Lead paint poisoning is a medical condition caused by increased levels of the metal lead in the blood, usually found in traces of paint. Lead may cause irreversible neurological damage as well as renal disease, cardiovascular effects, and reproductive toxicity.
Humans have been mining and using this heavy metal for thousands of years, poisoning themselves in the process due to accumulation and exposure. These dangers have long been known, though the modern understanding of their full extent and the small amount of lead necessary to produce them is relatively recent; blood lead levels once considered safe are now considered hazardous, with no known threshold. Reducing these hazards requires both individual actions and public policy regulations.