Paper: 'Analysis of Blood Lead Levels of Young Children in Flint, Michigan Before and During the 18-Month Switch to Flint River Water'

Hernán F. Gómez, Dominic A. Borgialli, Mahesh Sharman, Keneil K. Shah, Anthony J. Scolpino, James M. Oleske & John D. Bogden (2019): Analysis of blood lead levels of young children in Flint, Michigan before and during the 18-month switch to Flint River water, Clinical Toxicology, DOI: 10.1080/15563650.2018.1552003

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Abstract

Background: The toxicity of lead, like any xenobiotic, is directly linked to the duration of exposure and toxin concentration in the body. The elevation in blood lead levels (BLLs) in young Flint, Michigan children noted in time-periods before, and during the 18-month exposure to Flint River water (FRW) from 25 April 2014 to 15 October 2015 is well-known internationally. The length of time BLLs were elevated is unknown, yet key in understanding the potential health impact of the event. The objective of this study was to evaluate whether BLLs in Flint children were increased during the entire 18-month FRW exposure compared to similar earlier time periods.

Methods: We conducted a retrospective study analyzing BLLs from Flint children aged 5 years and under. The geometric mean (GM) BLLs and percentages of BLLs ≥5.0 μg/dL in Period I: 25 April 2006 to 15 October 2007 (earliest timeframe available for study) and Period II: 25 April 2012 to 15 October 2013 (timeframe immediately before the water switch), were compared to Period III, 25 April 2014 to 15 October 2015 (FRW exposure).

Results: There were 5663 BLLs available for study. GM ± SE BLLs decreased from 2.19 ± 0.03 μg/dL in Period I to 1.47 ± 0.02 μg/dL in Period II [95% CI, 0.64, 0.79]; p<.001 and decreased further to 1.32 ± 0.02 µg/dL during the FRW Period III [95% CI, 0.79, 0.95]; p<.001. The percentage of BLLs ≥5.0 μg/dL decreased from Period I (10.6%) to Period II (3.3%) [95% CI, 5.7, 8.8]; p<.001 and from Period I to Period III (3.9%) [95% CI, 5.0, 8.2]; p=.002. The 0.6% increase from Period II to Period III was not statistically significant [95% CI, −1.9, 0.57]; p=.30.

Conclusion: Analyses of GM and percentages ≥5.0 μg/dL of BLLs do not support the occurrence of a global increase in BLLs in young children of Flint during the entire 18-month period of FRW exposure.

Cutting to the chase....

Conclusions

The exposure of young children to FRW from 25 April 2014 to 15 October 2015 in Flint coincided with a decrease in BLLs of young children when compared to prior time-periods controlling for time-length studied, months and seasons. Over the three 18-month time-periods studied, GM BLLs decreased 39.7% and the percentage of children with BLLs above the CDC reference value decreased 63.2%; this occurred across all 9 wards in the community. Analyses of GM BLLs and percentages !5.0lg/dL do not support the common perception of an occurrence of a global increase in BLLs occurring during the 18-month FRW change in the young children of Flint. Additionally, national, state and local BLLs have historically been down-trending for years. Although the environmental hazard of the FRW switch was significant, it did not result in globally increased BLLs nor percentages above the CDC reference value during the entire 18-month FRW switch. These findings suggest that public health efforts to reduce BLLs of Flint children have been effective. Nevertheless, public health officials, legislators and clinicians should continue efforts and allocate resources to further decrease environmental lead exposure of all children in the nation.

Thanks to friend G. Tracy Mehan III for sending this paper my way.

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“The reports of my demise are well overblown.” - Former Michigan Governor Rick Snyder, quoted in the Lansing State Journal 

Comments

[Elaine Hanford]

This study addressed mean BLLs, failing to cite the actual range of BLLs detected in these children. It also does not consider whether any BLLs were high enough for those children to receive any chelation therapy ( Intravenous or oral chelating compounds such as EDTA, DMSA, or DMPS).
A more specific study which cites actual BLLs in Flint and elsewhere states that:
"In the rust-belt community of Flint, children were already at a higher risk for lead exposure from multiple sources before the highly publicized water crisis"
https://www.sciencedaily.com/releases/2018/03/180326090313.htm
Efforts and success in reducing BLLs in children in Flint should be viewed within this broader context.