Yet another study suggests that pharmaceuticals finding their way into the water supply may be linked to a troubling issue. A team of researchers has discovered that fish show autism-like gene expression after exposure to water containing antidepressants, such as Prozac and Effexor. The results may suggest an environmental trigger for autism, although the researchers caution this may only apply to genetically predisposed people.
They reached this conclusion by placing the antidepressants, as well as the Tegratol antiseizure med, into water tanks filled with fathead minnows. The concentration of the drugs were comparable to those found in aquatic systems. And tests showed genetic pathways affected were the same as those associated with idiopathic autism spectrum disorders, raising the possibility that pregnant women who drink water containing trace concentrations may pass them to the fetus.
“While others have envisioned a causal role for psychotropic drugs in idiopathic autism, we were astonished to find evidence that this might occur at very low dosages, such as those found in aquatic systems,” says Michael Thomas, an associate professor of biological sciences at Idaho State University and the lead author of the study, which was published this week in PLoS ONE. "This discovery implies that these drugs might be involved in the increase in autism in the past 30 years."
This is not the first time that water supplies containing traces of pharmaceuticals have generated concern. Four years ago, the Associated Press conducted a five-month inquiry and discovered that drugs were detected in drinking water supplies of 24 major metropolitan areas across the country (read here). A study last year indicated that active pharmaceutical ingredients were linked to changes in sexual characteristics of a type of fish in a river in France and, therefore, may have further damaging consequences on the larger ecosystem (see this).
Last fall, a bill was introduced in Congress to create a non-profit organization to develop a nationwide program for disposing of medicines. Known as the Pharmaceutical Stewardship Act, the non-profit would alsoo establish a commission to develop a strategy for preventing pharmaceutical contaminants from polluting waterways during the production process. Financing would be provided by the pharmaceutical industry. The bill went nowhere (back story and bill status).
More recently, a program was proposed in the state of Washington to safely dispose of unused prescription drugs lingering in medicine cabinets and dresser drawers. The proposal called for drugmakers to cover some of the costs, but the pharmaceutical industry resisted. The bill is still kicking around (see this and back story).
Although Thomas cautions that further study is needed, the suggested findings are likely to renew skepticism among some parents toward pharmaceutical products. For years, you may recall, there has been controversy over the extent to which some vaccines were linked to autism. Despite findings debunking the notion, many children are still not receiving scheduled vaccinations (see here and here).