Bottled water 3500 times worse for environment than tap, study finds

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The impact of bottled water on the environment is 3500 times greater than tap water, a study suggests.

Researchers at the Barcelona Institute for Global Health found that if the entire population of Barcelona drank bottled water the effect on species loss and resource use would be 1400 and 3500 times higher, respectively, than if tap water was consumed.

If the city consumed bottled water alone the cost of raw material extraction would also increase by £60.3 million ($119m) a year.

Around 60 per cent of Barcelona's 1.3 million inhabitants consume bottled water, according to figures from 2016, despite recent improvements to the drinking water supply.

Both tap water and bottled water may contain harmful chemicals, the researchers said, with disinfection by-products such as trihalomethanes (THMs) higher in tap water.

Long-term exposure to THMs increases risk of bladder cancer, they said. The study, in Science of the Total Environment, set out to evaluate the burden of bladder cancer in the population of Barcelona linked to tap water consumption, and the environmental impact of producing bottled water.

Environmental impacts were estimated based on waste generation and disposal, the use of electricity, chemicals and plastic to produce tap or bottled water. The researchers found a small risk of bladder cancer associated with tap water, but this is offset with the reduction in environmental impacts.

Cristina Villanueva, lead author, said: "Health reasons don't justify the wide use of bottled water. Yes, strictly speaking, drinking tap water is worse for local health, but when you weigh both, what you gain from drinking bottled water is minimal."

She said "active policies" are needed: "In Barcelona, we could have education campaigns to make the public aware that the health gains from drinking bottled water are minor compared to the environmental impacts.

"We need to improve access to public water, to fountains, to buildings where you can bring your own bottle and don't need to buy one. We need to facilitate access to public water in public streets."