High Lithium in Drinking Water Substantially Increases Risk of Autism: Study

Autism rates have reached new heights with boys being over four times more likely than girls to be diagnosed.Dubova/Shutterstock

Higher lithium concentrations in drinking water among pregnant women carry significant possibilities of raising the risk of autism among children, a new study has found.

The study, published in JAMA Pediatrics on April 3, looked into whether maternal exposure to lithium in drinking water is linked to autism spectrum disorder (ASD) in the offspring. Conducted in Denmark, the study analyzed 8,842 children diagnosed with ASD born between 2000 and 2013. Lithium levels in the water were categorized into four groups, with the first quartile representing the lowest lithium level and subsequent quartiles having higher concentrations of lithium.

Researchers found that high lithium levels in the second and third quartiles were associated with a 24 to 26 percent higher risk of autism compared to the first quartile. The risk in the fourth quartile was 46 percent higher.

“Estimated maternal prenatal exposure to lithium from naturally occurring drinking water sources in Denmark was associated with an increased ASD risk in the offspring. This study suggests that naturally occurring lithium in drinking water may be a novel environmental risk factor for ASD development that requires further scrutiny,” the study found.

Lithium, a naturally occurring trace element, is known to have mood-stabilizing effects. The element has been linked to cardiac malformations among newborns as well as miscarriages.

Lithium usually ends up in drinking water due to weathering of underground minerals. The level of the element in water is considered to be moderate to low in Denmark.

Lithium Contaminated Water

Beate Ritz, the lead author of the study and a professor of neurology at the David Geffen School of Medicine at UCLA, decided to look at potential links between lithium and autism risk after discovering that there was little research into how the element affects human brain development.

“Any drinking water contaminants that may affect the developing human brain deserve intense scrutiny,” she said, according to an April 3 news release.

“In the future, anthropogenic sources of lithium in water may become more widespread because of lithium battery use and disposal in landfills with the potential for groundwater contamination.”

Zeyan Liew, the first author of the study and an assistant professor of epidemiology at the Yale University School of Public Health, pointed out that earlier research done in Denmark had already shown that ingestion of lithium via drinking could affect the onset of adult-onset neuropsychiatric disorders.

The recent study also found that high lithium levels continued to pose a higher risk of autism diagnosis even when the data was divided up by subtypes of the disorder.

The link between lithium levels and autism risk was found to be slightly higher among individuals living in urban regions compared to rural areas and small towns.

Autism in the US, Genetic Links

The JAMA study comes as autism rates among children have been rising in the United States, according to the latest data by the U.S. Centers for Disease Control and Prevention (CDC).

In a study published last month, the CDC estimated that 1 in 36, or 2.8 percent, of 8-year-old children in the country are affected by autism. This is up from 1 in 44 in 2018 and 1 in 150 in 2002. Boys were found to be far more likely to develop autism than girls.

The study was conducted among 11 communities that are part of a CDC-funded program called the Autism and Developmental Disabilities Monitoring Network. Another national estimate put autism rates among children between the ages of 3 and 17 at 2.9 percent.

In an October 2022 study published in the International Journal of Health Geographics, researchers from the University of Utah proposed that ancestry contributed to the increased risk of autism, especially where and when one’s grandparents and their children were born.

The nutritional access of paternal grandparents during their childhood was found to have a direct impact on health outcomes among grandkids.

“Looking back at families and where and when they lived helped us detect clusters of individuals who seem to have a higher subsequent risk of autism among their descendants,” said senior author and environmental epidemiologist James VanDerslice from the University of Utah.