Health Risk Of Cd Research Articles

Ecological and health risk assessment of heavy metals in interior dust from college campus.

Contamination of college campus dust with heavy metals and the calculation of their ecological and health risks to the students and staff did not receive much attention except in recent years. This study aims to assess the ecological and human health risks of Cd, Cr, Cu, Pb, and Zn in interior dust of College of Science/University campus. An atomic absorption spectrophotometer was utilized to estimate the samples that were collected from 46 locations of the college campus including: classrooms, offices, and laboratories. The Pb, Cu, Cr and Zn metals in the interior dust of the College of Science pose low potential ecological risk, whereas Cd generates medium potential ecological risk. The gained results showed that the student and staff of the College are exposed to low non-cancerous health risks (HI < 1) caused by Cd, Cr, Cu, Pb, and Zn in interior dust. The total lifetime carcinogenic risks (TLCR) of Cd, Cr, and Pb are within the acceptable safe limit (10-6-10-4). The low non-carcinogenic health risks of Cd, Cr, Cu, Pb, and Zn and that the carcinogenic health risks of Cd, Cr and Pb fall within acceptable safe limits, measured in the interior dust of the campus of the College of Science, does not mean neglecting the continuous assessment of those risks.

Influence of Foliar Zinc Application on Cadmium and Zinc Bioaccessibility in Brassica chinensis L.: In Vitro Digestion and Chemical Sequential Extraction.

Foliar zinc (Zn) application can affect the accumulation and bioaccessibility of cadmium (Cd) and Zn in crops. However, the mechanisms by which foliar Zn application influences Cd and Zn bioaccessibility remain elusive. This study examined the effects of spraying ZnSO4 and ZnNa2EDTA on bioaccessibility and chemical forms of Cd and Zn in pakchoi (Brassica chinensis L.) shoots and evaluated human health risks via pakchoi consumption. Spraying ZnSO4 reduced the concentrations of ethanol-extractable (Fethanol) and deionized water-extractable (Fd-H2O) Cd, as well as the corresponding bioaccessible Cd concentrations (20.3-66.4%) and attendant health risks of Cd, whereas spraying high-dose ZnNa2EDTA significantly increased the concentrations of both Cd forms and bioaccessible Cd. Spraying ZnSO4 and high-dose ZnNa2EDTA significantly increased the concentrations of Zn in Fethanol and Fd-H2O and the corresponding bioaccessible Zn concentrations (0.8-8.3-fold). Fethanol and Fd-H2O were the primary sources of bioaccessible Cd and Zn, contributing more than 59% of the bioaccessible Cd and Zn. These results indicate that foliar Zn application can affect Cd and Zn bioaccessibility in pakchoi mainly by modulating Cd and Zn in Fethanol and Fd-H2O. These findings provide scientific support for the development of more efficient measures to produce safe and high-quality leafy vegetables from Cd-polluted soils.

Distribution characteristics of potentially toxic metal(loid)s in the soil and in tea plant (Camellia sinensis)

Potentially toxic metal(loid) assessment of tea and tea garden soil is a vital guarantee of tea safety and is very necessary. This study analyzed the distribution of seven potentially toxic metal(loid)s in different organs of the tea plants and soil at various depths in the Yangai tea farm of Guiyang City, Guizhou Province, China. Although soil potentially toxic metal(loid) in the study area is safe, there should be attention to the health risks of Cu, Ni, As, and Pb in the later stages of tea garden management. Soil As and Pb are primarily from anthropogenic sources, soil Zn is mainly affected by natural sources and human activities, and soil with other potentially toxic metal(loid) is predominantly from natural sources. Tea plants might be the enrichment of Zn and the exclusion or tolerance of As, Cu, Ni, and Pb. The tea plant has a strong ability for absorbing Cd and preferentially storing it in its roots, stems, and mature leaves. Although the Cd and other potentially toxic metal(loid)s content of tea in Guizhou Province is generally within the range of edible safety, with the increase of tea planting years, it is essential to take corresponding measures to prevent the potential health risks of Cd and other potentially toxic metal(loid)s in tea.

Cadmium accumulation in tropical island paddy soils: From environment and health risk assessment to model prediction

Cultivated soil quality is crucial because it directly affects food safety and human health, and rice is of primary concern because of its centrality to global food networks. However, a detailed understanding of cadmium (Cd) geochemical cycling in paddy soils is complicated by the multiple influencing factors present in many rice-growing areas that overlap with industrial centers. This study analyzed the pollution characteristics and health risks of Cd in paddy soils across Hainan Island and identified key influencing factors based on multi-source environmental data and prediction models. Approximately 27.07% of the soil samples exceeded the risk control standard screening value for Cd in China, posing an uncontaminated to moderate contamination risk. Cd concentration and exposure duration contributed the most to non-carcinogenic and carcinogenic risks to children, teens, and adults through ingestion. Among the nine prediction models tested, Extreme Gradient Boosting (XGBoost) exhibited the best performance for Cd prediction with soil properties having the highest importance, followed by climatic variables and topographic attributes. In summary, XGBoost reliably predicted the soil Cd concentrations on tropical islands. Further research should incorporate additional soil properties and environmental variables for more accurate predictions and to comprehensively identify their driving factors and corresponding contribution rates.

Spatiotemporal distribution and potential risks of metals and total petroleum hydrocarbons (TPHs) in seawater from the Zhifu Bay and its surrounding areas, Yellow Sea, China (2015–2019)

To investigate the concentrations, spatiotemporal distribution, correlation with environmental factors, and potential risks of four metals (Hg, Cu, Pb, and Cd) and total petroleum hydrocarbons (TPHs) in seawater from the Zhifu Bay and its surrounding areas, surface seawater samples were collected from 10 stations in spring, summer, and autumn of 2015–2019. Compared with values from other regions, the average concentrations of metals and TPHs were in the low and medium levels, respectively. Concentrations of all the study pollutants decreased in the offshore direction, suggesting that most of these pollutants are from land and nearshore sources. Annual variation patterns indicated decreasing trends of Cu and TPHs, and due to the seasonal differences in river discharges, rainfalls, and human activities, wet seasons (summer and/or autumn) exhibited higher concentrations of Hg, Cu, and TPHs than dry season (spring). The potential ecological risk of Cu and carcinogenic health risk of Cd suggest that the discharge of metals from the sea should be more strictly controlled.

Accumulation, migration and health risk of trace metals in a soil-strawberry-human system of the Yangtze River Delta region, China

Growing concern has been paid to metals in soil-strawberry system. In contrast, few attempts have been made to investigate bioaccessible metals in strawberries and further assess health risk based on bioaccessible metals. Moreover, the connections between soil parameters (e.g. soil pH, organic matter (OM), total and bioavailable metals) and metal transfer in soil-strawberry-human system still need to be systematically investigated as well. Considering that strawberries are extensively grown under plastic-shed conditions in China, a total of 18 paired plastic-shed soil (PSS) and strawberry samples were taken from the strawberry bases located in the Yangtze River Delta of China as a case study to assess accumulation status, migration and health risk of Cd, Cr, Cu, Ni, Pb, and Zn in the PSS-strawberry-human system. Overall, heavy application of organic fertilizers induced accumulation and contamination of Cd and Zn in PSS. In particular, 55.6% and 44.4% of PSS samples had considerable and moderate ecological risk caused by Cd, respectively. Despite no metal pollution in strawberry, PSS acidification mainly caused by high nitrogen input promoted Cd and Zn uptake by strawberry and enhanced bioaccessible concentrations of Cd, Cu, and Ni. In contrast, the increased soil OM caused by organic fertilizer application decreased Zn migration in PSS-strawberry-human system. Additionally, bioaccessible metals in strawberries induced limited non-cancer and cancer risk. To mitigate accumulation of Cd and Zn in PSS and metal transfer in the food chain, feasible fertilization strategies should be developed and carried out.

Climatic CO2 level-driven changes in the bioavailability, accumulation, and health risks of Cd and Pb in paddy soil–rice systems

Rising atmospheric carbon dioxide (CO2) and soil heavy metal pollution, which affects safe rice production and soil ecosystem stability, have caused widespread concern. In this study, we evaluated the effects of elevated CO2 on Cd and Pb accumulation in rice plants (Oryza sativa L.), Cd and Pb bioavailability, and soil bacterial communities in Cd–Pb co-contaminated paddy soils via rice pot experiments. We showed that elevated CO2 accelerates the accumulation of Cd and Pb in rice grains by 48.4–75.4% and 20.5–39.1%, respectively. Elevated CO2 levels decreased soil pH value by 0.2 units, which increased Cd and Pb bioavailability in soil but inhibited iron plaque formation on rice roots, ultimately promoting Cd and Pb uptake. 16S rRNA sequencing analysis revealed that elevated CO2 increased the relative abundance of certain soil bacteria (e.g., Acidobacteria, Alphaproteobacteria, Holophagae, and Burkholderiaceae). A health risk assessment showed that elevated CO2 markedly increased the total carcinogenic risk values for children, adult males, and adult females by 75.3% (P < 0.05), 65.6% (P < 0.05), and 71.1% (P < 0.05), respectively. These results demonstrate the serious performance of elevated CO2 levels in accelerating the bioavailability and accumulation of Cd and Pb in paddy soil–rice ecosystems, with particular risks for future safe rice production.

Tracking cadmium pollution from source to receptor: A health-risk focused transfer continuum approach

Cadmium (Cd) exposure poses a substantial risk to human health. Despite this, the multi-stage process through which Cd is released to the environment before being taken up and impacting human receptors has rarely been investigated. Here we utilized an integrated model involving Cd emissions, atmospheric transport, deposition, uptake by rice, receptor ingestion and metabolic processing in quantifying the critical emission sources and human health risks of Cd. Atmospheric Cd emissions in the study area in southeastern China were estimated at 147 kg (2016), with >53 % of emissions from non-ferrous metals (NFM) smelting activities. Atmospheric Cd depositions caused elevated Cd content in soil and rice, accounting for 3–79 % and 50–85 % of, respectively, soil and rice Cd. Cumulative frequency analysis showed that an estimated 1.3 % of predicted urine Cd through the consumption of Cd-contaminated rice and exceeded existing safety standards (1 μg g−1), thus highlighting the risks posed to health from high levels of Cd pollution. Applying stricter industrial emission standards to the NFM sector in particular and effective soil management practices could substantially reduce exposure to Cd pollution. The results contribute to understanding of the Cd transfer process and draw attention to the relative health benefits of interventions aimed at mitigating Cd levels and exposure risks at different stages along the Cd transfer continuum from source to receptor.

NMR technique revealed the metabolic interference mechanism of the combined exposure to cadmium and tributyltin in grass carp larvae.

Widespread human activity has resulted in the presence of different pollutants in the aquatic environment that does not exist in isolation. The study of the effects of contamination of aquatic organisms is of great significance. To assess the individual and combined toxicity of cadmium (Cd) and tributyltin (TBT) to aquatic organisms, juvenile grass carp (Ctenopharyngodon idella) were exposed to Cd (2.97mg/L), TBT (7.5μg/L), and their mixture MIX. The biological response was evaluated by nuclear magnetic resonance (NMR) analysis of plasma metabolites. Plasma samples at 1, 2, 4, 8, 16, 32, and 48days post-exposure were analyzed using detection by NMR technique. The typical correlation analysis (CCA) analysis revealed that TBT had the greatest effect on plasma metabolism, followed by MIX and Cd. The interference pathway to grass carp was similar to that of TBT and MIX. Both Cd and TBT exposure alone or in combination can lead to metabolic abnormalities in TCA cycle-related pathways and interfere with energy metabolism. These results provide more detailed information for the metabolic study of pollutants and data for assessing the health risks of Cd, TBT, and MIX at the metabolic level.

Foliar spray of combined metal-oxide nanoparticles alters the accumulation, translocation and health risk of Cd in wheat (Triticum aestivum L.)

Nanotechnology is promising for improving sustainable crop production and ensuring food safety due to its unique properties and minimum environmental impacts. Here, we investigated the effectiveness of foliar combined metal-oxide nanoparticles (NPs, 100 mg/L) on cadmium (Cd) accumulation, translocation and exposure risk in wheat under field condition. Results showed that ZnO NPs combined with MgO or Fe3O4 NPs significantly increased the grain yield (13.8% and 14.8%) and straw biomass (16.9% and 18.4%) as compared to the control. Co-applied ZnO NPs with MgO, TiO2 or CeO2 NPs enhanced Cd uptake in aboveground wheat (12.4%−16.9%), while ZnO NPs combined with MnO2, CuO, Fe3O4 or Fe2O3 NPs remarkably reduced Cd concentration in wheat grains (23.8%−33.6%). According to the Cd bioaccessibility and daily intake, the health risk of Cd in wheat grains was significantly decreased by 36.1%−48.1% under ZnO NPs in combination with Fe3O4, Fe2O3, CuO or MnO2 NPs treatment. In addition, foliar spray of combined NPs also improved the nutritional quality of wheat grains by increasing micronutrients (Ca, S, Zn, Fe, B), protein content and reducing phytic acid content, especially in the combination of ZnO and MnO2 NPs. Taken together, this work demonstrates a feasible approach to achieve higher Cd removal efficiency and lower Cd levels and health risks in wheat grains with a tailored combination of metal-oxide NPs.

The assessment of the soil-plant-animal transport of the risk elements at the locations affected by brown coal mining.

The North Bohemian Brown Coal Basin (Czech Republic) is suggested as a source of significant pollution in the surrounding environment with various pollutants, including risk elements. A total of 53 sampling points were selected within the North Bohemian region. The selected sampling points represented either the basin areas (affected by the coal mining and related activities) or the mountain areas (an area unaffected by the coal mining but characterized by the geogenic sources of the risk elements). At each of the sampling points, soils and respective dominant indigenous plant samples were collected. A suite of ecological indices, namely, individual pollution index (Ii), Nemerow index (PN), bioaccumulation factor (BAF), translocation factor (TF), and hazard quotient (HQ), were applied to estimate the environmental risk of As, Be, Cd, and Zn levels in soils, potential soil-plant transfer, and soil-plant-animal transport of these stated elements. The results from Ii showed that the maximum values of As, Be, Cd, and Zn in the investigated soils exceeded the preventive values, where the Ii value was up to 58 for As in the mountain areas, indicating severe pollution. At the same time, mild pollution was recorded in the case of Cd. For Be in the researched soils, its Ii assessment result was a wide range, varying between a clean environment and severe pollution. Whereas As and Be uptake by plants was limited and these elements were retained in the plant's roots, relatively high mobility and soil to plant shoots transport ability of Cd were recorded and documented by the TF values. The HQs calculated for selected herbivorous mammals in the area showed that the potential health risk of As and Be was limited to only plant roots in the hotspots with extreme As and Be contents. In comparison, substantial health risk of Cd was observed in the aboveground biomass of plants. Therefore, the potential remediation of the coal mining areas should be focused on (i) identification of the As and Be hotspots and (ii) to reduce the mobility and plant availability of Cd in the whole investigated area.

Calcined Oyster Shell-Humic Complex as Soil Amendment to Remediate Cd- and As-Contaminated Soil

Soil acidification in the subtropical region reduces soil productivity and increases the bioavailability of heavy metal(loid)s in soil. Here 800 °C-calcined oyster shell and leonardite-derived humic substance were combined to form a Ca-humic complex to remediate an acidic soil contaminated by cadmium (Cd) and arsenic (As) for safe vegetable production. In the pot experiment, the complex was added to soil as a soil amendment at 0%, 0.5%, 1.0%, 2.0%, and 5.0%. A 2.0% dose reduced Cd and As contents of the vegetable bok choy by 98% and 71%, respectively, alleviating the human health risk of Cd and As from the food chain. The unified bio-accessibility method (UBM) was followed to estimate the bio-accessibility of Cd and As. The complex at a 2.0% dose lowered soil Cd and As bio-accessibility in simulated gastric (BioG) and intestine (BioGI) compartments by 15.5% for BioG-Cd, 39.2% for BioGI-Cd, 28.8% for BioG-As, and 45.0% for BioGI-As, thus reducing the human health risk of Cd and As from soil ingestion. The use of oyster shell waste to produce Ca-humic complex as a soil amendment is a practical means of achieving dual agronomic and environmental benefits, from the remediation of soil contamination to the safe disposal of shell waste.

Health risk assessment using in vitro simulation in assessing bioavailability of cadmium in rice from main producing areas across China

Rice is a recognized source of cadmium (Cd) exposure. In this study, a total of 102 rice samples were obtained from main producing rice regions of China, and the bioavailability of Cd in rice were assessed by using an in vitro digestion method combined with a Caco-2 cell monolayer model. The results revealed that the average (range of) concentration of Cd in the rice samples was 0.2840 (0.0123-2.4710) mg/kg, and the average (range of) bioavailability of Cd in the rice samples was 23.94% (7.47-39.73%). We analyzed the recent rice consumption data and calculated the target hazard quotients (THQs) to evaluate the noncarcinogenic health risk of Cd in rice consumption for adults and children, respectively. We suggested that the most of investigated regions showed low risks of Cd in rice for general population, and the regions of Cd in rice near the limit deserves might be attracted more attention after taking bioavailability into account. PRACTICAL APPLICATION: The cadmium content of rice itself will affect its corresponding bioavailability to a certain extent. By studying the in vitro bioavailability of cadmium rice with different pollution levels, it is helpful for the dose selection of animal experiments or toxicity tests, and finally, we may provide some references for the establishment of appropriate treatment scheme of rice Cd poisoning.

Co-high-efficiency washing agents for simultaneous removal of Cd, Pb and As from smelting soil with risk assessment

Soil washing is considered a highly efficient technology due to its higher removal rate of multiple heavy metals from contaminated soil. However, previous studies on Cd, Pb and As washing agents for soils with complex contaminations did not consider the differences in As and Cd/Pb properties, resulting in the lack of effective washing compounds and washing conditions for soils with complex contaminations. Moreover, most traditional washing agents can cause secondary pollution. In this study, HEDTA and lactic acid (LA) treatments resulted in a higher Cd and Pb removal, while 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) was more effective in As removal. Most importantly, a new washing strategy was proposed with a new combined high-efficiency washing agents consisting of HEDP + LA + FeCl3 with a ratio of 6:3:1. Considering washing efficiency and consumption under optimal washing conditions, i.e. the soil/liquid (S/L) ratio of 1:20 and washing time of 48 h, the rates of Cd, Pb and As removal were 79.93%, 69.84% and 61.55%, respectively. In addition, washing process could influence the speciation of heavy metals, especially oxidizable and residual Cd and Pb fractions, as well as reducible As fraction. The washing process using the new washing agent can significantly reduce the pollution level and health risk of Cd, Pb and As contamination. The results of this study can provide an efficient washing agent for the remediation of heavy metal-contaminated soils at smelting sites, which will help protect human health.

Climate Co2 Levels-Driven Changes in the Bioavailability, Accumulation, and Health Risk of Cd and Pb in the Paddy Soil-Rice Ecosystem

Climate Co2 Levels-Driven Changes in the Bioavailability, Accumulation, and Health Risk of Cd and Pb in the Paddy Soil-Rice Ecosystem

Incorporating in vitro bioaccessibility into human health risk assessment of heavy metals and metalloid (As) in soil and pak choi (Brassica chinensis L.) from greenhouse vegetable production fields in a megacity in Northwest China

The rapid development of greenhouse vegetable production (GVP) in densely populated areas may cause the heavy metal/metalloid accumulation in soil and pose a threat to human health. In this study, 180 pairs of topsoil and pak choi (Brassica chinensis L.) samples were collected from GVP fields in Xi’an city in Northwest China to analyze health risks of Cd, Cr, Pb, and As in soil and pak choi combining in vitro bioaccessibility investigation. The results showed that Cd and Cr were common pollutants in both soil and pak choi. In the soil–pak choi system, the indexes of non-carcinogenic and carcinogenic risk for adults and children were 1.53, 2.68, and 1.37 × 10−4, 8.14 × 10−5, respectively, thereby indicating the presence of heavy metal/metalloid health risks for both groups. Based on the results, procedures to mitigate heavy metal/metalloid contamination risks should be discussed more during the development of GVP in the largest city in Northwest China.

Establishing a weighted methodology for human health risk assessment of cadmium based on its equilibrium speciation in groundwater

A weighted human health risk evaluation methodology that integrated fuzzy-synthetic evaluation and chemical equilibrium simulation was proposed. The method was applied to study the potential toxicity and morphological characteristics of cadmium (Cd) species in groundwater. The concentrations and activities of 15 Cd (II) ion species were conducted by Visual MINTEQ for optimizing average daily dose through ingestion pathway in the health risk model. Both carcinogenic and non-carcinogenic health risk of Cd (II) species for adults and children were conducted. The health risk assessment revealed that metal species of Cd2+ and CdCl + posed carcinogenic risk to adults. The carcinogenic risk of Cd2+ with the value 8.03E-04 and 5.43E-04 for adults and children demonstrated high carcinogenicity, respectively. Non-carcinogenic risk values for Cd (II) ion species were all less than 1 except for Cd2+. It was noteworthy that the non-carcinogenic risk index of Cd2+ and CdCl+ were slightly higher than those after weight assignment. Besides, the investigation indicated that conventional risk assessment may overestimate or underestimate risk levels and the health risk of Cd (II) species principally depended on their metal speciation associated affecting factor of pH in groundwater. The Nemero index for Cd (II) species showed a slight contamination accounted for a percentage of 13.33% of the sampling areas. Therefore, the methodology identified Cd2+ and CdCl + as the targeted species for contamination through the assessment. This strategy provided a solution of correlation degree optimization for groundwater health risk assessment and a reference for the administration to manage groundwater pollution.

In situ cadmium removal from paddy soils by a reusable remediation device and its health risk assessment in rice

Passivation is widely used in the remediation of cadmium (Cd) polluted soils. However, this technique could only reduce the bioavailability of soil Cd rather than remove Cd from the soils. Herein, it is crucial to develop an efficient in-situ technique to remove soil Cd, and further to uncover its effect and mechanism on crops and soil environment. In this study, a soil pot experiment was employed to investigate the effects of a well-designed reusable device on in situ Cd removal from the two paddy soils (red soil and brown soil), rice (Oryza sativa L) growth, and the associated health risk of Cd. The device contained three typical soil Cd amendments including cation exchange resin (CER), biochar (BC), and steel slag (SS). Each of the soil amendments was combined with slow-release fertilizer (SRF) or conventional compound fertilizers (CF). The results indicated that the device with CER, BC, and SS decreased soil Cd by 12.6%, 16.2%, and 19.8%, respectively. Thus, it reduced the rice Cd accumulation by 30.6%, 16.1%, and 29%, and increased the rice yield by 70.3%, 42.6%, and 55.4%, respectively. This could be stemmed from the improvement of photosynthesis and the reduction of oxidative damage, as well as the increase in the relative abundance of soil beneficial microbial community. Moreover, the grey correlation degrees and human health risk index (HRI) indicated that the in-situ removal device could diminish the health risk of Cd in rice. The findings reported in this work could provide a new solution to remediate heavy metal contaminated soils.

Study on the bioaccessibility and bioavailability of Cd in contaminated rice in vitro and in vivo.

Cadmium (Cd) is a widespread heavy metal pollutant in the environment that damages human health. In this study, the bioaccessibility and bioavailability of Cd in different Cd-contaminated rice (low pollution level cadmium rice (Rice-L, 0.111mg/kg),mediumpollutionlevelcadmiumrice(Rice-M, 0.400mg/kg), and high pollution level cadmium rice (Rice-H, 0.655mg/kg)) were estimated and determined by an in vitro digestion model Rijksinstituut voor volksgezondheiden milieu (RIVM), Caco-2 cell model, and mouse model. The results indicated that Cd in the oral cavity (15.65-28.28%) displayed the lowest bioaccessibility comparing with small intestine (90.04-94.73%) and the stomach (99.30-100.70%) in vitro after cooking. In addition, the results showed that the bioaccessibility of Cd in CdCl2 , CdCl2 +normal rice (Rice-N), Rice-H, Rice-M, Rice-L group were 99.29%, 92.57%, 90.04%, 94.73%, and 91.11%, respectively; the in vitro bioavailability of Cd in CdCl2 , CdCl2 +Rice-N, Rice-H, Rice-M, and Rice-L group were 27.50%, 20.78%, 21.90%, 26.90%, 36.46%, respectively, we found that the group of CdCl2 is significantly higher than CdCl2 +Rice-N and Rice-H (p<0.05), while the targets hazard quotient (THQ) value of rice ingested without considering the in vitro bioavailability is 2.7-4.6 times than the THQ value with considered and the relative bioavailability (RBA) of Cd in Rice-L, Rice-M, Rice-H are 80.25%, 64.32%, and 60.91%, respectively. These results indicate that the rice substrate has impact on the bioaccessibility and bioavailability of Cd, and might overestimate the health risks of Cd if bioavailability was not considered. PRACTICAL APPLICATION: Studying the bioaccessibility and bioavailability of cadmium in rice is a promising strategy to obtain a more accurate human health risk assessment of cadmium exposure in rice, as well as provide a theoretical basis for the formulation of cadmium limit standard in grain, which was also conducive to the rational and full utilization of rice resources in China.

Human Health Risk Distribution and Safety Threshold of Cadmium in Soil of Coal Chemical Industry Area

Cadmium (Cd) is a highly carcinogenic metal that plays an important role in the risk management of soil pollution. In this study, 153 soil samples were collected from a coal chemical plant in northwest China, and the human health risks associated with Cd were assessed through multiple exposure pathways. Meanwhile, by the Kriging interpolation method, the spatial distribution and health risks of Cd were explored. The results showed that the average concentration of Cd in the soil was 0.540 mg/kg, which was 4.821 and 5.567 times that of the soil background value in Ningxia and China, respectively. In comparison, the concentration of Cd in the soil was below the national soil environmental quality three-level standard (1.0 mg/kg). In addition, health risk assessment results showed that the total carcinogenic risk of Cd was 1.269 × 10−6–2.189 × 10−6, both above the acceptable criteria (1 × 10−6), while the hazard quotient was within the acceptable level. Oral intake and ingestion of soil particles were the main routes of exposure, and the carcinogenic risk control value of oral intake was the lowest (0.392 mg/kg), which could be selected as the strict reference of the safety threshold for Cd in the coal chemical soil. From Kriging, a prediction map can be centrally predicted on heavy metal pollution in the area surrounding the coal entrance corridor and pedestrian entrance. This study can provide a theoretical basis for the determination of the heavy metal safety threshold of the coal chemical industry in China.