The US Environmental Protection Agency (EPA) has taken enforcement action against the Asarco copper smelter in Hayden, Arizona, following complaints about toxic pollution.
The plant is alleged to have releases illegal amounts of lead, arsenic and eight other dangerous toxins for the last six years.
The EPA reported the findings to NPR and The Center for Public Integrity, which investigated air pollution and regulation in Hayden as part of the Poisoned Places series.
