Health Risk Assessment Of Heavy Metals In Groundwater In Jinghuiqu Irrigation District

Jinghuiqu Irrigation District is Jing River as its water resource for irrigation. It takes charge of Jingyang, Sanyuan, Gaoling, Yanliang, Lintong countries'irrigating task. After years of the large use of chemical fertilizers and the high development of industry, not only cause the groundwater resource decreased, but the water pollution in this area. Heavy metal pollution is the important reason for the pollution.In this paper, after field investigation, data collection and local hydrogeologic data analysis, I studied the temporal and spatial distribution of heavy metals in groundwater Jinghuiqu irrigation area. The results showed that, in November 2009, the rate of higher than chromium ion concentration standard was 25.53%; its concentration gradually increased from west to east, the highest concentration is in the northeast of Sanyuan County and Yanliang which are higher than drinking water health standards and irrigation water standards. The high point of the concentration of manganese ions are mainly distributed in the north of Sanyuan County and the south of Lintong, exceeding rate is 13.16%.Hg, Cd, As, Cu, Zn are reached the drinking water health standards.In order to study human health effects of groundwater in Jinghuiqu Irrigation District, according to the distribution characteristics of heavy metals in groundwater, applying EPA's health risk assessment model, I evaluated the adults and children's health risk assessment of the heavy metals in groundwater by drinking water and skin contact in this area. The results showed that:1.The personal annual risk of cancer for the adult and children in this area that caused by carcinogenic heavy metals by drinking water and skin contact were high. The maximum that caused by chromium ion were 0.0087a-1 and 0.00027a-1, which belong to the very high risk level that can cause a very high risk.2.The variety range of the health risk effect for adult in this area that caused by heavy metals by drinking water and skin contact is form 6.86×10-11 to 0.0043 a-1, which the maximum is in Jinjiayao.3.The personal annual risk due to heavy metals exposure through drinking water and skin contact which leading adults and children suffer the non-carcinogenic health hazards, are relatively small that belong to the low risk level.4. Comprehensive analysis various means of the total health risk that when non-cancer risk and cancer risk exist, heavy metals caused the cancer risk is far greater than the proportion of the total risk of non-carcinogenic risk; when drinking water ways and skin exposed at the same time, the drinking water leading tocause a larger health hazard than skin exposure pathway.