Acid rain contaminates water and soil, killing microbes, insects, fish, and other aquatic wildlife and vegetation. It corrodes stone and metal, and it damages automotive paint. Although contact with acid rain is not directly harmful to people, it can indirectly cause health problems.
Alkaline soil reduces the effects of acid rain. If it falls on other types of soil, it turns the soil acidic and kills soil-dwelling microbes and insects. Acid rain and snow in lakes and rivers can lower the pH level of the water so that it becomes too acidic to sustain aquatic life. Although it does not directly kill vegetation, acid rain leaches nutrients out of the soil, leaving behind elements such as aluminum, which turns soil toxic. Soil depletion leads to stunted plant growth, and plants may eventually die because the soil lacks the nutrients they need to grow and fight disease.
Trees at high altitudes are especially vulnerable, because they receive more snow and rain, and acid clouds and fog often surround them. Acid rain also accelerates the natural weathering of stone, corrodes metal and etches marks into vehicle paint. Although acid rain cannot burn a person's skin or eyes, it can cause respiratory and heart problems by depositing sulfate and nitrate particulates at ground level. This causes smog that weakens and irritates the respiratory system.