Illinois Water Fluoride: Updated Statistics

Illinois has maintained one of the nation’s longest-running mandatory water fluoridation programs, contributing to high statewide coverage and consistent oral health benefits. This article presents recent trends, coverage rates, cost savings, and comparative data to offer a clear statistical overview of Illinois’ water fluoridation landscape.

For decades, the Illinois Department of Public Health has closely monitored local community water systems to ensure that fluoride levels align with both historical legislation and updated federal guidelines. Below is an in-depth look at the key statistics, covering everything from percentage coverage and cost-saving calculations to regional comparisons with neighboring states.

Key Statistics

Below are a few quick data points illustrating Illinois’ water fluoridation status.

• 98.5% of Illinois residents received fluoridated water between 2005 and 2010.
• Over 90% of community water systems statewide maintain fluoride levels within ±0.1 ppm of the target.
• A 20–30% operational cost reduction occurred after lowering targets to 0.7 ppm in 2016.
• $32.19 in dental treatment expenses saved annually per capita due to fluoridation.

These figures underscore the high coverage and financial impact of Illinois’ fluoridation program. The following sections break down the data in more detail, covering coverage trends, health outcomes, and regional comparisons.

Historical and Current Fluoridation Coverage

Accurate documentation of coverage levels highlights the consistency of Illinois’ fluoridation program.

• Fluoridation has been mandatory in Illinois since 1967.
• From 2005 to 2010, about 98.5% of the state’s 12.8 million residents had access to fluoridated water.
• Even after adopting the new 0.7 ppm standard in 2016, coverage remained at 98.2% by 2018.
• Between 2020 and 2025, coverage rates have stabilized at around 98.2–98.5%, significantly above the national average of 72.7%.

Regular monitoring ensures that most community water systems meet state and federal guidelines. This high coverage rate is the backbone of Illinois’ broader oral health success metrics.

Monitoring and Compliance Data

Illinois enforces rigorous checks to keep fluoride levels at optimal concentrations.

• 1,842 community water systems undergo monthly monitoring for fluoride levels.
• 90% of these systems consistently remain within ±0.1 ppm of the recommended level.
• The state lowered its target from 0.9–1.2 ppm to 0.7 ppm in 2016, aligning with updated federal guidance.
• Post-2016 data showed no increased incidence of dental fluorosis under the new level.

By ensuring close adherence to state-mandated guidelines, Illinois maintains consistent fluoride distribution and mitigates any risk of overexposure.

Health Outcomes and Cost Savings

High coverage translates into measurable dental health improvements and notable economic benefits.

• Statewide tooth decay prevalence decreased by 25–30% due to fluoridation.
• $32.19 in avoided dental treatment costs are saved per person every year.
• Among low-income children, there are 40% fewer cavities in fluoridated regions.
• No reported cases of enamel discoloration from community water sources, with levels staying below the EPA threshold of 2.0 ppm.

These figures underline the tangible impact of fluoridated water, particularly in cost savings and enhanced oral health for vulnerable populations.

Regional Comparison: Illinois and Neighboring States

Adjacent states exhibit different fluoridation rates based on local mandates and policies.

• Kentucky stands at 99.7% fluoridation coverage.
• Wisconsin reports coverage at 87.9%, with higher untreated decay (18%) compared to Illinois (12%).
• Indiana records 76.4% coverage and higher Medicaid dental costs ($45 per capita), above Illinois’ $32.
• Missouri shows 70.6% coverage, also accompanied by higher Medicaid expenses ($45 per capita).

Variations in state mandates correlate directly with coverage rates and corresponding oral health costs.

Key Statistics Summary

• Illinois maintains 98.2–98.5% fluoridation coverage between 2020 and 2025.
• Statewide tooth decay prevalence is reduced by 25–30%.
• Up to $32.19 is saved per person annually on dental costs.
• 1,842 community water systems undergo monthly fluoride level checks.
• No recorded dental fluorosis cases from public water systems.

Overall, these statistics highlight Illinois’ robust coverage rates, consistent adherence to optimal fluoride levels, and the significant economic and dental health benefits associated with the state’s long-standing program.