The Minnesota Pollution Control Agency has released on Tuesday, a study that confirms that contamination of the Minnesota lakes and rivers is still growing and that new drugs and substances are appearing in the test samples collected from the waters. Furthermore, many remote lakes and rivers are now being polluted.
Since 2008, 11 lakes and 4 rivers that are in Minnesota have been sampled every year to evaluate how polluted by chemicals the waters are and what are the specific substances found in the water.
In 2008, the first year in which samples were collected, scientists discovered that, in the waters of Minnesota there were 125 dangerous substances. Now, after 7 years of sampling, scientists have a good feeling about what types of substances they are going to find on the surface of the waters, but that doesn`t mean that there aren`t any surprises.
Most of the substances commonly found are pharmaceutical drugs, disinfectants, antibiotics, hormones and DEET. DEET is an active insect repellant and it found its way into more that 90% of the samples collected. Some of the new drugs that scientists found in the waters this year, was metformin which is a substance used to treat diabetes and iopamidol which is a contrast substance used in X-rays.
Unlike other drugs and substances, iopamidol is not easily accessible to the population, therefore it is highly unlikely that people threw it in the water or disposed of it in some inappropriate way and this is how iopamidol ended up at the surface of rivers, so there is a lot of interest in finding out how this contrast substance made its way in to the samples.
Some scientist suggest that it might be carried through air particles from local medical facilities where contrast X-rays are performed, but this theory is not yet confirmed.
Researchers are worried about the consequences that exposure to such substances, might have on the ecosystem of those waters and they are still baffled regarding how some of these substances made their way to some remote areas. The usual place in which the residual substances are found is in the wastewaters downstream from plants, but seeing as they are making their way to more secluded waters, scientists tried to come up with explanations for why this happens.
Their suspicion is that the substances end up in those remote waters, through rain and snow, but they won`t be able to confirm this theory until later this summer when they will collect new samples.
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