Pharmaceutical Contaminants in Potable Water: Potential Concerns for Pregnant Women and Children

There has been increasing concern of late over measurable levels of pharmaceutical contaminants in drinking water. Because most data on water contaminants pertains to aquatic organisms, we wished to assess the risk of these contaminants to human health at currently reported levels. Unlike most other chemicals, there are large amounts of information for the effects of most pharmaceuticals to humans and the current model uses the clinical dose required to cause biological effects as an endpoint to assess risks for pregnant women, children, and the healthy adult population. Twenty-six drugs have been detected in water systems worldwide: 7 in drinking water, 16 in ground water and post-treatment effluent, and 3 in both. Current water treatment practices, clearly, do not always remove pharmaceutical residues. Although healthy adults are unlikely to be adversely affected at the levels of exposure reported, children were shown to have up to eightfold higher risk and may be exposed to several drugs that are contraindicated or not established for safe use in pediatric medicine. The time taken to ingest a single clinically used dose was 3.4–34,000 years. In addition, pregnant women may be exposed to several drugs that are teratogenic (range of % single doses ingested over 36 weeks was 0.0006–12.6%) and in the post-natal period to drugs that are not recommended during breastfeeding. Albeit at low levels, the exposure of pregnant women and children to contraindicated drugs through drinking water is of concern. Further research in this area should focus on integrated ecological and human health consequences of long-term, low-level exposure to pharmaceutical contaminants, particularly in pregnancy and childhood.