The consumption of bottled water has been increasing sharply in the last years on a global scale. According to previous research, this trend can be partly explained by subjective factors like risk perception, taste, odour, lack of trust in public tap water quality and marketing by bottled water companies. A new study led by the Barcelona Institute for Global Health, published in the journal Science of the Total Environment, was aimed at providing objective data about three different water consumption choices: bottled water, tap water and filtered tap water.
Since tap water quality might differ between cities or countries, the research team focused in the city of Barcelona, due to the robustness of available data. The Life Cycle Assessment was conducted using a specific software and a method called ReCiPe, which allowed researchers to estimate the damage to ecosystems and to resource availability as well as indirect impacts in human health derived from the production process of bottled and tap water. The Health Impact Assessment used data on water consumption patterns and on levels of chemical compounds in water supply from the Barcelona Public Health Agency.
Results showed that if the whole population of Barcelona decided to shift to bottled water, the production required would take a toll of 1.43 species lost per year and cost of 83.9 million USD per year due to extraction of raw materials. This is approximately 1,400 times more impact in ecosystems and 3,500 times higher cost of resource extraction compared to the scenario where the whole population would shift to tap water.
Tap water quality has increased substantially in Barcelona since the incorporation of advanced treatments over the last years. 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.
One of this subjective factors is the perceived presence of chemical compounds in tap water. While it is true that tap water may contain trihalomethanes (THM) derived from the disinfection process and that THMs are associated with bladder cancer, this study shows that due to the high quality of the tap water in Barcelona, the risk for health is small, especially when they take into account the overall impacts of bottled water.
The researchers say that their results show that considering both the environmental and the health effects, tap water is a better option than bottled water, because bottled water generates a wider range of impacts.
The use of domestic filters, in addition to improving the taste and odour of tap water, can reduce substantially THMs levels in some cases. For this reason, filtered tap water is a good alternative.
News Source: ISGlobal
