The amount of mercury released in the atmosphere is much more than previously estimated. According to a study, the quantity of mercury released in the atmosphere through consumer products and industrial processes from 1850 to 2010 is more than double of what previous estimates said.
The study, published online in the journal Environmental Science & Technology on August 15, says that tighter regulations in the last four decades have helped bring emission levels down. It also says that the commercial use of mercury “peaked in 1970 and has declined sharply since”.
According to a news report published by the American Association for the Advancement of Science, researchers compiled historical information from scientific literature and government reports for their estimates. While earlier studies focused on mercury emissions, this study has estimated the amount of mercury used in consumer products and also tracks emissions due waste disposal and pollution, the news report says.
The study estimates that 720,000 tonnes of mercury has been extracted from the ground since 1850. It also says that 57 per cent of mercury released since 1850 continues to circulate in the environment.
Mercury is a neurotoxin used in several products such as thermostats. It is most harmful when microbes convert it to a compound called methylmercury. Methylmercury enters the food web, getting collected particularly in fish.