SYDNEY (Reuters Life!) - Drinking untreated rainwater is safe for your health, according to an Australian study.

Rain drops on a car window reflects a man walking past a stock index board in Tokyo August 10, 2009. REUTERS/Kim Kyung-Hoon

Researchers from Melbourne’s Monash University looked at 300 homes that used rainwater collected in water tanks as their primary drinking source in what they described as a “world first” study that comes amid growing criticism of bottled water.

All of the homes were given a bench top filter and told it would remove any potential gastroenteritis-causing organisms from their water, but half of the devices did not contain filters.

Families recorded their health over a year and the researchers found that the rate of gastro cases recorded by these two groups were very similar and also matched the broader community who drank treated tap water.

“People who drank untreated rainwater displayed no measurable increase in illness compared to those that consumed the filtered rainwater,” researcher Karin Leder, head of the infectious diseases unit at Monash University’s department of epidemiology, said in a statement.

“This study confirms there is a low risk of illness ... Expanded use of rainwater for many household purposes can be considered and in current times of drought, we want to encourage people to use rainwater as a resource.”

Leder said some health authorities had doubts about drinking rainwater due to safety concerns, particularly in cities where good quality mainstream water was available.

Australia’s prolonged drought has prompted a rise in water tank installations.

But Leder did caution that the families involved in the study were routine rainwater drinkers and may already have built up defenses against possible infections.

The study came amid growing concern about the environmental impact of bottled water products, which are often transported long distances and packaged in plastic which clogs landfills.