In May 2016, the U.S. National Toxicology Program (NTP) released partial and preliminary findings from a series of 2-year studies designed to test whether cell phones can cause cancer. As we noted then, these studies raised significant questions more than they answered any. Last week the NTP released the long-awaited peer-review drafts for the completed study results, and not that much has changed. Nonetheless, scientists, regulators, and lawyers around the world will likely make sweeping pronouncements based on the results from this NTP study.
This set of studies was designed to maximize the likelihood of finding toxicological and carcinogenic effects due to cell phone radiation. They used large numbers of animals, both mice and rats, and exposed them to long stretches of extreme levels of cell phone radiation, far in excess of what the vast majority of people would experience.
Many news reports describing the research focus on the rat studies, since they show some hint of potential effects, particularly with a type of cancer in the heart called malignant schwannoma. Further muddying the waters, this was only observed in male rats while the control group had anomalously high death rates. Reports focusing on the rat studies neglect the fact that the mouse studies show no significant effects for any of the tested outcomes.
For a stronger critique of the study, see the review posted by Ars Technica.
Finally, Praedicat does not expect this study to move the needle on the risk of cell phone litigation. Its findings are inconclusive at best, and it simply cannot outweigh the epidemiological evidence that weighs against cell phones being a significant cause of cancer.
Do cellphones cause cancer? Despite years of research, there is still no clear answer. But two government studies released on Friday, one in rats and one in mice, suggest that if there is any risk, it is small, health officials said.