December 16, 2025

Arsenic reduction linked to lower risk of death

Arsenic is a naturally occurring toxic element that can contaminate groundwater. More than 100 million people around the world rely on water sources with unsafe levels of arsenic. Arsenic can also get into crops grown with contaminated water. Long-term exposure to arsenic has been tied to higher risks of death from cancer, heart disease, and other chronic illnesses. Previous research has shown that large-scale public health efforts to reduce arsenic exposure were tied to declining trends in these risks. For example, arsenic levels are regulated in drinking water in the U.S. However, most studies looked at community-level data, not changes in individuals.

A research team led by Drs. Yu Chen of NYU Grossman School of Medicine and Habibul Ahsan of the University of Chicago explored whether lowering an individual's arsenic exposure could reduce their risk of death. The team analyzed data from nearly 12,000 adults in Araihazar, Bangladesh, who participated in a study of arsenic levels and mortality in individuals over two decades. The participants lived in communities where well-water arsenic concentrations ranged from less than 1 to 864 micrograms (µg) per liter. About 80% of the participants were exposed to levels below 200 µg per liter The World Health Organization recommends no more than 10 µg per liter of arsenic in drinking water. The results were published in JAMA on November 17, 2025.

To assess participants' exposure to arsenic, the researchers measured arsenic levels in urine. These measurements were collected when people enrolled in the study between 2000 and 2002 and at up to five follow-up visits through 2018. The researchers also tracked deaths from chronic disease through 2022.

During the study period, measures were taken to reduce residents' arsenic exposure. These included labeling unsafe wells and installing deep, low-arsenic community wells. The team found that average urinary arsenic levels dropped by more than half between 2000 and 2018, from 283 to 132 µg per gram of creatinine (used to correct for hydration).

A drop in urinary arsenic levels was linked to lower chances of dying from major chronic diseases. For every 200 µg/gram creatinine decrease in arsenic levels, the chance of dying from any chronic disease declined by 22%. The chance of dying from cancer declined by 20% and the chance of dying from heart disease dropped by 23%. In contrast, people whose exposure rose over time had increased risk of death. These links held even after accounting for factors such as age, sex, education, body mass index, and smoking status.

People whose arsenic levels started out high and ended low were half as likely to die of chronic disease compared with those whose levels stayed high throughout the study. These participants whose levels fell from high to low had similar chances of dying from chronic disease as those whose levels started and stayed low.

The findings suggest that people who have been exposed to high arsenic levels can significantly lessen their chances of dying from chronic disease by reducing their exposure. The study underscores the importance of sustained efforts to ensure access to safe drinking water.

"We show what happens when people who are chronically exposed to arsenic are no longer exposed," says co-author Dr. Lex van Geen of Columbia University. "You're not just preventing deaths from future exposure, but also from past exposure."

Related Links

• Early-life sugar intake affects chronic disease risk
• Cardiovascular deaths likely to rise from extreme heat
• Arsenic factsheet
• Arsenic and drinking water (USGS)
• ToxFAQs™ for Arsenic (CDC)

References

Arsenic Exposure Reduction and Chronic Disease Mortality. Wu F, van Geen A, Graziano J, Ahmed KM, Liu M, Argos M, Parvez F, Choudhury I, Slavkovich VN, Ellis T, Islam T, Ahmed A, Kibriya MG, Jasmine F, Shahriar MH, Hasan R, Shima SA, Sarwar G, Navas-Acien A, Ahsan H, Chen Y. JAMA. 2025 Nov 17:e2519161. doi: 10.1001/jama.2025.19161. PMID: 41247717.

Funding

NIH's National Institute of Environmental Health Sciences (NIEHS).