Researchers in a recent study made a surprising discovery: Approximately 129,000 children under the age of six in Chicago, accounting for 68% of children in this age group, are exposed to lead-contaminated water.
Using machine learning, a technique of artificial intelligence, researchers at the Johns Hopkins Bloomberg School of Public Health estimated the likely lead content in tap water in households across Chicago. The analysis was based on an established dataset of results from 38,385 tap water tests conducted between 2016 and 2023 by those who were registered for a free, self-administered lead testing service.
„The threshold used by the researchers was the lowest detectable lead level in the water tests, one part per billion – roughly the equivalent of half a teaspoon of water in an Olympic swimming pool. More than two-thirds – 69% – of those tests exceeded this value. The machine learning model predicted that lead-contaminated water is expected in 75% of the city’s neighborhoods, affecting 68% of Chicago children under the age of 6,“ the press release stated.
Currently, the „action level“ for lead in drinking water set by the Environmental Protection Agency is 15 parts per billion (ppb), triggering additional measures by municipalities. The analysis found that 9% of the tests exceeded this threshold.
Furthermore, the study identified differences in exposure levels and testing rates among different racial groups, highlighting racial disparities related to lead exposure.
Lead is toxic, especially for children, and there is no „safe“ level of exposure to lead. Although the use of lead pipes was banned in 1986 due to the risk of water contamination, many cities, including Chicago, still have old lead pipes installed before the ban.
More than 9.2 million households in the US still receive water through lead pipes and supply lines. In Chicago, there are approximately 400,000 lead pipes serving around 2.7 million people, more than any other US city.
To address this issue, the EPA recommends that all cities in the US replace their main water supply lines within 10 years. However, due to the massive strain on water infrastructure, Chicago would have 40 years to comply with these regulations under this proposal.