The 8th graders have found a problem to research. The impact of water on land often changes the landscape. In this way, the land is lost in some places and gained in others. Sediments and Toxic Chemicals Sediment particles can carry chemicals on their surface. These chemicals can be nutrients, organic materials, or metals.
Scientists are particularly worried about the toxic materials that are trapped by sediments.
A toxin is a substance that can cause cancer or other harmful health effects. These chemicals can accumulate to dangerous levels and harm fish and wildlife. Bottom dwelling animals can become contaminated or killed when exposed to chemicals such as dioxin and heavy metals like arsenic and lead. Cloudy Water, Choking Sediments Sediments also harm aquatic life by clouding the water and covering the bottom. Sediments suspended in the water prevent light from reaching the plants.