When pollution is caused by nutrients and fertilizers, this is called nutrient pollution, and it leads to an overproduction of algae and other aquatic plants. This overabundance of plants and algae causes problems, because they cover the water surface and prevent sunlight from reaching the plants underwater.
Reverse T3 is actually an antithyroid -- T3 is the active thyroid that goes to the cells and stimulates energy and metabolism. Reverse T3 is a mirror image -- it actually goes to the receptors, sticks there, and nothing happens. So it blocks the thyroid effect. Reverse T3 is kind of a hibernation hormone, in times of stress and chronic illness, it lowers your metabolism.
Elevated reverse T 3 (RT 3) together with low-normal TSH and low-normal T 3, T 4 values, which is regarded as indicative for euthyroid sick syndrome, may also have to be investigated for chronic subacute thyroiditis (SAT) with output of subpotent hormones.