HP3 Metals in the Environment: Regulatory and Risk Concerns
254 Portland Ballroom
1:20 PM - 5:20 PM, Thursday
() Preliminary heavy metals risk assessment in drinking water coming from a mining area.
Lerdo de Tejada Brito, A.1, Gomez Balandra, M.A. 1, Sandoval Villasana, A. M. 1, Saldaña Fabela , P.1, López López, R.1, 1 Instituto Mexicano de Tecnología del Agua, Jiutepec, Morelos, Mexico
ABSTRACT- In order to identify heavy metals of concern, six monitoring field trips in 2002 were carried out in a mining area of the central part of Mexico. Seven sites were selected (38 samples in total) nearby a site of a projected dam for drinking water supply. Results pointed out that mercury showed two values above the national limit for drinking water (0.001 mg/L) with and interval of 0.002 to 0.014. Arsenic was in three samples higher than the standard of 0.035 mg/L, with values between 0.11 and 0.45. On the other hand, lead concentrations were fifteen times higher than 0.01 mg/L with a minimum value of 0.1 and a maximum of 0.63 mg/L. Although concentrations are going to be diminished with a treatment proposed, a cancer risk was preliminary estimated with the found arsenic concentrations. Considering the life daily average intake (LDAI), the chronic reference doses (CRD) and the water exposure factor (WEF), the hazard coefficient resulted from the ration between LDAI/CRD was 0.0158137 lower than 1 and the risk cancer obtained from WEF x LDAI was 7.116165 x 10-7. With these results it can be concluded that even the direct river water intake is lower than the intake permitted for a cancer risk level of one in a million. Rapid risk assessment methods are very useful to find out potential risk in using some drinking water sources, although its confidence and veracity need to be proved and reinforced.
Key words: drinking water, heavy metals, risk assessment