokers (0·196 and 9·458 μg/d) than among non-smokers (0·181 and 8·757 μg/d; P value < 0·005). Maternal age, educational level and region of origin were also associated with higher BaP intake. In all women, major contributors to PAH intake were processed/cured meats, cereals/potatoes and shellfish. Elevated first trimester dietary BaP was associated with a significant reduction in birth weight (fourth v. first quartile: β = -142·73 g, P value < 0·05). Active and passive smokers had higher dietary PAH exposure during pregnancy because of higher intake of processed meats and shellfish. As tobacco smoke is an additional route of PAH exposure, the added dietary burden in these women is of concern.

Excretion characteristics of urinary 8‐hydroxydeoxyguanosine after dietary exposure to polycyclic aromatic hydrocarbons

Urinary 8-hydroxydeoxyguanosine (8-OHdG) is considered a noninvasive marker for oxidative stress and also a marker of carcinogenic potential for compounds such as polycyclic aromatic hydrocarbons (PAHs). Although human studies have investigated urinary 8-OHdG concentrations in PAH-exposed workers and the general population, the background level and excretion kinetics of urinary 8-OHdG in humans remain unclear. Two feeding experiments (consumption of barbecued meat of 15 and 30 g/kg for Experiments 1 and 2, respectively) were conducted to examine the excretion characteristics of urinary 8-OHdG. All urine voided over 7 days was collected, but only first morning (approximately 8 A.M.) and last afternoon (approximately 5 P.M.) samples were analyzed for 8-OHdG. Mean background urinary 8-OHdG concentration was 4.76 microg/g creatinine. Statistically significant increases (P < 0.05) in urinary 8-OHdG concentration were observed on the afternoon of the 3rd and 2nd days after barbecued meat consumption for Experiments 1 and 2, respectively. A pattern of diurnal fluctuation (P < 0.05) in 8-OHdG excretion rate was evident, in that the excretion of 8-OHdG was faster during the night than during the day. Additionally, significant (P < 0.05) and strong (r > 0.6) correlations were found between urinary 8-OHdG measured 2-3 days after exposure to barbecued meat, and 1-hydroxypyrene (1-OHP) and 3-hydroxy-benzo[a]pyrene (3-OHBaP) concentrations measured within a half day after such exposure. The current results demonstrate a lag in excretion of urinary 8-OHdG relative to 1-OHP and 3-PHBaP after dietary PAH exposure. These relationships highlight the importance of sampling time when assessing PAH-related DNA lesions through urinary 8-OHdG.

Inhalation and dietary exposure to polycyclic aromatic hydrocarbons and urinary 1-hydroxypyrene in non-smoking university students

To examine which exposure pathway, dietary or inhalation, contribute more to the exposure to, and/or internal dose of, polycyclic aromatic hydrocarbons (PAHs) of non-smoking Japanese. Duplicated diet, personal air samples and 24-h urine were collected from 14 non-smoking male university students without occupational exposure and the concentrations of PAHs in diet and air and that of 1-hydroxypyrene (1-OHP) in urine were measured with HPLC-fluorescence detector. Daily dietary exposure contributed more than 90% of the total (diet + inhalation) daily exposure level for pyrene (diet/inhalation: 757/1.2 ng/day), benzo[k]fluoranthene (25/1.7 ng/day) and benzo[a]pyrene (91/2.1 ng/day). Urinary excretion of 1-OHP (median: 37 ng/day) was statistically significantly correlated only with dietary PAHs exposure level but not with inhalation. Countermeasures to lower PAHs levels in atmosphere has been successful in Japan and more attention should be directed to dietary exposure to PAHs for reducing cancer risk in general population.