The Environmental Protection Agency plans to test 256 Jefferson County residential properties amid concerns that lead in the Big River is contaminating soil.
The St. Louis Post-Dispatch reports that testing is expected to be completed by midsummer. Recent studies and samples indicated widespread lead contamination in the flood plain that extends from Leadwood in St. Francois County to the confluence with the Meramec River near Eureka.
The contamination is linked to long-gone lead mining operations that date to the early 1800s.
Lead contamination in children can interrupt normal brain development and has been linked to behavioral problems.