NCBUY: Since the volcano began erupting in early October, it has been pumping out 50 to 250 tons a day of sulfur dioxide, the lung-stinging gas that causes acid rain and contributes to haze. At peak, that’s more than double the amount from all the state’s industries combined.

Normally, the state’s No. 1 polluter is a coal-fired power plant owned by the Canadian firm TransAlta. The plant churned out 200 tons a day of sulfur dioxide until regulators demanded $250 million worth of renovations, bringing the level down to 27 tons a day.

Worldwide, sulfur dioxide emissions from volcanoes add up to about 15 million tons a year, compared to the 200 million tons produced by power plants and other human activities.