Halogenated and parent polycyclic aromatic hydrocarbons in vegetables: Levels, dietary intakes, and health risk assessments

Dietary exposure to polycyclic aromatic hydrocarbons-contaminated Talinum Triangulare grown along polluted river

The research aims to evaluate the source, dispersion, and human health risk assessment of PAH-contaminated Talinum Triangulare grown along the polluted Ikpoba River. The freeze-dried vegetables were sonicated with dichloromethane for an hour and then concentrated using a rotary evaporator. The extract was purified using a glass column with anhydrous Na2SO4 and silica gel and analyzed using gas chromatography-mass spectrometry (GC-MS). The distribution of the contaminants showed that Pyrene < Benzo(a)anthracene ≤ Fluorene < Phenathrene ≤ Naphthalene ≤ Acenaphthene < Anthracene ≤ Acenaphthylene, while Pyrene < Benzo(a)anthracene < Fluorene < Phenathrene < Acenaphthalene ≤ Naphthalene < Anthracene < Acenaphthylene in wet and dry periods, respectively. The average ∑8 PAHs was 0.85 mg/kg and 0.75 mg/kg in wet and dry periods, respectively, and showed a decrease of 17.64% from wet to dry periods. The daily average dose revealed that the infant male and the adult female consumed the least and highest doses of T. Triangulare (TT), respectively. Furthermore, the hazard quotient and hazard index were < 1 for all the target groups, with adult females having higher values in both seasons. However, the incremental life cancer risk of the target group was between potential and high-potential cancer risk, with adolescent males and adult females more prone to low and high cancer risk, respectively. The isomer ratio and multivariate statistics revealed the sources of the PAH-contaminated TT to be more from pyrolysis.

Quantitative characterization of resident' exposure to typical semi-volatile organic compounds (SVOCs) around a non-ferrous metal smelting plant

To comprehensively characterize residents' exposure to major semi-volatile organic compounds (SVOCs), samples of indoor floor wipes, size-segregated airborne particles, gaseous air, food, and paired skin wipes were simultaneously collected from residential areas around a large non-ferrous metal smelting plant as compared with the control areas, and three typical SVOCs (including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and halogenated PAHs (HPAHs)) were determined. Comparison and correlation analysis among matrices indicated PAHs were the major contaminants emitted from metal smelting activities compared to HPAHs and PCBs, with naphthalene verified as the most important characteristic compound, and their accumulation on skin may be a comprehensive consequence of contact with floor dust and air. While patterns of human exposure pathways for the SVOCs were found to be clearly correlated to their vapor pressure, dermal absorption was the major contributor (51.1-76.3%) to total carcinogenic risk (TCR) of PAHs and HPAHs for surrounding residents, especially for low molecular weight PAHs, but dietary ingestion (98.6%) was the dominant exposure pathway to PCBs. The TCR of PAHs exceeded the acceptable level (1 × 10-4), implying smelting activities obviously elevated the health risk. This study will serve developing pertinent exposure and health risk prevention measures.

Ecological pollution and health risk monitoring assessment of polycyclic aromatic hydrocarbons and heavy metals in surface water, southeastern Nigeria

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are predominant pollutants linked with anthropogenic activities across a host of environmental mediums. The level of pollution, ecological and health risk were assessed in surface water from Ekulu in Enugu metropolis, Nigeria for 17 PAHs and selected HMs (As, Cd, Cr, Cu, Pb, Ni, Zn) components. PAHs and HMs were determined using a gas chromatography-flame ionization detector (GC-FID) and atomic adsorption spectrophotometer (AAS). The total PAHs in station A (3.17mg/l), B (1.51mg/l), and C (1.83mg/l) were due to high molecular weight (HMW) PAHs than low molecular weight (HMW) PAHs. HMs contents were within USEPA and WHO minimum contamination levels (MCL) except Cr and Pb. The molecular diagnostics of PAHs showed that incomplete combustion of carbonaceous compounds was dominant, while petrogenic was insignificant across all samples. The ecological indices of PAHs and HMs varied from medium to high pollution due to anthropogenic activities that pose a threat to the ecosystem. The non-carcinogenic models showed that hazard index (HI) ranged from PAHs (0.027 - 0.083) and HMs (0.0067 - 0.087) which is less than unity implying no adverse health issues. The lifetime cancer risk (LCR) for PAHs (4.21×10-4 - 9.61×10-4) and HMs (1.72×10-5 - 3.98×10-5) suggested significant cancer risk is possible over some time for a population of 1 in 10,000 and 100,000 for both PAHs and HMs exposure for 70 years. Therefore, there is an urgent need for proper pollution control and mitigation plan to preserve both age groups from being continuously exposed to anthropogenic activities in the Ekulu River and further study should be carried out to monitor the available toxicants.

Green synthesis of phloroglucinol-urotropine porous polymer: Ingenious miniaturized solid phase extraction for efficient purification and determination of polycyclic aromatic hydrocarbons in lotus roots

Polycyclic aromatic hydrocarbons (PAHs) posed a serious threat to food safety and human health due to long-term emission. In this work, a new method was established using phloroglucinol-urotropine porous polymer (PU-PP) in a pipette tip for solid phase extraction (PT-SPE) for the first time and used prior to determination of four PAHs (phenanthrene, anthracene, fluoranthene, and pyrene) in lotus roots. Synthesis of the PU-PP adsorbent was green compared with alternatives; urotropine was used as a cross-linker and ethanol-water as the solvent. PU-PP-based PT-SPE had the advantages of low solvent consumption, good purification, practicability, stability, and low-cost. The proposed pre-purification method offered low limits of detection (0.09-0.28 ng/g) and good recoveries (84.6-114.3 %, RSDs ≤ 5.6 %) for determination of the four PAHs, which were detected at trace concentrations in samples. This new method provides an alternative for monitoring trace pollutants in aquatic plant ingredients.

Unregulated discharge of wastewater in the Mahanadi River Basin: Risk evaluation due to occurrence of polycyclic aromatic hydrocarbon in surface water and sediments

Exposure to polycyclic aromatic hydrocarbons (PAHs) through contaminated water may adversely affect human health and ecology. Water and sediment samples collected from the Mahanadi River Basin (MRB) were analyzed for the presence of sixteen priority PAHs. Results showed that the concentrations of Σ16 PAHs in water and sediments ranged from 13.1 to 685.4 μg/L and 302.6 to 728.2 ng/g. In river water samples, the highest mean concentrations were recorded for Acenaphthylene (18.73 ± 11.61 μg/L) and Benzo(a)Anthracene (10.11 ± 8 μg/L). On the contrary, the maximum concentration was recorded for Phenanthrene (96.18 ± 50.66 ng/g) and Pyrene (76.69 ± 22.73 ng/g) in sediment samples. Human health risk assessment suggests low risk, with incremental lifetime cancer risk (ILCR) being 37.44 × 10^-5 for children and 21.82 × 10^-5 for adults. In contrast, ecological risk assessment showed a high toxic equivalent quotient of 40.68 ng/g and mutagenic equivalent quotient of 39.74 ng/g suggesting elevated adverse risk to aquatic species.

Transcriptomics and metabolomics analyses provide insights into the difference in toxicity of benzo[a]pyrene and 6-chlorobenzo[a]pyrene to human hepatic cells

The toxicological information of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs), as derivatives of PAHs, is still relatively lacking. In this study, a combination of transcriptomics and metabolomics approach was adopted to explore the changes in toxicity to human L02 hepatocytes after chlorination of benzo[a]pyrene (B[a]P) at 6 position. In general, 6-Cl-B[a]P produced a stronger toxicity to human hepatic cells than did parent B[a]P. When exposure concentrations were 5 and 50 nM, 6-Cl-B[a]P caused a weaker transcriptomic perturbation relative to B[a]P, whereas a stronger metabolomic perturbation, a stronger oxidative stress and a stronger inhibition effect on cell viability were caused by 6-Cl-B[a]P than did parent B[a]P. Pathway enrichment analysis indicated that 6-Cl-B[a]P produced a more widely perturbation to metabolic pathways than did B[a]P. Although they both significantly impaired the function of mitochondrial electron transport chain (ETC), the exact mechanism is different. B[a]P suppressed the expression of 20 genes regulating mitochondrial ETC mainly via AhR activation. However, 6-Cl-B[a]P produced a stronger inhibition on the activities of complexes I and V than did B[a]P. Meanwhile, 6-Cl-B[a]P also exhibited a stronger inhibition effect on mitochondrial β oxidation of fatty acid. Furthermore, 6-Cl-B[a]P and B[a]P both significantly disturbed the nucleotide metabolism, glycerophospholipid metabolism and amino acid metabolism in L02 cells.

Parental exposure 3-methylcholanthrene disturbed the enterohepatic circulation in F1 generation of mice

3-methylcholanthrene (3 MC) is an environmental compound belonging to the PAHs and is reportedly thought to be a risk factor for the prevalence of hepatic function disorder. Here, a dose of 0.5 mg/kg of 3 MC was given to 4-week-old male and female mice (F0) in their diet for 6 weeks. After exposure, then the mice were mated between different groups. The first filial (F1) generation offspring of exposed or unexposed parental mice were sacrificed at the age of 5 weeks (F1-5 W), and the potential effects on the F0 and F1 offspring were evaluated. The results showed that the total bile acids (TBAs) in the serum and feces in F0 females and female F1-5 W individuals born from female mice exposed to 3 MC decreased, while the TBAs in the liver increased. The transcriptional levels of major genes participating in synthesis, regulation, transportation and apical uptake was also altered correspondingly. In addition, the transcription of some genes related to inflammation was enhanced in these mice. Further investigation revealed that in addition to distinct changes in the mucus secretion, tight junction proteins and ion transport were induced, and antimicrobial peptides were also disrupted in the intestine of F0 mice and F1-5 W female offspring of maternal mice exposed to 3 MC. Our results suggested that exposure to 3 MC, but not male exposure, had the potential to interfere with BAs metabolism, affecting gut barrier function. Females were more seriously affected than males.

Effectiveness of plants and green infrastructure utilization in ambient particulate matter removal

Air pollution is regarded as an increasingly threatening, major environmental risk for human health. Seven million deaths are attributed to air pollution each year, 91% of which is due to particulate matter. Vegetation is a xenobiotic means of removing particulate matter. This review presents the mechanisms of PM capture by plants and factors that influence PM reduction in the atmosphere. Vegetation is ubiquitously approved as a PM removal solution in cities, taking various forms of green infrastructure. This review also refers to the effectiveness of plant exploitation in GI: trees, grasslands, green roofs, living walls, water reservoirs, and urban farming. Finally, methods of increasing the PM removal by plants, such as species selection, biodiversity increase, PAH-degrading phyllospheric endophytes, transgenic plants and microorganisms, are presented.

In situ phytoremediation of polycyclic aromatic hydrocarbon-contaminated agricultural greenhouse soil using celery

Although celery has been established as an effective plant in the remediation of organic pollutant-contaminated soil, few studies have investigated the associated biological processes in rhizosphere and the effect of celery on agricultural field remediation in situ. In this study, a polycyclic aromatic hydrocarbon (PAH)-contaminated agricultural greenhouse was used as the experimental site, and three celery species (Apium graveolens L., Oenanthe javanica (Blume) DC., Libanotis seseloides (Fisch. & C.A. Mey. ex Turcz.) Turcz.) were applied for in situ remediation. After 90 days, the PAH dissipation rate of the L. seseloides treatment was highest (50.21%), and most of the PAHs were limited to its roots (translocation factor 0.516). This suggested that L. seseloides is a potential species for phytoremediation coupled with agro-production. The culturable microbial population and invertase activity results strongly supported that O. javanica is suitable for the establishment of exogenous bacteria-celery co-remediation techniques. Pearson's correlation analysis showed that the polyphenol oxidase (PPO) activity was highly significantly positively correlated with the PAH dissipation rate (r = 0.984, P < 0.01), and we suggest that PPO can be used as a microecological index during PAH remediation.

Occurrence, health risk assessment and regional impact of parent, halogenated and oxygenated polycyclic aromatic hydrocarbons in tap water

Recently, derivates of parent polycyclic aromatic hydrocarbons (PAHs) have aroused increasing concerns due to potential health problems they cause. In this study, we first found the coexistence of PAHs, chlorinated PAHs (Cl-PAHs), brominated PAHs (Br-PAHs) and oxygenated PAHs (OPAHs) in tap water. Twenty-six compounds including 13 PAHs, 5 Cl-PAHs, 5 Br-PAHs, and 3 OPAHs were detected. Total concentrations of PAHs (2.50-56.90 ng L^-1) and OPAHs (n.d. to 80.34 ng L^-1) were relatively higher than those of Cl-PAHs (0.30-11.28 ng L^-1) and Br-PAHs (n.d. to 8.20 ng L^-1). We calculated the 95th percentile incremental lifetime cancer risk (ILCR) values of PAHs and HPAHs. In all sampling sites, although no ILCR values for PAHs and HPAHs were higher than 1.00E-06, results still indicates there is still a low cancer risk existed. In addition, regional impact was established by combining ILCR values with population density. Predicted cancer incidence (PCI, people km^-2) was calculated to evaluate regional impact more comprehensively. The results were different from previous hypothesis that sampling sites with high ILCR values may not necessarily present high regional impacts. After total PCI of each district was summed, all calculated districts of Beijing, China were at low regional impact.

Evaluation of PAHs in edible parts of vegetables and their human health risks in Jinzhong City, Shanxi Province, China: A multimedia modeling approach

Knowledge of the origins of polycyclic aromatic hydrocarbon (PAH) in vegetables is essential to reduce human health risks induced by dietary exposure. The current study developed a vegetation-advanced multimedia model, SESAMe-Veg, to identify the major uptake pathway of 15 priority PAHs in vegetables and assess the PAHs in edible parts of cabbages and carrots in Jinzhong City, Shanxi Province, China. The model was well evaluated against site- and plant-specific measurements. Edible parts exhibited lower PAH concentrations than the other parts for both vegetables. The estimated concentrations of ΣPAH15 were 79 ng/g in cabbage shoots and 83 ng/g in carrot roots. Higher concentrations were estimated in shoots of the leafy vegetable than in roots of the root vegetable for most PAHs. Although air-shoot is the major transport pathway, 98% was deposition of particles, which was attached outside and could be removed relatively easily by washing. Soils might be the origin of PAHs inside vegetables, especially for lighter PAHs. PYR was more likely to be stored in roots than other congeners. The translocation of PAHs inside vegetables was negligible. Adulthood dietary exposure to local vegetables probably caused a high health risk; however, contributions from consuming cabbages and especially carrots were low. Females generally exhibited slightly higher risks than males of exposure to PAHs in local vegetables. Considering the dominant role of particle deposition, carefully vegetable washing before ingestion could reduce this risk. This study has provided a functional tool to evaluate vegetable contamination by PAHs. CAPSULE: A vegetation-advanced multimedia model of PAHs in different parts of vegetables and other environmental media was developed to evaluate the potential health risk to local populations of different sexes and ages via vegetable ingestion.

Halogenated polycyclic aromatic hydrocarbons in edible aquatic species of two Asian countries: Congener profiles, biomagnification, and human risk assessment

Seventy-five contaminants including chlorinated/brominated/parent polycyclic aromatic hydrocarbons (Cl/Br/PAHs) were investigated in 29 edible aquatic species from the Indian Ocean near Sri Lanka and 10 species from the Pacific Ocean near Japan. Concentrations of total ClPAHs and BrPAHs in the samples were 2.6-57 and 0.30-9.5 ng/g-dry weight from the Indian Ocean, and 0.35-18 and 0.03-3.3 ng/g-dry weight from the Pacific Ocean, respectively. Comparing the profiles of Cl/BrPAHs among the samples, congeners of chlorinated and brominated pyrene were predominant components and enhanced the potential for biomagnification in the sample from the off-shore pelagic environment in the Indian Ocean. The incremental lifetime cancer risks estimated by intake of the targets in consuming aquatic organisms showed that approximately one-third of studied organisms exceeded the acceptable risk level for Sri Lankans.

Simultaneous Determination of Typical Chlorinated, Oxygenated, and European Union Priority Polycyclic Aromatic Hydrocarbons in Milk Samples and Milk Powders

An increasing number of studies have suggested that PAH contamination in dairy products demands high concern. This study established an efficient determination method for the European Union 15 + 1 PAHs and four PAH derivatives in dairy samples using a QuEChERS method coupled with GC-QqQ-MS. The optimized method obtained a recovery of 63.38-109.17% with a precision of 3.82-15.62%, and the limit of detection and limit of quantification were 0.08-0.78 and 0.27-2.59 μg/kg, respectively. The validated method was then successfully applied to identify the 20 PAHs in 82 dairy samples, including 43 commercial milk samples and 39 milk powders. The total PAH concentrations ranged from 2.37 to 11.83 μg/kg, and benzo[a]pyrene was only quantified in one milk and one milk powder sample at 0.35 and 0.42 μg/kg, respectively. The concentrations of PAH4 in milk samples and milk powders were not quantified (nq)-3.99 and nq-4.51 μg/kg, respectively. The results confirmed the appreciable occurrence of PAHs in dairy products, especially in infant formula. The data in this study provide a scientific basis for assessment on origin tracing, dietary exposure, and health risk of PAHs and their derivatives.

Health Risk Assessment, Composition, and Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Drinking Water of Southern Jharkhand, East India

The studies on polycyclic aromatic hydrocarbons (PAHs) occurrence, distribution, health risk, and composition in drinking water are limited in India and worldwide. The main objective of this study was to find the contaminant sources, composition, health risk, and distribution of USEPA's 16 priority pollutant PAHs in the drinking water samples collected between July 2019 to September 2019 from six districts of Southern Jharkhand. The Σ_16PAHs mean ± standard deviation [SD] concentration values were ordered as East Singhbhum (ES) (21.5 ± 14.8 ng L^-1) > West Singhbhum (WS) (16.57 ± 13.21 ng L^-1) > Saraikela Kharsawan (SK) (11.48 ± 9.92 ng L^-1) > Khunti (KH) (10.32 ± 9.09 ng L^-1) > Simdega (SM) (9.96 ± 7.85 ng L^-1) > Gumla (GU) (9.41 ± 8.63 ng L^-1). The results show that ES and WS districts' groundwater samples were more contaminated by the PAHs, which may be attributed to the presence of many small-, medium-, and large-scale industries and high vehicular density in these districts. The concentrations of lower molecular weight ring (3-rings) and middle molecular weight ring (4-rings) PAHs were dominant throughout all drinking samples. The concentration of the 3-ring PAH Anthracene and 4-ring PAH Fluoranthene were dominant in all districts. The molecular ratios suggested that the potential sources of PAHs are fuel combustion and coal, grass, and wood burning. Risk assessment shows that the incremental lifetime cancer risk and risk index (RI) were ranged from 0.02 × 10^-10 to 4.93 × 10^-10 for children and 0.01 × 10^-10 to 2.98 × 10^-10 for adults. The RI values for seven carcinogenic PAHs were 8.83 × 10^-10 for children and 7.38 × 10^-10 for adults. Although the carcinogenic risks were within the permissible values, chronic exposure to PAHs through the ingestion of drinking water could still be a human health concern.

Quantification of Brominated Polycyclic Aromatic Hydrocarbons in Environmental Samples by Liquid Chromatography Tandem Mass Spectrometry with Atmospheric Pressure Photoionization and Post-column Infusion of Dopant

A sensitive method for the quantification of brominated polycyclic aromatic hydrocarbons (BrPAHs) in environmental samples is yet to be developed. Here, we optimized the analytical conditions for liquid chromatography tandem mass spectrometry with atmospheric pressure photoionization and post-column infusion of dopant (LC-DA-APPI-MS/MS). We then compared the sensitivity of our developed method with that of conventional gas chromatography high-resolution MS (GC-HRMS) by comparing the limits of quantification (LOQs) for a range of BrPAHs. Finally, to evaluate our developed method, 12 BrPAHs in sediments and fish collected from Tokyo Bay, Japan, were analyzed; 9 common PAHs were also targeted. The LOQs of the developed analytical method were 14 - 160 times lower than those of GC-HRMS for the targeted BrPAHs. The developed analytical method is a sensitive approach for determining the concentrations of BrPAHs in sediment and fish samples.

The combination of warming and copper decreased the uptake of polycyclic aromatic hydrocarbons by spinach and their associated cancer risk

Both climate warming and co-contamination of polycyclic aromatic hydrocarbons (PAHs) and heavy metals are environmental issues of great concern. However, the interactive effects of warming and heavy metals on PAH accumulation in edible plants and the PAH-associated health risk remain unclear. In this study, enclosed soil/water-air-plant microcosm experiments were conducted to explore the effects of copper (Cu), warming (+6 °C), and their combination on the uptake of four deuterated PAH (PAH-d₁₀) by spinach (Spinacia oleracea L.) in aged soil. PAH-associated health risks for soil, plant, and air exposure pathways were also assessed. The results showed that both individual Cu or warming decreased the PAH-d₁₀ concentrations in root and shoot (non-normalized by lipid content) as well as the total PAH-associated cancer risk. Although antagonism existed between warming and Cu, compared to the presence of Cu, warming further reduced the spinach uptake of PAHs-d₁₀ and total PAH-associated cancer risk, and the reductions were stronger at higher Cu levels. The inhibitory effect of the binary combination on PAH-d₁₀ root uptake was attributed to decreased root lipid content and phytoavailable concentrations of PAHs-d₁₀ in soil as a consequence of biodegradation, aging effect and cation-π interaction. The antagonism between warming and Cu on spinach uptake could be explained by their opposite effects on PAH-d₁₀ biodegradation and the inhibition of the cation-π interaction caused by warming. Additionally, the shoot uptake of PAHs-d₁₀ was mainly controlled by their soil to air to shoot partitioning. The findings suggest that the interactive effects of climate warming and co-existing pollutants should be taken into account for the assessment of plant uptake and health risk of PAHs.

Oxidative damage mediates the association between polycyclic aromatic hydrocarbon exposure and lung function

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) is related to decreased lung function. However, whether oxidative damage is involved in this relationship remains unclear. This study was aimed to explore the potential mediating role of oxidative DNA or lipid damage in the association between PAH exposure and lung function.

METHODS

The urinary levels of monohydroxy polycyclic aromatic hydrocarbon metabolites (OH-PAHs) and lung function parameters were measured among 3367 participants from the baseline of the Wuhan-Zhuhai cohort. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane (8-iso-PGF2α) were determined to evaluate the individuals' oxidative DNA and lipid damage degrees, respectively. Linear mixed models were used to investigate the associations of urinary OH-PAHs, 8-OHdG and 8-iso-PGF2α with lung function parameters. Mediation analysis was further conducted to assess the potential role of oxidative damage in the association between urinary OH-PAHs and lung function.

RESULTS

Each one-percentage increase in the sum of urinary OH-PAHs, high-molecular-weight or low-molecular-weight OH-PAHs (ƩOH-PAHs, ƩHMW OH-PAH or ƩLMW OH-PAHs, respectively) was associated with a 0.2152-, 0.2076- or 0.1985- ml decrease in FEV₁, and a 0.1891-, 0.2195- or 0.1634- ml decrease in FVC, respectively. Additionally, significantly positive dose-response relationships of ƩOH-PAHs, ƩHMW OH-PAH and ƩLMW OH-PAHs with urinary 8-OHdG or 8-iso-PGF2α, as well as an inverse dose-response relationship between urinary 8-OHdG and FVC, were observed (all P for trend < 0.05). Mediation analysis indicated that urinary 8-OHdG mediated 14.22% of the association between ƩHMW OH-PAH and FVC.

CONCLUSION

Higher levels of oxidative DNA damage might be involved in the decreased levels of FVC caused by high-molecular-weight PAH exposure.

Risk assessment of polycyclic aromatic hydrocarbons and their chlorinated derivatives produced during cooking and released in exhaust gas

Cooking exhaust gas includes polycyclic aromatic hydrocarbons (PAHs) that are unintentionally generated during cooking, which exposes the cook and others in the vicinity to these toxic compounds. However, information on the occurrence of PAHs, particularly their chlorinated derivatives (ClPAHs), in cooking exhaust gas is limited. Here, we determined the concentrations of 12 PAHs and 20 ClPAHs in cooking exhaust gas emitted during gas-grilling of a Pacific saury using a typical Japanese fish grill in an indoor kitchen. The total concentrations of PAHs and ClPAHs in the cooking exhaust gas were 3400 and 19 ng m^-3, respectively. All 12 PAHs were detected in the cooking exhaust gas, with phenanthrene (2100 ng m^-3), fluorene (630 ng m^-3), and anthracene (200 ng m^-3) detected at the highest concentrations. Four of the 20 ClPAHs were detected, with 9-monochlorinated phenanthrene detected at the highest concentration (12 ng m^-3). The exposure rates for the cook to the PAHs and ClPAHs in the cooking exhaust gas, estimated using the National Institute of Advanced Industrial Science and Technology - Indoor Consumer Exposure Assessment Tool (AIST-ICET), were in the range of 7.2-72 ng-BaP_eq kg^-1 day^-1 (toxic equivalent concentrations relative to the toxicity of benzo[a]pyrene), which was comparable with that for dietary ingestion of cooked foods (54 ng-BaP_eq kg^-1 day^-1). A risk assessment of exposure to PAHs and ClPAHs in cooking exhaust gas in the indoor environment revealed that this gas may pose a health risk to the cook (incremental lifetime cancer risk: 2.1 × 10^-6 to 2.1 × 10^-5), indicating that further investigations are warranted.

Polycyclic aromatic hydrocarbons in edible oils and fatty foods: Occurrence, formation, analysis, change and control

Numerous studies have demonstrated that dozens of polycyclic aromatic hydrocarbons (PAHs) are mutagenic, genotoxic and strongly carcinogenic. PAHs are found to be widely present in foods contaminated through multiple paths. Due to their lipophilic nature, these compounds easily accumulate in edible oils and fatty foods where they can range from no detection to over 2000μg/kg. Compared to precursor PAHs, researchers have seldom studied the presence of PAH derivatives, especially in food matrices. This chapter includes the physical and chemical characteristics of PAHs and their types, occurrence, sample pretreatment and instrumental determination methods, and their formation, change and control in edible oils and fatty foods. The occurrence and formation of PAH derivatives in foods are much less investigated compared to those of their precursor PAHs. Although the removal of matrix effects and accuracy remain difficult for current rapid determination methods, a prospective research direction of PAH analysis for large-scale screening is in demand. To date, physical absorption, chemical oxidation and biodegradation have been widely used in PAH removal techniques. Specific types of bacteria, fungi, and algae have also been used to degrade PAHs into harmless compounds. However, most of them can only degrade a range of LPAHs, such as naphthalene, anthracene and phenanthrene. Their ability to degrade HPAHs requires further study. Moreover, it is still a great challenge to maintain food nutrition and flavor during the PAH removal process using these methods.

Association between exposure to polycyclic aromatic hydrocarbons and attention deficit hyperactivity disorder in children: a systematic review and meta-analysis

Some studies have shown that exposure to polycyclic aromatic hydrocarbons (PAHs) is a dangerous factor for attention deficit hyperactivity disorder (ADHD). This systematic review and meta-analysis aimed to clarify this relationship, and to collect and analyze all the relevant evidences in published reports of epidemiologic studies. PubMed, Science Direct, Web of Science, Scopus, and Google Scholar databases were searched through September 31, 2018. The study quality was evaluated using the Newcastle-Ottawa Scale. Moreover, fixed- and random-effect models were used. The data in this meta-analysis were presented as adjusted odds ratio (AOR). From 959 articles, six articles were included in the systematic review, and for meta-analysis, one study (that was not AOR) was excluded. The participants included in the studies were 2799 with the age range of 5-15 years old, and 93.6% were living in America. Four of the studies were placed in one group, due to having a common author (Perera). Moreover, a significant association was found between PAH exposure and ADHD in these studies (odds ratio = 2.57, 95% CI = 1.75-3.78); however, in all studies, there was no significant association between PAH exposure and ADHD for children (overall odds ratio = 1.99, 95% CI = 0.96-4.11) with low heterogeneity (I² = 28.73%; P value < 0.001). This study provided a systematic review and meta-analytic evidence for the association between PAH exposure and ADHD by a small number of studies. Further research study can be conducted in various countries. Graphical Abstract.

Exposure of metals and PAH through local foods and risk of cancer in a historically contaminated glassworks area

BACKGROUND

Production of crystal glass and colored art glassware have been going on in the south-eastern part of Sweden since the 1700s, at over 100 glassworks and smaller glass blowing facilities, resulting in environmental contamination with mainly arsenic (As), cadmium (Cd), lead (Pb) and polycyclic hydrocarbons (PAH). High levels of metals have been found in soil, and moderately elevated levels in vegetables, mushrooms and berries collected around the glassworks sites compared with reference areas. Food in general, is the major exposure source to metals, such as Cd and Pb, and PAHs. Exposure to these toxic metals and PAH has been associated with a variety of adverse health effects in humans including cancer.

OBJECTIVE

The aim of the present study was to evaluate the occurrence of cancer in a cohort from the contaminated glasswork area in relation to long-term dietary intake of locally produced foods, while taking into account residential, occupational and life styles factors.

METHODS

The study population was extracted from a population cohort of 34,266 individuals who, at some time between the years 1979-2004, lived within a 2 km radius of a glassworks or glass landfill. Register information on cancer incidence and questionnaire information on consumption of local foods (reflecting 30 years general eating habits), life-time residence in the area, life style factors and occupational exposure was collected. Furthermore, blood (n = 660) and urine (n = 400) samples were collected in a subsample of the population to explore associations between local food consumption frequencies, biomarker concentrations in blood (Cd, Pb, As) and urine (PAH metabolite 1-OHPy) as well as environmental and lifestyle factors. The concurrent exposure to persistent organic pollutants (POPs) from food was also considered. A case-control study was performed for evaluation of associations between intakes of local food and risk of cancer.

RESULTS

Despite high environmental levels of Cd, Pb and As at glasswork sites and landfills, current metal exposure in the population living in the surrounding areas was similar or only moderately higher in our study population compared to the general population. Reported high consumption of certain local foods was associated with higher Cd and Pb, but not As, concentrations in blood, and 1-OHPy in urine. An increased risk of cancer was associated with smoking, family history of cancer, obesity, and residence in glasswork area before age 5 years. Also, a long-term high consumption of local foods (reflecting 30 years general eating habits), i.e. fish and meat (game, chicken, lamb), was associated with increased risk of various cancer forms.

CONCLUSIONS

The associations between consumption of local food and different types of cancer may reflect a higher contaminant exposure in the past, and thus, if consumption of local food contributes to the risk of acquiring cancer, that contribution is probably lower today than before. Furthermore, it cannot be ruled out that other contaminants in the food contribute to the increased cancer risks observed.

Pollution of polycyclic aromatic hydrocarbons (PAHs) in drinking water of China: Composition, distribution and influencing factors

Polycyclic aromatic hydrocarbons (PAHs) are a kind of persistent toxic substances, which have been frequently detected in environmental media. However, studies on their occurrences and distributions in drinking water are insufficient and their composition profiles in drinking water are still not clear. In this study, we investigated 16 priority polycyclic aromatic hydrocarbons (PAHs) in drinking water from different administrative level cities throughout mainland China, analyzed the influences of anthropogenic activities on PAHs, and assessed the health risk of the PAHs in drinking water. On the national scale, the sum concentration of the 16 priority-controlled PAHs (∑₁₆PAHs) designated by the U.S. Environmental Protection Agency (USEPA) was in a range of 3.89-231.39 (mean 56.25) ng L^-1. With the decline of ∑₁₆PAHs, the concentration of 3-ring PAHs decreased, while its proportion increased, indicating 3-ring PAHs might be more difficult to remove than other PAHs in drinking water. The geographical distribution of PAHs in drinking water of China was in a descending order of West (69.81 ng L^-1) > South (61.95 ng L^-1) > North (58.63 ng L^-1) > East (39.21 ng L^-1) > Northeast China (37.93 ng L^-1). ∑₁₆PAHs in drinking water of Prefecture-level City was the greatest (71.49 ng L^-1) followed by Provincial Capital (52.12 ng L^-1), County-level City (50.98 ng L^-1) and Municipality (33.92 ng L^-1). ∑₁₆PAHs was significantly negatively correlated with the per capita GDP of sampling city (P < 0.01, n = 78), implying that waterworks is an effective way to control and reduce PAH pollution in drinking water. The carcinogenic risk of the 16 PAHs in drinking water of China was much greater than the non-carcinogenic risk.

Health risk from dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in a typical high cancer incidence area in southwest China

This study was designed to test whether the dietary intake of polycyclic aromatic hydrocarbons (PAHs) is a potential exposure source relating to the high cancer incidence area in southwest China. Duplicate plate method was used to collect food samples in rural and urban sites in the region. Questionnaire surveys were conducted among 300 local residents to obtain their dietary habits and 50 subjects were chosen to collect the samples. The 16 priority PAHs (PAH₁₆) in composite food samples for each individual subject were measured, and non-carcinogenic and carcinogenic risks were analyzed based on the results of Monte Carlo method. The average concentration of the PAH₁₆ in food samples was 12.04 ± 8.52 ng g^-1. The life time average daily benzo(a)pyrene equivalent (BaP_eq) exposure dose was 6.07 × 10^-6 mg kg^-1 day^-1. Although non-carcinogenic risk was found to be within a controllable range, the average incremental lifetime cancer risk (ILCR) was 3.7 × 10^-5 for rural subjects and 6.1 × 10^-5 for urban subjects, which is comparable with other regions in China. The serious risk level of 10^-4 was exceeded by 10.7% of urban residents and 2.1% of rural residents. This study implies that dietary exposure to PAHs is a potential exposure source to the high cancer in the region, and further cancer risk control strategies need to be formulated.

Distributions and multiple sources of chlorinated polycyclic aromatic hydrocarbons in the air over Japan

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have been detected in the air at discrete sites in Japan, but there is no information on their distributions throughout Japan. This study was a widespread survey of atmospheric concentrations of ClPAHs throughout Japan. The majority of 24 species of ClPAHs were detected in either the gas or particle phase at all sampling sites. The concentrations were weakly related to human population densities. The relationships between total concentrations of ClPAHs and PAHs suggested that atmospheric ClPAHs at ~70% of the sites were derived from common sources of PAHs. A ternary diagram based on diagnostic ratios of 1-chloropyrene, 7-chlorobenz[a]anthracene, and 6-chlorobenzo[a]pyrene normalized to 3-chlorofluoranthene suggested that waste combustion was the likely source of ClPAHs in summer and that vehicular emissions and coal burning were the likely sources of ClPAHs in winter. A heat map analysis estimated from the concentrations of individual compounds at each site suggested that there were three categories of sources at the sites: i) common sources of ClPAHs and PAHs that had moderate impacts, ii) common sources of ClPAHs and PAHs that had high impacts, and iii) specific sources of ClPAHs.

Heavy Metal Exposure Alters the Uptake Behavior of 16 Priority Polycyclic Aromatic Hydrocarbons (PAHs) by Pak Choi ( Brassica chinensis L.)

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are predominant pollutants normally coexisting at electronic waste dumping sites or in agricultural soils irrigated with wastewater. The accumulation of PAHs and HMs in food crops has become a major concern for food security. This study explored the hydroponic uptake of 16 priority PAHs and 5 HMs (Cd, Cr, Cu, Pb, and Zn) by pak choi ( Brassica chinensis L.). PAHs exhibited stronger inhibition on pak choi growth and physiological features than HMs. Five HMs were categorized into high-impact HMs (Cr, Cu, and Pb) and low-impact HMs (Cd and Zn) with distinct behavior under the coexposure with PAHs, and low-impact HMs showed synergistic toxicity effects with PAHs. Coexposure to PAHs and HMs slightly decreased the uptake and translocation of PAHs by pak choi, possibly attributing to the commutative hindering effects on root adsorption or cation-π interactions. The bioconcentration factors in PAHs + HMs treatments were independent of the octanol-water partition coefficient ( K_ow), owing to the cation-π interaction associated change of K_ow and induced defective root system. This study provides new insights into the mechanisms and influential factors of PAHs uptake in Brassica chinensis L. and gives clues for reassessing the environmental risks of PAHs in food crops.

Accumulation characteristics and potential risk of PAHs in vegetable system grow in home garden under straw burning condition in Jilin, Northeast China

The accumulation characteristics and potential risk posed by polycyclic aromatic hydrocarbons (PAHs) in soils and vegetables grown in the home garden and agricultural field were investigated in this research. The average concentrations of 16 PAHs in soils and vegetables in the home garden were 508.9 ng/g and 197.3 ng/g, respectively, and in agricultural fields were 589.9 ng/g and 171.3 ng/g, respectively. The 16 PAHs concentrations of vegetables in the home garden were a little higher than in agricultural field. The most abundant PAHs in soils and vegetables was Phe, followed by Fla and Pyr in our study area. The concentrations of low-molecular-weight PAHs (L-PAHs) were higher in vegetables as compared to higher molecular weight 4-6 ring PAHs (H-PAHs). The results of plant concentration factor (PCF) indicated that L-PAHs have greater mobility in our research. Based on the results of PAH ratios, the main sources of the PAHs in soils were determined to be the combustion of biomass, coal, and petroleum. The total values of incremental lifetime cancer risk (ILCR) for males and females induced by soils and vegetables in home garden and agricultural field were all about 10^-7 and 10^-10. All the ILCRs value were lower than the baseline value, indicated that the carcinogenic risk for the soils and vegetables contaminated with PAHs in our study area for the residents was negligible.

Characterization of polycyclic aromatic hydrocarbons (PAHs) in vegetables near industrial areas of Shanghai, China: Sources, exposure, and cancer risk

Dietary consumption of contaminated vegetables may contribute to polycyclic aromatic hydrocarbon (PAH) exposure in humans; however, this exposure pathway has not been examined thoroughly. This study aims to characterize the concentrations of PAHs in six types of vegetables grown near industrial facilities in Shanghai, China. We analyzed 16 individual PAHs on the US EPA priority list, and the total concentration in vegetables ranged from 65.7 to 458.0 ng g^-1 in the following order: leafy vegetables (romaine lettuce, Chinese cabbage and Shanghai green cabbage) > stem vegetables (lettuce) > seed and pod vegetables (broad bean) > rhizome vegetables (daikon). Vegetable species, wind direction, and local anthropogenic emissions were determinants of PAH concentrations in the edible part of the vegetable. Using isomer ratios and principal component analysis, PAHs in the vegetables were determined to be mainly from coal and wood combustion. The sources of PAHs in the six types of vegetables varied. Daily ingestion of PAHs due to dietary consumption of these vegetables ranged from 0.71 to 14.06 ng d^-1 kg^-1, with contributions from Chinese cabbage > broad bean > romaine > Shanghai green cabbage > lettuce > daikon. The daily intake doses adjusted by body weight in children were higher than those in teenagers and adults. Moreover, in adults, higher concentrations of PAHs were found in females than in males. For individuals of different age and gender, the incremental lifetime cancer risks (ILCRs) from consuming these six vegetables ranged from 4.47 × 10^-7 to 6.39 × 10^-5. Most were higher than the acceptable risk level of 1 × 10^-6. Our findings demonstrate that planting vegetables near industrial facilities may pose potential cancer risks to those who consume the vegetables.