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Guo G.-X.,University of Chinese Academy of Sciences | Ju Y.-W.,University of Chinese Academy of Sciences | Zhai H.,China Ordnance Industry Survey and Geotechnical Institute | Xu L.,Hydrogeology and Engineering Geology Team of Beijing | And 2 more authors.
Huanjing Kexue/Environmental Science | Year: 2014

In order to evaluate the groundwater quality of Tongzhou area in Beijing Plain and to discuss the characteristics of its distribution by the view of hydrochemistry, a total of 151 groundwater samples, collected within study area in the dry period of 2008 according to the geological and hydrogeololgical condition of Tongzhou area, were classified as shallow, middle and deep groundwater, respectively. Based on the data, the groundwater quality was evaluated by the method of F value. The mean and variance of main chemical constituents of groundwater samples were presented. Almost all the quaternary groundwater of Chaobai river pluvial fan belonged to the alkaline water type. The evaluation results based on the analysis results showed that from shallow to deep, the quality of groundwater in Beijing became better. The total areas of groundwater belonging to class IV and V area were 884 km2, 599 km2and 94 km2 respectively for shallow, middle and deep groundwater. The evaluation results showed that the main exceeding chemical constituents were TDS, hardness, NH4 +, F-and total Fe. Most exceeding samples belonged to middle and deep aquifers. The main types of shallow groundwater were HCO3-Ca·Mg-and HCO3·Cl-Ca·Na·Mg, while the chemical types of mid-deep groundwater were mostly HCO3-Na·Ca-and HCO3·SO4 2--Na·Ca type due to the increased Na+, SO4 2- and Cl- concentration. Study results showed that the quality of shallow groundwater became worse mainly due to human activities. The deterioration of groundwater quality in mid-deep aquifers was due to both human activities and natural occurrence of poor-quality water.

Yang Z.-P.,Chongqing University | Wang L.,Chongqing University | Zhai H.,China Ordnance Industry Survey and Geotechnical Institute | Zhao J.-J.,Chongqing University | Lu W.-X.,Jilin University
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2015

An extensive survey was conducted to evaluate the health risk of potentially toxic heavy metals in near-surface urban dust environment of Changchun, P. R. China. 232samples were collected, using a systematic sampling strategy with a sampling density 3~5 composite dust samples (about 1. 5m above the ground surface) per km in urban sit. X-ray fluorescence spectroscopy (XRF), atomic fluorescence spectrophotometry (AFS) and graphite furnace atomic absorption spectrometry (GF-AAS) were employed to analyze the Cu, Pb, Zn, Cr, As, Hg and Cd concentration of urban dust, respectively. The results indicated that the mean concentration of As, Cd, Cr, Cu, Hg, Pb and Zn in the near-surface urban dusts of Changchun was 23.26, 0.62, 94.53, 68.41, 0.24, 93.63 and 416.71 mg/kg, respectively, which are significant higher than the value of Changchun topsoils, meanwhile, which also shows that the urban dust in Changchun was polluted. The results of health risk assessment showed that children has had greater health risks than adults, the exposure doses for children were 7.3 times higher than those for adults, except for As which is 7.9 times higher. The exposure pathway which resulted in the highest level of risk for human exposed to near-surface dust was ingestion of this material, which was followed by dermal contact. As for the aggregate non-carcinogenic health risk (HI), As was of most concern regarding the potential occurrence of health impact, which was followed by Cr, Pb, Cu, Zn, Cd and Hg. The average non-carcinogenic health risk index for children and adults were 1.11 and 0.14, respectively. Of the three carcinogenic metals concerned in present study As, Cr and Cd, As was of most concerned. The average aggregate carcinogenic health risk index (RISKt) was 6.35μl05, which was higher than the EPA advised values. However, except for some locations, risk values of both cancer and non-cancer health risk obtained in present study were in the receivable range on the whole. ©, 2015, Zhongguo Huanjing Kexue/China Environmental Science. All right reserved.

Li W.,University of Chinese Academy of Sciences | Wang M.-Y.,University of Chinese Academy of Sciences | Liu L.-Y.,China Ordnance Industry Survey and Geotechnical Institute | Wang H.-F.,University of Chinese Academy of Sciences | Yu S.,University of Chinese Academy of Sciences
Arabian Journal of Geosciences | Year: 2015

Heavy metals in domestic water are a serious threat to human health. In this study, 139 groundwater samples were collected from rural wells in the villages of five cities in the middle region of the North China Plain along two transects. Statistical analysis and human health risk assessment were conducted to determine the distribution of heavy metals and the associated human health risk from ingestion and dermal adsorption of local groundwater. The results show that the mean concentrations of heavy metals in local groundwater are in the order: Mn > Zn > Cr > Ni > As > Se > Cu > Pb > Cd; with the exception of some sampling stations of Mn and Ni, concentrations for all metals have not exceeded the drinking water standard. Most of the highest pollution stations are in the middle part of urban areas. Mn–As and Cr–Cu are divided into groups by cluster analysis, indicating either the same source or similar transport behaviors. All of the values of the calculated HItotal (the non-carcinogenic risk) range from 1.28 × 10−2 to 5.54 × 10−1, indicating no or slight chronic risk to residents from heavy metals in groundwater. Average values of Ringestion (carcinogenic risk caused by ingestion) for As, Cr, and Cd are between 1 × 10−6 and 1 × 10−4, indicating a slight carcinogenic risk from heavy metals in groundwater. Although several policies have already been implemented in the study area to ensure the safety of drinking water for residents, the local administration should continue to direct significant attention to groundwater pollution from heavy metals. © 2015 Saudi Society for Geosciences

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