An estimated 94 percent of lead in the atmosphere results from automobile and industrial emissions.
Atmospheric lead falls back to the earth in rain and affects soil, plants, and water sources.
Lead in water is invisible, colorless, and odorless. The daily intake of lead differs greatly in individuals due to eating habits, location, and water consumption as well as size and age of the individual. Lead does not have any beneficial effect on humans or animals. Rather, it reacts with enzymes within the body to slow or stop essential physiological reactions. When the concentration is so high storage in the bone is saturated, blood lead levels begin to affect nerve tissue.