Lead has been listed as a pollutant of concern to EPA's Great Waters Program due to its persistence in the environment, potential to bioaccumulate, and toxicity to humans and the environment. The amount of lead in the blood can be measured to determine if exposure to lead has occurred. This method was commonly used to screen children for potential lead poisoning. Methods to measure lead in teeth or bones by X-ray fluorescence techniques are currently being developed. Lead also affects the nervous system.
Children are particularly sensitive to the neurotoxic effects of lead.
Other effects from chronic lead exposure in humans include effects on blood pressure and kidney function, and interference with vitamin D metabolism. Animal studies have reported effects similar to those found in humans, with effects on the blood, kidneys, and nervous, immune, and cardiovascular systems noted. EPA has not established an RfC or an RfD for lead. However, the lowest blood lead levels at which this occurs has not been established. These effects may be seen from acute as well as chronic exposures.