Mercury is an incredibly stubborn toxin. Once it is emitted from the smokestacks of coal-fired power plants, among other sources, the gas can drift through the atmosphere for up to a year before settling into oceans and lakes. It can then accumulate in fish as toxic methylmercury, and eventually harm the people who consume the fish.
What’s more, mercury that was previously emitted can actually re-enter the atmosphere through evaporation. These “legacy emissions” can drift and be deposited elsewhere, setting off a cycle in which a growing pool of toxic mercury can circulate and contaminate the environment for decades or even centuries.
A new MIT study finds that the longer countries wait to reduce mercury emissions, the more legacy emissions will accumulate in the environment, and the less effective any emissions-reducing policies will be when they are eventually implemented.
In a paper published today in the journal Environmental Science and Technology, researchers have found that, for every five years that countries delay in cutting mercury emissions, the impact of any policy measures will be reduced by 14 percent on average. In other words, for every five years that countries wait to reduce mercury emissions, they will have to implement policies