LAW360: Environmental groups told a California federal judge during bench trial openings Wednesday that new studies show clear links between prenatal fluoride exposure and children’s lower IQ levels, while the EPA defended current regulations allowing low levels of fluoride in drinking water and underscored that “the dose makes the poison.”

The attorneys’ statements kicked off what is expected to be a two-week trial in San Francisco before U.S. District Judge Edward Chen in yearslong litigation first launched by Food & Water Watch Inc., the Fluoride Action Network and other groups against the U.S. Environmental Protection Agency in April 2017.

The lawsuit seeks to force the EPA to make a new federal rule under the Toxic Substances Control Act that would ban fluoride from being added to drinking water. Local municipalities have added fluoride to the water for decades to boost public dental hygiene and prevent dental decay.

The plaintiffs sued after the agency denied their petition making a similar request, which could affect roughly 200 million Americans, and the case has been seen as a test of citizen’s and nonprofits’ power to compel the government to regulate chemicals based on a judge’s reading of scientific research and expert testimony.

The legal fight went to a first bench trial in 2020, with the environmental groups asking the court to declare that fluoride in tap water posed a risk to human health. But Judge Chen suspended litigation for years to give the EPA time to conduct another study and reevaluate fluoride’s risks.

In October 2022, the litigation resumed, and the second trial began Wednesday with plaintiffs’ counsel, Michael Connett of Waters Kraus & Paul, telling the judge that trial evidence will show the latest scientific studies link lower IQ levels in children to prenatal exposure to fluoride.

Connett compared the dangers of fluoride exposure to serious developmental brain damage and neurotoxicity that can be caused by exposure to lead even in small amounts, and as support, he pointed to the D.C. Circuit’s 1976 split decision in Ethyl Corp. v. U.S. EPA, which banned lead in gas and found that the EPA had a basis to infer the existence of a “significant risk” under the Toxic Substances Control Act, or TSCA, based on the “inconclusive but suggestive results of numerous studies.”

Connett told the judge that plaintiffs concede that “de minimis” exposure to fluoride isn’t risky, but he said “that doesn’t mean that there’s no risk,” and the evidence is “rather clear and overwhelming” that high doses of fluoride is a cause of neurodevelopment defects.

But Judge Chen repeatedly pointed out that in large doses, everything can be dangerous, and “knowing that if you go to an extreme, almost everything is a hazard.”

Connett acknowledged the judge’s point, but said the case ultimately presents the question of how the EPA should regulate chemicals based on “inferred risk” when the exposure level is below the hazard level, and in reviewing the latest scientific studies, the court should “look at the margins to protect the most vulnerable.”

Connett noted that 0.7 mg/L is the current average level of fluoride in most communities’ drinking water, but animal and human studies analyzing levels of 1.5 mg/L of fluoride and lower show pregnant women who are exposed have offspring with lower IQ rates. He added that the EPA’s suggestion that only higher doses of fluoride are risky is absurdly hazardous.

He also pointed out that the number of people exposed to fluoride is “nothing short of massive,” and “we have so much fluoride water it’s hard to know” where all fluoride is coming from in urine samples, particularly since humans not only absorb fluoride from drinking water, but also other food products.

“There will always be uncertainties in risk assessments,” Connett said. “The fact there are uncertainties is to be expected. You will never have all pieces of the puzzle complete … But you can’t wait for the last piece of the puzzle to fit in before you take action. That’s not the standard that the EPA holds itself to under TSCA.”

However, during the EPA’s opening statement, Paul A. Caintic cited the Renaissance-era physician Paracelsus’ adage “the dose makes the poison,” and he noted that the plaintiffs have to show with a preponderance of evidence that 0.7 mg/L of fluoride presents an unreasonable risk in light of science.

The results of the recent scientific studies are “too inconsistent and too unclear” to conclude that low levels of fluoride represent an unreasonable risk of harm, Caintic said.

“It’s not that we have less studies [on low levels of fluoride exposure], it’s that the studies that we do have point to different directions,” he said.

But Judge Chen pressed the attorney on his position, asking “doesn’t the fact you have studies going both ways suggest that there’s certainly some uncertainty there?”

The judge also questioned why low levels of fluoride exposure wouldn’t be considered reasonable risk, particularly since adding 0.7 mg/L of fluoride in drinking water in addition to other forms of fluoride consumption could put the exposure “over the line,” and be “the straw that breaks the camel’s back,” or the “incremental difference that gets you over the goal line.”

Caintic responded that there is not enough known about other levels of fluoride consumption, and again he argued that the science is too inconsistent and unclear on the matter.

“We believe that the science speaks for itself,” he said, adding, “It’s important to focus not only what the [IQ] study found, but what it didn’t find. That kind of cherry-picking is not the right way to assess science. We should not base the quality of study based solely on its results.”

After opening statements, the plaintiffs called to the stand Dr. Howard Hu, a professor at the University of Southern California, who testified on papers he co-authored regarding the Early Life Exposures in Mexico to Environmental Toxicants project in Mexico City, which has studied neurobehavioral outcomes of prenatal and postnatal exposures to fluoride since 2012.

During his direct examination, Hu testified that the latest study involved more than 200 children between the ages of 4 and 12, and it shows that the more fluoride found in the urine of their pregnant mothers, the lower non-verbal — as opposed to verbal — IQ levels resulted in their children, regardless of their genders.

Hu’s analysis found that the children’s IQ scores were approximately 3 and 2.5 points lower in association with a 0.5 mg/L increase in prenatal exposure, according to court documents. His analysis additionally noted that that impact on IQ is significant, given that more than 25% of pregnant women in artificially fluoridated areas have urinary fluoride levels above 1 mg/L, with approximately 5% having in excess of 2 mg/L.

On the stand, Hu also criticized a study cited by the EPA that did not show similar IQ drop links. Hu said the rival study didn’t address the fact that the sample population regularly consumed large amounts of seafood, noting that the omega 3 fatty acids found in seafood may have “overwhelmed” the neurotoxicological effects of fluoride.

Under cross-examination, however, Hu conceded that he has not specifically studied fluoride levels in seafood, or account for seafood diets in his own study.

The bench trial will continue Thursday morning with a new witness.

The environmental groups are represented by C. Andrew Waters and Michael Connett of Waters Kraus & Paul and Christopher T. Nidel of Nidel & Nace PLLC.

The EPA is represented by Brandon N. Adkins and Paul A. Caintic of the U.S. Department of Justice’s Environment and Natural Resources Division and Emmet P. Ong of the U.S. Attorney’s Office for the Northern District of California.

The case is Food & Water Watch Inc. et al. v. EPA et al., case number 3:17-cv-02162, in the U.S. District Court for the Northern District of California.

–Editing by Michael Watanabe.

Correction: An earlier version of this story misidentified the attorney for the EPA who gave opening statements. The error has been corrected.

Original article online at: https://www.law360.com/articles/1792295/fluoride-risk-trial-opens-with-claim-exposure-drops-kids-iq?copied=1