Amid unusually heated rhetoric, the U.S. Senate on June 20 defeated efforts to nullify the Mercury and Air Toxics Standards, known as MATS. Proposed by the Environmental Protection Agency, MATS establishes national limits for mercury and other toxic substances released into the air by power plants. Limits would become effective in 2016. The resolution to nullify MATS was defeated 53 to 46. Five Democrats voted for nullification. Five Republicans, including Tennessee’s Lamar Alexander, voted to uphold the measure.
From a medical standpoint, the debate boils down to jobs versus the health of children. An overlooked question: How many jobs are worth the health of one child?
Mercury is an unforgiving, environmental toxin. One-third of the mercury in our environment stems from natural sources — volcanic eruptions and natural erosion of rocky formations. One-third arises from coal-fired power plants. Other important sources include cement kilns, factories that manufacture bleach and pool chemicals, gold mining and trash incinerators.
Once mercury is dispersed into the atmosphere, it may circulate for years before eventually settling in fresh and salt waters. Elemental mercury is toxic whether inhaled or ingested, exposing brain and kidneys to injury. Much more toxic is methyl-mercury (MeM). Micro-organisms in the waters slowly convert insoluble, elemental mercury to MeM, which is rapidly absorbed by all organisms. Through a process of “bio-magnification” MeM is progressively concentrated as smaller life forms are eaten by larger and larger fish and aquatic mammals.
Concentration of MeM in freshwater fish has led to health advisories for consumption of catches in many locales, including some streams in Tennessee. Certain species of seafood, including swordfish, ahi tuna and mackerel concentrate MeM, which poses health risks to fetuses and young children. No method of preparation or cooking can remove MeM from fish.