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| December 17, 2014 Post 54 |
| More on Plastics |
This winter I will periodically post bits and pieces of a work in progress tentatively scheduled for publication in 2015. The book is based in part on Sara B's 2013 cruise around the lake. Part Two to be posted soon will discuss solutions to the plastic problem.
When I had lunch with Dr. Mason I looked at my glass of ice water and asked if there were microbeads in it. She assured me that the municipal water treatment plants did a good job of removing solids. But they don't remove all the chemicals that now enhance our lake water.
Endocrine disrupters are chemicals that interfere with the hormones that regulate vertebrate development in the egg or womb and subsequent growth and metabolism after birth. The differentiation of tissues in the womb that determines an individual's destiny is an incredibly intricate and sensitive process that is still not fully understood. Hormones act in concentrations of parts per trillion or even less. This system is based on organic molecules much like those found in synthetic compounds and can be derailed or jammed up by those molecules.
These man made hormone mimics only became widely recognized about 20 years ago after a ground breaking study of transgenerational health impacts of chemicals in Great Lakes animals by Dr. Theo Colborn. Her book "Our Stolen Future" published in 1996 helped open a new area of research on chemicals in the environment. Colborn researched many aspects of the sabotage of our endocrine systems including effects of oil and gas well production on nearby populations. She wrote shortly before her own passing in December 2014 “Endocrine disrupters) dehumanize the human race by stealing the ability to love, socialize, enjoy each other, and sit down to converse with others in order to solve problems.”
When I first went to a scientific conference on toxins in the lake back around 1980, lab equipment able to detect these substances at parts per trillion concentrations was just becoming widely available to researchers. We now know plastics are not inert in the environment.
Long term low dose exposure studies are tricky to do. One problem at least in studying human health effects is that there is no large population of humans on earth that hasn't been exposed to some amount of plastic to serve as an experimental control group. The best a group of experts convened by the FDA could come up with for health effects was; "BPA at concentrations found in the human body is associated with organizational changes in the prostate, breast, testis, mammary glands, body size, brain structure and chemistry, and behavior of laboratory animals.”
But there have been studies that showed adverse health effects of plastic on animals. BPA was banned by the FDA as a component in plastic baby bottles because of possible interference with the growth and development of infant humans a few years ago.It is still used to line cans used in the food processing business. And of course, hundreds of other synthetic chemicals are also capable of scrambling the endocrine system's intricate workings as it directs embryonic development.
Plastic bits leach other substances besides BPA and also attract and concentrate toxins and heavy metals that are present in the water. These adsorb onto the surface of the particles. In one lab study minnows that were fed a diet that included a 10% mix of plastic bits collected from San Diego Bay showed liver abnormalities and damage after two months. One fish developed a tumor that took over 25% of its liver. Another group of fish that were fed “clean” plastic bits also showed abnormalities but to a statistically significant lesser extent. The researchers suspect that both chemicals from the plastic and other compounds associated with it including PAH's and fire retardants caused the damage.
Next we'll consider how to reduce the amount of chemical pollution in our Great Lake