Acid rain, artwork. Acid rain is caused by the release of sulphur dioxide and nitrogen oxides into the atmosphere. These chemicals are a byproduct of burning fossil fuels, especially coal. In the atmosphere they react with water to form acids. The acids may fall as dry depositions, such as particulates or gases, or wet depositions, such as rain or snow. The acid damages vegetation and soaks into soil where it leaches out nutrients, stunting plant growth, and toxic metals. Where the water from the soil runs off into lakes and rivers the toxic metals accumulate and acidity levels rise, poisoning aquatic life. The acid rain may also fall directly on these bodies of water, further raising their acidity levels.