Common plastic causes brain damage in monkeys

Scientists have suggested lowering the 'safe' daily consumption limit of one of the most widely-used plastics.

Plastic types Bisphenol A (BPA), the basic constituent of polycarbonate plastic, is everywhere from reusable water bottles and baby bottles to CDs and DVDs, from dental sealants to the lining of 'tinned' food cans. It is known that small amounts of it can leach out of the container into the food or drink but the industry has always maintained that the levels are safe. Now research at the Yale University School of Medicine in New Haven, Connecticut says it causes brain damage in monkeys even at the safe dose.

'Our primate model indicates that BPA could negatively affect brain function in humans,' said study investigator Tibor Hajszan.

Hajszan and colleagues examined the influence of continuous exposure to BPA at a daily dose representing the US Environmental Protection Agency's current reference safe daily limit (50 micrograms per kilogram) in young adult African green monkeys.

According to their report in last week's Proceedings of the National Academy of Sciences, BPA completely abolished the formation of some nerve connections in two key regions of the brain concerned with thinking and mood - the hippocampus and prefrontal cortex.

'Based on these findings, we think the Environmental Protection Agency may wish to consider lowering its safe daily limit for human BPA consumption,' said Hajszan.

Whether the amount of BPA that leaches out of containers into food and beverages is a risk to health and the environment has long been a subject of controversy. Critics say that although every study of BPA backed by the plastics industry has declared it safe, 90% of the 160+ non-industry studies have detected harmful effects including hormone-related illnesses and cancer. BPA is banned in Canada and many US companies say they are trying to reduce their use of it.

BPA may leach from type 3 and type 7 plastics.