Previous studies revealed that Honghu Lake was polluted by trace elements due to anthropogenic activities. This study investigated the spatial distribution of trace elements in Honghu Lake, and identified the major pollutants and control areas based on the fuzzy health risk assessment at screening level. The mean total content of trace elements in surface water decreased in the order of Zn (18.04 μg/L) > Pb (3.42 μg/L) > Cu (3.09 μg/L) > Cr (1.63 μg/L) > As (0.99 μg/L) > Cd (0.14 μg/L), within limits of Drinking Water Guidelines. The results of fuzzy health risk assessment indicated that there was no obvious non-carcinogenic risk to human health, while carcinogenic risk was observed in descending order of As > Cr > Cd > Pb. As was regarded to have the highest carcinogenic risk among selected trace elements because it generally accounted for 64% of integrated carcinogenic risk. Potential carcinogenic risk of trace elements in each sampling site was approximately at medium risk level (10−5 to 10−4). The areas in the south (S4, S13, and S16) and northeast (S8, S18, and S19) of Honghu Lake were regarded as the risk priority control areas. However, the corresponding maximum memberships of integrated carcinogenic risk in S1, S3, S10–S13, S15, and S18 were of relatively low credibility (50–60%), and may mislead the decision-makers in identifying the risk priority areas. Results of fuzzy assessment presented the subordinate grade and corresponding reliability of risk, and provided more full-scale results for decision-makers, which made up for the deficiency of certainty assessment to a certain extent.

No abstract

Abstract:The contents of seven toxic metals (Cu, Cr, Cd, Zn, Pb, Hg and As) in soils from Central China, including Henan Province, Hubei Province and Hunan Province, were collected from published papers from 2007 to 2017. The geoaccumulation index, health risk assessment model and statistics were adopted to study the spatial contamination pattern, to assess the human health risks and to identify the priority control pollutants. The concentrations of soil metals in Central China, especially Cd (1.31 mg/kg), Pb (44.43 mg/kg) and Hg (0.19 mg/kg), surpassed their corresponding background values, and the I geo values of Cd and Hg varied the most, ranging from the unpolluted level to the extremely polluted level. The concentrations of toxic metals were higher in the southern and northern parts of Central China, contrasting to the lowest contents in the middle parts. For non-carcinogenic risk, the hazard index (HI) values for the children in Hubei Province (1.10) and Hunan Province (1.41) exceeded the safe level of one, with higher health risks to children than adults, and the hazard quotient (HQ) values of the three exposure pathways for both children and adults in Central China decreased in the following order: ingestion > dermal contact > inhalation. For carcinogenic risk (CR), the CR values for children in Hubei Province (2.55 × 10 −4 ), Hunan Province (3.44 × 10 −4 ) and Henan Province (1.69 × 10 −4 ), and the CR for adults in Hubei Province (3.67 × 10 −5 ), Hunan Province (4.92 × 10 −5 ) and Henan Province (2.45 × 10 −5 ) exceeded the unacceptable level (10 −4 ) and acceptable level (10 −6 ), respectively. Arsenic (As) appeared to be the main metalloid for both children and adults causing the high carcinogenic risk. For sustainable development in Central China, special attention should be paid to Cd, Hg, Cr, Pb and As, identified as the priority control soil metals. Importance should also be attached to public education, source control, and the remediation of the highly contaminated soils, especially in the areas where it can endanger the groundwater. Furthermore, it is necessary to appropriately adjust the industrial structure and cooperate more to form a complete economic zone.

The awareness of occupational health risk management in the electronics industry is weak in China, and many Chinese occupational health management regulations have not been effectively implemented. China’s current occupational hazards classification method and the Environmental Protection Agency (EPA) inhalation risk assessment model recognized internationally were used to perform health risk assessments for a chip manufacturing company in the electronics industry in order to determine the existing problems and put forward the optimization proposals of the occupational hazards classification method in China. The results showed that the detected concentrations of toxic and harmful chemicals in all testing points did not exceed the occupational health exposure limits in China. According to the EPA inhalation risk assessment model, the highest values of non-carcinogenic risks of ammonia, chlorine, fluoride, sulfuric acid, hydrogen chloride, ethylene glycol, phosphine, boron trifluoride, isopropanol, benzene, and xylene were 5.10, 67.12, 1.71, 45.98, 1.83, 1.43, 160.35, 46.56, 2.52, 5.55, and 5.37, respectively, which means workers in electronic chip manufacturing companies exposed to these chemicals have higher occupational health risks. However, on the basis of the occupational hazards classification method, the occupational health risks of exposure to the toxic and hazardous chemicals are relatively harmless operations. The evaluation results of the EPA inhalation risk assessment model are generally higher than those of the occupational hazards classification method. It’s recommended to refine the value of occupational exposure limit B, taking more characteristics of the hazard factors into account and fuzzifying the parameters to optimize the occupational hazards classification method. At the same time, it is suggested that the electronic chip manufacturing company should conduct anti-virus risk management covering in three aspects: increasing the awareness of occupational hazards, enhancing system ventilation, and improving personal health management measures.

China is an agriculturally-producing country and the safety of its vegetables will have an extensive attention at home and abroad. Recently, contamination of soils and vegetables caused by mining activities is of great social concern because of the potential risk to human health, especially to the residents whom live near metal or metalloid mines. In this study, 18 topsoil and 141 vegetable samples were collected from the contaminated areas in Daye City Hubei Province, China and the concentrations of copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) were analyzed. A self-designed questionnaire was assigned to obtain the exposure scenario and the USEPA health risk assessment model was adopted to assess two type of risks (non-carcinogenic risks and carcinogenic risks) of vegetables to humans. The results showed that the average contents of metal(loid)s in soils exceeded the background value of Daye City. The average contents of metal(loid)s, especially As, Cd, Pb, in three kinds of vegetables were significantly higher than the permissible values based on Chinese national standard. Leafy vegetables had relatively higher concentrations and the transfer factors of As (0.015), Cd (0.080) and Pb (0.003) were comparable to leguminous and fruit vegetables. Leguminous vegetables had relatively higher concentrations and transfer factors of Cu (0.032) and Zn (0.094) than leafy and fruit vegetables. The transfer factors from soil to plants follows a decreasing order as Cd (0.068), Zn (0.047) > Cu (0.023) > As (0.006), Pb (0.002). Furthermore, health risk assessment revealed the following results: the non-carcinogenic risk decreased in the order of children, adult, adolescent, while the carcinogenic risk followed a decreasing order of adult, adolescent, children; the calculated carcinogenic and non-carcinogenic risk of the metal(loid)s by vegetable consumption decreased in the order of leafy vegetables > fruit vegetables > leguminous vegetables. The relatively lower transfer factors and lower risks may suggest that leguminous and fruit vegetables are more suitable for planting in Daye City. Based on the contributions of five kinds of metal(loid)s from three types of vegetables, Cd and As are found to be the dominant sources of health risk.