New research from Harvard University indicates that the amount of mercury in the environment is much higher than previously thought. Prior estimates put mercury levels around 720,000 metric tons; the new study suggests it's actually 2 ½ times that number.

 

Before we understood mercury was a dangerous neurotoxin, it was used in an array of consumer products, from thermometers to latex paint. Silver mining alone, which peaked in the 1890s, resulted in some 100,000 metric tons of mercury pollution. We are still experiencing the ill effects.

 

Once released, mercury endures in the environment. The Harvard study found that nearly 60 percent of the mercury in our soil, air and water dates back hundreds to thousands of years.

 

Mercury is most harmful when microbes convert it into a compound called methylmercury. In this form, it can accumulate in the fat of fish. Consuming too much mercury-laden fish can cause neurological and cardiovascular damage.

 

Today, most new mercury emissions are from coal-fired power plants and artisanal gold mining. Vinyl chloride, a key ingredient in vinyl and plastics, also uses mercury in its production. The Minamata Convention, created in 2013, requires participating nations to phase out mercury emissions. But targets don't account for mercury's long legacy effects.

 

The study's authors urge the adoption of tighter regulations to avoid future human health risks. To date, the total cost of methylmercury exposure in the U.S. and Europe has been estimated to be more than $15 billion.

 

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