Assessment of source-oriented health risk associated with the oral ingestion of heavy metals in dust within an iron/steel smelting-affected area of the North China Plain.

Heavy metals (HMs) from iron/steel smelting activities pose notable risks to human health, especially to those living around industrial facilities of North China Plain, the base of China's steel production. In this study, 78 outdoor windowsill dust samples were collected around a large-scale iron/steel smelter with more than 65 years of production history in the western North China Plain. Nine HMs were analysed to comprehensively assess the health risks by integrating Monte Carlo simulation, oral bioaccessibility, and source apportionment. Results showed serious pollution with Cd, Pb, and Zn based on their geo-accumulation index values and concentrations. Four potential sources including industrial sources (49.85%), traffic sources (21.78%), natural sources (20.58%), and coal combustion (7.79%) were quantitatively identified by multivariate statistical analysis. The oral bioaccessibilities of HMs determined by the physiologically based extraction test ranged from 0.02% to 65.16%. Zn, Mn, Cd, and Pb had higher bioaccessibilities than other HMs. After incorporating oral bioavailability adjustments, noncarcinogenic and carcinogenic risks were significantly reduced, especially for adults. The mean hazard index (HI) for children and adults was below the safety threshold (1.0), whereas the mean of the total carcinogenic risk (TCR) based on HM bioaccessibilities in the gastric phase remained above the acceptable level (1.0E-06) (children: 5.20E-06; adults: 1.16E-06). Traffic sources warranted increased concern as it substantially increased TCR. Cd was identified as the priority pollution in iron/steel smelting areas. Assessing source-oriented health risks associated with oral ingestion exposure can guide the management and control of HM contamination within iron/steel smelting-affected areas.

Driving forces and relationship between air pollution and economic growth based on EKC hypothesis and STIRPAT model: evidence from Henan Province, China.

The aim of this research is to analyze the main influencing factors and relationship between atmospheric environment and economic society. Using the panel data of 18 cities in Henan Province from 2006 to 2020, this paper employed some advanced econometric estimation included entropy method, extended environmental Kuznets curve (EKC) and STIRPAT model to conduct empirical estimations. The results show that most regions in Henan Province have verified the existence of the EKC hypothesis; and the peak of air pollution level in all cities of Henan Province generally occurred in around 2014. Multiple linear Ridge regression indicated that the positive driving forces of air pollution in most cities in Henan Province are industrial structure and population size; the negative driving forces are urbanization level, technical level and greening degree. Finally, we used the grey GM (1, 1) model to predict the atmospheric environment of Henan Province in 2025, 2030, 2035 and 2040. What should pay close attention to is that air pollution levels in northeastern and central Henan Province will continue to remain high.

Community characteristics of macroinvertebrates and ecosystem health assessment in Qin River, a main tributary of the Yellow River in China.

To know well the ecosystem health status of Qin River, a main tributary of the Yellow River and the largest river in Jincheng region, macroinvertebrates from 49 sampling sites in the Qin River and its largest tributary, the Dan River, were investigated, and community characteristics were analyzed in the autumn of 2020; a Benthic index of Biotic Integrity (B-IBI) was established based on four metrics by a series of steps. The results showed that a total of 38 species of macroinvertebrates were collected and identified, belonging to 6 orders and 19 families, consisting of 17 Insecta species, 13 Gastropoda species, and 4 Oligochaeta species. Four species in Insecta belonged to EPT (E, Ephemeroptera; P, Plecoptera; T, Trichoptera); 10 species in Insecta belonged to Chironomidae and Tipulidae families. All species in Gastropoda belonged to Basematophora order, and, especially, Bellamya aeruginosa is highly tolerant to nutrients. All species in Oligochaetes belonged to Tubificidae family, which indicates eutrophication and low-dissolved oxygen. The dominant species in the study were Ephemera orientalis, Chironomus riparius Meigen, and Limnodrilus claparedianus. The final B-IBI scores varied from 0.75 to 3.75, with 5 sites in "excellent," 10 sites in "good," 10 sites in "normal" status, 12 sites in "poor" status, 12 sites in "very poor." "Very poor" and "poor" sites were mainly located in the middle reach of the Qin River and upper-middle reach of the Dan River in Jincheng region. B-IBI strongly differentiated the reference sites and impaired sites, suggesting the suitability of the B-IBI in the Qin River basin. Significantly negative correlations between NH4+-N, TN, and B-IBI indicated the B-IBI characterized well the influence of nitrogen pollution.

The Impact of Land Use Structure Change on Utilization Performance in Henan Province, China.

Because of the trends in population growth and rapid industrialization and urbanization, the intensity and structure of land use are undergoing great changes. Henan Province is an important economic province and a major grain producing and energy consumption area, and its land use plays a key role in the sustainable development of the whole of China. This study takes Henan Province as the research object, selects panel statistical data from 2010 to 2020, and discusses the land use structure (LUS) in Henan Province in terms of three aspects: information entropy, analysis of land use dynamic change, and land type conversion matrix. Based on the indicator system "social economy (SE)-ecological environment (EE)-agricultural production (AP)-energy consumption (EC)", a land use performance (LUP) evaluation model was constructed to judge the performance of various land use types in Henan Province. Finally, the relational degree between LUS and LUP was calculated through the grey correlation. The results show that among the eight land use types in the study area since 2010, land used for water and water conservancy facilities increased by 4%. In addition, transport and garden land changed significantly, and was mainly converted from cultivated land (decreased by 6674 km2) and other land. From the perspective of LUP, the increase in ecological environment performance is the most obvious, while agriculture performance is lagging behind; it is worth paying attention to the energy consumption performance, which is decreasing year by year. There is an obvious correlation between LUS and LUP. LUS in Henan Province presents a gradually stable state, and the transformation of land types promotes LUP. Proposing an effective and convenient evaluation method to explore the relationship between LUS and LUP is very beneficial in helping stakeholders to actively focus more on optimizing land resource management and decision making for the coordinated and sustainable development among agricultural, socio-economic, eco-environmental, and energy systems.

Health risk assessment of heavy metals in road dust from the fourth-tier industrial city in central China based on Monte Carlo simulation and bioaccessibility.

Health risks caused by heavy metal (HM) exposure in road dust has attracted extensive attention, but few studies have focused on the health risks of residents living in small- and medium-sized cities with rapid industrialization and urbanization. Thus, 140 road dust samples were collected across Anyang, a typical fourth-tier industrial city in central China, which were analysed for 10 different HMs (Mn, Zn, Pb, V, Cr, As, Cd, Ni, Cu and Co). Monte Carlo simulation and bioaccessibility were used to quantify the health risks of heavy metals comprehensively in road dust. Results revealed a remarkable accumulation of Mn, Zn, Pb, Cd and Cu. According to the Geo-accumulation index and potential ecological risk index, Cd was priority control pollutant. Moreover, 55.0% of the road dust samples reached heavily polluted level, and 52.86% of the samples were at high ecological risk levels. These results illustrated that HM contamination was serious and universal in the road dust of Anyang. The occurrences of HMs were allocated to traffic emissions, natural sources, industrial activities and agricultural activities with contribution rates of 35.4%, 6.0%, 41.6% and 17.0%, respectively. Except for Zn in the gastric phase, all other HMs had relatively low bioaccessibilities in the gastrointestinal system, usually less than 20%. The bioaccessibilities of most HMs were higher in the gastric phase, except for Cr, Ni and Cu, which remained higher in the intestinal phase. The non-carcinogenic risk and carcinogenic risk were remarkably reduced when considering the HM bioaccessibilities in the gastrointestinal system, especially for adults. The outcomes of this paper are valuable for understanding HM contamination in road dust and highlight the importance of risk assessment for populations living in the fourth- and fifth-tier cities.

Health risk assessment of PM2.5 heavy metals in county units of northern China based on Monte Carlo simulation and APCS-MLR.

The key areas of China's urbanization process have gradually shifted from urban areas to county-level units. Correspondingly, air pollution in county towns may be heavier than in urban areas, which has led to a lack of understanding of the pollution situation in such areas. In view of this, 236 PM2.5 filter samples were collected in Pingyao, north of the Fen-Wei Plain, one of the most polluted areas in China. Monte Carlo simulation was used to solve the serious uncertainties of traditional HRA, and the coupling technology of absolute principal component score-multiple linear regression (APCS-MLR) and health risk assessment (HRA) is used to quantitatively analyze the health risks of pollution sources. The results showed that PM2.5 concentration was highest in autumn, 3.73 times the 24 h guideline recommended by the World Health Organization (WHO). Children were more susceptible to heavy metals in the county-level unit, with high hazard quotient (HQ) values of Pb being the dominant factor leading to an increased non-carcinogenic risk. A significant carcinogenic risk was observed for all groups in autumn in Pingyao, with exposure to Ni in the outdoor environment being the main cause. Vehicle emissions and coal combustion were identified as two major sources of health threats. In short, China's county-level population, about one-tenth of the world's population, faces far more health risks than expected.

Pollution effect assessment of industrial activities on potentially toxic metal distribution in windowsill dust and surface soil in central China.

Boundaries between industrial and urban areas in developing countries are not clearly defined, but pollution effect assessment of industrial activities on potentially toxic metal (PTM) distribution in these areas has rarely been investigated. Fifteen villages and eight communities surrounding the industrial areas from Anyang, China, were chosen as research objects in this study. A total of 78 windowsill dust and 78 surface soil samples were collected to determine the pollution levels, spatial distribution and risk indices of nine PTMs. PTM concentrations (expect Cr, Mn and Ni in surface soil) in the surveyed region were higher than the local soil background values. Amongst these PTMs, serious Cd and As pollution was discovered, and Cd and As in windowsill dust and surface soil exceeded the background value by 73.00 and 9.59, 9.74 and 10.92 times, respectively. Compared with the Igeo in surface soil, a large degree of variation in Igeo for the different PTMs was found in windowsill dust. The interpolated spatial distribution of dust Cr, Zn, Pb, Cd and soil Mn, Ni and Cu had a gradually decreasing pollution trend from the south to the north due to the prevailing wind directions in winter in the study area. Results of multivariate statistics reflected that industrial production and traffic emission affected the concentration of PTMs in windowsill dust and surface soil. The non-carcinogenic risks for children (soil: 12.4; dust: 19.2) were larger than those for adults (soil: 1.02; dust: 1.51). This finding suggested that industrial activities caused serious harm to the residents around industrial areas.

Health risk assessment and bioaccessibilities of heavy metals for children in soil and dust from urban parks and schools of Jiaozuo, China.

Urban parks and schools sever as the mainly activity areas for children, but risk assessment posed by heavy metals (HMs) from soil and dust in these area has rarely been investigated. In this study, six urban parks and seven schools in Jiaozuo, China, were taken as research objects to understand the contamination level and bioaccessibility of HMs from soil and dust in urban parks and schools. The results indicated that Zn, Cu, Pb, Cd, As, Ni and Co from soil and dust were above the background values, especially Zn and Cd in dust, and As and Cd in soil. Serious Cd pollution was discovered, and respective Cd concentrations in soil and dust were 17.83 and 7.52 times the background value. Additionally, the average concentration and bioaccessibility of Zn, Mn, Pb, Cd, Cr, Ni and Co in dust were both higher than in soil. High concentration and high bioaccessibility of HMs in dust suggested that HMs contamination were serious and universal in Jiaozuo. The concentrations of most HMs were higher in the gastric phase, except for Cu and Cd which remained higher in the intestinal phase. Both in the gastric phase and intestinal phase, Mn, As and Cd in soil and dust both have high bioaccessibility which all exceed 10%. The carcinogenic and non-carcinogenic risks base on the total HMs for children (soil: 7.93, 1.96E-05; dust: 6.44, 3.58E-05) were greater than those for adults (soil: 6.35E-01, 1.32E-05; dust: 5.06E-01, 2.42E-05), and urban parks and schools posed high potential risk for children. Therefore, assessment the risk posed by HMs contamination of soil and dust in urban parks and schools is vital and urgent for children.

Differences in the risk assessment of soil heavy metals between newly built and original parks in Jiaozuo, Henan Province, China.

Differences in the concentrations of heavy metals between newly built and original parks remain incompletely understood. In this work, two newly built and four original parks in Jiaozuo, China, were taken as research objects. Using the geo-accumulation index, ecological risk assessment index and human health risk model, differences in heavy metal pollution between the two types of parks were determined. In the surveyed region, five heavy metals, namely, Zn, Cu, As, Ni and Co, polluted the environment. Serious As pollution was discovered, and respective As concentrations in the soils of newly built and original parks were 5.9 and 3 times the background value. The concentrations of Zn, Mn, As, Pb, Cr and Ni in newly built parks were higher than those in the four original parks, although the concentrations of Cu and Co between the two types of parks were not significantly different. The carcinogenic and non-carcinogenic risks of these metals in newly built parks (adults: 4.27E-05, 1.08; children: 2.53E-04, 8.94) were greater than those in original parks (adults: 2.57E-05, 0.67; children: 1.52E-04, 5.39), and newly built parks posed higher potential risk than original parks. Therefore, the concentration of heavy metals in soil must be assessed before former industrial sites are transformed into parks.

The bioavailability of selenium and risk assessment for human selenium poisoning in high-Se areas, China.

Enshi prefecture of Hubei Province is well known for human selenium (Se) poisoning in the early 1960s in China. Sporadic cases of Se poisoning in livestocks are still being found. In this study, Se levels in water, cropland soils and various crops from high-Se areas of Enshi were measured to investigate the distribution and bioavailability of Se in the environments, as well as probable daily intake (PDI) of Se for local residents. The total Se in surface water ranged from 2.0 to 519.3µg/L with a geometric mean of 46.0±127.8 µg/L (n=48), 70.5-99.5% of which was present in the form of Se(VI). The soil Se concentration varied from 2.89 to 87.3 µg/g with a geometric mean of 9.36±18.6 µg/g (n=45), and most of Se was associated with organic matter (OM-Se). The total Se in rice, corn, and vegetable samples were 2.11±2.87 µg/g (n=21), 3.76±11.6 µg/g (n=16), and 2.09±3.38 µg/g (n=25), respectively. Stream water Se is likely leached from carbonaceous shale and mine wastes, leading to Se accumulation in paddy soils. OM-Se may play an important role in Se uptake by rice plant in high-Se area of Enshi. The PDI of Se is approximately 2144 µg/day, and Se concentration in blood is estimated at about 3248 µg/L, posing a potential chronic Se poisoning risk to local residents. Cereal consumption (48.5%) makes a great contribution to human daily Se intake, followed by vegetables (36.6%), meats (8.5%), and drinking water (6.4%). However, when assessing health risk on human in high-Se areas, the contribution of drinking water to daily Se intake cannot be ignored due to high Se content and dominant Se(VI) species. Local inhabitants should be advised not to grow crops in high-Se lands or irrigate using high-Se water. If possible, they should drink pipe water and consume foods mixed with those from outside the high-Se areas.