Plastic? Males, beware

We come into contact with it more than we realize — in cellphones, DVDs, CDs, eyeglasses, water bottles, baby bottles, consumer electronics, household appliance, airplanes, automobiles, most food and beverage cans, adhesives, car primers, dental sealants, flame retardants and a host of other consumer products. It is bisphenol A, a compound used to make plastic products. It has had a long love affair with modern industry and consumers but it has also been linked with many diseases and conditions like cancer and many neurological conditions. It has also been linked to many conditions wherein bodies of water contaminated with it produce fish with “mixed” sexual organs. In one study I came across in the journal

, bisphenol A was clearly shown to “feminize” tadpoles — it prompted hormones to make for females instead of males. Most recently, it has been shown to impair other skills that males value — “driving skills.”

Males, of most species, value their navigation and exploratory skills because their female counterparts prefer them over those who cannot find their way. In other words, those traits get the girl. That makes a lot of sense for females because it is not productive to partner with someone who always gets lost, although it does seem funny (at first, anyway). In a recent study published in The Proceedings of the National Academy of Sciences last July 11, 2011, scientists have shown that deer mouse whose mothers were fed diets contaminated with bisphenol A while they were pregnant until the litter was weaned (25 days after birth), had male litter that had severe problems with navigation and exploration skills. 

Having established how important navigation and exploration skills are to males, especially deer mice who have no cars or GPS or cannot read Google maps, this is a big “uh-oh” to the prospects of this set of deer mice. And indeed, the study showed that the female deer mice preferred the ones whose mothers well, ate no “plastic” diet and whose litter did not have their “driving skills” severely compromised. If the point of nature is to make sure life goes on through reproduction, having a partner who is lost drastically reduces the female chances of reproducing. Thus, it is the end of the road for these fellas.

Bisphenol A and other modern-day contaminants like pesticides have come to be known as “endocrine disruptors” or substances that mess with the way our hormones are produced or guided in terms of our development. That is why their effects are so widespread. These hormones ride in our circulatory system. The scientists who conducted the research did mention in their study that they did not just do this study because they were particularly fond of deer mice but because they had “broad implications for other species, including our own.” They figured that these could be good “biomarkers,” which means those biological parts/processes in organisms that signal the contamination of environmental contamination in our midst.  

I know that the study showed the lost navigation skills of male deer mice. But I cannot help but think what could account for the human male’s resistance to asking for directions if they get lost. I wonder if this navigation behavior phenomenon among human males is a modern day condition and if so, could plastic be something that they could blame it on? If that checks out, gentlemen, considering what plastics do to fish and tadpoles, you should not feel so bad. Not yet, anyway.  

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