Under cross-examination, Savitz told the court he sat on that panel at the same time that the EPA was paying him $500 per hour — totaling between $137,000 to $150,000 for 275-300 hours of work — as a litigation expert for the EPA in this trial examining that very question. Judge Chen asked Savitz if Health Canada knew he was serving as an expert witness in this case when they invited him to the panel. Savitz said the agency did.
Regarding his work reviewing the NTP fluoride report, Savitz said NASEM determined the first draft of the NTP’s report, which classified fluoride as a neurotoxin, fell short of providing “a clear and convincing argument” that supported its assessment. Savitz told the court he didn’t think NTP’s conclusions were “wrong” but that they were stated in a way that could be “misused” as a tool for setting or changing water policy on water fluoridation. Savitz said he thought that after the revisions, the communication was “tempered” and “more consistent”.
Savitz testified that because two of the four major cohort studies discussed in the trial (MIREC and ELEMENT), found a statistically significant effect of fluoride on IQ at low levels, and two did not (Odenseand INMA), there was too much uncertainty to definitively conclude that it posed a danger at current levels of water fluoridation. Judge Chen asked, “I take it the converse would also apply? Which is that given this mix [of results] you can’t foreclose that there is an effect at U.S. drinking levels?” Savitz conceded this was true.
Judge Chen asked, given Savitz’s response and the NTP’s findings, if it makes sense to assume that there is a concern about current drinking water levels. Chen also asked Savitz if he took issue with NTP’s conclusion that there is an association between fluoride exposure and lowered IQ at 1.5 mg/L - just over two times current fluoridation levels. Savitz said he had no reason to challenge it, but he hadn’t corroborated it.
Savitz said another flaw was that the NTP used high-quality ecological studies - studies of endemic fluoride in other countries - as some evidence to show the effects of fluoride and that those could be confounded by other variables. Chen pointed out that the studies would have controlled for that issue. Savitz conceded they did.
On cross-examination, Connett also pointed out that in Savitz’s own work on arsenic in China, his team studied endemic arsenic at high concentrations to show evidence for arsenic’s toxic effects. They also used that data to consider toxic exposure levels in the U.S., using the same methods NTP scientists and other researchers were using endemic fluoride data, which Savitz criticized.
Connett also asked Savitz if he believed his own statements on uncertainty by quoting from Savitz’s textbook, “Interpreting Epidemiological Evidence: Connecting Research to Applications.” Savitz wrote in the book that “to claim we have insufficient evidence does not resolve the problem for those who make public health decisions, because inaction is an action.”
Throughout his testimony, Savitz maintained there was no strong evidence for the neurotoxic effects of fluoride exposure at “low levels,” which extended up to 2 mg/L. On cross-examination, Connett presented him with data from the NTP report and also from at least one key study showing this link. Savitz conceded he hadn’t read those studies. In fact, in addition to the NTP report, he said he had read only about 10 studies on fluoride and neurotoxicity.
EPA’s risk analyst Dr. Stanley Barone took the stand again as the final in-person witness in nine days of testimony at the Phillip Burton Federal Courthouse in San Francisco. FAN attorneys called Dr. Barone earlier to comment on the EPA’s risk analysis methodology even though he’s an expert witness for the EPA. The EPA called him back to testify to the quality of the evidence on fluoride and IQ for a hazard assessment.
Dr. Barone admitted in his testimony that fluoride is neurotoxic at relatively low levels and that EPA’s key expert on fluoride’s neurotoxicity, David Savitz, conceded flaws in his own study as our landmark fluoride trial drew to a close. Fluoride causes “neurotoxic harm,” and does so at relatively low levels, Barone admitted under cross-examination.
Barone said there simply isn’t enough data available for EPA to implement its risk assessment process for fluoride. Pharmacokinetic modeling that predicts how a chemical will be absorbed and metabolized by the body, hasn’t yet been done, he said. But on cross-examination, Attorney Michael Connett forced Barone to concede several of the FAN’s key points.
“You do not dispute that fluoride is capable of causing neurodevelopment harm, correct?” Connett asked. “I do not,” Barone said, adding that he said that in his deposition.
“You agree that the current evidence is suggestive that low-dose fluoride causes neurodevelopmental effects? Correct?” Connett asked. Barone said the “hazard ID” - the level at which a toxin causes effects - “is probably in the suggestive range but is highly uncertain.”
“You agree that fluoride is associated with neurotoxic effects at water fluoride levels exceeding two parts per million?” Connett asked. After first evading the question, Barone conceded.
Connett asked if Barone agreed there should be a “benchmark margin of uncertainty” of 10 for fluoride neurotoxicity. That means the lowest allowable human exposure level should be at least 10 times the hazard level, which Barone conceded may be approximately 2 parts per million. Barone said that is generally true for toxic chemicals under TSCA.
Water fluoridation levels in the U.S. are currently 0.7 parts per million, also referred to as milligrams per liter (mg/L), which would place them well above the
allowable level if they were regulated through TSCA’s norms.
Barone also conceded that the NTP’s report linking fluoride to neurotoxicity at 1.5 mg/L is a rigorous, high-quality review and that the NTP is one of the world leaders in doing such reviews.
“Do you feel comfortable as a risk assessor,” Connett asked, “exposing pregnant women to a level of fluoride that is so high that the kidney is oversaturated?” Barone avoided answering, commenting instead on other foods containing fluoride.
Connett asked a second time, “Are you comfortable then with a pregnant woman having so much fluoride in her circulating system that their kidney has lost the ability to efficiently process it?”
EPA lawyers objected to the question as “vague and argumentative” but Chen overruled.
Barone then sat in silence for several seconds before responding, “Again, putting this in context, my comfort level I don’t think is germane.”