The Environmental Protection Agency tightened the regulatory limit on airborne lead for the first time in 30 years Thursday, lowering the legal maximum to a tenth of what it was on the grounds that it poses a more serious threat to children than officials had realized.
The new rule came in response to more than 6,000 studies since 1990 studies that have linked low levels of lead to damage to children's nervous systems that can lead to IQ loss and permanent learning disabilities, EPA administrator Stephen Johnson said. In adults, it can cause increased blood pressure and decreased kidney function.
The main way humans are exposed to lead is from ingesting tainted dirt or dust.
The EPA last set a standard for lead at 1.5 micrograms per cubic meter of air in 1978. The new standard is 0.15 micrograms per cubic meter.
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Emissions of lead into the air dropped by 97 percent since 1978, mainly because the government banned it in gasoline, Johnson said. But today more than 16,000 facilities such as cement factories and steel plants emit an estimated 1,300 tons of lead into the air annually.
“The new stronger standards address these remaining emissions and offer a shield to protect the health of our nation's children,” Johnson said.