Water is one of the most valuable resources on Earth. Rainwater fills reservoirs that supply drinking water, provide a habitat for fish to live, and nourishes the soil with water necessary for vegetation. Rain water, however, can also have a negative effect on the Earth when it causes erosion or when it has a high pH.
Acid rain affects the overall pH level of a body of water. This can alter the ecosystem living in the water: acidic waters can kill individual fish and decrease the biodiversity in the waters. It can also kill plants that are sensitive to high pH levels and eliminate food sources. The increased presence of nitrogen in acid rain, according to the Environmental Protection Agency, can also lead to an increase in toxic algae, which can effect the safety of shellfish consumed by humans.
A study by the Medicine, Nursing and Health Sciences Department at Monash University found that drinking untreated rainwater does not pose an increased risk of illness. The study followed two groups, those that drank treated water and those that drank untreated rain water. According to the study, drinking rainwater does not pose health risks and could pose as a solution if water became scarce. It could also decrease the need for people to drink bottled water, which has led to waste that overruns landfills.
When soil moves from one location to another, it is referred to as erosion. The impact of rain water striking the surface can cause soil erosion. Erosion is a concern for farmers as their valuable, nutrient rich top soil can be washed away from rain water. It can also weaken structures such as bridges or wash out roads. Vegetation can decrease the amount of soil that is eroded during a rain.