“Tap water quality has increased substantially in Barcelona since the incorporation of advanced treatments over the last years,” said researcher Cristina Villanueva. “However, this considerable improvement has not been mirrored by an increase in tap water consumption, which suggests that water consumption could be motivated by subjective factors other than quality.”
The benefits of tap water
For the study, the researchers combined two methodologies -- one used for assessing environmental risks and benefits and the other for measuring health outcomes. The Life Cycle Assessment (LCA) gauges the environmental impact of bottled water, while the Health Impact Assessment (HIA) looks at the health-related outcomes. Using data from the Barcelona Public Health Agency, the team explored how bottled water and tap water impact the environment and consumers’ health.
Ultimately, tap water proved to be more beneficial to both the environment and consumers’ health than bottled water. The researchers estimated that if the entirety of Barcelona switched exclusively to bottled water, the cost of materials would be 3500 times higher and the burden on the environment would be 1400 times higher than if the city only used tap water. They said bottled water production on this scale would also impact the safety of ecosystems and contribute to the loss of some species of plants and animals.
Making a city-wide shift to tap water would also yield health benefits. The researchers found that tap water could add years onto residents’ life expectancies, especially if it was supplemented with filtration devices.
The researchers explained that the public perception of tap water and the perceived damages to consumers’ health are what drive most people to choose bottled water over tap water. However, they hope these findings help to shift that notion.