The arsenic-Alzheimer's disease link: Emerging evidence and unanswered questions.

Arsenic is a toxic heavy metal that reaches humans primarily through contaminated groundwater, presenting a persistent global public health concern. Chronic exposure, even at concentrations lower than current safety standards, disturbs brain development and function, raising concern that arsenic may contribute to Alzheimer's disease (AD). Wei et al. investigate early-life arsenic exposure and AD using Swedish national registries and geographic variation in groundwater arsenic. This work represents a critical step toward understanding whether historical environmental exposures in northern Europe have increased late-life neurodegenerative risk and underscores the importance of treating arsenic as a potentially modifiable environmental risk factor for AD.