“Toxicohistrionics”: Flint, Michigan and the Lead Crisis

Abstract

See related article, p 158 See related article, p 158 In this volume of The Journal, Gómez et al report an in-depth analytical view of events that occurred in Flint, Michigan, in 2014 and 2015.1Gómez H.F. Borgialli D.A. Mahesh Sharman M. Keneil K. Shah B. Scolpino A.J. et al.Blood lead levels of children in Flint, Michigan: 2006-2016.J Pediatr. 2018; 197: 158-164Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar The events in Flint, which apparently arose from a change in the water supply, entered the public realm through news outlets rather than the scientific literature. On September 24, 2015, data released to the public triggered a media firestorm. By April 20, 2016, a report on National Public Radio opened with a paragraph that read, “Lead seepage into the drinking water in Flint, Michigan, has caused a massive public health crisis and prompted President Obama to declare a federal state of emergency there.”2Kennedy M. Lead-laced water in Flint: a step-by-step look at the makings of a crisis: the two-way.https://www.npr.org/sections/thetwo-way/2016/04/20/465545378/lead-laced-water-in-flint-a-step-by-step-look-at-the-makings-of-a-crisisDate: 2016Google Scholar This “public health crisis” was based in large part on a study that found an increase in the percent of subjects with elevated blood lead levels from 2.1% to 4.0%. At the time, I found myself asking, “Does this imply that the geometric mean blood lead level doubled or the number crossing an arbitrary threshold doubled or perhaps even the number requiring treatment doubled?” Some of those scenarios would indeed be troubling for any physician treating children. The data as published in February 2016, by Hanna-Attisha et al are accurate as presented, but left many questions.3Hanna-Attisha M. LaChance J. Sadler R.C. Champney Schnepp A. Elevated blood lead levels in children associated with the flint drinking water crisis: a spatial analysis of risk and public health response.Am J Public Health. 2016; 106: 283-290Crossref PubMed Scopus (657) Google Scholar The focus was on a single point change from 2013 to 2015 given as pre and post change in the water supply. The data show the change in percentage of blood lead levels of >5 µg/dL, the current upper limit of normal, between the 2 events. Gómez et al take a closer look at the Flint data and have answered many questions, and raised a number of issues about how we in the scientific community communicate risk and statistics.1Gómez H.F. Borgialli D.A. Mahesh Sharman M. Keneil K. Shah B. Scolpino A.J. et al.Blood lead levels of children in Flint, Michigan: 2006-2016.J Pediatr. 2018; 197: 158-164Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar These authors conclude that, over an 11-year span, blood lead levels in this community continued to decrease and that it is impossible to differentiate the increase that occurred in 2015 from other random variations over time. A similar change occurred in 2010-2011. The mean blood lead level did not double. It increased by 0.11 µg/dL. No children underwent chelation therapy in this time. The authors are to be congratulated for a straightforward presentation of the data. Based on this more comprehensive view of the data, the furor over this issue and the resultant firings and criminal actions seem way out of proportion to the actual risks to children from lead exposure. There certainly were good reasons to repair the damages to the Flint water system. The finding of increased lead levels in the water would be sufficient to prompt changes. Other risks such as Legionnaire's disease may also have been demonstrated.4Pelley J. Beyond lead: Flint water strongly tied to Legionnaire's disease.Sci Am. 2016; (Accessed January 15, 2018)https://www.scientificamerican.com/article/beyond-lead-flint-water-strongly-tied-to-legionnaire-s-disease/Google Scholar In retrospect, however, there was no reason to escalate to a lead-related public health crisis, particularly because, from a purely objective statistical standpoint, the changes seen could simply have been due to random variation. The use of 2 data points may contribute to the logical fallacy post hoc ergo propter hoc: establishing a cause–effect relationship based on temporal sequence. The question is whether a different presentation of the data and more critical journalistic review could have prevented this event? Percent increases and terms like doubling, as repeated by the media, may not present a meaningful measure of risk. As has been extensively studied, blood lead levels in the US have decreased from a mean of 15 µg/dL in the mid-1970s5Annest J.L. Pirkle J.L. Makuc D. Neese J.W. Bayse D.D. Kovar M.G. Chronological trend in blood lead levels between 1976 and 1980.N Engl J Med. 1983; 308: 1373-1377Crossref PubMed Scopus (293) Google Scholar to the current levels, which are generally <2 µg/dL.6Wheeler W. Brown M. Blood lead levels in children aged 1-5 years—United States, 1999-2010.MMWR Morb Mortal Wkly Rep. 2013; 62: 245-248PubMed Google Scholar This commendable success is on the basis of elimination of lead in gasoline, canning, paint, and other sources with improved nutrition particularly with iron supplementation. Flint, Michigan, seems to have shared in this success and has continued to decrease to a mean of 1.15 µg/dL in 2016. I have in the past used the term “toxicohistrionics” to describe public and professional overreactions to substances in our food chain or environment where real risk has been exchanged for theoretical risk.7Rauh V.A. Garfinkel R. Perera F.P. Andrews H.F. Hoepner L. Barr D.B. et al.Impact of prenatal chlorpyrifos exposure on neurodevelopment in the first 3 years of life among inner-city children.Pediatrics. 2006; 118: e1845-e1859Crossref PubMed Scopus (532) Google Scholar Many times this reporting is on the basis of weak but statistically significant associations found in the realm of epidemiology. It is pleasant to comment on a study that reports critically analyzed epidemiologic data on an event where reporting in the media and publication never gave us a real sense for the degree of “crisis.” I do not wish to seem to be unduly critical of the Hanna-Attisha et al publication, because it reflects a trend in the current literature to use percentages and partial data instead of more granular and undigested detail.3Hanna-Attisha M. LaChance J. Sadler R.C. Champney Schnepp A. Elevated blood lead levels in children associated with the flint drinking water crisis: a spatial analysis of risk and public health response.Am J Public Health. 2016; 106: 283-290Crossref PubMed Scopus (657) Google Scholar This tactic may, however, lead to untoward public perception of statistics when such words as “doubling” used employed. “Doubling” may represent an increase of 400 per thousand to 800 per thousand, which everyone would agree is an issue. However, going from 1 per billion to 2 per billion is also doubling. The authors of this article have wisely steered away from the issue as to whether the subtle increase of blood lead levels would have any perceptible impact on this population.1Gómez H.F. Borgialli D.A. Mahesh Sharman M. Keneil K. Shah B. Scolpino A.J. et al.Blood lead levels of children in Flint, Michigan: 2006-2016.J Pediatr. 2018; 197: 158-164Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar I would point to a noted lead researcher, Dr Howard Hu, who when commenting on the situation in Flint, Michigan, said that “low-level lead exposure can be mitigated by good parenting, good schooling and good nutrition.”8Shell E.R. Gauging the effects of lead.Sci Am. 2016; 315: 23-24Crossref PubMed Scopus (1) Google Scholar Certainly, the data do not support the wild accusations in the media of devastating harm. Is there any problem with overstating the risks? Indeed, the concern would be that by overly focusing on this issue, we are not focusing on the equally important issues of nutrition, education, housing, and inner-city stress and violence that many have pointed to as prominent risk factors in the development of lower socioeconomic children. In shifting our focus from a more balanced perspective, we may be falling short in advocating for the children in our nation. Blood Lead Levels of Children in Flint, Michigan: 2006-2016The Journal of PediatricsVol. 197PreviewWe evaluated the increases in blood lead levels (BLLs) observed in young children in Flint, Michigan, during their exposure to corrosive Flint River water during the years 2014 and 2015 and compared their BLLs to those of Flint children measured during the years 2006-2013 and 2016. Full-Text PDF