Contrary to some claims, unleaded gasoline need not contain higher amounts of benzene a known carcinogen than leaded gas, if fuel specifications are properly set. The exposure to benzene from gasoline mainly comes from evaporation of gasoline fumes, which occur with or without catalytic converters. The use of unleaded gasoline without catalytic converters therefore need not increase health risks. Benzene evaporation should be controlled in all cases. Health Risks Lead is a heavy metal that has long been known as a neurotoxin, a substance that adversely affects the nervous system even at low levels of exposure.
Recent studies indicate that no safe level of lead exists.
Children are especially susceptible to lead because their digestive systems have fast absorption rates for heavy metals. Because lead particles settle on surfaces, children ingest contaminated dust and soil simply by putting their fingers in their mouths or by chewing on contaminated toys. Poor children are most at risk because malnourishment or physical stress intensifies disabilities caused by lead absorption. For adults, even low levels of lead absorption occurring usually through inhalation causes hypertension, blood pressure, and heart disease. Jakarta has 130,000 cases of hypertension each year due to lead.