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Lead has been mined and smelted for more than two thousand years, and it has been recognized as toxic for nearly as long. It can affect every organ of the body, but in particular, it is a neurotoxin associated with cognitive problems.
Until the 1970s, lead in house paint was a leading source of lead poisoning; in fact, the disease was once also known as painter’s colic. The greatest concern was its effect on children. In addition to physical symptoms, children exposed to lead can have lower I.Q.s and behavioral problems.
In the U.S., Legislation banned lead in house paint sold after 1978. A recent study showed that lead levels in American children dropped dramatically after this law took effect, with children’s I.Q.s raised two to five points.
But because many children live in houses built before the ban took effect, some are still susceptible to lead poisoning. The Centers for Disease Control has numerous programs to help identify and remediate lead problems.
By the time lead was introduced as an additive to gasoline in 1922, it had already been recognized as a public health menace. But, it wasn’t until 1990 that an amendment to the Clean Air Act phased out the use of lead in gasoline sold after 1995.
In the U.S. and all other countries that have removed lead from gasoline, blood levels of lead have dropped. Some countries still permit leaded gasoline, and imported children’s toys are frequently recalled for lead problems.
But in the U.S., at least, this is a good-news environmental story. We recognized an environmental hazard and had the public and political will to legislate a change to eliminate it.
Photo, taken on March 26, 2006, courtesy of Wayne Marshall via Flickr.