Federal and state officials are cracking down on a smelter in Chicago’s Pilsen neighborhood after tracing high levels of toxic lead in the air outside an elementary school less than two blocks away.

In a legal complaint filed today, the U.S. Environmental Protection Agency accused H. Kramer and Co. of emitting illegal amounts of brain-damaging pollution detected between October and January at Perez Elementary School, 1241 W. 19th St.

At the same time, the Illinois EPA asked Attorney General Lisa Madigan to take enforcement action against H. Kramer, one of the biggest sources of lead in the Chicago area.

The Tribune first reported early this month that average lead levels in the air at Perez were at or above federal limits during three three-month periods in 2010. Lead pollution exceeded health standards during a fifth of the days monitored last year and, on one day in December, spiked more than 10 times higher that the federal limit.

Alarmed by the results, officials put another lead monitor on the roof of nearby Juarez Community Academy last month in an attempt to pinpoint the culprits. Perez is just north of the smelter, while Juarez is less than two blocks west.

Monitoring data show that between October and January the highest concentrations of lead came when winds generally blew from the smelter toward the elementary school, according to the U.S. EPA complaint.

More stringent limits on airborne lead emissions are part of a decades-long campaign to protect kids from lead poisoning. A growing number of studies show that even tiny amounts of the metal ingested or inhaled can damage the brains of young children and trigger learning disabilities, aggression and criminal behavior later in life. Most scientists say there is no safe level of exposure.

Illinois expanded its statewide network of lead monitors to Perez and five other locations after a 2008 Tribune story revealed how President George W. Bush's administration had exempted dozens of polluters from scrutiny.

Faced with a court order, the U.S. EPA that year lowered the maximum amount of lead allowed in the air to 0.15 micrograms per cubic meter, a standard that is 10 times more stringent than the former limit. Violations are determined by three-month rolling averages.

To enforce the rule, federal officials had planned to require lead monitors near polluters emitting at least a half-ton of the metal a year. But in response to industry lobbying, the Bush White House set the threshold at a ton of lead or more, slashing the number of factories monitored nationwide by 60 percent.

Some states decided to follow the EPA's original advice. In Illinois, that meant putting a new monitor in Pilsen, where H. Kramer churned out as much as 1,450 pounds of lead (or 0.725 tons) a year as recently as 2007.

The smelter has since reduced its emissions in response to pressure from community leaders and environmental regulators. But federal and state officials question whether the company’s efforts were effective enough to meet tougher health standards.

Todd Wiener, an attorney for H. Kramer, said the company will not comment on the complaint until it receives more information from the environmental agencies.

After inspectors in late February discovered smoke hovering inside the smelter building, the U.S. EPA cited H. Kramer for violating the federal Clean Air Act. Now the agency is going after the smelter specifically for violating the federal lead standard.

The complaint is related to a larger investigation in Pilsen, where federal and state officials are responding to “environmental justice” complaints that the predominantly Latino, low-income neighborhood is disproportionately affected by air pollution.

After gathering more than a year of results from the lead monitor in Pilsen, officials took a closer look at dozens of polluters within a three-mile radius of the elementary school, including the nearby Fisk coal-fired power plant. Fisk is another big industrial source of lead in Pilsen, but it is southeast of Perez and appears to be an unlikely source of the lead detected outside the school.

mhawthorne@tribune.com