Objective: To compare blood lead levels in females of childbearing age, 12-50 years, living within and adjacent to Flint, Michigan, before, during, and after the Flint River water exposure and compare the levels to those that have been shown to cause fetal loss and preterm birth.
Methods: The switch in the community water source to the Flint River occurred on April 25, 2014, and was reverted to the original source on October 15, 2015. Using a retrospective cross-sectional study design using geocoded blood lead levels obtained from all females of childbearing age available from a single hospital database, we compared blood lead levels for the following 18-month time periods: April 25, 2012-October 15, 2013 (PRE), April 25, 2014-October 15, 2015 (DURING), and April 25, 2016-October 15, 2017 (POST).
Results: Results are reported as geometric mean (95% CI). Within Flint, PRE blood lead levels in females of childbearing age were 0.69 micrograms/dL (95% CI 0.63-0.75), DURING blood lead levels were 0.65 micrograms/dL (95% CI 0.60-0.71), and POST blood lead levels were 0.55 micrograms/dL (95% CI 0.54-0.56). DURING Flint River water exposure blood lead levels were not significantly different than the PRE Flint River water time period. POST Flint River water exposure blood lead levels were significantly lower than both PRE and DURING levels. Overall, lower blood lead levels were found outside the Flint boundary in all cohorts.
Conclusion: Blood lead levels in Flint females of childbearing age did not increase during the Flint River water exposure and subsequent 18-month time period. Mean blood lead levels during the Flint River water exposure are not consistent with the markedly higher blood lead levels reported in the literature to be associated with fetal loss, low birth weight, or preterm birth.