Anti-bacterial agent found in dolphins

Former Dateline Earther Lisa Stiffler — now blogging and doing news-aggregation at Sightline.org — calls to our attention a recent study showing worrisome buildup of a controversial germ-killing chemical in dolphins off the East coast.

Triclosan, which is found in three-quarters of liquid hand soaps and one-quarter of bar soaps, is known to cause effects on the reproductive system of frogs at extraordinarily low levels in lab tests. Get this: as little as 0.03 parts per billion has made a difference in the hormone-controlling endocrine systems of lab frogs. 

This week’s story by Brett Israel comes to us courtesy another one of those fairly new non-profit journalism outfits, Environmental Health News.

"Help me! There's triclosan in here!" Photo by National Oceanic and Atmospheric Administration

It outlines how triclosan’s bacteria-killing properties have not been shown in studies to affect rates of disease transmission, but the chemical is known to build up in fatty tissues and bioaccumulate as it works its way up the food chain. Sound familiar? It should — just as PCBs and other chemicals are being found in marine mammals at alarming rates, particularly in the Pacific Northwest.

The East coast tests were performed on dolphins found off South Carolina, where one-third of the dolphins had traces of triclosan, and in Florida’s Indian River Lagoon, where it was found in one-quarter of the animals tested.

It marks the first time the chemical has been found in wild marine mammals.

Using triclosan may not be the greatest thing for human health, either. One study found that, when combined with chlorine in tap water, it can form chloroform gas. You don’t want that. And, consider that triclosan’s chemical structure is similar to that of the thyroid hormone, which regulates a variety of human body functions, including growth, development and the metabolic rate.

The American Medical Association in 2000 said it would be a good idea to lay off the triclosan until we know more about the consequences:

No data exist to support (its) efficacy when used in such products or any need for them, but increasing data now suggest growing acquired resistance to these commonly used antimicrobial agents. Studies also suggest that acquired resistance to these antimicrobials in bacteria may also predispose these organisms to resistance against therapeutic antibiotics, but further research is needed. In light of these findings, there is little evidence to support the use of antimicrobials in consumer products such as topical hand lotions and soaps. However, there is also little evidence to link the use of these agents in consumer products to the general problem of increased resistance to therapeutic antibiotics. Considering the available data and the critical nature of the antibiotic resistance problem, it may be prudent to avoid the use of antimicrobial agents in consumer products.

Ciba, the Swiss firm that makes triclosan, has announced intentions to remove it from a number of consumer products regulated by the U.S. Environmental Protection Agency, including clothing, even though the agency has given it a provisional clean bill of health. Ciba said it was responding to market pressures, not regulatory concerns, and that it will continue to use triclosan in soaps.