Polar Bears eat mostly seals. Seals eat mostly fish. Fish, especially cold water fish, are high in Vitamin A, a consequence of fish eating mostly algae (microalgae in particular) or plankton in their diets. Or the fish have eaten other fish who eat the microalgae.
By the time an apex predator like a Polar Bear eats the seals, truly vast amounts of Vitamin A accumulate in the bear. Enough to make the Polar Bear’s liver poison to humans; there’s enough Vitamin A in a Polar Bear’s liver that eating even a small amount it will kill you, as early polar explorers discovered to their sorrow.
The process is called bioaccumulation. A biologic process or series of processes that cause a substance to selectively accumulate in animals, usually apex or near-apex predators.
Why should you care? Because humans, heaven help our planet, are also an apex predator.
The traces of mercury that contaminate coal are vented into the atmosphere. They land on the ocean – the planet is, after all, mostly ocean – and get ingested by plankton. Plankton get eaten by fish, which get eaten by bigger fish, which, in turn, get eaten by humans. Bioaccumulation happens to us. We are what we eat, and that can sometimes be really bad news.
Some toxins the human body can excrete, over varying amounts of time. Others, especially heavy metals, remain in the human body, accumulating over time until they disrupt one bodily system or another. Some toxins disrupt the hormones in our body, especially by-products from plastics. They may or may not remain in the body long but their effects can be permanent. Toxins and heavy metals are especially dangerous for children, where they can induce birth defects, developmental disabilities and subtler problems.
There are some 82,000 different chemicals registered with the Enviornmental Protection Agency. The EPA has performed testing and research on just 200 of them. That’s two-tenths of one percent. The other 99.8%? We have no evidence of their impact on humans or the environment in general. Since 1978, the EPA has been successful in restricting only five chemicals (PCBs, chlorofluorocarbons, dioxin, asbestos, and hexavalent chromium), and the ban on asbestos was overturned in 1991.
Some of those untested chemicals have been dumped into the environment in unimaginable quantities. More than 10,000 gallons of 4-methylcyclohexane methanol, abbreviated as MCHM, used to “clean” coal, were spilled into the Elk River, a tributary of the Ohio River and the drinking water source for half of West Virginia. How toxic is it? We don’t know? Does it cause long term harm to people or the environment? We don’t know. Does it bioaccumulate? We don’t know. If yo’re cynical enough, you could say we are running an experiment to find out.
We have transformed our planet into an uncontrolled science experiment. We dump these substances into the test tube that is our home with no idea how they interact with each other, with the environment or with ourselves. We don’t even know which ones bioaccumulate and which ones don’t.
We eat, drink, breathe and touch this stuff every day.
WC’s sister-in-law, a sweet and wonderful woman, was diagnosed recently with metastatized lung cancer. She has never smoked; the disease is almost certainly a consequence of stuff we have put in the air. One of those 82,000 chemicals altered the cellular structure of her lung tissue, with this result.
What have we done? To ourselves, to our loved ones, to our planet?