Researchers in a world-first study by Monash University in Australia found rainwater is safe for household use.
study was led by Associate ProfessorKarin Lederfrom the Department of Epidemiology and Preventive Medicine in conjunction with
Water Quality Research Australia (previously the Cooperative Research Centre
for Water Quality and Treatment).
"Until now, there has
been no prospective randomised study to investigate the health effects of
rainwater consumption, either in Australia or internationally," Leder
The study involved 300 volunteer households in
Adelaide that were given a filter to treat their rainwater. Only half of the
filters were real while the rest were “sham” filters that looked real but did
not contain filters.
The homeowners did not know whether
they had a real filter. 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. People who drank untreated rainwater
displayed no measurable increase in illness compared to those that consumed the
filtered rainwater," Leder says.
Adelaide as the location for the study since it is the city with the highest
use of rainwater tanks in Australia.
In the announcement,
Leder said some health authorities had doubts about drinking rainwater due to
safety concerns, particularly in cities where good-quality mains-water is
"This study confirms there is a low risk of
illness. 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
"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," she
Source: Monash University