Global skepticism about the safety of drinking water at an all-time high, study flags

29 Aug 2024 --- More than half of adults worldwide expect to be seriously harmed by their water within the next two years, according to a recent survey. We catch up with two of the authors of a new study led by international health experts from Northwestern University and the University of North Carolina, US, who provided valuable insights about public perceptions of drinking water safety.

“The association between self-reported anticipated harm and perceived public corruption may be partially explained by a decades-long decline in general trust in public institutions which, tellingly, is tracked in some locations by changes in bottled water consumption,” Sera Young, professor of anthropology and global health at Northwestern and senior author of the new study, tells Nutrition Insight.

A distrust in water quality negatively impacts health, nutrition, psychological and economic well-being — even when the water meets safety standards — because perceptions shape attitudes and behaviors.

“Trust in the capabilities and will of political institutions and leaders may influence risk perceptions, which are strongly and consistently associated with each other. For instance, a study in Australia found that political outlook influenced support for a local potable water recycling scheme and contributed to biases in information recognition and processing,” Young explains.

“Similarly, a study in the Netherlands found that generalized political trust was the strongest predictor of trust in water managers.”

Joshua Miller, Ph.D., Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, tells us that recent reports show that billions of people cannot access safely managed drinking water services and that water quality issues are shared globally.

“Many consumers similarly do not know the objective quality of their water. As such, individuals must evaluate water risks based on its taste and smell, prior experiences and personal beliefs,” Miller explains.

Feared harm from the water supply

The study in Nature Communications journal used nationally representative data from 148,585 adults in 141 countries from the Lloyd’s Register Foundation World Risk Poll. The researchers observed a high prevalence of anticipated harm from the water supply, with the highest in Zambia, the lowest in Singapore and an overall mean of 52.3%.

Doubts about water safety were prevalent even in countries with consistent access to basic drinking water services, including the US, where 39% of those polled anticipated serious harm from drinking water in the short term.

“If we think our water is unsafe, we will avoid using it. When we mistrust our tap water, we buy packaged water, which is wildly expensive and hard on the environment; drink soda or other sugar-sweetened beverages, which is hard on the teeth and the waistline; and consume highly processed prepared foods or go to restaurants to avoid cooking at home, which is less healthy and more expensive,” Young says.Perceptions about water quality influence all aspects of its use and the maintenance of related infrastructure.  

“Individuals exposed to unsafe water also experience greater psychological stress and are at greater risk of depression.”

The researchers also identified key characteristics of people who thought their drinking water would harm them. Women, city dwellers, individuals with more education and those struggling with their current incomes were more likely to anticipate harm from their drinking water.

“There will be lower willingness to use, maintain and pay for drinking water services if water is not trusted, correctly or incorrectly,” Young explains.

The researchers found that higher corruption perception index scores were the strongest predictor of anticipated harm from drinking water, more so than factors like infrastructure and Gross Domestic Product.

“The association between public corruption and anticipated harm from drinking water makes sense. If your government is unjust or unable to perform its duties, it’s reasonable to assume that your water may not be safely managed,” says Miller.

“Although risk perceptions do not always align with actual future harm, it is important because it increases psychosocial stress and influences health-related behaviors.”

Distrust in drinking water leads to the erosion of investment and use in public water infrastructure. To help restore public trust in drinking water, the researchers recommend that officials make testing more readily available, translate test results, replace lead pipes, provide at-home water filters when contaminants are detected and improve access to safe drinking water.

Meanwhile, new research by the Pennsylvania State University, US, reveals that the number of US children experiencing simultaneous food and water insecurity more than doubled between 2005 and 2020, with black and Hispanic children several times more likely to be facing this situation.

Difficult to assess quality

The researchers note that it is difficult for consumers to judge the hazards and safety of their water supply because many contaminants are invisible, odorless and tasteless. Without adequate information, many are left to evaluate the safety of their water based on prior experiences, media reports and personal values and beliefs.

“Poor drinking water quality and access may also contribute to human migration. Officials not only need to improve public trust in drinking water, but also need to do more to improve access to safely managed drinking water services — millions of individuals globally use water from unprotected wells or lakes and streams — as well as ensure that the water that is being supplied is of high quality,” says Miller.

The co-authors are proponents of rapid tests to detect common contaminants, akin to what was used for COVID-19 and strategies to get people to trust safe water. They suggest that future research collects information on objective drinking water quality and how people perceive the safety of their water to inform the factors that drive water risk perceptions and how people use water.

“People mostly act on what they believe, not based on the results of some test. If you mistrust your water, you are unlikely to use it. So, understanding how people think about and use their water can help us to anticipate issues like how to prove the safety of tap water,” says Young.

Miller notes that distrust in water quality leads to poorer mental health, a decrease in hydration efforts and changes in the prepared foods. “In a different study, we found that perceptions of water safety influenced how caregivers feed their infants, including breastfeeding duration and the types of complementary foods prepared,” he says.

“If people don’t trust their water quality, they may be less likely to pay for it, impacting the sustainability of water services. We can build pipes, but if people don’t trust their safety, they may not use them or invest in their upkeep,” Miller concludes.

By Inga de Jong