The story of acid rain from the 1970s is preserved in newspaper headlines, textbooks, and, it turns out, the soils of the northeastern United States. Forty years after humans first began tackling the problem, the impact of acid rain still lingers in New York, Vermont, New Hampshire, and Maine, according to a new study. But the research also shows the first signs of recovery.
At the height of the acid rain problem, sulfur dioxide from burning coal drifted into the atmosphere and lowered the pH of rainwater. When this acidic rain fell to the ground, it leached calcium from the soil, depriving plants of a key nutrient. Acid rain also dissolved aluminum-rich minerals, freeing the metal to further poison plants.
To combat the problem, the U.S. Congress imposed strict emission regulations on industry in 1970 through the Clean Air Act, which was strengthened in 1990. By 2003, sulfur dioxide raining down on the northeastern United States had decreased by as much as 40%. But were soils improving, too?
Read the rest of the article at Science magazine online.
A tip of the hat to the Environmental News Network for alerting us to this article.
