January 16, 2013 by APRIL McCARTHY
Use PVC Pipes In Your Home or Business? Chemicals Leached Trigger Infertility and Obesity Even In Successive Generations
One day, we may find all PVC piping at the hardware store with a sticker that says "TBT-free." Until then, buyer beware. According to a new study, the chemical tributyltin (TBT) which is found in marine paints and PVC plastic,
leads to infertility and obesity for multiple generations even without subsequent exposure.
TBT compounds are considered toxic chemicals which have negative effects on human and environment. The compounds are moderately to highly persistent organic pollutants (POPs) that biomagnify up the marine predators' food net. Some scientists estimate that almost 50% of all babies worldwide will have at least one birth defect due to POPs.
Most water distribution systems for drinking water and sewer piping below city infrastructure is ignorantly being upgraded to PVC materials by the standards set by many municipal governments who have been ill-advised that PVC is beneficial for the environment. This misguided belief has health and marine activists sounding the alarm bells.
One common example is leaching of TBT from marine paints into the aquatic environment, causing irreversible damage to the aquatic life. Tributyltin has also been linked to obesity in humans, as it triggers genes that cause the growth of fat cells.
TBT causes marine organisms suffer from imposex: females develop male sexual characteristics such as a penis. Trace amounts of just 2.4 nanograms of TBT per litre are needed to produce sexual changes. This causes infertility and even death. In severe cases males can develop egg sacs. TBT also causes immunosuppression, leading to secondary infections.
After exposing pregnant mice to TBT in concentrations similar to those found in the environment, researchers saw increased body fat, liver fat and fat-specific gene expression in their “children,” “grandchildren” and “great-grandchildren” -- none of which had been exposed to the chemical.
These findings suggest that early-life exposure to endocrine-disrupting compounds such as TBT can have permanent effects of fat accumulation without further exposure, said study leader Bruce Blumberg, UC Irvine professor of pharmaceutical sciences and developmental & cell biology. These effects appear to be inherited without DNA mutations occurring.
The study appears online Jan. 15 in Environmental Health Perspectives, a publication of the National Institute for Environmental Health Sciences.
Human exposure to TBT can occur through PVC plastic particles in dust and via leaching of the chemical and other related organotin compounds from PVC pipes and containers.
Significant levels of TBT have been reported in house dust -- which is particularly relevant for young children who may spend significant time on floors and carpets. Some people are exposed by ingesting seafood contaminated with TBT, which has been used in marine hull paint and is pervasive in the environment.
Blumberg categorizes TBT as an obesogen, a class of chemicals that promote obesity by increasing the number of fat cells or the storage of fat in existing cells. He and his colleagues first identified the role of obesogens in a 2006 publication and showed in 2010 that TBT acts in part by modifying the fate of mesenchymal stem cells during development, predisposing them to become fat cells.
April McCarthy is a community journalist playing an active role reporting and analyzing world events to advance our health and eco-friendly initiatives.