Lead Toxicity: Low-Level Environmental Exposure

"Introduction Lead poisoning is as ancient as Roman history, and indeed lead has been used extensively by the Romans and described by the Romans. The purpose of the manuscript is not to discuss classic lead toxicity and lead poisoning effects, but to address the concept of low-level environmental lead toxicity and poisoning. Low-Level Environmental Exposure In developed countries lead poisoning is not prevalent; however, in developing countries lead poisoning is extremely common, to such an extent that world-wide lead toxicity and lead poisoning remain the most common of occupational poisoning. The most common occupational and environmental exposures to lead are encountered in the manufacturing of lead batteries, paints and colors; lead compounds; rubber products and glass; grinding, dicing and cutting by power tools, products containing lead; sanding down from the application of lead paints and glazes; inhalation of lead oxide fumes in the demolition of old industrial buildings and cutting lead pipes with gas powered burning torches; firearm instructors; and law enforcement agents in the process of firearm instruction. The most common environmental nonindustrial exposure to lead is via the drinking water and in communities residing around incinerators, toxic dumps, and manufacturing industries utilizing lead and releasing lead into the environment. Organic lead compounds have been added to petrol as anti knock agents for over half a century, and exposure may result from handling of these compounds in refineries or during cleaning out of tanks which contained leaded petrol. In the last 10 years, studies by the Environmental Protection Agency, as well as other international regulatory agencies, have shown that chronic low-level exposure to lead is associated with societal problems, such as brain dysfunction in children exposed to lead in drinking water, neurobehavioral changes in adults, hypertension and chronic kidney disease. As a result, the Environmental Protection Agency has moved to reduce the lead concentration in drinking water to very low levels. This notion of low level toxicological exposure to lead is changing the presenting picture of lead toxicity. While in the past the classic presentation would be the patient who has been exposed to high levels of lead and developed abdominal pain, anemia and neurological changes, the picture now becomes more subtle, as a result of prolonged low-level exposure which affects mainly the central nervous system and causes neurobehavioral changes. Also, the issue of prolonged lead exposure and hypertension has recently been recognized as a societal problem and a cause for hypertension and kidney disease. "