“The district, located in San Joaquin Valley, receives an estimated five inches of rain per year, according to the Columbia University blog State of the Planet. Such little rainfall would not be adequate to transport noxious levels of selenium, boron, and chromium, which are found naturally in the soil.
However, the agricultural runoff caused from pumping more than one million acre-feet of water annually for irrigation carries high levels of the chemicals into the San Joaquin River and its secondary waterways.
In limited doses, the three chemicals are beneficial. For example, boron aids in construction of sturdy bones and muscles. The highest level of boron human adults can ingest without negative effects is 20 mg, according to Medline Plus. Higher dosages can cause impotency headaches, tremors, and diarrhea.
High levels of the chemicals have had an adverse effect on animals as well. During the 1970s, the U.S. Fish and Wildlife Service began receiving reports of deceased and malformed birds and fish. In 1983, birds at the Kesterson Wildlife Refuge perished in droves due to selenium poisoning, according to the Napa Valley Register.”
Read more: Lake Scientist











Recent Comments