Nov 05, 2009

Australian Study Suggests Rainwater Safe to Drink

Participants drank rainwater and compared health with those who drank filtered

A study by Monash University researchers into the health of families who drink rainwater has found that it is safe to drink.

The research was led by Associate Professor Karin Leder from the Department of Epidemiology and Preventive Medicine, in conjunction with Water Quality Research Australia.

"This is the first study of its kind,” Leder said. “Until now, there has been no prospective randomized study to investigate the health effects of rainwater consumption, either in Australia or internationally.”

The study involved 300 volunteer households in the Australian city of Adelaide, who were given a filter to treat their rainwater. Only a half of the filters were real, while the rest were “sham” filters that looked real but did not contain filters.

The householders did not know whether they had a real filter or not. Families recorded their health over a 12-month period, after which time the health outcomes of the two groups were compared.

"The results showed that rates of gastroenteritis between both groups were very similar,” Leder said. “People who drank untreated rainwater displayed no measurable increase in illness compared to those that consumed the filtered rainwater.”

Adelaide was the location chosen for the study as it the city with the highest use of rainwater tanks in Australia.

Leder said some health authorities had doubts about drinking rainwater due to safety concerns.

"This study confirms there is a low risk of illness,” she said. “The results may not be applicable in all situations; nevertheless, these findings about the low risk of illness from drinking rainwater certainly imply that it can be used for activities such as showering/bathing where inadvertent or accidental ingestion of small quantities may occur.

"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.”

The study was funded by the National Health and Medical Research Council and Water Quality Research Australia.