Study finds slightly higher risk of autism diagnosis in areas with more lithium in drinking water, but experts say more research is needed
A new study found a moderately higher risk of autism spectrum disorder in children born to pregnant people exposed to tap water with higher levels
A new study found a moderately higher risk of autism spectrum disorder in children born to pregnant people exposed to tap water with higher levels of lithium, but experts caution that this association does not show a direct link between the two. About 1 in 36 children in the US is diagnosed with autism spectrum disorder (ASD) each year, according to data from the US Centers for Disease Control and Prevention. Scientists still don’t know the exact cause of autism, a developmental disorder. Genetics may be a factor, but some have been looking at potential environmental causes, too. Cases may be on the rise, but that is also unclear. One study published this year on cases in the New York-New Jersey area found that autism diagnosis rates tripled among certain age groups between 2000 and 2016. A 2021 report found similar increases in cases, but the CDC says the increased number of cases is most likely linked to more doctors screening for the condition. Lithium is an alkali metal that can be found naturally in some food and ground water. It’s used in batteries, grease and air conditioners, as well as in the treatment of bipolar disorder and some blood disorders. Its levels in US drinking water are not regulated, according to the US Geological Survey. A new study, published Monday in the journal JAMA Pediatrics, found a small association between lithium and autism diagnosis in Denmark, where the researchers say the level of lithium in drinking water is similar to that in American water systems.
The researchers checked a database of people with psychiatric disorders for children born between 2000 and 2013 to find information on 8,842 cases of ASD and 43,864 participants who did not have ASD. They then measured the concentration of lithium in 151 public waterworks that served more than half of the Danish population and mapped out where pregnant people lived in relation. As lithium levels in water increased, there was a modest increased risk of an ASD diagnosis. Specifically, compared with people at the lowest exposure level, those who had the second and third highest exposure during pregnancy had a 24% to 26% higher risk of ASD diagnosed in children. The group with the highest exposure had a 46% higher risk than those at the lowest level of exposure. The researchers could not tell how much water the pregnant people drank, but they picked Denmark in part because residents there consume some of the lowest amounts of bottled water in Europe. Experts say it’s important to note that the research can’t show that lithium exposure leads directly to an autism diagnosis. Further study is required, said study co-author Dr. Beate Ritz, a professor of neurology in the David Geffen School of Medicine at UCLA, and a professor of epidemiology and environmental health at the UCLA Fielding School of Public Health. “Any drinking water contaminants that may affect the developing human brain deserve intense scrutiny,” Ritz said in a news release.
The BriefWire