3Reza R, Singh G. Assessment of heavy metal contamina- tion and its indexing approach for river water[J]. Inter- national Journal of Environment Science and Technolo- gy, 2010, 7(4) :785-792.
4USEPA(US Environmental Protection Agency). Risk Assessment Guidance for Superfund Volume L. Human Health Evaluation Manual (Part A)[OL]. (2012-02-06) [2013-04-02]. http://www, epa. gov/oswer/riskassess- ment/ragsa/.
5Kim E Y, Little J C, Chiu N. Estimating exposure to chemical contaminants in drinking water[J]. Department of Civil and Environmental Engineering, 2004, 38 (6): 1799-1806.
6USEPA(US Environmental Protection Agency). Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part E) [OL]. (2012-05- 06) [2013-04-02]. http: // www. epa. gov/oswer/ riskassessment/ragsa/.
8Miguel E D, Iribarren I, Chacon E, et al. Risk-based evaluation of the exposure of children to trace elements in playgrounds in Madrid (Spain) [J]. Chemosphere, 2007, 66(3) :505-513.
9USEPA(US Environmental Protection Agency). Inte- grated Risk Information System (IRIS)EOL]. (2012- 03-03) E2013-04-05]. http://www, epa. gov/iris/.
10WHO (World Health Organization). Guidelines for drinking-water quality, fourth edition[-OL]. (2012-08- 09)[2013-04-05]. http://www, who. int/water sani- tation_health/dwq/gdwq3 rev/zh/index, html.