Illinois has one of the highest lead poisoning rates in the USA, where nearly 10% of children with elevated blood lead levels live in Illinois. 40% of children in Illinois live in high risk zip codes, many of which are rural. 83 (out of 105) counties are primarily rural, and about 74 or so of those have multiple zip codes that are labeled as high risk zones. Part of why there is such high risk in rural areas is not only lead pipes, but because there are so many pre-1978 housing units that have not been updated which contain lead paint or other lead materials that children can be exposed to.
When the CDC tested 24,000 lead tests in Chicago, it showed that 1,000 of those tests were positive for a lead level of over 15 ppl, 8,000 found a lead level of 5 ppl, and 6,720 found a lead level of less than 1 ppl. These tests mainly showed up in black and Latino areas. On top of that, Chicago has about 400 thousand lead pipes still in use, with multiple grants from the state and federal governments to replace them, but has yet to do it. Peoria still has about 10,000 lead pipes in service, mainly in the older part of the city. As a result, 1 in 20 children test positive for high lead levels. Peoria is committed to removing the lead pipes still in service at no cost to the homeowners.
With more testing, new infrastructure, and awareness, harmful levels of lead in children are slowly decreasing, but it is still a very prevalent problem.
Sources:
Revealed: the ‘shocking’ levels of toxic lead in Chicago tap water | Chicago | The Guardian
New report finds ‘shocking’ levels of lead in Chicago water : NPR
The quest to replace Peoria’s drinking water lead pipes | CIProud.com (centralillinoisproud.com)
The first graph shows Elevated Blood Level tests (EBL) in children under 3 years of age per county. Anything above 5 µg/dL (micrograms per deciliter) is cause for concern.
The second graph shows the number of pre-1978 housing units in the county which have a high risk of lead contamination, and its correlation to EBL in children (graph 1).