If trapped, they can cause excessive growth of fibrous lung tissue, which leads to permanent injury. Children, the elderly, and people suffering from heart or lung disease are especially at risk. Sometimes factories release heated water into rivers. This kills creatures that are not used to the warmer environment. Air pollution can cause diseases and harm crops.
Insects are often the first creatures to be affected by pollution.
They are usually exposed to pesticides and chemicals. Birds then eat these insects, get poisoned and die. Small animals are harmed by pesticides. Field mice eat seeds that have been exposed to pesticides. Then, larger animals such as foxes and hawks consume the smaller creatures and eventually die too, due to accumulation of so much poison in their bodies.