[Pollution and Potential Ecological Risk Assessment of Heavy Metals in Surface Sediments of Tangxun Lake].

In order to understand the pollution characteristics, spatial distribution, potential sources, and ecological risk of heavy metals in the sediments of Tangxun Lake, the contents of heavy metals (As, Hg, Cd, Cr, Cu, Pb, Zn, and Ni) in the surface sediments of Tangxun Lake were analyzed, and the pollution status and potential ecological risk degree of heavy metals in the sediments were evaluated using the geo-accumulation index and potential ecological risk index. The potential sources of heavy metal pollutants were analyzed by correlation and principal component analysis. The results showed that except for Cr, the contents of other heavy metals were higher than their background values. The contents of Hg, Cd, Zn, and Cu were higher in the southwest and northeast corners of the lake, which may come from the combined pollution of sewage discharge, fisheries, and surrounding industrial and agricultural activities. The geo-accumulation index and potential ecological risk showed that Hg and Cd were in moderate pollution; Cu, Pb, and Zn were in non-light pollution; and As, Cr, and Ni were in non-pollution. Except for Hg and Cd, there were serious and serious potential ecological risks, and the other elements were at a low risk level. The heavy metals in the surface sediments of Tangxun Lake showed a high ecological risk level.

[Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 Under Winter Haze Conditions in Central China: A Case Study of Huanggang, Hubei Province].

To explore the pollution characteristics and potential health risks of heavy metals in PM2.5 on haze days in Central China, PM2.5 samples were collected from the Huanggang monitoring station, a regional observation point in Central China, between January 13 and 24, 2018. The contents of Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sn, and Pb in PM2.5 were analyzed by inductively coupled plasma mass spectrometry(ICP-MS), and the enrichment factor method was used to determine the potential risk based on the exposure model recommended by the Environmental Protection Administration(EPA). The results showed that during the observation period, the concentrations of Zn in PM2.5 were highest, and the concentrations of the carcinogens As and Cd were higher than the secondary standard limits of China's ambient air quality standard(GB 3095-2012), with 70% of these elemental concentrations accounting for the largest proportion in the middle haze period. The enrichment factor analysis showed that Cd, Sn, Co, Pb, and Zn were the most abundant elements, especially during the middle haze period, and were mostly derived from transportation and coal combustion. The results of the human health risk assessment showed that exposure via hand-mouth feeding was the main non-carcinogenic risk, and the exposure and non-carcinogenic risks of children were significantly higher than those of adults. Pb poses a non-carcinogenic risk to children, while heavy metals in PM2.5 pose no non-carcinogenic risks to adults and carcinogenic heavy metals pose no carcinogenic risks.

[Distribution, Sources and Risk Assessment of the PAHs in the Surface Sediments and Water from the Daye Lake].

8 surface sediments and 8 water samples were collected from the Daye Lake in August 2015.The 16 kinds of EPA control polycyclic aromatic hydrocarbons (PAHs) were analyzed by GC-MS.The results showed that the PAHs concentrations of surface sediments and water ranged from 35.94 ng·g-1 to 2032.73 ng·g-1 and from 27.94 ng·L-1 to 242.95 ng·L-1,with average contents of 940.61 ng·g-1 and 107.77ng·L-1,respectively.The distribution of PAHs in surface sediments indicated that the contents in the center samples were higher than those in the bank samples,but the water showed nearly the opposite tendency.The 4-5 rings high molecular weight PAHs were the main components in the surface sediments,and the 2,4 and 5 rings PAHs were given priority in water.Compared with the other domestic and oversea lakes,the PAHs pollution of the Daye Lake was at a moderate level.Source apportionment showed that the PAHs in surface sediments and water from the Daye Lake came from the combustion source,HWM-PAHs were the dominant part of the PAHs in the sediment,reflecting the sediment PAHs pollution under the effects of mining and smelting over a long period;All monomer PAHs and total PAHs content in sediment did not exceed the ERM and FEL limiting values,showing that there was no particularly serious ecological risk caused by PAHs in the surface sediments from the Daye Lake;the incremental lifetime cancer risks assessment showed that the uptake risk of PAHs in Daye Lake water through the ingestion and dermal absorption were both in the acceptable range recommended by the USEPA,but all sites had higher risk than the acceptable risk level recommended by the Sweden environmental protection agency and Royal society.The pollution of seven carcinogenic PAHs needs prevention and control.

Polycyclic aromatic hydrocarbons (PAHs) in multimedia environment of Heshan coal district, Guangxi: distribution, source diagnosis and health risk assessment.

Mining activities are among the major culprits of the wide occurrences of soil and water pollution by PAHs in coal district, which have resulted in ecological fragilities and health risk for local residents. Sixteen PAHs in multimedia environment from the Heshan coal district of Guangxi, South China, were measured, aiming to investigate the contamination level, distribution and possible sources and to estimate the potential health risks of PAHs. The average concentrations of 16 PAHs in the coal, coal gangue, soil, surface water and groundwater were 5114.56, 4551.10, 1280.12 ng g(-1), 426.98 and 381.20 ng L(-1), respectively. Additionally, higher soil and water PAH concentrations were detected in the vicinities of coal or coal gangue dump. Composition analysis, isomeric ratio, Pearson correlation analysis and principal component analysis were performed to diagnose the potential sources of PAHs in different environmental matrices, suggesting the dominant inputs of PAHs from coal/coal combustion and coal gangue in the soil and water. Soil and water guidelines and the incremental lifetime risk (ICLR) were used to assess the health risk, showing that soil and water were heavily contaminated by PAHs, and mean ICLRcoal/coal-gangue and mean ICLRsoil were both significantly higher than the acceptable levels (1 × 10(-4)), posing high potential carcinogenic risk to residents, especially coal workers. This study highlights the environmental pollution problems and public health concerns of coal mining, particularly the potential occupational health hazards of coal miners exposed in Heshan.