The breathe more rapidly and inhale more pollutants per pound of body weight. They spend more time engaged in vigorous outdoor activities than adults. Children are uniquely susceptible to environmental hazards because They have a higher metabolic rate than adults, which affects the absorption and metabolism of toxicants. They have a different breathing zone than adults, closer to the floor, where dust, dirt and toxic heavy metals such as lead are deposited. Pesticides an herbicides applied to lawns used as play areas may present a risk.
Seniors are at particular risk from airborne pollutants because of advancing age.
There is a progressive decrease in the functions of several organs and body systems, including the skin, heart, lungs, kidneys, and immune system. The elderly have had a longer period of time to experience the cumulative effects of some environmental pollutants. The body's barriers to the entrance of harmful substances change with advancing age. Changes in the skin may permit increased absorption and decreased clearance of foreign substances in the lung. Declines in blood flow to both liver and kidney, in part due to steady annual decline in cardiac output after age 30, may result in a decreased ability to detoxify and eliminate toxic substances.