Smelting Remains a Public Health Risk Nearly a Century Later: A Case Study in Pueblo, Colorado, USA

Pueblo, Colorado has a long history of smelting activities, and recent studies raised concerns about lead exposure. This study tested 240 children in Pueblo for blood lead levels (BLLs) and found a significant association between distance from old smelters and children BLLs. Around 7.5% of Pueblo children had BLLs above the Centers for Disease Control and Prevention reference level of 5 µg/dL for elevated BLL, and 18.3% had BLLs between 3.3–4.9 µg/dL. Out of the 36 children who lived near former smelters, 13.9% had BLLs above 5 µg/dL vs. 6.37% for children living away from old smelters. The proportion of Pueblo children with elevated BLL was nearly three times the 2007–2010 United States national average (7.5% vs. 2.6%), and this was higher in the immediate vicinity of old smelters (13.9% vs. 2.6%). Genetic polymorphisms for ALAD-1 or ALAD-2 alleles, which play a role in susceptibility to lead toxicity, were not associated with children BBLs. Around 38.5% of houses sampled near the smelters had topsoil lead levels higher than the Environmental Protection Agency’s benchmark of 400 mg/kg. Our study resulted in the addition of areas of Pueblo to the EPA Superfund National Priorities List in December 2014, and cleanup is currently underway to minimize the public health risks.