Drinking water, lead untreated

An adverse effect of lead on pregnancy rate has been noted in some animal studies (Kennedy et al. 1975). Acute-duration gavage administration of 390 mg lead/kg/day as lead acetate to rats resulted in a sharp decrease in pregnancy rates. This effect was not noted at 39 mg lead/kg/day. The study limitations include a lack of measurement of blood lead levels and lack of statistical analysis of pregnancy incidence. A decrease in the number of implantations was noted in untreated female mice that were mated to males that had been treated with 141 mg/kg/day lead chloride in the drinking water for 3 months... 

Poorly maintained or damaged sewers that leak may also contaminate water resources. Where sewers run close to drinking-water mains there is a danger that more direct contamination through ingress into the water mains may occur. System failures may also lead to the discharge of untreated sewage into water bodies. 

---