Facility Safety Management

Weekly E-Newsletter

July 24, 2007

Since You Can’t Molt, Limit Exposure to Heavy Metals

By  Michael D. Shaw

One of the oldest known classes of toxic air contaminants are the so-called heavy metals, especially lead, mercury, and cadmium, which have no recognized beneficial effect in metabolism.

People have spoken of lead poisoning for centuries, and “mad as a hatter” referred to the nerve damage inflicted on workers in that trade, who picked up mercury from dyes.

Unfortunately, for us humans, those nasty substances simply tend to build up in our systems, and at some level can have quite damaging effects. As such, we’ve been avoiding them long before specific regulations were even in place.

But what about animals that can’t avoid these exposures? It now appears that certain crustaceans not only molt to allow growth, they molt to get rid of toxics, as well.

Lauren Bergey and Judith Weis of Rutgers University looked at fiddler crabs from two very different environments. The clean crabs came from The Jacques Cousteau National Estuarine Research Reserve in southwestern New Jersey, and the dirty crabs came right from Linden, close to a sewage treatment plant and various industrial facilities.

The Linden crabs were able to get rid of 76% of their body’s lead in a single molt. Talk about your ultimate skin peel.