Natural lithium in drinking water may increase the chances of developing autism, as a new study has found that pregnant women who drank water with higher levels of this metal had a moderately increased risk of their children being diagnosed with the disorder on the autism spectrum (ASD).
The research may be the first to identify natural lithium found in drinking water as a potential environmental risk factor for autism, but it does not show a causal relationship between drinking the liquid and the disorder, only a possible association between in utero exposure to lithium and a diagnosis of autism, say the researchers at the Yale School of Public Health and UCLA Health who conducted the study.
Lithium is one of the naturally occurring metals found in water, and some research has indicated that it may influence a key molecular pathway involved in neurodevelopment and autism, said Dr. Beate Ritz, a professor of neurology at the School David Geffen of Medicine at UCLA, professor of epidemiology and environmental health at the UCLA Fielding School of Public Health and lead author of the study, which has been published in JAMA Pediatrics.
“Any contaminant in drinking water that may affect fetal development requires extensive testing, and lithium levels in drinking water are not routinely monitored at present”
Some lithium compounds are used to treat depression and bipolar disorder because they have a mood-stabilizing effect, but there are data linking lithium use by pregnant women to increased risk of miscarriage or miscarriage. born with birth defects or heart defects, so there is controversy about the safety of taking these drugs during pregnancy.
“This study is important because previous research has shown that chronic, low-dose lithium intake through drinking may influence the development of adult-onset neuropsychiatric disorders, but no study has evaluated whether lithium from drinking water consumed by pregnant women affects their children’s neurodevelopment,” says Zeyan Liew, assistant professor of epidemiology (environmental health) at the Yale School of Public Health and first author of the study, adding: “Any contaminant in drinking water that could affect fetal development requires a comprehensive analysis. “Currently, lithium levels in drinking water are not routinely monitored.”
Health risks of lithium contamination
The Yale and UCLA researchers, collaborating with colleagues in Denmark, analyzed medical record data for the entire population of Denmark and lithium levels at 151 public water works in Denmark, which provide the water supply for about half of the country’s population. They used information from the civil registry to find out the addresses of the women’s homes at the time of pregnancy to identify which water supply works supplied their homes.
They also used a national database of patients with psychiatric disorders to identify children born between 1997 and 2013 and compared 12,799 who had been diagnosed with autism to 63,681 children who did not have an autism diagnosis. These scientists took into account the characteristics of the mothers, some socioeconomic factors, and exposure to air pollution, as these are aspects that have been linked to an increased risk of autism in children.
They found that as lithium levels increased, the chances of an autism diagnosis also increased. Compared with the lowest quartile of recorded lithium levels—those in the 25th percentile—lithium levels in the second and third quartiles were associated with a 24% to 26% increased risk of autism. In the highest quartile, the risk was 46% higher compared to the lowest quartile. The association between lithium levels and autism risk was somewhat greater in those who lived in urban areas compared to smaller towns and rural areas.
Nicole Deziel, associate professor of epidemiology (environmental health sciences) at YSPH and an expert on environmental contaminants who was not involved in the study, explained that the findings have relevant implications: “There has been substantial growth in the commercial use of lithium as a fundamental component of batteries for mobile electronic devices and electric vehicles. “Mismanagement of lithium mining waste or improper disposal of lithium-containing products could increase contamination of drinking water supplies.”
“As we move away from fossil fuels to curb climate change, we must adopt new technologies responsibly, so as not to create new environmental health hazards. Understanding the potential public health impacts of lithium is important for exposed populations now and to help inform a responsible energy transition,” she concludes.
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