Lithium in tap water: The connection to autism - a cause or correlation?
A recent study published in the journal JAMA Pediatrics has found a moderate link between higher levels of lithium in drinking water and an increased risk of autism spectrum disorder (ASD) in children born to pregnant women exposed to these contaminants. However, experts caution that the association does not imply a direct causal relationship.
According to the US Centers for Disease Control and Prevention, about 1 in 36 children in the US is diagnosed with ASD each year. The exact cause of autism remains unknown, but research has been ongoing to identify potential environmental factors. Lithium, an alkali metal found naturally in some food and groundwater, is commonly used in batteries, grease, air conditioners, and as a treatment for bipolar disorder.
The new study analyzed data from 8,842 cases of ASD and 43,864 participants without ASD, examining the concentration of lithium in public waterworks serving over half of the Danish population. The results showed that pregnant women living in areas with higher levels of lithium in their tap water had an increased risk of having a child diagnosed with ASD.
The study found that children born to mothers exposed to high levels of lithium were 24% to 26% more likely to be diagnosed with ASD, compared to those at the lowest exposure level. The researchers could not determine how much water the pregnant women consumed, as this was not recorded in the data.
While the findings are intriguing, experts stress that they do not establish a direct link between lithium exposure and autism diagnosis. "We need more research," says Dr. Beate Ritz, co-author of the study. "The associations we found may be due to other factors or population characteristics."
Dr. Max Wiznitzer, director of the Rainbow Autism Center at University Hospitals Rainbow Babies and Children's Hospital in Cleveland, notes that studies on lithium exposure during pregnancy for mental health disorders have not shown a connection with ASD. He suggests that more research is needed to understand the relationship between lithium and autism.
The study's findings are complex, as lithium levels associated with a potential ASD risk also have been linked to lower rates of hospitalization for psychiatric disorders and suicide. Developing guidelines for lithium in drinking water that protect the entire population while minimizing risks will require careful consideration.
Experts emphasize that establishing causality between environmental exposures and ASD is challenging due to the complexity of human biology and the many potential confounding factors. "We are bombarded with environmental stressors, and we need to figure out how to safely navigate them," Dr. Wiznitzer notes.
A recent study published in the journal JAMA Pediatrics has found a moderate link between higher levels of lithium in drinking water and an increased risk of autism spectrum disorder (ASD) in children born to pregnant women exposed to these contaminants. However, experts caution that the association does not imply a direct causal relationship.
According to the US Centers for Disease Control and Prevention, about 1 in 36 children in the US is diagnosed with ASD each year. The exact cause of autism remains unknown, but research has been ongoing to identify potential environmental factors. Lithium, an alkali metal found naturally in some food and groundwater, is commonly used in batteries, grease, air conditioners, and as a treatment for bipolar disorder.
The new study analyzed data from 8,842 cases of ASD and 43,864 participants without ASD, examining the concentration of lithium in public waterworks serving over half of the Danish population. The results showed that pregnant women living in areas with higher levels of lithium in their tap water had an increased risk of having a child diagnosed with ASD.
The study found that children born to mothers exposed to high levels of lithium were 24% to 26% more likely to be diagnosed with ASD, compared to those at the lowest exposure level. The researchers could not determine how much water the pregnant women consumed, as this was not recorded in the data.
While the findings are intriguing, experts stress that they do not establish a direct link between lithium exposure and autism diagnosis. "We need more research," says Dr. Beate Ritz, co-author of the study. "The associations we found may be due to other factors or population characteristics."
Dr. Max Wiznitzer, director of the Rainbow Autism Center at University Hospitals Rainbow Babies and Children's Hospital in Cleveland, notes that studies on lithium exposure during pregnancy for mental health disorders have not shown a connection with ASD. He suggests that more research is needed to understand the relationship between lithium and autism.
The study's findings are complex, as lithium levels associated with a potential ASD risk also have been linked to lower rates of hospitalization for psychiatric disorders and suicide. Developing guidelines for lithium in drinking water that protect the entire population while minimizing risks will require careful consideration.
Experts emphasize that establishing causality between environmental exposures and ASD is challenging due to the complexity of human biology and the many potential confounding factors. "We are bombarded with environmental stressors, and we need to figure out how to safely navigate them," Dr. Wiznitzer notes.