Ingestion Exposure Pathways Research Articles

Appraisal of contamination, hydrogeochemistry, and Monte Carlo simulation of health risks of groundwater in a lithium-rich ore area.

This study incorporated hydrogeochemical facies, the entropy-weighted water quality index (EWQI), multivariate statistics, and probabilistic human exposure assessment to investigate hydrogeochemistry, analyze groundwater quality, and estimate potential risks to human health in a lithium-rich ore area (Jadar River basin, Serbia). The findings designated the Ca·Mg-HCO3 hydrogeochemical type as the predominant type of groundwater, in which rock weathering and evaporation control the major ion chemistry. Due to the weathering of a lithium-rich mineral (Jadarite), the lithium content in the groundwater was very high, up to 567mg/L, with a median value of 4.3mg/L. According to the calculated EWQI, 86.4% of the samples belong to poor and extremely poor quality water for drinking. Geospatial mapping of the studied area uncovered several hotspots of severely contaminated groundwater. The risk assessment results show that groundwater contaminants pose significant non-carcinogenic and carcinogenic human health risks to residents, with most samples exceeding the allowable limits for the hazard index (HI) and the incremental lifetime cancer risk (ILCR). The ingestion exposure pathway has been identified as a critical contaminant route. Monte Carlo risk simulation made apparent that the likelihood of developing cancerous diseases is very high for both age groups. Sensitivity analysis highlighted ingestion rate and human body weight as the two most influential exposure factors on the variability of health risk assessment outcomes.

Quantitative SARS-CoV-2 exposure assessment for workers in wastewater treatment plants using Monte-Carlo simulation

Several studies on COVID-19 pandemic have shown that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originating from human stool are detected in raw sewage for several days, leading to potential health risks for workers due to the production of bioaerosols and droplets during wastewater treatment process. In this study, data of SARS-CoV-2 concentrations in wastewater were gathered from literatures, and a quantitative microbial risk assessment with Monte Carlo simulation was used to estimate the daily probability of infection risk through exposure to viable infectious viral airborne particles of the workers during four seasons and under six environmental conditions. Inhalation of bioaerosols and direct ingestion of wastewater droplets were selected as exposure pathways. Spearman rank correlation coefficients were used for sensitivity analysis to identify the variables with the greatest influence on the infection risk probability. It was found that the daily probability of infection risk decreased with temperature (T) and relative humidity (RH) increase. The probability of direct droplet ingestion exposure pathway was higher than that of the bioaerosol inhalation pathway. The sensitivity analysis indicated that the most sensitive variable for both exposure pathways was the concentration of SARS-CoV-2 in stool. So, appropriate aeration systems, covering facilities, and effective ventilation are suggested to implement in wastewater treatment plants (WWTPs) to reduce emission concentration. Further to this, the exposure time (t) had a larger variance contribution than T and RH for the bioaerosol inhalation pathway. Implementing measures such as adding more work shifts, mandating personal protective equipment for all workers, and implementing coverage for treatment processes can significantly reduce the risk of infection among workers at WWTPs. These measures are particularly effective during environmental conditions with low temperatures and humidity levels.

Pollution and health risk assessment of mine tailings contaminated soils in India from toxic elements with statistical approaches

The rapid mining activities of mica mines in Giridih district, India, have led to toxic metal pollution of agricultural soil. This is a key concern for environmental risk and human health. 63 top soil samples were collected at a distance of 10 m (Zone 1), 50 m (Zone 2), and 100 m (Zone 3) from near 21 mica mines with agriculture fields. The mean concentration of total and bio-available toxic elements (TEs - Cr, Ni, Pb, Cu, Zn, and Cd) was higher in zone 1 across three zones. The Positive matrix factorization model (PMF) and Pearson Correlation analysis were used to identify waste mica soils with TEs. Based on PMF results, Ni, Cr, Cd, and Pb were the most promising pollutants and carried higher environmental risks than the other TEs. Using the self-organizing map (SOM), zone 1 was identified as a high-potential source of TEs. Soil quality indexes for TEs risk zone 1 were found to be higher across three zones. Based on the health risk index (HI), children are more adversely affected than adults. Monte Carlo simulations (MCS) model and sensitivity analysis of total carcinogenic risk (TCR), children were more affected by Cr and Ni than adults through ingestion exposure pathways. Finally, a geostatistical tool was developed to predict the spatial distribution patterns of TEs contributed by mica mines. In a probabilistic assessment of all populations, non-carcinogenic risks appeared to be negligible. The fact that there is a TCR can't be ignored, and children are more likely to develop it than adults. Mica mines with TEs contamination were found to be the most significant anthropogenic contributor to health risks based on source-oriented risk assessment.

Physicochemical properties of water in an intensive agricultural region in Bangladesh: a preliminary study for water quality and health risk assessment

ABSTRACT There are many reservoirs, ponds and Korotoa River in the capital of ancient Pundranagar, Bangladesh, which is an intensive agricultural region. Since different industries are operated for the preparation of different agricultural instruments and agrochemicals are extensively applied to the agricultural soils which mix with the river and pond water and these water bodies may be contaminated with trace elements. In this study, levels of nine trace elements (Cr, As, Cu, Ni, Zn, Cd, Fe, Mn and Pb) and physicochemical properties in surface water from one river and five ponds were measured and compared with water quality guidelines. In addition, health risks, pollution status and possible sources of trace elements were assessed. The mean concentrations of As, Cd, Pb, Cr, Ni, Cu, Fe, Mn and Zn in pond water were 0.059, 0.033, 0.067, 0.136, 0.133, 0.280, 0.733, 0.127 and 0.266 mg/L and river water were 0.055, 0.037, 0.054, 0.104, 0.120, 0.230, 0.702, 0.125 and 0.200 mg/L, respectively. Except Cu and Zn, the mean concentrations of trace elements were above the water quality permissible standards indicating water from these sources is not safe for human use. The WQI values suggested that the water quality is excellent to poor water quality class. Health risk indices indicated that As in water via ingestion exposure pathway may pose both non-carcinogenic and carcinogenic health risks to the residents where the non-carcinogenic risk to the residents is raised from ingestion of As, Cd, Cr and Pb from water.

Multi-parametric analysis of groundwater quality to assess human health risk and hydrogeochemical processes in an agriculturally intensive alluvial aquifer of Northwest India

ABSTRACT Groundwater is one of the most vital sources of irrigation in semi-arid regions of India, and in Punjab, India this resource is being highly exploited due to intensive agricultural practices. In the present study, groundwater quality in Bathinda district of Punjab, India was evaluated to know its suitability for drinking and human health risk associated with direct use of groundwater. To examine the suitability of groundwater for drinking purposes, drinking water quality index (DWQI) approach was used. Non-carcinogenic human health risk associated with the presence of fluoride and nitrate in groundwater was evaluated for the adults and children, through dermal and oral ingestion exposure pathways. Further, to know the processes governing the aquifer geochemistry, Gibbs plot, interionic relationships and principal component analysis were carried out. The results of the present investigation revealed that quality in 73% groundwater samples was not suitable for direct consumption. The results of hazard index (HI) indicated that 91% samples in case of men and 95% samples in case of women and children have HI value more than 1. There is a high non carcinogenic human health risk potential due to direct use of groundwater, and children and women are more prone to this risk. The inter-ionic relationships exhibited that evaporation processes due to semi-arid hot type climate, silicate weathering, shallow groundwater level, interaction of canal and ground water along with the agricultural return flow mainly controlled the groundwater chemistry in the area under investigation.

Probabilistic risk assessment of soil contamination related to agricultural and industrial activities

Soil contamination related to industrial and agricultural activities were associated with many adverse health effects and climate change could exacerbate this effect. However, the evidence on this topic in low and middle-income countries (LMICs) is still scarce. We, therefore, aimed to investigate the heavy metals (HMs) concentrations in topsoil around Lake Urmia (which dried about 50 % of it in recent years). Accordingly, 96 surface soil samples were collected from an area of about 4000 km2 in 2019. An inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to measure the HMs concentrations, including cadmium (Cd), arsenic (As), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), lead (Pb) and zinc (Zn). Health risk assessment of exposure to HMs was performed using Monte Carlo simulations technique. The mean concentrations of Zn, Cu, Ni, Co, Pb, Cr, As and Cd were 68.66, 35, 31.66, 15, 14.4, 11.2, 7.04, and 0.26 mg/kg, respectively, which was in the allowable range of USEPA guideline. The mean enrichment factor (EF) values for Zn, Cd, Cu, Cr, Ni, Pb, Co and As were1.3, 1.9, 1, 1.2, 1.7, 2.8, 1.8 and 2, respectively. Carcinogenic risks of exposure to HMs for inhalation, dermal and ingestion exposure pathways were at safe level. Similarly, the hazard index (HI) was at safe level (HI < 1). The sensitivity analysis indicated that the exposure duration (ED) for As, exposure frequency (EF) for Cd and Ni, concentration (Csoi) for Cr and Pb had the highest impact on ELCR values. Our finding confirmed that HMs concentrations around Lake Urmia had no health risk for inhabitants.

Variations, health risks, pollution status and possible sources of dissolved toxic metal(loid)s in stagnant water bodies located in an intensive agricultural region of Turkey

There are many reservoirs, ponds and lakes in the Meriç-Ergene River Basin (Turkey), which is an intensive agricultural region. Since agrochemicals are extensively applied to the agricultural soils in the basin, these water bodies may be contaminated with toxic metal (loid)s (TMs). However, no study has been conducted to determine TM levels in the water bodies. In this study, levels of seven TMs (Cr, As, Cu, N, Zn, Cd and Pb) in surface water samples taken from 25 different stagnant water bodies (11 reservoirs, 12 ponds and 2 lakes) in the dry and wet seasons were measured and compared with water quality guidelines. In addition, spatial and seasonal variations, health risks, pollution status and possible sources of TMs were assessed. The mean As concentration of the lakes was significantly higher due to drainage water from paddy fields. The ponds had higher total mean TM concentration likely due to their low water volume. Surface runoff from rainfall caused the Cr, Zn, Cd, Pb and Cu concentrations to increase in the wet season. Only the mean As concentration of the lakes in the dry season was above the drinking water standards. Metal pollution indices showed low contamination of the water bodies in both seasons. Health risk indices indicated that As in the lakes in the dry season via ingestion exposure pathway may pose both non-carcinogenic and carcinogenic health risks to the residents. The results of factor and correlation analyses showed that among the studied TMs, only As originated from anthropogenic sources. The findings of this study revealed that agricultural activities caused As pollution in the lakes, while the reservoirs and ponds were not significantly affected by agricultural activities. We suggest that the levels of TMs in all water bodies should be measured at regular intervals to check the quality of surface water.

Impact of paddy fields on water quality of Gala Lake (Turkey): An important migratory bird stopover habitat

Gala Lake is an internationally important lake due to its location on one of the world's most important bird migration routes. For this reason, water quality of the lake is of great concern. However, the lake surrounded by paddy fields may face eutrophication and toxic metal contamination due to excessive use of fertilizers and pesticides. In this study, impact of paddy fields on water quality of the Gala Lake was investigated. The concentrations of metal(loid)s and physico-chemical parameters in surface water samples taken from the lake were measured and compared with water quality guidelines. Also, human health risks and contamination status of metal(loid)s were assessed. The mean NO2, SRP and BOD concentrations in the lake exceeded the permissible levels for both salmonid and cyprinid waters. The mean BOD value indicated contaminated water quality in the lake, while mean COD and SRP values indicated lightly contaminated water quality. The mean As, Cr and Pb values in the winter exceeded the drinking water limits set by WHO and EC, while the mean Cr and Zn values exceeded the limit values for the protection of freshwater aquatic organisms set by USEPA. Similarly, heavy metal pollution index and the degree of contamination values in the winter indicated that the lake water is moderately polluted. Health risk assessment results revealed that As and Cr in the lake water via ingestion exposure pathway may pose both non-carcinogenic and carcinogenic health risks to the residents. The results of this study indicated that paddy fields are a major source of nutrients, organic matter and toxic metal(loid)s to the Gala Lake. To improve the water quality of the lake, we suggest that excessive use of fertilizers and pesticides should be controlled to reduce metal(loid) and nutrient loads from the paddy fields.

Variability in plant trace element uptake across different crops, soil contamination levels and soil properties in the Xinjiang Uygur Autonomous Region of northwest China

This study investigated contamination status of eight trace elements (As, Cd, Cr, Hg, Pb, Cu, Zn and Ni) in farmland soils and crops at 535 sites across the Xinjiang Uygur Autonomous Region, Northwest China. Land use types of the sampling sites included vegetable patch, grain field and orchard. Our experimental results indicated all farmland soils were considered as trace element contamination based on the Nemerow comprehensive pollution index (NCPI > 1). However, 91.97% of the crop samples were uncontaminated according to the Chinese Risk Control Standard. Soils from the vegetable patch showed higher pollution level comparison with that from grain field and orchard. Health risks for both non-carcinogenic and carcinogenic risks were calculated through crop ingestion exposure pathway. Grain samples showed highest health risks, followed by melon and fruit, and vegetables. The health risks of crops were mainly driven by Cr and Cd. Crop consumption may pose risks for children but not adults. The source of trace element contamination in the different farmland soils varied and may be attributed to the different agricultural activities. Plant type had a greater influence on the trace element accumulation in crops compared with soil trace element contents and physicochemical properties.

Pollution status, ecological and human health risks of heavy metals in soil from some selected active dumpsites in Southeastern, Nigeria using energy dispersive X-ray spectrometer

ABSTRACT Thestudyevaluatedthepollutionstatus, ecologicalandhumanhealthrisksofheavymetalsin some selected active dumpsite[Aba(dumpsite-1), Nnewi (dumpsite-2), Abakaliki (dumpsite-3) and Nekede (dumpsite-4)] in south-eastern Nigeria. Quintuplicate sub-samples were collected using soil auger at a depth of 0–20 cm from four different points (North, East, West and South) of each dumpsite while control samples for each dumpsite were collected 20 km away, where there were little human activities and no presence of active dumpsites. Elemental analysis was carried out on samples using energy dispersive x-ray fluorescence spectrometer. Ten heavy metals selected were in the order; dumpsite-1 (Cu > Fe > Pb > Zn > As > Co > Ni > Mn > Cr > Cd), dumpsite-2 (Fe > Pb > Zn > Cu > Co > Mn > Ni > As > Cr > Cd), dumpsite-3 (Fe > Zn > Mn > Ni > Co > Cu > Pb > As > Cr > Cd) and dumpsite-4 (Fe > Zn > Pb > Co > Ni > Cu > Mn > Cr > As > Cd). Pollution status of the dumpsites was determined using metal pollution index, enrichment factor, pollution load index, and geoaccumulation index. The dumpsites studied were polluted in the order; dumpsite-1> dumpsite-2> dumpsite-4 > dumpsite-3. Health risk evaluation by ingestion, inhalation and dermal pathways for adults and children was modelled. Results showed children are more at risk than adult with As, Pb and Ni identified with the highest risks. The ingestion exposure pathway was the major contributor to both non-cancer and excess lifetime cancer risk followed by dermal and then inhalation. This quantitative evidence demonstrates the need for remediation of soils within dumpsites so as to protect residents, especially children from heavy metal pollution in the environment.

Spatially resolved distribution, sources and health risks of heavy metals in size-fractionated road dust from 57 sites across megacity Kolkata, India

This work reports the first assessment of contamination levels, source contributions and health risks associated with heavy metals (HMs) in road dust from Kolkata, the second-most polluted metropolis in India. To this end, samples collected from 57 locations across 6 land-use categories: residential, roadside, traffic, railway, port and industrial areas in the city during 2018 were analyzed for 11 major and trace metals (Ca, Mg, Fe, Al, Mn, Ni, V, Cu, Zn, Cr, Pb) in three size fractions: <75 μm, 75–125 μm and 125–300 μm. Overall, Mn, Zn, Cr, Pb, V, Cu and Ni were enriched in the smallest fraction by factors of 1.2–2.7. Based on metal distribution across land-use categories, crustal dust (Fe, Al, V), construction activities (Ca, Mg), metallurgical processes (Pb), and non-exhaust abrasive emissions from brake, tire and paint wear (Cu, Zn, Cr) were found to be significant. HMs such as Cu, Zn, Cr and Pb were considerably enriched over background levels as suggested by three contamination indices: Enrichment Factor (EF; overall range: 2.4–12.0), Index of Geo-accumulation (Igeo; overall range: 1.1–3.4), and Pollution Index (PI; overall range: 3.1–15.6). Geospatial mapping identified HM contamination hotspots (integrated PI >4) in west-central and northern parts (the older sections) of the city represented by industrial, port, and traffic-congested residential areas. Using positive matrix factorization (PMF), the following sources were apportioned for the three size fractions: crustal dust (48–66%), construction activities (18–20%), vehicular abrasion (7–21%), industrial emissions (5–8%), a Cr-dominated mixed source (6%) and an unassigned source (7%). Finally, health risk assessment in the form of cumulative hazard index (HI) and incremental lifetime cancer risk (ILCR) found that children (mean HIchildren: 1.29 and ILCRchildren: 2E-04) are comparatively more vulnerable than adults (mean HIadults: 0.22 and ILCRadults: 8E-05) to HM exposure, with the ingestion exposure pathway dominating over dermal contact and inhalation.

Human health risk assessment of pharmaceuticals in treated wastewater reused for non-potable applications in Sharjah, United Arab Emirates

Pharmaceuticals and personal care products are an integral part of societal health yet their presence in various environmental compartments, including treated wastewaters, has sparked concerns towards possible human and ecological health effects. The current study aims to characterize human health risks posed by ten pharmaceuticals quantified in wastewater treatment plant effluents where water is reused mainly for landscape irrigation. Receptors were identified as children playing in green areas, adult landscape workers, and adult users of athletic and golf courses irrigated by treated wastewater. The human health risk assessment model exhibited safe exposure (RQ < 1) to all pharmaceuticals for all receptors through both dermal and ingestion exposure pathways. RQs were highest for the landscape worker followed by children playing in green areas and then adult using the athletic fields. RQs were highest to lowest in the following order of pharmaceuticals: acetaminophen, metoprolol, ciprofloxacin, erythromycin, ofloxacin, sulfadiazine, sulfamethoxazole, sulfapyridine, risperidone, and sulfamethazine. Such risk assessment findings aid in supporting decisions to optimize wastewater treatment and reuse strategies, as well as safeguard public and environmental health.

Health Risk Assessment of Trace Metals in Various Environmental Media, Crops and Human Hair from a Mining Affected Area.

Long term exposure to trace metals in various media is of great concern for people living in known pollution sources, such as mining and industrial activities. Health risk assessment and human hair analysis can provide important information for local environmental management. Information on distribution characteristics of trace metals in soil, water, sediment, air, local crops, and human hair from a typical mining area in southern China was collected. Results show there exists severely trace metal contamination in soil, sediment, and air. Arsenic and Pb contents in the local children’s hair are higher than the upper reference values, and the accumulation of residents’ hair trace metals shows great correlation with the ingestion and inhalation pathways. Arsenic contributes 52.27% and 58.51% to the total non-cancer risk of adults and children, respectively. The cancer risk of Cd in adults and children are 4.66 and 3.22 times higher than the safe level, respectively. Ingestion exposure pathway of trace metals largely contributes to the total non-cancer and cancer effect. The metals As, Cd, and Pb are major risk sources and pollutants that should be given priority for management, and ingestion pathway exposure to trace metals through soil and crops should be controlled.

Development of emergency planning zone for high temperature gas-cooled reactor

Emergency planning zone (EPZ) is a basic element of nuclear emergency planning, whose architecture is mainly determined by the characteristics of early light water reactors (LWRs) at present. As a candidate of Gen IV reactors, high temperature gas cooled reactor (HTR) is required to consider the issue of EPZ in current regulation framework of nuclear emergency. The issue we discussed here is based on high temperature gas cooled reactor pebble-bed module (HTR-PM) being constructed at Shidao Bay, Shandong Province, China. Since HTR is much different from LWRs in design concept, system configuration and accident characteristics, the emergency planning developed for HTR can be simplified comparing to the current LWR-based emergency planning. HTR, like HTR-PM, implements inherent safety features and ensures the elimination of severe core damage and large release of radioactive material. So that EPZ needs to be adjusted to match the safety features of HTR to reduce the cost of construction and operation, and enhance the feature of good neighbor. The commonly used technical framework introduced in NUREG-0396, which is documented by Nuclear Regulatory Commission (NRC) is adopted as base to discuss the EPZ issue. The accidents need to be considered during EPZ development, including the design basis accidents (DBAs) and emergency reference release categories (ERRCs), are firstly confirmed according to the accident characteristics of HTR-PM. We conclude that radii of EPZ for plume exposure pathway and ingestion exposure pathway can both be the same as exclusion area boundary, which supports the further simplification of nuclear emergency of HTR.

Children's Lead Exposure: A Multimedia Modeling Analysis to Guide Public Health Decision-Making.

Background:Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)’s National Drinking Water Advisory Council (NDWAC) recommended establishment of a “health-based, household action level” for lead in drinking water based on children’s exposure.Objectives:The primary objective was to develop a coupled exposure–dose modeling approach that can be used to determine what drinking water lead concentrations keep children’s blood lead levels (BLLs) below specified values, considering exposures from water, soil, dust, food, and air. Related objectives were to evaluate the coupled model estimates using real-world blood lead data, to quantify relative contributions by the various media, and to identify key model inputs.Methods:A modeling approach using the EPA’s Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia and Integrated Exposure Uptake and Biokinetic (IEUBK) models was developed using available data. This analysis for the U.S. population of young children probabilistically simulated multimedia exposures and estimated relative contributions of media to BLLs across all population percentiles for several age groups.Results:Modeled BLLs compared well with nationally representative BLLs (0–23% relative error). Analyses revealed relative importance of soil and dust ingestion exposure pathways and associated Pb intake rates; water ingestion was also a main pathway, especially for infants.Conclusions:This methodology advances scientific understanding of the relationship between lead concentrations in drinking water and BLLs in children. It can guide national health-based benchmarks for lead and related community public health decisions. https://doi.org/10.1289/EHP1605

Health risks associated with municipal waste combustion on the example of Laskowa commune (Southern Poland)

ABSTRACTThis study presents the results of an analysis of combustion waste, namely fly ashes produced from the burning of solid fuels mixed with municipal waste. Heavy metal concentrations in the fly ashes examined fell within the following ranges (mg/kg): Cd 0.39–0.79, Cr 13.48–58.51, Ni 17.01–49.37 and Pb 14.95–59.74. As this type of waste does not exceed the limit values of pollutants for organic and organic-mineral fertilisers, it is often discarded on agricultural land or dumped in illegal landfills. Fine particles of fly ashes travel considerable distances and pose a risk to human health as they stick to people's hands during field works. The mean hazard quotient (HQ) values for non-carcinogenic forms of the elements analysed were 1.06E+00 for children and 1.47E-01 for adults. A HQ>1 indicates the probability of adverse health effects. The study has shown that the dominant exposure pathway was ingestion, which accounted for approx. 91% of total health risk, while the respective percentages for other pathways were less than 9% for dermal contact and 0.05% for inhalation. The highest health risk in the ingestion exposure pathway was observed for Cr (HQing = 4.50E-01 for children, HQing = 5.23E-02 for adults) and Pb (HQing = 4.31E-01 for children, HQing = 5.01E-02 for adults). Health risk associated with the presence of Ni and Cd in the material analysed was markedly lower. For carcinogenic forms, the Risk index was established at 6.13E-08 for children and 2.13E-07 for adults. As the exposure limit (10E-5) was not exceeded, the conditions in the area studied should be considered satisfactory.

Investigation and health risk assessment of heavy metals in soils from partial areas of Daye city, china

Heavy metals (Cu and Pb) in four sampling sites from parts areas of Daye city were collected. Concentrations of Cu and Pb in soils in sampling sites were detected, the enrichment degree was measured by geo-accumulation index, and the human health risks were calculated by applying the human health risk assessment model. The results show that the concentrations of Cu and Pb of soils in some areas are much more than Daye City, Hubei Province soil background value. The concentration of Cu and Pb in Xiaganwan soil sample has a higher value and the concentration of Cu (110.17 mg·kg-1) exceeds the soil environmental quality standards. The values of Igeo of Cu and Pb in the soil in some areas of Daye city are 1 except Xiaganwan sample is 2. For human health risk assessment, the non-cancer risk of Cu in three routes of exposure is less than Pb. The non-cancer risk both adults and children are less than 1 and show a general trend of HQ in oral ingestion exposure pathway > HQ in inhalation exposure pathway>HQ in skin contact exposure pathway. It will not cause significant non-carcinogenic health effects on the human body.

Characterization and geochemistry of technogenic magnetic particles (TMPs) in contaminated industrial soils: Assessing health risk via ingestion

The objective of this study was the detailed characterization of “technogenic” magnetic particles (TMPs) separated from contaminated industrial soils. Moreover, non-carcinogenic health risk posed by “technogenic” metals Pb and Zn via the ingestion exposure pathway was carried out. Volume magnetic susceptibility (κ) was measured directly in the field around a chemical industry in Sindos industrial area, Northern Greece. Representative soil samples were collected from the sites where elevated κ values were recorded. Mass specific magnetic susceptibility (χlf) depended on the content of TMPs and ranged from 52.6×10−8m3kg−1 to 821.2×10−8m3kg−1 with the maximum values detected in the immediate vicinity of the industrial unit where the most contaminated soils were also identified. Mineralogically the TMPs exhibited a dominant iron spinel phase, while other iron-bearing phases such as hematite and lepidocrocite were detected. Morphologically, Fe-rich spherules and irregular-shaped particles were the most commonly observed particles in TMPs, revealing various Fe contents often associated with elevated heavy metal contents. TMPs exhibited significantly higher concentrations of trace elements compared to non-magnetic fractions (NMFs) indicating that potentially harmful elements (PHEs) are preferentially enriched in the TMPs. Furthermore, for the first time, a health risk assessment study for the incidental soil magnetic fractions (MFs) ingestion of the “technogenic” metals Pb and Zn was carried out based on U.S. Environmental Protection Agency (U.S.E.P.A.) guidelines, incorporating oral bioaccessibility measurements using the BARGE Unified Bioaccessibility Method (UBM). Significant fractions (>50%) of Pb and Zn occur in bioaccessible forms in the TMPs and both children and adults are experiencing potential health risk since determined HQs values were significantly higher than safe level (=1).

Refinement of arsenic attributable health risks in rural Pakistan using population specific dietary intake values

BackgroundPrevious risk assessment studies have often utilised generic consumption or intake values when evaluating ingestion exposure pathways. If these values do not accurately reflect the country or scenario in question, the resulting risk assessment will not provide a meaningful representation of cancer risks in that particular country/scenario. ObjectivesThis study sought to determine water and food intake parameters for one region in South Asia, rural Pakistan, and assess the role population specific intake parameters play in cancer risk assessment. MethodsA questionnaire was developed to collect data on sociodemographic features and 24-h water and food consumption patterns from a rural community. The impact of dietary differences on cancer susceptibility linked to arsenic exposure was evaluated by calculating cancer risks using the data collected in the current study against standard water and food intake levels for the USA, Europe and Asia. A probabilistic cancer risk was performed for each set of intake values of this study. ResultsAverage daily total water intake based on drinking direct plain water and indirect water from food and beverages was found to be 3.5Lday−1 (95% CI: 3.38, 3.57) exceeding the US Environmental Protection Agency's default (2.5Lday−1) and World Health Organization's recommended intake value (2Lday−1). Average daily rice intake (469gday−1) was found to be lower than in India and Bangladesh whereas wheat intake (402gday−1) was higher than intake reported for USA, Europe and Asian sub-regions. Consequently, arsenic-associated cumulative cancer risks determined for daily water intake was found to be 17 chances in children of 3–6years (95% CI: 0.0014, 0.0017), 14 in children of age 6–16years (95% CI: 0.001, 0.0011) and 6 in adults of 16–67years (95% CI: 0.0006, 0.0006) in a population size of 10,000. This is higher than the risks estimated using the US Environmental Protection Agency and World Health Organization's default recommended water intake levels. Rice intake data showed early life cumulative cancer risks of 15 chances in 10,000 for children of 3–6years (95% CI: 0.0012, 0.0015), 14 in children of 6–16years (95% CI: 0.0011, 0.0014) and later life risk of 8 adults (95% CI: 0.0008, 0.0008) in a population of 10,000. This is lower than the cancer risks in countries with higher rice intake and elevated arsenic levels (Bangladesh and India). Cumulative cancer risk from arsenic exposure showed the relative risk contribution from total water to be 51%, from rice to be 44% and 5% from wheat intake. ConclusionsThe study demonstrates the need to use population specific dietary information for risk assessment and risk management studies. Probabilistic risk assessment concluded the importance of dietary intake in estimating cancer risk, along with arsenic concentrations in water or food and age of exposed rural population.

Ecological and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Water from Middle and Lower Reaches of the Yellow River

In surface water from the middle and lower reaches of the Yellow River, total equivalent concentrations of 16 US EPA priority PAHs were calculated based on the measured concentrations. Ecological risk assessment approaches, including hazard quotient and overlapping areas of probability density curves, were performed to evaluate the combined ecological risks of PAHs to the aquatic organisms. The result from hazard quotient indicated that risk quotient of mollusks and zooplankton surpassed 0.1, suggesting potential risks. The potentially affected fractions of PAHs obtained from overlapping areas of probability density curve varied from 11.2% (dry season) to 5.1% (rainy season), which implied that PAHs had been posing pressures on the ecosystem. Health risk based on the incremental lifetime risk for PAHs was conducted to evaluate human cancer risk and noncarcinogenic hazard in the studied area. The results indicated that health risks mainly came from ingestion exposure pathway. The total cancer risks were in the range of 10−8 to 10−7, lower than the baseline value of acceptable risk (10−6). Moreover, non-carcinogenic hazard indices of PAHs ranging from 10−6 to 10−5 were much lower than the threshold values (1.0). These results indicated that the water from middle and lower reaches of Yellow River might pose no health risk on local residents as a source of drinking water.