Can arsenic exposure during pregnancy increase autism risk?

What's actually in it

Inorganic arsenic from contaminated drinking water and some foods (rice, apple juice, some seafood) crosses the placenta during pregnancy. It also passes into breast milk. The developing brain is one of the primary targets of arsenic toxicity during perinatal exposure.

Arsenic disrupts the same neurological signaling pathways that are implicated in autism spectrum disorder: glutamate signaling, mitochondrial function in neurons, and oxidative stress in brain tissue.

What the research says

A 2026 study in Ecotoxicol Environ Saf exposed animals to arsenic during the perinatal period and tracked offspring behavior. The offspring showed autism-like behavioral changes including social deficits and repetitive behaviors. Nicotinamide mononucleotide (NMN) reduced the behavioral effects, confirming that the mechanism involves mitochondrial dysfunction in developing brain cells.

This is animal data, so direct translation to human autism risk requires caution. But the plausibility of the mechanism and arsenic's established neurotoxicity make this a serious concern.

Test your water for arsenic, particularly if you use well water. Use an appropriate filter if levels are detected. Store filtered water in glass food storage to avoid adding additional chemical exposure.