More than half of adults surveyed worldwide expect to be seriously harmed by their drinking water in the next two years, according to a new study. Led by global health experts from Northwestern University and the University of North Carolina at Chapel Hill, the study sought to understand public perceptions of drinking water safety. The study, “Self-reported expected harm from drinking water in 141 countries,” was published in the journal Nature communication.

Because perceptions shape attitudes and behaviors, distrust of water quality negatively impacts people’s health, nutrition, psychological and economic well-being – even when the water meets safety standards.

“If we believe our water is not safe, we will not use it,” says Sera Young, professor of anthropology and global health at Northwestern University and lead author of the new study.

“When we don’t trust our tap water, we buy bottled water, which is extremely expensive and harmful to the environment; we drink soda or other sugary drinks, which are bad for our teeth and our figure; and we eat highly processed ready meals or go to restaurants to avoid cooking, which are unhealthier and more expensive,” Young said. “People who come into contact with unsafe water also experience greater psychological stress and are at higher risk for depression.”

Young is a Morton O. Schapiro Faculty Fellow at the Institute for Policy Research, a Faculty Fellow at the Paula M. Trienens Institute for Sustainability and Energy, and co-leader of the Making Water Insecurity Visible Working Group at the Buffett Institute for Global Affairs.

Using nationally representative data from 148,585 adults in 141 countries from the Lloyd’s Register Foundation’s 2019 World Risk Poll, the authors found that the prevalence of expected harm from water supplies is high, with the highest rates in Zambia and the lowest rates in Singapore, with an overall average of 52.3%.

They also identified key characteristics of those who feared harm from their drinking water. Women, urban dwellers, those with higher education, and those struggling with their current income were more likely to fear harm from their drinking water.

Surprisingly, the researchers found that higher corruption perception index scores were the strongest predictor of expected harm from drinking water, ahead of factors such as infrastructure and gross domestic product.

Moreover, even in countries with consistent access to basic drinking water services, doubts about the safety of water were widespread. This was also the case in the United States, where 39% of respondents feared that drinking water could cause serious harm in the short term.

“Our research underscores the imperative to both provide clean drinking water and ensure that people have confidence in their water source,” said Joshua Miller, a doctoral student at the UNC Gillings School of Global Public Health and lead author of the study.

The researchers point out that because many contaminants are invisible and odorless and tasteless, it is difficult for consumers to assess the dangers and safety of their water supply. Without adequate information, many must judge the safety of their water based on past experiences, media reports and personal values ​​and beliefs.

“It’s also possible that people are right about the safety of their water,” Young said. “The good people of Flint didn’t trust their water, and they were absolutely right.”

The co-authors suggest actions that authorities can take to increase public confidence in drinking water, including efforts to make testing more accessible, translate test results, replace lead pipes, provide water filters for home use when contaminants are found, and improve access to safe drinking water.

“This kind of work can lead to greater attention and political will to prioritize these services in national development plans and strategies and move us closer to achieving universal access to safe drinking water,” said Aaron Salzberg, director of the Water Institute at the UNC Gillings School of Global Public Health.

Previously, Salzberg served as Special Coordinator for Water Resources at the U.S. Department of State, where he was responsible for developing and implementing U.S. foreign policy on drinking water and sanitation, water resources management, and transboundary water issues.