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In this research, enrichment factor (EF) and pollution load index were utilized to explore the contamination characteristics of toxic elements (TEs) in park dust. The results exhibited that park dust in the study area was mainly moderately polluted, and the EF values of dust Cd, Zn, Pb, Cu and Sb were all > 1. The concentrations of Cr, Cu, Zn and Pb increased with the decrease of dust particle size. The investigation results of chemical speciation and bioavailability of TEs showed that Zn had the highest bioavailability. Three sources of TEs were determined by positive matrix factorization model, Pearson correlation analysis and geostatistical analysis, comprising factor 1 mixed sources of industrial and transportation activities (46.62%), factor 2 natural source (25.56%) and factor 3 mixed source of agricultural activities and the aging of park infrastructures (27.82%). Potential ecological risk (PER) and human health risk (HHR) models based on source apportionment were exploited to estimate PER and HHR of TEs from different sources. The mean PER value of TEs in the park dust was 114, indicating that ecological risk in the study area was relatively high. Factor 1 contributed the most to PER, and the pollution of Cd was the most serious. There were no significant carcinogenic and non-carcinogenic risks for children and adults in the study area. And factor 3 was the biggest source of non-carcinogenic risk, and As, Cr and Pb were the chief contributor to non-carcinogenic risk. The primary source of carcinogenic risk was factor 2, and Cr was the cardinal cancer risk element. [ABSTRACT FROM AUTHOR]

Non-ferrous metal smelting activities have always been considered as one of the foremost anthropogenic sources of potentially toxic elements (PTEs). The enrichment factor (EF) and pollution load index (PLI) were used to evaluate the pollution level of soil PTEs; positive matrix factorization (PMF), correlation analysis, and geostatistics were utilized to quantify the sources of soil PTEs; and potential ecological risk (PER) and human health risk (HHR) of different sources from farmland, construction land, and natural land were quantifiably determined via combined PTE sources with PER and HHR assessment models. Taking the smelting area of Daye City as an example, the evaluation results of EF and PLI showed that the soil PTE pollution in the study area was serious, especially Cd and Cu. And four sources were quantitatively allocated as agricultural practices (12.14%), traffic emissions (23.07%), natural sources (33.46%), and industrial activities (31.33%). For PER, industrial activities were the largest contributor to PER, accounting for 55.66%, 56.30%, and 55.36% of farmland, construction land, and natural land, respectively, and Cd was the most dangerous element. In terms of HHR, industrial activities were also the cardinal contributors under the three land use types. Children were exposed to serious non-carcinogenic risks under three land use patterns and slight carcinogenic risk in construction land (1.06E − 04). Significantly, the carcinogenic risk of children in farmland (9.06 × 10−5) was very close to the threshold (1 × 10−4), which requires attention. Both non-carcinogenic and carcinogenic risk for adults were all at acceptable levels. The health risks (carcinogenic and non-carcinogenic risks) of children from four different sources were distinctly higher than those of adults. Consequently, strict management and control of industrial activities should be given priority, and the management of agricultural practices should not be ignored. [ABSTRACT FROM AUTHOR]

Large-scale smelting activities release large amounts of potentially toxic elements (PTEs) in fine particles. These particles floating in the air eventually settle on leaves, roads, and even indoors. In smelting areas, indoor environments are generally considered relatively safe. However, these areas are not taken seriously and need to be assessed. This paper systematically studied pollution characteristics, main sources and health risks of ten potentially toxic elements, PTEs (Mn, Ni, Cu, Zn, Hg, Cd, As, Cr, Pb, and Tl), of dust samples from different indoor environments in smelting areas using various methods. Therefore, this study analyzed dust samples from 35 indoor environments. The enrichment factors showed that the indoor dust samples were extremely enriched by Cd and Cu and significantly enriched by Hg, Pb, As, and Zn. The result of the spatial distribution showed that the high-value PTEs were mainly distributed near the Cu smeltery. Three sources were quantitatively assigned for these PTEs, and they were industrial smelting and traffic activities (44.40%), coal-fired activities (18.11%), and natural existence (37.49%). Based on the calculation of health risk, the value of THI for children was 7.57, indicating a significant non-carcinogenic risk. For carcinogenic risk, the values of TCR for children and adults were 2.91×10−2 and 2.97×10−3, respectively, which were much higher than the acceptable risk value 1×10−4. Combining health risk assessment with source discrimination, we found that the industrial discharges and traffic activities were the most main source of non-cancer and cancer risks. Therefore, smelting activities should be more strictly monitored, and traffic emission management should be strengthened. [ABSTRACT FROM AUTHOR]

It is necessary to establish local geochemical baseline concentrations (GBCs) due to the lack or the inapplicability of regional background values in the study area. The establishment of GBCs of heavy metal (HM) in soil helps in making the accurate assessment of pollution, and then provides a basis for pollution control. Based on this, a case study was undertaken to study the GBCs of the Jiedong District, Guangdong Province, China. In this research, cumulative frequency distribution curves were utilized to determine the local GBCs in the subsoils. The determined GBCs of Cr, Hg, As, Pb, Ni, Cd, Cu, Zn, Co and V were 39.91, 0.072, 11.48, 47.62, 12.70, 0.17, 14.22, 64.54, 6.31, and 68.14 mg/kg, respectively. The average concentrations of Hg, As, Pb, Cd, Cu and Zn in the topsoils exceeded the corresponding baseline concentrations. In particular, the contents of Cd and Hg were 1.53 and 2.22 times higher than GBCs. According to this baseline criterion, enrichment factor (EF), pollution load index (PLI) and ecological risk index (RI) were applied to assessing HM pollution. EF and PLI suggested that most areas were under moderate contamination, while Hg and Cd pollution was more serious. And the RI values presented that the potential ecological risks were low in most parts of the study area. The possible origins of HMs were identified by combining positive matrix factorization with EF and geostatistics. Comprehensive analysis indicated that Hg and Cd were related to industrial activities, such as textile and garment processing, plastic and rubber production and metal manufacturing. Arsenic and part of Cu mainly came from agricultural activities, namely the use of pesticides, fertilizers and livestock manures. Lead and Zn were mainly attributed to traffic emissions. Chromium, Ni, V, Co, and part of Cu were originated from natural source controlled by parent materials. The corresponding contributions of these sources were 20.61%, 24.20%, 19.22% and 35.97%, respectively. This work provides information to prevent and control the soil HM pollution by proposing the efficient management of anthropogenic sources. [ABSTRACT FROM AUTHOR]

A total of 321 surface soil samples were collected from Huilai County, Guangdong Province, Southern China. Concentrations of 12 metals (Cr, Hg, As, Pb, Ni, Cd, Cu, Zn, Sb, Sn, Ti, and V) were measured. The mean concentrations of As, Pb, Cd, Zn, Sn, and Ti were higher than their corresponding soil background values, especially for As, Cd, and Sn, which were 1.36, 2.50, and 2.77 times of the background values, respectively. And the results of enrichment factor and pollution load index suggested that soil metals in the study area were moderately contaminated, but pollution of As, Cd, and Sn was relatively serious. According to one-way analysis of variance, there were significant differences in concentrations of Hg, As, Pb, Cd, Zn, and Sn between different land use types, indicating that they were associated with the anthropogenic inputs. The potential sources of metals were quantitatively apportioned by positive matrix factorization, and combined with correlation analysis and geostatistical. The results showed that Cr, Ni, Ti, and V mainly originated from natural sources. Lead, Zn, and partially, Cd mainly came from traffic emissions. Arsenic, Cu, and partially, Sb were ascribed to agricultural practices. Mercury, Sn, partially, Cd, and Sb were derived from industrial activities. Their corresponding contributions were 36.88%, 22.14%, 20.87%, and 20.11%, respectively. [ABSTRACT FROM AUTHOR]

Many studies have suggested that organic matter (OM) substantially reduces the bioavailability and risks of mercury (Hg) in soils and sediments; however, recent reports have supported that OM greatly accelerates Hg methylation and increases the risks of Hg exposure. This study aims to summarize the interactions between Hg and OM in soils and sediments and improve our understanding of the effects of OM on Hg methylation. The results show that OM characteristics, promotion of the activity of Hg-methylating microbial communities, and the microbial availability of Hg accounted for the acceleration of Hg methylation which increases the risk of Hg exposure. These three key aspects were driven by multiple factors, including the types and content of OM, Hg speciation, desorption and dissolution kinetics and environmental conditions. [ABSTRACT FROM AUTHOR]

Soil cadmium (Cd) contamination resulted from mining and smelting is a major environmental concern, and health risk associated with Cd exposure to multi-media through muti-pathway is increasing. Cd concentrations in soils, vegetables and paddy rice were investigated, and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine, South China. A total of 87 soil samples were found to exceed the China's maximum permission level (MPL) for Cd, while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi (XY) Village. Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village. Cadmium accumulation in plants is in the order of celery > lactuca sativa L > Chinese cabbage > Romaine lettuce > asparagus lettuce > mustard > cabbage mustard > cabbage. The mean hazard quotient (HQ) of all villages is in the range of [5.29, 25.75], and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA (2009) threshold limit value of 10. Moreover, human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake, followed by vegetables intake, soil ingestion, inhalation, and dermal contact. The results indicate that Cd has a huge potential risk on human health for the local residents. [ABSTRACT FROM AUTHOR]