Lead exposure urban soil risk and ancient brain development clues

Two new scientific analyses, one of modern urban soil and another of ancient fossil teeth, underscore that lead has been a persistent hazard for humans for millennia and remains a present-day public health risk. Researchers studying soil across Chicago found widespread contamination that could put children at elevated risk of elevated blood lead levels, while an interdisciplinary team analyzing fossilized teeth concluded that episodic lead exposure affected hominids for at least two million years and may have influenced aspects of human brain development.

In Chicago, researchers led by Thorstenson analyzed 1,750 soil samples from the city's 77 community areas and applied the Environmental Protection Agency's Integrated Exposure Uptake Biokinetic model to estimate children's blood lead outcomes. More than half of the samples exceeded the EPA screening level of 200 parts per million, with localized hot spots surpassing 300 parts per million. Using the exposure model and accounting for household income, housing age and proximity to industrial land, the team estimated that roughly 27 percent of children across the city could be at risk of elevated blood lead levels, rising to about...