<P> Since lead has been used widely for centuries, the effects of exposure are worldwide . Environmental lead is ubiquitous, and everyone has some measurable blood lead level . Atmospheric lead pollution increased dramatically beginning in the 1950s as a result of the widespread use of leaded gasoline . Lead is one of the largest environmental medicine problems in terms of numbers of people exposed and the public health toll it takes . Lead exposure accounts for about 0.2% of all deaths and 0.6% of disability adjusted life years globally . </P> <P> Although regulation reducing lead in products has greatly reduced exposure in the developed world since the 1970s, lead is still allowed in products in many developing countries . In all countries that have banned leaded gasoline, average blood lead levels have fallen sharply . However, some developing countries still allow leaded gasoline, which is the primary source of lead exposure in most developing countries . Beyond exposure from gasoline, the frequent use of pesticides in developing countries adds a risk of lead exposure and subsequent poisoning . Poor children in developing countries are at especially high risk for lead poisoning . Of North American children, 7% have blood lead levels above 10 μg / dL, whereas among Central and South American children, the percentage is 33 to 34% . About one fifth of the world's disease burden from lead poisoning occurs in the Western Pacific, and another fifth is in Southeast Asia . </P> <P> In developed countries, people with low levels of education living in poorer areas are most at risk for elevated lead . In the US, the groups most at risk for lead exposure are the impoverished, city - dwellers, and immigrants . African - American children and those living in old housing have also been found to be at elevated risk for high blood lead levels in the US . Low - income people often live in old housing with lead paint, which may begin to peel, exposing residents to high levels of lead - containing dust . </P> <P> Risk factors for elevated lead exposure include alcohol consumption and smoking (possibly because of contamination of tobacco leaves with lead - containing pesticides). Adults with certain risk factors might be more susceptible to toxicity; these include calcium and iron deficiencies, old age, disease of organs targeted by lead (e.g. the brain, the kidneys), and possibly genetic susceptibility . Differences in vulnerability to lead - induced neurological damage between males and females have also been found, but some studies have found males to be at greater risk, while others have found females to be . </P>

When did we find out lead was poisonous