Where mercury comes from

Mercury from coal combustion, volcanoes and other sources goes into the air and then falls back to Earth in rain and snow. In the U.S., about half of all mercury emissions come from coal-fired power plants. In Minnesota, taconite plants are also a large source of mercury emissions. Both industries are moving to cut their mercury emissions.

Mercury that falls back to Earth can come from local and regional sources, but also from as far away as China. That mercury can become toxic — called methylation — as it moves through the ecosystem, and it can build up in small creatures, fish and animals that eat fish, including loons, eagles and people.

For more than a decade, Minnesota has moved to remove mercury from air emissions, consumer products and even crematoriums and dental offices. And the federal government earlier this year moved to cut mercury emissions from power plants nationwide.

Tags: lake superior, news, health, environment