Soil Ingestion Research Articles

Model based prediction of age-specific soil and dust ingestion rates for children

BackgroundSoil and dust ingestion can be a primary route of environmental exposures. Studies have shown that young children are more vulnerable to incidental soil and dust ingestion. However, available data to develop soil and dust ingestion rates for some child-specific age groups are either lacking or uncertain.ObjectiveOur objective was to use the Stochastic Human Exposure and Dose Simulation Soil and Dust (SHEDS-Soil/Dust) model to estimate distributions of soil and dust ingestion rates for ten age ranges from infancy to late adolescents (birth to 21 years).MethodsWe developed approaches for modeling age groups previously not studied, including a new exposure scenario for infants to capture exposures to indoor dust via pacifier use and accounting for use of blankets that act as a barrier to soil and dust exposure.ResultsOverall mean soil and dust ingestion rates ranged from ~35 mg/day (infants, 0–<6 m) to ~60 mg/day (toddlers and young children, 6m–<11 yr) and were considerably lower (about 20 mg/day) for teenagers and late adolescents (16–<21 y). The pacifier use scenario contributed about 20 mg/day to the median dust ingestion rate for young infants. Except for the infant age groups, seasonal analysis showed that the modeled estimates of average summer mean daily total soil plus dust ingestion rates were about 50% higher than the values predicted for the winter months. Pacifier use factors and carpet dust loading values were drivers of exposure for infants and younger children. For older children, influential variables included carpet dust loading, soil adherence, and factors that capture the frequency and intensity of hand-to-mouth behaviors.SignificanceThese results provide modeled estimates of children’s soil and dust ingestion rates for use in decision making using real-world exposure considerations.Impact statementThe parameterization of scenarios to capture infant soil and dust ingestion and the application of SHEDS-Soil/Dust to a broader age range of children provides additional estimates of soil and dust ingestion rates that are useful in refining population-based risk assessments. These data illuminate drivers of exposure that are useful to both risk management applications and for designing future studies that improve upon existing tracer methodologies.

Soil Ingestion, a Key Determinant of Exposure to Environmental Contaminants. The Case Study of Chlordecone Exposure in Free-Range Pigs in the French West Indies

Soil Ingestion, a Key Determinant of Exposure to Environmental Contaminants. The Case Study of Chlordecone Exposure in Free-Range Pigs in the French West Indies

Carbofuran residues in soil and consumption risks among farmers growing vegetables in Ubon Ratchathani Province, Thailand

&lt;abstract&gt; &lt;p&gt;Farmers in Khi Lek Subdistrict, Muang District, Ubon Ratchathani Province, Thailand have been known to persistently use pesticides, especially carbofuran, in their agricultural fields. This indeed poses a risk to farmers' health and ecosystem. However, there has been no report pointing out this problem. The purpose of this study was to determine carbofuran residues in soil in four villages in Khi Lek Subdistrict, Muang District, Ubon Ratchathani Province, Thailand, where pesticides were widely used for vegetables. The quick, easy, cheap, effective, rugged and safe (QuEChERS) method was used to extract the samples, which were then analyzed utilizing high-performance liquid chromatography with a mass spectrometry detector. The health risks of carbofuran exposure through soil ingestion among 485 farmers were investigated by using the hazard quotient (HQ). The concentration of carbofuran in 10 soil samples was less than 0.01 mg/kg. The overall average of the farmers' daily dose of carbofuran in Villages 5, 8, 9 and 10 ranged from 3.9×10&lt;sup&gt;-9&lt;/sup&gt; mg/kg-day to 5×10&lt;sup&gt;-9&lt;/sup&gt; mg/kg-day, and the hazard quotient (HQ) indicated an acceptable level for health risks. However, this study found that 98.97% of the farmers ate food and 97.53% drank water while farming. As a result of this, they may still be exposed to pesticides. Since the factors contributing to human health risks include the length of exposure, frequency of exposure, and farmer body weight, this study suggests that the government should be concerned because the current pattern of pesticide use still poses an immediate health risk to the farmers. While The farmers should be trained in safe pesticide usage while safe pesticide practice should also be promoted.&lt;/p&gt; &lt;/abstract&gt;

Integrated review of the nexus between toxic elements in the environment and human health.

Emerging pollutants in the environment due to economic development have become a global challenge for environmental and human health management. Potentially toxic elements (PTEs), a major group of pollutants, have been detected in soil, air, water and food crops. Humans are exposed to PTEs through soil ingestion, consumption of water, uptake of food crop products originating from polluted fields, breathing of dust and fumes, and direct contact of the skin with contaminated soil and water. The dose absorbed by humans, the exposure route and the duration (i.e., acute or chronic) determine the toxicity of PTEs. Poisoning by PTEs can lead to excessive damage to health as a consequence of oxidative stress produced by the formation of free radicals and, as a consequence, to various disorders. The toxicity of certain organs includes neurotoxicity, nephrotoxicity, hepatotoxicity, skin toxicity, and cardiovascular toxicity. In the treatment of PTE toxicity, synthetic chelating agents and symptomatic supportive procedures have been conventionally used. In addition, there are new insights concerning natural products which may be a powerful option to treat several adverse consequences. Health policy implications need to include monitoring air, water, soil, food products, and individuals at risk, as well as environmental manipulation of soil, water, and sewage. The overall goal of this review is to present an integrated view of human exposure, risk assessment, clinical effects, as well as therapy, including new treatment options, related to highly toxic PTEs.

Contribution of &lt;sup&gt;40&lt;/sup&gt;K arising from agropastoral activities to the total effective dose by plant ingestion in the Far-North, Cameroon

&lt;abstract&gt; &lt;p&gt;This study assesses the level of radioactivity, its corresponding dose and risk in areas of intense agropastoral activities in the Mayo-Sava, Mayo-Tsanaga and Mayo-Kani Divisions of the Far North region of Cameroon. The ultimate aim is to show that beyond the geological structure and mineralogical composition of the soil, agricultural fertilizers and animal droppings from livestock farming can contribute significantly to the elevation of the &lt;sup&gt;40&lt;/sup&gt;K-induced radioactivity level in an environment. Natural radionuclide analysis was carried out on 55 soil samples collected from the three aforementioned localities, using a laboratory NaI (Tl) gamma spectrometer. The mean activity concentrations of &lt;sup&gt;238&lt;/sup&gt;U, &lt;sup&gt;232&lt;/sup&gt;Th and &lt;sup&gt;40&lt;/sup&gt;K were 41, 59 and 529 Bq/kg respectively. The total effective dose to the public and the risk of cancer morbidity were generated by RESRAD-ONSITE code version 7.2. The 0.7 mSv/year maximum total effective dose was estimated at time &lt;italic&gt;t&lt;/italic&gt; = 38 years, with contributions of 56%, 37.3%, 3.9%, 2.1%, 0.7% and 0.07% from plant ingestion, external exposure, meat ingestion, milk ingestion, soil ingestion and inhalation, respectively. Potassium-40 (&lt;sup&gt;40&lt;/sup&gt;K) from plant ingestion is the major contributor. The doses in the initial year of agropastoral activity and the total excess cancer risk were 0.3 mSv/year and 1.165×10&lt;sup&gt;-3&lt;/sup&gt; respectively. The &lt;sup&gt;40&lt;/sup&gt;K contributions to effective dose from plant ingestion obtained in this work are high compared to areas where agropastoral activities are not intensive. This may be due to the various fertilizers and animal droppings distributed in nature which are very rich in potassium. Although potassium is essential to life, it is nevertheless necessary for radiation protection to take into account this type of radiological exposure which is not without harmful effects on the environment and health.&lt;/p&gt; &lt;/abstract&gt;

Heavy metal pollution of soils and risk assessment in Houston, Texas following Hurricane Harvey

In August 2017, after Hurricane Harvey made landfall, almost 52 inches of rain fell during a three-day period along the Gulf Coast Region of Texas, including Harris County, where Houston is located. Harris County was heavily impacted with over 177,000 homes and buildings (approximately 12 percent of all buildings in the county) experiencing flooding. The objective of this study was to measure 13 heavy metals in soil in residential areas and to assess cancer and non-cancer risk for children and adults after floodwaters receded. Between September and November 2017, we collected 174 surface soil samples in 10 communities, which were classified as “High Environmental Impact” or “Low Environmental Impact” communities, based on a composite metric of six environmental parameters. A second campaign was conducted between May 2019 and July 2019 when additional 204 soil samples were collected. Concentrations of metals at both sampling campaigns were higher in High Environmental Impact communities than in Low Environmental Impact communities and there was little change in metal levels between the two sampling periods. The Pollution Indices of lead (Pb), zinc, copper, nickel, and manganese in High Environmental Impact communities were significantly higher than those in Low Environmental Impact communities. Further, cancer risk estimates in three communities for arsenic through soil ingestion were greater than 1 in 1,000,000. Although average soil Pb was lower than the benchmark of the United States Environmental Protection Agency, the hazard indices for non-cancer outcomes in three communities, mostly attributed to Pb, were greater than 1. Health risk estimates for children living in these communities were greater than those for adults.

Effects of soil-extractable metals Cd and Ni from an e-waste dismantling site on human colonic epithelial cells Caco-2: Mechanisms and implications

E-wastes release toxic metals including Cd, Cu, Ni, Pb and Zn into nearby soils during dismantling process. However, their adverse effects and the associated mechanisms on human intestinal epithelium are poorly understood. In this study, their toxic effects on human colonic epithelial cells Caco-2 and the underlying mechanisms were assessed basing on three soils from Wenling e-waste dismantling site. Since soil-extractable metals are more available for gastrointestinal absorption, we used phosphate buffer saline solution to extract metals at solid to liquid ratio of 1:2. Among metals, total Cd and Ni exceeded the risk screening values in three soils, being 3.8–8.8 and 42.4–155 mg/kg. Furthermore, high extractable-metals at 5.9, 1.9, and 0.87 mg/kg Cd (20–67%) and 4.6, 6.4, and 12.4 mg/kg Ni (3.6–29%) were observed for Soil-1, -2 and -3, respectively. All three extracts triggered cytotoxicity, with Soil-2 showing the strongest inhibition of cell viability. Higher production of reactive oxygen species and stronger inhibition of antioxidant enzymes SOD1 and CAT were observed in Soil-2 and -3. Upregulation of proinflammatory mediators (IL-1β, IL-8 and TNF-α) and apoptosis-regulatory genes (GADD45α, Caspase-3, and Caspase-8) were observed. Our data suggest that soil extracts induced cytotoxicity, oxidative damage, inflammatory response, and cell apoptosis in Caco-2 cells, indicating soil ingestion from e-waste dismantling site may adversely impact human health.

Assessment of natural radionuclides and heavy metals contamination to the environment: Case study of Malaysian unregulated tin-tailing processing industry

The tin tailing processing industry in Malaysia has operated with minimal regard and awareness for material management and working environment safety, impacting the environment and workers in aspects of radiation and heavy metal exposure. RIA was conducted where environmental samples were analyzed, revealing concentrations of 226Ra, 232Th and 40K between the range of 0.1–10.0, 0.0–25.7, and 0.1–5.8 Bq/g respectively, resulting in the AED exceeding UNCEAR recommended value and regulation limit enforced by AELB (1 mSv/y). Raeq calculated indicates that samples collected pose a significant threat to human health from gamma-ray exposure. Assessment of heavy metal content via pollution indices of soil and sediment showed significant contamination and enrichment from processing activities conducted. As and Fe were two of the highest metals exposed both via soil ingestion with an average of 4.6 × 10−3 mg/kg-day and 1.4 × 10−4 mg/kg-day, and dermal contact with an average of 5.6 × 10−4 mg/kg-day and 6.0 × 10−4. mg/kg-day respectively. Exposure via accidental ingestion of soil and sediment could potentially cause adverse non-carcinogenic and carcinogenic health effect towards workers in the industry. Correlation analysis indicates the presence of a relationship between the concentration of NORM and trace elements.

Distribution of heavy metals and related health risks through soil ingestion in rural areas of western Japan

The distribution of heavy metal concentrations and related human health risks were investigated for Shimabara City, Nagasaki Prefecture. The purpose was to clarify the potential for heavy metal contamination in an area already known to be affected by nitrate pollution. A total of 188 soil samples was collected at 47 sites. The heavy metal content of the soil was measured in laboratory using an X-ray analyzer. The highest contents of heavy metals exceeded common background concentration in Japanese soils. The highest concentrations of Cu and Zn appear to be related to application of livestock waste in agriculture. Principal component and cluster analyses were performed to classify the sampling sites based on soil content of heavy metals. Three principal components (PCs) were extracted with the first PC explaining crustal constituents, the second explaining application of livestock waste, and the third explaining other types of anthropogenic pollutants. The cluster analysis resulted in 5 groups regarding the sampling locations. In total, 44% of sampling locations belonged to Group 1 and 46% to Group 2, distributed over the agricultural land in the northern part of the city and the urban area in the southern part of the city, respectively. There is a potential temporal health risk for the Pb content at specific locations in the area.

Potential Human Exposure to Mercury (Hg) in a Chlor-Alkali Plant Impacted Zone: Risk Characterization Using Updated Site Assessment Data

Industrial activities have resulted in severe environmental contamination that may expose rural and urban populations to unacceptable health risks. For example, chlor-alkali plants (CAPs) have historically contributed mercury (Hg) contamination in different environmental compartments. One such site (a burden from the Soviet Union) is located in an industrial complex in Pavlodar, Kazakhstan. Earlier studies showed the CAP operating in the second half of the twentieth century caused elevated Hg levels in soil, water, air, and biota. However, follow-up studies with thorough risk characterization are missing. The present study aims to provide a detailed risk characterization based on the data from a recent site assessment around the former CAP. The ⅀HI (hazard index) ranged from 9.30 × 10−4 to 0.125 (deterministic method) and from 5.19 × 10−4 to 2.54 × 10−2 (probabilistic method). The results indicate acceptable excess human health risks from exposure to Hg contamination in the region, i.e., exposure to other Hg sources not considered. Air inhalation and soil ingestion pathways contributed to the highest ⅀HI values (up to 99.9% and 92.0%, respectively). The residential exposure scenario (among four) presented the greatest human health risks, with ⅀HI values ranging from 1.23 × 10−2 to 0.125. Although the local urban and rural population is exposed to acceptable risks coming from exposure to Hg-contaminated environmental media, an assessment of contamination directly on the former CAP site on the industrial complex could not be performed due to access prohibition. Furthermore, the risks from ingesting contaminated fish were not covered as methyl-Hg was not targeted. An additional assessment may be needed for the scenarios of exposure of workers on the industrial complex and of the local population consuming fish from contaminated Lake Balkyldak. Studies on the fate and transport of Hg in the contaminated ecosystem are also recommended considering Hg methylation and subsequent bioaccumulation in the food chain.

Potential driving forces and probabilistic health risks of heavy metal accumulation in the soils from an e-waste area, southeast China

The integrated analysis of the distribution characteristics, health risks, and source identification of heavy metals is crucial for formulating prevention and control strategies for soil contamination. In this study, the area around an abandoned electronic waste dismantling center in China was selected as the research area. The probabilistic health risks caused by heavy metals were evaluated by the Monte Carlo simulation. Random forest, partial least squares regression, and generalized linear models were utilized to predict heavy metal distributions and identify the potential driving factors affecting heavy metal accumulation in soil. The relationships of spatial variation between the heavy metal contents and environmental variables were further visualized. The results revealed that cadmium (Cd) and copper (Cu) were the primary soil pollutants in the study area and caused high ecological risks. The probabilistic health risk assessment indicated that the non-carcinogenic and carcinogenic risks for all populations were acceptable. However, children are more susceptible to heavy metal soil contamination than adults. The sensitivity analyses indicated that the total contents of soil heavy metals and soil ingestion rate were the dominant factors affecting human health. The random forest model, with R2 values of 0.41, 0.65, 0.57, 0.71, and 0.58 for Cd, Cu, Ni, Zn, and Pb, respectively, predicted the heavy metal concentrations better than the other two models. The distance to the nearest industrial enterprise, industrial output, and agricultural chemical input were the main factors affecting Cd, Cu, Zn, and Pb accumulations in the soil, and soil pH and soil parent material were the primary factors influencing Ni accumulation in the soil. The visualization results of the geographically weighted regression model showed a significant relationship between soil heavy metal contents and industrial activity level. This study could be utilized as a reference for policymakers to formulate prevention and control strategies for heavy metal pollution in agricultural areas.

Acute and chronic health risk assessment for inhalation and ingestion exposure in acrylic acid leak accidents

We established a hypothetical acrylic acid leak accident scenario, conducted a health risk assessment of local residents, and compared an actual accident case to the hypothetical scenario. The exposed subjects were divided into four age groups, and a noncarcinogenic health risk assessment was conducted for inhalation and soil ingestion. In the hypothetical scenario, 40 tons of acrylic acid was leaked in Ulsan for 1 h from midnight on January 1, 2017. In the actual accident case, 3 L of acrylic acid was leaked in Hwaseong, Gyeonggi Province, for 1 h from 11:00 am on March 5, 2020. The environmental concentration of acrylic acid was calculated using the dynamic multimedia environmental model. Noncarcinogenic assessment of the hypothetical scenario showed the hazard quotient exceeded 1 across all age groups, suggesting that a health risk is likely to occur due to inhalation exposure to acrylic acid resulting from a chemical accident. In addition, Hazardacute exceeded 1 until 2 h after the accident under the hypothetical scenario, indicating the likelihood of a health risk. Thus, we propose a methodology that can assess changing concentrations in a hazardous chemical leak from a chemical accident based on the time, place, the chemical’s behaviors in different environmental media, and the health risk posed by the exposure of the chemical to local residents in the area affected by the accident.

Estimation of health risks due to copper-based nanoagrochemicals.

This study estimated health risks due to two types of copper-based nanoagrochemicals (Cu (OH)2 and CuO nanoparticles (NPs)), during inadvertent ingestion of soil and consumption of leafy vegetables for a hypothetical exposure scenario. The dissolution of copper-based nanoagrochemicals in human digestive system was considered for estimating realistic doses. No risk was found during soil ingestion (hazard quotient (HQ) <1). HQ (no dissolution of Cu (OH) 2 nanopesticides) (HQ= 0.015) comes out to be 2 times higher than that of HQ (100% dissolution of Cu (OH)2 nanopesticides into copper ions) (HQ= 0.007). In case of risk from consumption of leafy vegetables, the following order of risk was found (high to low HQ value): Cu (OH)2 (HQ= 1925) >CuO NPs (1402). Combined exposure of Cu (OH)2 nanopesticide through soil ingestion as well as consumption of contaminated edible leafy vegetables resulted in health risks. The calculated maximum allowable applicable concentration values of Cu (OH)2 and CuO NPs without posing risk to human and plant toxicity were found to be 1.14 and 0.45 mg/L, respectively. These findings can be used now for deciding safe use of copper-based nanoagrochemicals.

Predictive capabilities of in vitro colon bioaccessibility for estimating in vivo relative bioavailability of arsenic from contaminated soils: Arsenic speciation and gut microbiota considerations

Arsenic (As) transformation by human gut microbiota has been evidenced to impact As toxicity and human health. However, little is known about the influence of gut microbiota on As bioavailability from incidental ingestion of soil. In this study, we assessed As relative bioavailability (RBA) using an in vivo mouse model and As bioaccessibility in the colon phase of in vitro assays. Strong in vivo-in vitro correlations (R2 = 0.70–0.92, P < 0.05) were observed between soil As RBA (10.2%–57.7%) and colon bioaccessibility (4.8%–49.0%) in 13 As-contaminated soils. Upon in vitro incubation of human colon microbiota, we found a high degree of As transformation and 65.9% of generated As(III) was observed in soil residues. For in vivo mouse assay, DMA(V) accounted for 79.0% of cumulative urinary As excretion. Except for As(V), dominant As species including As(III), DMA(V) and As sulfides were also detected in mouse feces. Gut bacteria (families Rikenellaceae and Marinifilaceae) could be significantly correlated with As intake and excretion in mice (P < 0.05). Our findings provide evidence that gut microbiota can affect transformation, bioavailability, and fate of the orally ingested soil As in human gastrointestinal tract.

Modeling multimedia fate and health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the coastal regions of the Bohai and Yellow Seas

Using an improved multimedia fate model, this study simulated the spatial distributions, partitioning behaviors, and mass exchanges of PAH16 (16 species with priority by the USEPA) in multiple environmental compartments in the coastal regions of the Bohai and Yellow Seas, Northern China. The model predictions generally matched well with the measured results, as the deviations of most points were within one order of magnitude in the air, freshwater, and 3 soil compartments. The estimated concentrations of ΣPAH16 in the northern part were higher than those in the southern part, which was consistent with the emissions of each part. Approximately 97.6% of the ΣPAH16 mass was distributed in soils; therefore, soils served as the dominant sink of PAH16. The estimated net flux of ΣPAH16 from air to soil ranged from 0.4 to 10.7 mg/m2/year (an average of 3.2 mg/m2/year), and the estimated flux of deposition from air to soil fell in the range of 0.4–10.8 mg/m2/year (an average of 3.2 mg/m2/year), which served as the dominant process at the air-soil interface. The estimated net flux of ΣPAH16 from air to freshwater ranged from −15.3 to 9.4 mg/m2/year (an average of −0.3 mg/m2/year), and the reversed volatilization flux from freshwater to air ranged from 0.01 to 21.1 mg/m2/year (an average of 3.7 mg/m2/year). This situation indicated notable spatial variations and volatilization as the main process affecting the direction of net flux at the air-freshwater interface. Deterministic risk assessment and probabilistic risk assessment were conducted. The overall health risks of the studied regions were acceptable, while the excess lifetime cancer risk (ELCR) by air inhalation was greater than that by soil ingestion. CapsuleMultimedia fate model-predicted distributions and compositions of PAH16 in different compartments, compartmental exchange fluxes and directions, and deterministic and probabilistic ELCR via different exposure pathways were assessed.

Antimony, beryllium, cobalt, and vanadium in urban park soils in Beijing: Machine learning-based source identification and health risk-based soil environmental criteria

The pollution situation of antimony (Sb), beryllium (Be), cobalt (Co), and vanadium (V) is poorly understood, although they are widely used in daily life and production processes. Moreover, threshold levels (“soil environmental criteria”, SEC) for these pollutants are lacking in China, which impedes effective soil quality management. This study explored pollution characteristics for park soils in urban area of Beijing, China at first. Then multivariate statistical analysis and machine learning model were used to identify the main sources of pollutants. Additionally, probabilistic health risk and SEC were studied to assess the risks of pollutants and manage soil pollutants. The results revealed that the overall pollution levels of Be, Co, Sb, and V were low, but Be and Sb were enriched to varying degrees. Source apportionment showed that Sb (85.5%) was mainly derived from fuel combustion and industrial legacy, Co (66.7%) and V (82.5%) from natural processes, and Be from the natural background (39.3%) and anthropogenic sources (53.8%). Risk assessment indicated that the pollutants' carcinogenic and noncarcinogenic risks were negligible. Exposure frequency and soil ingestion rate were the most important parameters affecting health risks. The SEC of Be, Co, Sb, and V were 31, 39.7, 41.3, and 348 mg/kg, respectively, all of which are higher than the corresponding soil quality standards in China, indicating that current soil quality standards may be too conservative for urban park land. This study provides a reference for the management of soil pollutants in Beijing's urban parks, and the formulation of soil environmental quality standards.

Potentially toxic elements dynamics in the soil rhizospheric-plant system in the active volcano of Fogo (Cape Verde) and interactions with human health

Volcanic eruptions disturb directly and indirectly the ecosystems. Direct impact occurs on the soil–plant system with an input of new elements and indirect hazard occurs by consumption of these plants. Fogo island (Cape Verde Republic) has an active volcano and the last eruption occurred in 2014–15, expelling large amounts of materials that spread all over the island. Soils and edible plants were collected all over the island. Pollution indexes reveal contamination in all samples, mostly due to Hg and Ni and with moderate contribution of Co, Cr, Cu and Pb. Mercury is the PTE with higher contribution to the non-carcinogenic hazard quotient, both by soil ingestion and inhalation. Carcinogenic risk exceeds the target risk in all samples with the higher contribution of Ni. Transfer factor from soils to plants decreasing order is Mn > As > Zn > Cr > Cu > Cd > Pb > Ni > Co > Hg, being < 1 except for As and Mn (TF > 1 point to a significant accumulation of elements in edible plants). The hazard risk index and targeted hazard quotient shows that potential negative health outcomes can be induced by As, Cr, Cu, and Zn by consumption of edible plants.

Evaluation of heavy metal exposure pathways on children from an informal e-waste processing village in Viet Nam

Attempts were made to assess the contributions of different pathways of heavy metal exposure to the carcinogenic and non-carcinogenic risks based on the field samplings and questionnaire surveys of children residing in an informal e-waste processing village and a reference village in Viet Nam. The results showed that the ingestion of cooked rice contributed the most (69.20 − 99.60%), followed by the ingestion of soil (0.32 − 29.53%), to the environmental health risks of exposure to a mixture of Pb, Cd, Cr, Ni, and As in children from the two villages. Ingestion of drinking water and dermal contact of soil, however, contributed negligibly. It was found that the non-carcinogenic risk of each heavy metal from four pathways was less than 1, with Ni (0.48), As (0.44), Cd (0.23), Cr (0.19), and Pb (0.14), meaning these heavy metals are unlikely to cause an adverse non-carcinogenic risk to a child. It was also found that the carcinogenic risks for each heavy metal, except that for dermal contact of soil to children were higher than the benchmark value of 10−6 set by USEPA, indicating the likelihood of carcinogenic risks to children, especially to those aged 8 − 10 years. Children whose parents were engaging in e-waste processing activities and those who lived in a distance less than 10 m from an e-waste processing site sustained greater carcinogenic and non-carcinogenic risks.

Health Risk Assessment of Metals via Multi-Source Oral Exposure for Children Living in Areas with Intense Electronic Manufacturing Activities.

Oral ingestion is the predominant pathway of metal(loid)s exposure. In this study, the health risks of typical metal(loid)s (including Mn, As, Cr, Cd, and Pb) via multi-source, oral pathways for children aged 3–12 years, living in an area of China dominated by the electronic manufacturing industry, were studied based on the field sampling of duplicated diet, soil, and drinking water. Child-specific ingestion parameters were measured (except the soil ingestion rates, which were from a previous study of the same population), and a Monte Carlo method was applied to determine the uncertainty of the risk assessment. It was observed that children living in such environments were at risk of metal(loid)s exposure, with the accumulative carcinogenic risk exceeding the maximum acceptable level. Food intake was identified to be the primary exposure pathway. Moreover, Pb and Cr were the major risk elements to local children’s health. Compared with primary school students, kindergarten children experienced a higher risk. This study highlights that high attention should be paid to children living in suburban areas dominated by the electronic manufacturing industry, and that priority should be given to studies on metal(loid)s exposure deriving from different types of food and their corresponding bioavailability, in order to further discern the precise risk sources to protect children’s health.

Ecological and human health risks of manure-borne steroid estrogens: A 20-year global synthesis study

Estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estriol (E3) are persistent in livestock manure and present serious pollution concerns because they can trigger endocrine disruption at part-per-trillion levels. This study conducted a global analysis of estrogen occurrence in manure using all literature data over the past 20 years. Besides, predicted environmental concentration (PEC) in soil and water was estimated using fate models, and risk/harm quotient (RQ/HQ) methods were applied to screen risks on children as well as on sensitive aquatic and soil species. The estradiol equivalent values ranged from 6.6 to 4.78 × 104 ng/g and 12.4 to 9.46 × 104 ng/L in the solid and liquid fraction. The estrogenic potency ranking in both fractions were 17β-E2> E1>17α-E2>E3. RQs of measured environmental concentration in the liquid fraction pose medium (E3) to high risk (E1, 17α-E2 & 17β-E2) to fish but are lower than risks posed by xenoestrogens. However, the RQ of PECs on both soil organisms and aquatic species were insignificant (RQ < 0.01), and HQs of contaminated water and soil ingestion were within acceptable limits. Nevertheless, meticulous toxicity studies are still required to confirm (or deny) the findings because endocrine disruption potency from mixtures of these classes of compounds cannot be ignored.