Lead is a naturally occurring metal. Lead usually combines with other chemicals to form lead compounds. Lead was once used in many products like paint, ceramics, caulk, and gasoline, but concerns about its health effects have led to greatly reduced usage. However, it may still be present in some batteries, ammunition, and some metal products. US EPA banned the use of lead in automotive gasoline additives in 1996, but lead is still in some aviation fuel.
Environmental Fate and Transport
Lead does not break down in the environment. Lead particles emitted into the air can travel a long way before landing. Lead on the ground can remain within the soil indefinitely. The extent to which lead gets into groundwater depends on what form (compound) the lead is in and the soil type.
Exposure to lead can occur through eating food or drinking water that contains lead. Water from pipes soldered with lead can result in lead exposure. Exposure can occur from chips or dust from lead-based paint that is breaking down, or from working, playing, or otherwise spending time in areas where the soil contains lead. Exposures can also occur at jobs or while engaging in certain hobbies (for example, stained glass) where lead is used. Some healthcare products from other countries, alternative treatments, or folk remedies may contain lead.
Lead can harm most of the systems and organs in your body, but especially the nervous system. Long term exposure effects include learning, memory, and attention problems, as well as weakness in fingers, wrists, or ankles. Other possible effects include anemia, kidney damage, blood pressure increases, brain damage, or death. Lead exposure can cause premature births or miscarriages and can lead to reproductive organ damage in men.
Fetuses and children are especially vulnerable to lead poisoning. Possible effects on children include impaired mental development and growth. Children who ingest lots of lead can develop anemia, stomachache, weakness, and brain damage. Some of these effects may persist into adulthood.
The preceding paragraphs are summarized from the ToxFAQs™ for Lead published by the Agency for Toxic Substances and Disease Registry.
U.S. EPA's Integrated Risk Information System states that lead is a probable human carcinogen.
The National Institutes of Health has determined that lead and lead compounds are reasonably anticipated to be human carcinogens.
The International Agency for Research on Cancer has determined that "Inorganic lead compounds are probably carcinogenic to humans", and that "Organic lead compounds are not classifiable as to their carcinogenicity to humans" (IARC, page 378).