The United States Congress has also taken action to clean up acid rain. It established the Acid Rain Program to set limits on sulfur and nitrogen emissions of electric plants and automobiles. By the year 2010,the limits will have reduced sulfur pollution released into the air by 10 milliontons. The United States and Canada also are eorking together to reduce levels of air pollution. In addition,European contries have signed agreements to significantly reduce levels of sulfur dioxide in the coming years.