Human exposure to microplastics contained in food has become a significant concern owing to the increasing accumulation of microplastics in the environment. In this paper, we summarize the presence ...of microplastics in food and the analytical methods used for isolation and identification of microplastics. Although a large number of studies on seafood such as fish and shellfish exist, estimating the overall human exposure to microplastics via food consumption is difficult owing to the lack of studies on other food items. Analytical methods still need to be optimized for appropriate recovery of microplastics in various food matrices, rendering a quantitative comparison of different studies challenging. In addition, microplastics could be added or removed from ingredients during processing or cooking. Thus, research on processed food is crucial to estimate the contribution of food to overall human microplastic consumption and to mitigate this exposure in the future.
Sorption by soil organic matter (SOM) is considered the most important process affecting the bioavailability of hydrophobic organic chemicals (HOCs) in soil. The sorption capacity of SOM for HOCs is ...affected by many environmental factors. In this study, we investigated the effects of soil pH and water saturation level on HOC sorption capacity of SOM using batch sorption experiments. Values of soil organic carbon-water partition coefficient (KOC) of six selected polycyclic aromatic hydrocarbons (PAHs) were measured in an artificial soil under various soil pH and water saturation conditions. Passive sampling was used to measure KOC with polydimethylsiloxane as the sampling material. Regardless of soil pH, KOC increased with increasing soil water saturation level for lower-molecular-weight PAHs. In contrast, KOC decreased with increasing soil water saturation level for higher-molecular-weight PAHs. Despite some fluctuations, KOC tended to decrease with increasing soil pH at all water saturation levels. This indicates that earlier studies on the effects of soil pH on KOC under saturated conditions could be extended to unsaturated soils. These KOC tendencies were reproduced in three different natural soils, suggesting that the effects of soil water saturation level and pH might be generalized, at least for PAHs. The PAH sorption capacity of SOM was found to be resilient under dynamic soil pH conditions, which can be used to adjust the effects of soil pH.
Children can get affected by polycyclic aromatic hydrocarbons (PAHs) while they interact with play area soil/rubber surfacing and exposed to PAHs by dermal contact, inhalation and hand-to-mouth ...activity. A comparative study has been conducted on PAHs profiling and probable cancer risk of children from PAHs present in uncovered playground surface soil and poured rubber surfaced playground dust. Surface soil and dust samples have been collected from 14 different children parks around the Korea University campus, Seoul, Republic of Korea. Concentrations of 16 PAHs in the soils/dust were found to be in a range of 2.82–57.93 μg g
−1
. Profiling of the PAHs from the playground soils/dust reveals 3-ring PAHs are dominating with 79.9% of total PAHs content, on an average. The diagnostic ratio analysis confirms that vehicular exhaust and fossil fuel burning are likely the main sources of high molecular weight carcinogenic PAHs, whereas low molecular weight PAHs have pyrogenic origin. The probabilistic health risk assessment using Monte Carlo simulations for the estimation of the 95% cancer risk exposed to the PAHs from the surfaced playgrounds shows a little higher value than the USEPA safety standard (1.3 × 10
−5
). Sensitivity analysis revealed exposure duration and relative skin adherence factor for soil as the most influential parameters of the assessment. Noticeably, cancer risk is approximately 10 times higher in poured rubber surfaced playgrounds than in uncovered soil playgrounds.
•Biomimetic mild extraction was performed to profile the bioaccessible soil PAHs.•Total PAHs were 67.02–95.21μg/g and bioaccessible PAHs were 19.30–36.66μg/g.•Risk assessment on PAHs from exhaustive ...extraction overestimates the risk.•2.87–2.89 fold over estimation of risk without considering bioaccessibility.
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Populations living in the vicinity of oil refinery sludge deposition sites may be at greater risk of potential exposure to polycyclic aromatic hydrocarbons (PAHs) through inhalation, ingestion, and direct contact with contaminated media. Three Indian oil refinery sludge deposition sites (at Haldia, Barauni and Guwahati) were chosen for study. Soil samples were collected from three different locations at each site. Mild solvent extraction by butanol and exhaustive extraction by acetone/hexane have been conducted to estimate the bioaccessible PAHs beside the total extractable PAHs content of the soil samples. Concentrations of 13 PAHs in the soils were found to be in a range of 67.02–95.21μg/g and bioaccessible PAHs were in a range of 19.296–36.657μg/g. A probabilistic health risk assessment with bioaccessibility considerations was carried out using Monte Carlo simulations for the estimation of the cancer risk exposed to the PAHs. The 90th percentiles cancer risks with bioaccessibility considerations of soil PAHs for children is 6.506E−05 and for the adults the risk is 6.609E−05. Risk assessments on extracted PAHs from exhaustive solvent extraction can overestimate the risk by 2.87–2.89 folds at 90% confidence level with respect to the biomimetic mild extraction procedure using butanol. According to USEPA above 1×10−6 extra risk of cancer is an alarm towards management. So, public health issues due to PAHs is imminent in these oil refinery vicinity areas. Sensitivity analysis revealed exposure duration (ED) and relative skin adherence factor for soil (AF) as the most influential parameters of the assessment. The profiling and risk assessment study with bioaccessibility considerations of PAHs from soil indicates that high PAHs concentration can lead to higher cancer risk for the vicinity area residents and local government should take immediate management actions.
Present study was carried out to assess and understand potential health risk and to examine the impact of vehicular traffic on the contamination status of urban traffic soils in Dhanbad City with ...respect to polycyclic aromatic hydrocarbons (PAHs). Eight urban traffic sites and two control/rural site surface soils were analyzed and the contents of 13 priority PAHs was determined. Total PAH concentration at traffic sites ranged from 1.019μgg−1 to 10.856μgg−1 with an average value of 3.488μgg−1. At control/rural site, average concentration of total PAHs was found to be 0.640μgg−1. PAH pattern was dominated by four- and five-ring PAHs (contributing >50% to the total PAHs) at all the eight traffic sites. On the other hand, rural soil showed a predominance of low molecular weight three-ring PAHs (contributing >30% to the total PAHs). Indeno123-cdpyrene/benzghiperylene (IP/BgP) ratio indicated that PAH load at the traffic sites is predominated by the gasoline-driven vehicles. The ratio of Ant/(Ant+Phe) varied from 0.03 to 0.44, averaging 0.10; Fla/(Fla+Pyr) from 0.39 to 0.954, averaging 0.52; BaA/(BaA+Chry) from 0.156 to 0.60, averaging 0.44; and IP/(IP+BgP) from 0.176 to 0.811, averaging 0.286. The results indicated that vehicular emission was the major source for PAHs contamination with moderate effect of coal combustion and biomass combustion. Carcinogenic potency of PAH load in traffic soil was nearly 6.15 times higher as compared to the control/rural soil.
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•Total PAH in traffic soil of Dhanbad varied from 1.019μgg−1 to 10.856μgg−1.•Traffic sites were dominated by 4 & 5 ring while control sites by 3 ring PAHs.•PCA study revealed vehicular emission as major source for PAH contamination.•Carcinogenic potency of traffic soil was nearly 6.15 times higher than rural soil.
The total concentrations of 13 detected polycyclic aromatic hydrocarbons (PAHs) in different traffic soil samples of Dhanbad heavy mining area, India, were between 8.256 and 12.562 µg/g and were ...dominated by four ring PAHs (44%). Diagnostic ratio study revealed that fossil fuel burning and vehicular pollution are the most prominent sources of the PAHs in roadside soil even at a heavy coal mining area. The 90th percentiles cancer risks determined by probabilistic health risk assessment (Monte Carlo simulations) for both the age groups (children and adults) were above tolerable limit (>1.00E-06) according to USEPA. The simulated mean cancer risk was 1.854E-05 for children and 1.823E-05 for adults. For different exposure pathways, dermal contact was observed to be the major pathway with an exposure load of 74% for children and 85% for adults. Sensitivity analysis demonstrated relative skin adherence factor for soil (AF) is the most influential parameter of the simulation, followed by exposure duration (ED).
Profiling and cancer risk assessment on the polycyclic aromatic hydrocarbons (PAHs) content of coal ashes produced by the major coal combustion plants from the eastern coalfield region in India was ...conducted. Thirteen PAHs were detected on coal ashes collected from ash deposition sites of major thermal power plants and the profiling of the PAHs was done. Benzoapyrene equivalents (BaP
eq
) for individual PAHs were calculated and applied to the probabilistic assessment model from US EPA (1989). Monte Carlo simulations were conducted to assess the risk of inhabitants exposed to PAHs through the dust of the coal ash deposition site. In fly ash, the range of total amount of carcinogenic PAHs was from 3.50 to 6.72 µg g
−1
and for the bottom ash, the range was 8.49 to 14.91 µg g
−1
. Bottom ashes were loaded with ample amounts of 5- and 6-ring carcinogenic PAHs, whereas fly ashes were dominated by medium molecular weight PAHs. The simulated mean cancer risks from fly ashes were 2.187 E-06 for children and 3.749 E-06 for adults. For the case of bottom ash, the mean risks were 1.248 E-05 and 2.173 E-05 respectively for children and adults. Among all the three exposure routes, dermal contact was the major and caused 81% of the total cancer risk. The most sensitive parameters were exposure duration and relative skin adherence factor for soil, which contributed the most to total variation. The 90% risks calculated from the bottom ashes (2.617 E-05 for children and 4.803 E-05 for adults) are marginally above the acceptable limit (>1.000 E-06) according to US EPA. In this study, a comprehensive risk assessment on carcinogenic PAHs present in coal ashes was done for the first time that may be helpful to develop potential strategies against occupational cancer risk.
A carcinogenic risk assessment of polycyclic aromatic hydrocarbons in soils and sediments was conducted using the probabilistic approach from a national perspective. Published monitoring data of ...polycyclic aromatic hydrocarbons present in soils and sediments at different study points across India were collected and converted to their corresponding BaP equivalent concentrations. These BaP equivalent concentrations were used to evaluate comprehensive cancer risk for two different age groups. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties of risk estimation. The analysis denotes 90% cancer risk value of 1.770E−5 for children and 3.156E−5 for adults at heavily polluted site soils. Overall carcinogenic risks of polycyclic aromatic hydrocarbons in soils of India were mostly in acceptance limits. However, the food ingestion exposure route for sediments leads them to a highly risked zone. The 90% risk values from sediments are 7.863E−05 for children and 3.999E−04 for adults. Sensitivity analysis reveals exposure duration and relative skin adherence factor for soil as the most influential parameter of the assessment, followed by BaP equivalent concentration of polycyclic aromatic hydrocarbons. For sediments, biota to sediment accumulation factor of fish in terms of BaP is most sensitive on the total outcome, followed by BaP equivalent and exposure duration. Individual exposure route analysis showed dermal contact for soils and food ingestion for sediments as the main exposure pathway. Some specific locations such as surrounding areas of Bhavnagar, Raniganj, Sunderban, Raipur, and Delhi demand potential strategies of carcinogenic risk management and reduction. The current study is probably the first attempt to provide information on the carcinogenic risk of polycyclic aromatic hydrocarbons in soil and sediments across India.
The role of preferential biodegradation in the reduction of cancer risk caused by polycyclic aromatic hydrocarbons (PAHs) has been studied. A consortium of microorganisms isolated from aged oil ...refinery exposed soil was used to degrade 13 PAHs content extracted from an urban traffic site soil. The biodegradation arranged in a batch process with a mineral salt broth, where PAHs were the sole carbon source. 70.46% biodegradation of the total PAHs occurred in an incubation period of 25 days. Sequential or preferential biodegradation took place as the lower molecular weight (LMW) PAHs were more prone to biodegradation than that of the higher molecular weight (HMW) PAHs. Microorganisms from the isolated consortia preferred the simpler carbon sources first. The relatively higher carcinogenicity of the HMW PAHs than that of the LMW PAHs leads to only 40.26% decrement in cancer risk. Initial cancer risk for children was 1.60E−05, which was decreased to 9.47E−06, whereas, for the adults, the risk decreased to 1.01E−05 from an initial value of 1.71E−05. The relative skin adherence factor for soil (AF) turned out to be the most influential parameter with 54.2% contributions to variance in total cancer risk followed by the exposure duration (ED) for children. For the adults, most contributions to the variance in total cancer risk were 58.5% by ED and followed by AF.
This is a discussion on the technical note entitled, “Public Health Risk Assessment following Exposure to PAH-contaminated Soils - Specific Considerations for Bioaccessibility and Other Exposure ...Parameters”. Presence of some serious issues in the technical note on understanding the scopes and concepts of the original research article have been highlighted. The prevailing unclear definition of bioaccessibility and bioavailability in the scientific community may have been caused the misunderstanding of the scope of our original study. On an effort to clear this idea we feel privileged to write this discussion.
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