The largest sources of mercury pollution are power plants which emit around 50 tons of mercury pollution per year. Among other sources of mercury pollution are metal smelting, chlorine chemical plants, cement plants, etc.
Coal-fired power plants are particularly dangerous because coal is naturally contaminated with mercury, so when burned in power plants to generate electricity it also releases mercury into the air.
Mercury belongs to persistent pollutants because it doesn't break down as some other pollutants do, although it has to be said that its danger decreases significantly over time (as mercury eventually becomes covered by successive layers of sediment after being settled into the beds of rivers, lakes and oceans).
The scientists have in 2006 calculated that three times more mercury now falls out of the sky than before the industrial revolution of more than 200 years ago.
Texas is considered to be the US state most exposed to mercury pollution. This is because Texas has the largest number of dirty coal-fired plants in the country.
In United States coal-fired plants account for approximately 40% of all mercury emissions.
Gold mining is also a significant source of mercury pollution in the world. According to the US Environmental Protection Agency (EPA) artisanal and small-scale gold mining releases approximately 400 metric tons of airborne elemental mercury each year.
Mercury pollution will likely continue to grow in years to come because power hungry economies of China and India rely heavily on coal power plants to drive their economies forward which will lead to an increased coal-burning.
Mercury pollution could become a serious issue in Arctic area because Arctic ice is rapidly melting up, releasing trapped mercury back into the oceans and into the food chain. For instance, the mercury levels in Arctic ringed seals and beluga whales have increased fourfold over the last 25 years.
Mercury is very dangerous neurotoxin that is able to pass through the placenta and poison fetal brain development. Exposure to mercury in the early stages of life can lead to permanent neurological and brain damage.
It is estimated that more than 6 percent of U.S. women of childbearing age have mercury levels high enough to put their developing children at increased risk for developmental problems.
The best solution to tackle mercury pollution issue is to establish much stricter mercury pollution standards for coal-fired plants.