Incremental Lifetime Cancer Risk Research Articles

Determination of phthalic acid esters (PAEs) along with probabilistic health risk assessment in fruit juice samples in Tehran, Iran.

In the present study, magnetic solid phase extraction (MSPE) method and gas chromatography-mass spectrometry (GC/MS) technique were used to measure 6 PAE in fruit juice samples. The mean of total phthalic acid esters (ƩPAEs) in all samples was 3.55 ± 0.66µg/L. The mean concentration of DEHP (bis(2-ethylhexyl) phthalate) in samples was 0.82 ± 0.31µg/L, which was lower than the mentioned United States Environmental Protection Agency (USEPA) standard level in drinking water (6μg/L for DEHP). The pineapple juice samples (4.44 ± 0.57µg/L) and mango juice samples (2.77 ± 0. 1µg/L) had maximum and minimum mean levels of ƩPAEs, respectively. Also, results showed that brand B (3.76 ± 0.87µg/L) and samples in the time of expiration date (3.64 ± 0.72µg/L) had the highest PAE levels. The rank order Chronic Daily Intake (95%) values for adults were DEHP ([Formula: see text]) > butylbenzyl phthalates (BBP) ([Formula: see text]) > diethyl phthalate (DEP) ([Formula: see text]) and for children were DEHP ([Formula: see text]) > BBP (9.07E-04) > DEP ([Formula: see text]), which were below the tolerable daily intake (TDI) value. The noncancer risk of PAEs based on the target hazard quotient (THQ) was acceptable (< 1). The results exhibited that the Incremental Lifetime Cancer Risk (ILCR) was below the permissible limit (< [Formula: see text]). Therefore, the risk of carcinogenicity and noncarcinogenicity of PAEs in juices does not have adverse effects on human health.

Simultaneous Analysis of Mycotoxins, Potentially Toxic Elements, and Pesticides in Rice: A Health Risk Assessment Study.

Rice is a widely consumed food worldwide; however, it can be a source of pollutants, such as potentially toxic elements (PTEs), mycotoxins, and pesticides. Sixty rice samples imported from Pakistan (PAK), India (IND), and Thailand (THAI), as well as domestic Iranian (IRN) rice, were collected from Bushehr, Iran, and investigated for the contamination of PTEs, including arsenic (As), lead (Pb), cadmium (Cd), and nickel (Ni); pesticides, including chlorpyrifos, trichlorfon, diazinon, fenitrothion, and chlorothalonil; mycotoxins, such as aflatoxin B1 (AFB1), zearalenone (ZEN), ochratoxin A (OTA), and deoxynivalenol (DON); and molds. Estimated daily intake (EDI) and hazard quotient (HQ) of pollutants and hazard index (HI) and incremental lifetime cancer risk (ILCR) of rice types for the Iranian adult population were calculated. The content of PTEs in Iranian rice was not higher than Iran's national standard limits. In contrast, other types of rice (imported) had at least one PTE above the permissible level. OTA content was below the detection limit, and all other mycotoxins were within the allowable range in all rice types. Thai rice was the only group without pesticides. The HI order of rice types was as follows: HIPAK = 2.1 > HIIND = 1.86 > HIIRN = 1.01 > HITHAI = 0.98. As was the biggest contributor to the HI of Iranian and Thai rice, and diazinon in the HI of Pakistani and Indian rice. The calculation of ILCR confirmed that the concentrations of Ni and Pb in Pakistani and Ni and As in Indian, Thai, and Iranian rice were not acceptable in terms of lifetime carcinogenic health risks.

Polycyclic aromatic hydrocarbons in the surface water and sediment along Euphrates River system: Occurrence, sources, ecological and health risk assessment

This study presented for the first time a comprehensive measurement campaign of 16 PAHs along the Euphrates River for five months, in both water and sediment samples. Our study revealed that the PAHs contamination increased along the flow direction due to the increasing non-point pollution and the return flows of agriculture. The 5–6 rings PAHs were dominant in water and sediment samples with an average of 42 % and 50 %, respectively. The diagnostic ratios of PAHs suggest that the pollution of these compounds originated mainly from petroleum product combustions. The carcinogenic PAHs formed 46 % and 55 % of the total measured compounds in water and sediment samples, respectively, which highlights potential ecological and human health risks. Based on sediment quality guidelines (SQGs), most sites exhibit an effect range between low and medium. The calculated incremental lifetime cancer risk (ILCR) for adult and children were in the 10−2–10−3 range, which is 3–6-fold higher than what was reported in the literature. These observations call for urgent attention from environmental authorities of countries sharing this key water source in Western Asia.

The pollution characteristics, source identification and health risks of multiple classes atmospheric SVOCs with complex emission sources of the petrochemical plant and other industries

SVOCs are ubiquitous air contaminants, whilst little was known about their environmental fates and sources in atmosphere in ambient areas around petrochemical and other industries. Herein, the levels of typical SVOCs, polycyclic aromatic hydrocarbons (PAHs), organophosphate flame retardants (OPFRs), polybrominated diphenyl ethers (PBDEs), phthalate acid esters (PAEs), and alternative plasticizers (APs), were investigated in atmosphere of residential areas around a petrochemical industry plant. The plant is bordering a developing metropolis, with highly developed modern industries and transportations. PAEs (128.7 ± 72.2 ng/m3) were found with the highest levels in atmosphere, followed by APs (19.1 ± 14.6 ng/m3), PAHs (13.6 ± 5.01 ng/m3), OPRs (3.89 ± 1.85 ng/m3), and PBDEs (0.08 ± 0.06 ng/m3). Seasonal variation was observed for SVOCs in the particulate and gaseous phases (p < 0.05), with higher concentrations of PAEs, APs, and OPFRs in summer than winter, whereas the opposite for PAHs. Chemical properties of compounds will influence the G-P partitioning of SVOC in the atmosphere. The sources of SVOCs in the study area are complex, and mainly from plastics manufacturing (20.9%), chemical additive application (46.5%), and petroleum combustion (32.9%). The estimated lifetime lung cancer risk of PAHs was moderate in the residential areas, and was higher in winter than summer. In contrast, the incremental lifetime cancer risk for di (2-ethylhexyl) phthalate inhalation was below the acceptable level. The petrochemical plant was one of the primary sources of PAHs in the investigated area, posing a nonnegligible risk to the surrounding residents. This study enhanced our understanding of the environmental fates and health risks of multiple classes of SVOCs in atmosphere with complex emission sources near the petrochemical plant and other industries.

Illegal Mining and Armed Banditry in Katsina State, Nigeria: What is their Contribution to the Heavy Metal Pollution of a Popularly Consumed Vegetable?

The health risk to the population from exposure to heavy metals in an area that have witnessed a surge in illegal mining activities, cattle rustling and banditry were evaluated in the current study. Cabbage leaves sample from Makiya village, Jibia local Government area, Katsina State, Nigeria was evaluated for the presence of heavy metals using Atomic Absorption Spectrophotometry. The health risks of the evaluated heavy metals in the sample to the population were assessed using the Target Hazard Quotient (THQ) and Health Risk Index (HRI)) to assess the possible non-carcinogenic effect and the Incremental Lifetime Cancer Risk (ILCR) for the cancer risks. The result of the mean concentration value of the evaluated heavy metal Pb from the sample falls above the Maximum Allowable Concentrations (MAC) of heavy metals in leafy vegetables. The concentrations of the other metals including Fe, Cu, Zn, Ni, Mn and Cd evaluated in the sample were within the permissible values The result of the Target Hazard Quotient (THQ) associated with the evaluated heavy metals exposure through consumption of the sample for adults and children were all below 1. The combined health risks for all the metals in the sample for the adults and children population represented as the HRI were below 1, the result of the Incremental Life Cancer Risk (ILCR) for both the adults and children population shows that all the heavy metals have ILCR that falls within the safety limit for cancer risk. Because of the above permissible Pb concentration in the analysed cabbage leaves sample, it can be deduced that the vegetable is not safe for consumption.

Environmental and human health risk assessment of polycyclic aromatic hydrocarbons in the Musa estuary (northwest of Persian Gulf), Iran

A comprehensive investigation of PAHs' occurrence and distribution in the water, sediment, and fish samples of Musa estuary was conducted. Concentrations of 16 PAHs in water, sediment and two commercial fish ranged from 0.14 to 0.66 ng/l, 67.21 to 82.92 ng/g dw, 50.25 to 99.39 ng/g fdw in J. belangerii, and 40.14 to 76.93 ng/g fdw in B. orentalis, respectively. High molecular weight PAHs (HMW-PAHs) were generally predominant compared to low molecular weight PAHs (LMW-PAHs). Additionally, the study of the PAHs fingerprints, using specific ratios, suggests the predominance of a pyrolytic origin for observed PAHs. 4-ring PAHs were observed more in the two species, whereas the PAHs in sediments were dominated by three and five ring compounds. The Incremental lifetime Cancer Risk (ILCR) for fish was ≤10 E 10−5, showed a minimal possible risk of cancer for children and adult.

Biochar reduces uptake and accumulation of polycyclic aromatic hydrocarbons (PAHs) in winter wheat on a PAH-contaminated soil

Biochar has been used previously for remediation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soils for years, which has achieved remarkable results in improving removal of soil PAHs and reducing PAHs uptake in crops. However, the underlying mechanism of biochar application in reducing the uptake and accumulation of PAHs in winter wheat remains unclear. Pot trials using PAHs-contaminated soils were conducted for whole plant growth period of winter wheat, which were amended with 2% (w/w) bamboo biochar (BB), coconut shell biochar (CB) and maize straw biochar (MSB) or not (CK). Compared with CK, application of the three types of biochar significantly (p < 0.01) reduced grain PAHs concentration, the total equivalent concentration (TEC) values and the incremental lifetime cancer risk (ILCR) of grain PAHs, indicating that application of biochar reduced the exposure risk of PAHs in wheat grain, especially for MSB. Consistently, application of the three types of biochar significantly (p < 0.05) reduced uptake and accumulation of PAHs in root and stem of wheat, which may be due to that application of biochar enhanced the degradation of PAHs in the rhizosphere soil. Compared with CK, application of the three types of biochar significantly (p < 0.05) reduced the concentration of PAHs in the rhizosphere soil by 15.9%, 26.1% and 33.7%, respectively. It was found that the degradation rate of HMW PAHs (high molecular weight PAHs, 5-6 ring PAHs) was significantly (p < 0.05) higher than that of LMW PAHs (low molecular weight PAHs, 2-4 ring PAHs) regardless of types of biochar used. Additionally, application of the three types of biochar significantly increased the relative abundance of dominant bacterial phyla and genera in soil. Redundancy analysis and correlation analysis results also showed that there was a strong correlation between the removal rate of PAHs and dominant bacteria in the rhizosphere soil. The present study indicated that biochar could reduce dietary risk of PAHs in wheat grains mainly by increasing the abundance of bacteria related to PAHs degradation, promoting the biodegradation of PAHs in the rhizosphere soil and consequently reducing PAHs uptake in wheat.

Sources, Compositions, and Health Risks of PM2.5-bound PAHs at the Rural Area along with the “Coal to Gas” Law

The “Coal to Gas” (CTG) policy in north China markedly altered the characteristics of polycyclic aromatic hydrocarbons (PAHs) in PM2.5. Existing researches about CTG impacts on components, sources, and health risks of PM2.5-bound PAHs mainly focused on metropolitan area, whereas they were lacking in rural area of north China. Here, we deployed an intensive observation in winter of 2020 at a rural site in the central area of the Beijing-Tianjin-Hebei (BTH) region. A positive matrix factorization (PMF) model and an incremental lifetime cancer risk (ILCR) model were utilized to examine the PAH sources and health risks. Higher daily average PM2.5 of 81.5 µg m–3 in the sampling period than 75 µg m–3 of the National Air Quality Standard Grade II indicated the air pollution in rural area was still serious. The total PAHs increased obviously from diurnal 86.2 ng m–3 to nocturnal 151 ng m–3 because of the nocturnal high intensity of heating, with the increases of 20.7%, 85.5%, and 76.3% for low, medium, and high molecular weight PAHs, respectively. Vehicular exhaust (VE), coal burning (CB), industrial source (IS), biomass burning (BB), and oil spill and leakages (OSL) were the main PAH contributors, with the average daily contributions of 32.7%, 21.5%, 18.3%, 15.9%, and 11.6%, respectively. Lower CC contribution of 27.6% in winter of 2020 than 27.6% in winter of 2019 indicated the positive role of CTG policy. However, the nocturnal CC fraction increased by 680% compared with the diurnal value, and CC had become the largest contributor in the nighttime. BB contribution was up to 18.3%, evidencing that biomass utility should be managed in term of the biomass burning was prohibited in BTH rural area. Moreover, the nocturnal average BaPeq equivalent concentration exhibited higher levels than those in the daytime. The nocturnal ILCR values of adults and children was 9.35 × 10–6 and 2.66 × 10–6, exceeding the acceptable threshold, suggesting there was a potential carcinogenic risk.

Incremental Lifetime Cancer Risk of PAHs in PM2.5 via Local Emissions and Long-Range Transport during Winter

Our study covers the chemical characteristics and health risks of PM2.5 from 2019-2020 at National Taiwan University and City Tunnel in Taipei, Taiwan. Positive Matrix Factorization (PMF) was used to quantify the potential sources of polycyclic aromatic hydrocarbon (PAH). The influences of local pollution (LP), long range transport (LRT) and Power Plant are shown by using bivariate polar plot (BPP), Potential source contribution function (PSCF) and Enrichment Factor (EF) with Positive Matrix Factorization (PMF). Besides, chemical analysis included PAHs, carbonaceous species (OC/EC), water-soluble ions, and trace metals, respectively. Our results indicated that vehicle emissions (gasoline engines: 20.8%, diesel engines: 23.3%) and coal combustion (55.9%) were the major sources of PAHs in the urban site, with higher levels in LP than in LRT. The mean PM2.5 concentrations during the daytime was 13.0 ± 5.64 µg m-3, higher than 10.4 ± 5.16 µg m-3 at nighttime, reflecting high traffic emissions and anthropogenic aerosols during the day. Similar phenomenon was observed for PAHs in the daytime of 3.26 ± 2.36 ng m-3 and 1.91 ± 1.14 ng m-3 at nighttime. Also, due to higher NO3- and K levels, the ions and metals had higher values in the daytime and weekdays than at nighttime and weekends. In contrast, in the City Tunnel, the PM2.5 concentrations difference at the tunnel inlet and tunnel outlet during the daytime was significantly higher 36.4 µg m-3 compared to 27.4 µg m-3 at nighttime due to the heavy traffic during the day. As well, the OC/EC mass fractions at the tunnel inlet and tunnel outlet were 4.00 and 2.73. PSCF revealed a greater value (> 0.6) in the coastal areas of Inner Mongolia and Mainland China, due to long-range transport and industrial emissions. The incremental lifetime cancer risk (ILCR) of Cr6+ was higher in metal (2.60 × 10-5) but did not exceed its tolerable limits.

Ecological and health risks of polycyclic aromatic hydrocarbons in the sediment core of Phayao Lake, Thailand

Polycyclic aromatic hydrocarbons (PAHs) in sediment cores from Phayao Lake were investigated in terms of their concentration, distribution, and potential effects on the environment and human health. The concentration of Σ16PAHs ranged from 77.6 to 1251.1 ng g-1. Additionally, low molecular weight PAHs (two or three fused aromatic rings) were dominant, indicating that the main source of PAHs is the incomplete combustion of organic sources. The toxic equivalent quantities (TEQs) of 16 PAHs varied from 2.67 to 155.09 ng g-1, with an average of 38.29 ± 46.69 ng g-1. Furthermore, the TEQs of 9 known carcinogenic PAHs averaged 20.77 ± 30.63 ng g-1. B[a]P had the highest TEQ, followed by D[a,h]A and B[k]F, with values of 16.93 ± 25.49, 13.89 ± 15.37 and 2.12 ± 3.64, respectively. The RQ(NCs) of ∑PAHs (RQ∑PAHs(NCs)) ranged from 1.65 × 10-4 to 6.27 × 10-1 with an average value of 1.18 × 100 ± 1.52 × 100. Moreover, RQ(NCs) was less than 1 for individual PAHs, indicating a minor risk. However, RQ(MPCs) was less than 1 for individual PAHs, indicating a moderate risk. The results showed a significant incremental lifetime cancer risk (ILCR) from sediment-bound PAHs with dermal absorption, followed by ingestion and inhalation, as the prevalent route of exposure. The measured ILCR values of all PAHs were less than 10-6 for both adults and children, which were lower than the baseline value, indicating that each PAH poses a low risk of cancer to humans. This study provides information for control and preventive actions to limit future PAH pollution in Phayao Lake.

Impacts of Sandstorms on Chemistries of Ambient PAHs in a Small City in North China

Sandstorm events frequently perplex northern China, addressing the people's concern due to subsequent increases in the toxicity and carcinogenicity of PM2.5-bound PAHs (PB-PAHs) in receptor area of sand dust. Here, we enacted a field campaign in a small city between Beijing and Baoding in spring of 2021 covering the sandstorm period (SSP) and non-sandstorm period (NSSP) to examine the sandstorm impacts on chemistries of PB-PAHs. SSP exhibited a slightly high average PAH concentrations of 10.3 ng m–3 than 9.16 ng m–3 in the NSSP. At the same time, the average PM2.5 concentrations obviously increased from 60.7 μg m–3 to 75.2 μg m–3. Positive matrix factorization (PMF) analysis manifested that sandstorm largely enhanced the oil leakage and combustion (OLC) fractions from 18.0% in the NSSP to 34.4% in the SSP. Potential source contribution function (PSCF) indicated that OLC partly came from sandstorm origin area–Inner Mongolia. Low diagnostic ratios of FA / (FA + PY) in the SSP also indicated OLC was more important. Accordingly, the largest contributor of incremental lifetime cancer risks (ILCRs) changed from vehicle exhaust (VE) (36.2%) in the NSSP to OLC (34.4%) in the SSP. VE and industrial emission (IE) contributions decreased obviously due to emission control and traffic limitation in the SSP. Coal burning (CB) still held a high contribution to PAHs regardless of the implementation of “coal to gas” law in the sampling area. In addition, sandstorms increased the levels of high molecular weight PAHs (HMW-PAHs) with high toxicity by 4.07%. ILCRs for adults and children increased from 3.90 × 10–7 to 4.74 × 10–7 and from 2.41 × 10–7 to 2.93 × 10–7, respectively, in the SSP, which should be more concerned.

Pollution characteristics and human health risk of potentially toxic elements associated with deposited dust of sporting walkways during physical activity

Sporting walkways are planned features designed to facilitate physical exercise in urban areas. Potentially toxic elements (PTEs) associated with deposited dust (DD) of urban sporting walkways (USWs), suburban sporting walkways (SSWs) and residential sporting walkways (RSWs) in Jeddah, Saudi Arabia, were measured and interpreted in relation to concentration, spatial distribution, pollution level and human health risk. The elemental concentrations followed a similar pattern, but were generally lower than those in road dust. Pb, Zn, Cu, Cd, and As had elevated Crustal Enrichment Factors (>10), ranging up to 185 for Cd. Except for Fe, ∑PTE concentrations were in the following order: USWs (1431 mg/kg) > SSWs (1073 mg/kg) > RSWs (892 mg/kg). Based on the spatial pattern and enrichment factor, and ecological risk values, sporting walkways (SWs) had moderate to heavy pollution levels of Cd, As, Pb, Zn and Cu, and heavy to extreme pollution level of Cd in USWs. Cd presented a high ecological risk, accounting for 85% of the summed ecological risk indices of the elements with elevated concentration. Carcinogenic and non-carcinogenic risks for children and adults follow the order: USWs > SSWs > RSWs. Ingestion was the main pathway for carcinogenic and non-carcinogenic risks, well exceeding that for the dermal and inhalation pathway. Most risks to human health were generally within the acceptable range, although risks to children were generally higher than those to adults, by a factor of 5.5 for non-carcinogenic risk. Incremental Lifetime Cancer Risks for individual elements did not exceed 10−4 for any element.

Health risk assessment of potentially harmful substances from fly ashes generated by coal and coal waste combustion

Lignite and coal waste used as feed fuels in thermal power plants (TPPs) and semi-industrial fluidized bed boiler (FBB), as well as their representative fly ashes (FAs), were examined. Fly ashes were compared employing anions and cations content in correspondent water extracts, trace elements and polycyclic aromatic hydrocarbon concentrations, as well as health risk assessments of substances known to be of concern for public health. Fluoride and sulfate contents in water extracted FAs are far below the legislation limits for waste, classifying all investigated FAs as non-hazardous. Among investigated trace elements, Cd content is the lowest, while Mn content is the highest. The highest enrichment ratios are noticed for As, Pb, Hg, Cu, V and Cr. The results indicate that total PAHs content is elevated in FA from the combustion of coal waste (AFB), with fluoranthene prevailing. The cancer risk of As and the non-cancer risk of As and Ni in some FAs surpass their respective permissible limits. The incremental lifetime cancer risk of an adult population indicates a potential PAHs risk in AFB, whereas all other fly ashes are within safe limits.

Polycyclic Aromatic Hydrocarbons (PAHs) in household dust: The association between PAHs, Cancer Risk and Sick Building Syndrome

In this study, indoor dust samples were collected from 40 houses in Shiraz; Iran, and analyzed to determine 16 Polycyclic Aromatic Hydrocarbons (PAHs) using Gas chromatography–mass spectrometry (GC-MS). The study participants completed the questionnaires consisting of a series of questions for collecting information about symptoms of sick building syndrome and parameters affecting PAHs concentrations (including traffic congestion in the area, floor level, house renovation, building age, etc.). The total PAHs concentrations in the settled dust samples ranged from 31 to 453 ngg−1 so that, phenanthrene, naphthalene and fluoranthene were the predominant congeners. Diagnostic ratios and principal component analysis (PCA) indicated the predominance of vehicular (especially diesel vehicle emissions) and cooking emissions, as the two major sources of PAHs, in indoor dust. The results of statistical analysis showed a significant association between the total PAHs concentrations and SBS symptoms (headache, skin dryness, itching, and inflammation). In addition, based on health risk assessment, the mean ILCR (Incremental Lifetime Cancer Risk) value was reported to be 3.85 × 10−5 for adults and 4.36 × 10−5 for children, indicating potential cancer risk as a result of exposure to household dust containing PAHs. The findings of this study can provide useful information to improve the quality of the indoor environment of houses.

Concentrations of potentially toxic and essential trace elements in marketed rice of Bangladesh: Exposure and health risks

Rice is a major dietary source of essential trace elements required for the human body but also can be an exposure pathway to different potentially toxic trace elements. This study determined various essential and toxic trace elements in rice from Bangladeshi markets and their possible health risks. Concentrations of essential and toxic trace elements in rice varied significantly from location to location. Mean concentrations (mg kg−1 as dry weight) of essential trace elements were found in the following order - Zn>Mn>Cu>Fe>Mo>Se>Co - and were within their maximum allowable limits. The average concentrations (mg kg−1) of toxic trace elements were as follows: As: 0.17, Cr: 0.18, Ni: 0.55 and Pb: 0.18, while 7% and 40% of the rice samples surpassed, respectively, the EU recommended limits of As and Pb. This study revealed that rice could be a primary exposure pathway of toxic elements, leading to either noncarcinogenic or carcinogenic health problems for daily rice consumers. The non-carcinogenic health risk was mainly associated with As which contributed 77% to the hazard index. The carcinogenic risk measured as incremental lifetime cancer risk (ILCR) was high (>10−4) with As, Cr and Ni, while Pb showed a moderate (<10−4) carcinogenic risk to adults. Rice can substantially be contaminated by trace elements other than As with potential human health risks. Consequently, regular monitoring of the marketed rice grain is demanded, backed up by viable mitigation strategies for reducing toxic elements uptake by rice grains.

Spatial distribution of polycyclic aromatic hydrocarbons in dust and soils from informal trade sites in southern Nigeria: Implications for risk and source analysis

Polycyclic aromatic hydrocarbons (PAHs) are a group of semi-volatile and persistent organic compounds considered priority pollutants because of their pervasive nature and high toxicity to the ecosystem and humans. Therefore, this study aimed to evaluate the PAH concentrations in dust and soils around informal trade sites (ITS) in Nigeria to determine the level of risk, sources, and significance of these activities to the PAH load of the environment. The 16 US EPA PAHs in dust and soils from ITS were determined by gas chromatography-mass spectrometry (GC-MS). The PAH concentrations in dust from these informal trade sites varied from 120 to 8790, 56 to 4780, and 102–1090 μg kg−1 for automobile mechanic workshops (AMW), car dismantling (CDS), and material recovery sites (MRS), respectively, whereas those of soils ranged from 3000 to 95,500, 554 to 14,700, and 966–25,200 μg kg−1 for AMW, CDS, and MRS respectively. The PAH profiles indicated that 3- to 5-ring PAHs were prominent in dust and soils around the ITS. The concentrations of the US EPA 16 PAHs in dust and soils from these ITS showed no correlation with organic matter, while the concentrations of PAH homologues in soils of these ITS showed no correlation with those of dust. Incremental lifetime cancer risk (ILCR) values in the magnitude of 10−4 to 101 were obtained for adult and childhood exposure to PAHs in dust and soils from these ITS. Exposure to PAHs in dust from these ITS gives rise to less risk than for soils. The results indicated that automobile mechanic workshops contribute more PAHs to the environment than car dismantling and material recovery activities. The source analysis showed that the PAH contamination of these sites arises from burning of biomass, plastic materials, and oils, and emissions from vehicles.

Occurrence, sources, and potential risk of polycyclic aromatic hydrocarbons in southern Xinjiang, China

Abstract Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants of global concern, mainly originating from industrial activities, biomass combustion, and vehicle emissions. With the acceleration of industrialization, the surrounding environment of the industrial area may have potential health effects on the population. Therefore, we focused on the occurrence, source, and health risk assessment of PAHs in soil, plants, and water near industrial areas in southern Xinjiang, China. The occurrence of PAHs in different soil layers (0–10, 10–30, and 30–50 cm) was studied, with PAHs mainly concentrated in the topsoil (11.50–34.68 ng/g). In plants, PAHs varied from 56.63 to 597.28 ng/g, with the highest concentrations in reed (267.29–597.28 ng/g). Total PAHs in water ranged from 4183.85 to 24803.45 ng/L, with an average of 10,240 ng/L. 3-ring PAHs were the dominant species in soil, plants, and water with 55, 69, and 59%, respectively. PAHs isomer ratio results indicated that PAHs in soil, plants, and water mainly came from fossil fuels and biomass combustion. Incremental lifetime cancer risk estimation results demonstrated that adults might face higher potential health risks than children. Adults’ dermal contact was the dominant route of exposure, while oral ingestion was the dominant exposure pathway for children. The total carcinogenic risk value of corn is much higher than that of walnuts and red dates, indicating that PAHs pollution in corn must be taken seriously. The results can clarify the local pollution situation, and provide suggestions for improving pollution prevention and control measures.

Levels, distribution, sources and children health risk of PAHs in residential dust: A multi-city study in China

BackgroundPolycyclic aromatic hydrocarbons (PAHs) are typical residential pollutants mainly from biofuel combustion that impose inevitable risk to children. The PAHs in residential dust is universal in most Chinese households with an obvious public health concern. MethodsIn this observational study, a total of 235 residential dust samples from 8 Chinese cities (Panjin, Shijiazhuang, Lanzhou, Luoyang, Xi'an, Wuxi, Mianyang, and Shenzhen) were collected from April 2018 to March 2019, which were extracted and analyzed for 16 priority PAHs by HPLC/FD-UV. Diagnostic ratios, hierarchical clustering analysis and principal component analysis were applied simultaneously for source apportionments. Incremental lifetime cancer risk was employed to estimate children's health risks based on the assumed exposure scenarios. Spearman correlation, Mann-Whitney U test, Kruskal-Wallis H test and Partial Least Squares were used to screen the factors affecting the concentration of PAHs in residential dust. ResultsThe median concentration of ∑16PAHs in residential dust from 8 cities was 44.11 μg/g (0.04 - 355.79 μg/g). ∑16PAHs were found both higher in dust samples in heating season and from downwind households only in Mianyang (p < 0.05). The leading two sources of PAHs were combustion processes and automobile exhaust emissions based on four principal components that accounted for 74.29 % of the total variance. Indoor air environmental factors, household characteristics, and residents' behavioral lifestyles may be the influencing factors of residential dust PAHs. The carcinogenic risk of children aged 0 - 5 years, under the moderate exposure level of PAHs in residential dust, exceeded the acceptable level (10−5 - 10−4 for dermal contact and 10−6 - 10−5 for ingestion). ConclusionsThere was serious PAHs pollution in residential dust under actual living conditions in eight cities across China. More evidence-based measures were needed to control PAHs pollution to safeguard children's health according to appointed sources and influencing factors in residential dust.

Health risk indices associated with heavy metals from vegetables cultivated in Tsagero District, Rimi Local Government Area, Katsina State, Nigeria

Local preservation of vegetables involves drying to enhance shelf life. The drying processes could, in turn, contaminate the vegetables with environmental heavy metals. Ingestion of foods contaminated with heavy metals may lead to an increase in the chances of incurring cancer and other health disorders in the consumer population. This study investigated heavy metals contaminations and health risks associated with the consumption vegetables from Turaji, Tsagero District, Rimi Local Government Katsina State, North west Nigeria. The vegetables were three samples of Solanum lycopersicum L. (tomato) as fresh tomato, tomatoes sun-dried along tarred road side, and tomatoes air-dried on farmland soil; three samples of Capsicum annuum (sweet pepper) as fresh sweet pepper, sweet pepper sun-dried along tarred road side and sweet pepper air-dried on farmland soil. The samples were grinded, ashed and digested with HNO3 and HCl separately using standard methods. The heavy metals (Cu, Ni, Fe, Cr, Cd, Mn, Zn, and Pb) contents of the samples were analyzed using atomic absorption spectrophotometry. Daily intake, non-carcinogenic and carcinogenic risks as well as hazard indices of the heavy metals were determined. Results of the study showed that the vegetables analyzed generally have low levels of the heavy metals, with Ni being below detection level (BDL) in all the samples. All of the detected heavy metals concentrations were below the maximum permissible limits as set by the regulatory agencies. The calculated target hazard quotient (THQ) Health risk indices (HRIs) of the evaluated heavy metals in all the samples were therefore, less than 1. The Incremental Life time Cancer Risk (ILCR) to the population from consumption of the samples lies within the safe limit (≤10-4). From the results, these vegetables are hence, safe for human consumption.

Exposure to Inorganic Arsenic in Rice in Brazil: A Human Health Risk Assessment.

In certain populations, rice is the main source of exposure to inorganic arsenic (iAs), which is associated with cancer and non-cancer effects. Although rice is a staple food in Brazil, there have been few studies about the health risks for the Brazilian population. The objective of this study was to assess the risks of exposure to iAs from white rice and brown rice in Brazil, in terms of the carcinogenic and non-carcinogenic effects, and to propose measures to mitigate those risks. The incremental lifetime cancer risk (ILCR) and hazard quotient (HQ) were calculated in a probabilistic framework. The mean ILCR was 1.5 × 10-4 for white rice and 6.0 × 10-6 for brown rice. The HQ for white and brown rice was under 1. The ILCR for white and brown rice was high, even though the iAs concentration in rice is below the maximum contaminant level. The risk for brown rice consumption was lower, which was not expected. Various mitigation measures discussed in this report are estimated to reduce the risk from rice consumption by 5-67%. With the support of public policies, measures to reduce these risks for the Brazilian population would have a positive impact on public health.