Presence of organochlorine contaminants in bottled drinking water from Mexico City

Concentrations of organic contaminants (organochlorine pesticides and biphenyls) were studied in bottled drinking water (BDW) from Mexico City where consumption is high and considered a healthy alternative to the potable water network. The results of 36 samples (1.5 L and 19 L presentations, 18 samples of each) showed the presence of seven pesticides (HCH-hexachlorocyclohexane isomers, heptachlor, aldrin and p,p'-DDE'-dichlorodiphenyldichloroethylene) and some polychlorinated biphenyls-PCBs (28, 58 and 101). The concentrations were compared with the drinking water standards set by NOM-127-SSA1–1994, USEPA (United States Environment Protection Agency) and the World Health Organization (WHO) for pesticides and NOM-127-SSA1–1994 for biphenyls. The concentrations of the majority of organochlorine pesticides were within drinking water standards (0.01 μg L⁻¹) except for β-HCH in BDW samples 3, 5 and 6 with values of 0.121, 0.136 and 0.192 μg L⁻¹, respectively. The total PCBs concentration in BDW did not represent any hazard to human health, according to Mexican regulations, which establish a maximum permissible level of 0.50 μg L⁻¹. A BDW quality monitoring program is recommended and further research on ways of reducing the presence of organochlorine contaminants to prevent bioaccumulation and toxicological effects over population with emphasis in those that with constant consumption.