Safety of drinking rainwater sinks further

A NEW study has claimed that rainwater almost everywhere on Earth - even in Antarctica - is too toxic for human consumption.

Yet, we are continually told not to waste natural resources and encouraged to collect rainwater for household use, as many families all around the world do. So is the new discovery a cause for alarm?

New findings on rainwater

Researchers at the University of Stockholm have found that potable water all over the planet exceeds levels of PFAs (per- and poly-fluoroalkyl substances commonly used in non-stick cookware, waterproof clothing and stain resistant fabrics) as prescribed by the latest US guidelines on safe drinking water.

Also known as “forever chemicals” because they don’t break down, PFAs (now some 4,700 of them) have been used by consumer goods manufacturers since the 1950s. As these man-

made chemicals leak into the environment during production, use and disposal, they are in the air we breathe, the water we drink and the food we eat.

But once scientists reported the harmful effects of some PFAs on human health, the acceptable levels of these in drinking water have been continuously monitored, revised and reduced over the last two decades.

The latest health advisory from the US Environmental Protection Agency has seen a drastic decrease in the recommended level for four PFAs, widely present in rainwater. Hence, based on that, the Swedish study claims “rainwater everywhere should be judged unsafe to drink” - including the treated rainwater coming out of taps in New York and Washington.

Was rainwater ever safe?

Though rain is commonly believed to be the purest form of water, by the time it is collected by us for household consumption it is usually contaminated by chemical, bacterial and viral pollutants as it falls.

Of course - location matters. The purity of raindrops in, say, a bustling city would be vastly different from those falling in remote forested areas. So before man’s growing polluting footprint on the planet, rainwater was safe enough to drink. Even now, in some places with low levels of contaminants, consuming water from the heavens is possibly less of a health risk than that flowing in the public drinking water supply.

However, most municipal and health authorities such as the Center for Disease Control & Prevention advise against drinking collected rainwater before treating it in some way, such as boiling, to prevent illness and disease outbreaks.

Waste not, want not

In India of course, especially in rural areas, harvesting rainwater for crops, household needs and drinking, has been a traditional practice for generations. And with more than half the population lacking in access to safe potable water, conserving rainwater for consumption is more a necessity than a choice - the new alarm over high levels of PFAs notwithstanding.

It is certainly not something that would bother Telengana resident Ponnada Vasantha Kumar who firmly believes that drinking rainwater - which he has been doing for 34 years - is his secret to good health. The retired banker from Sangareddy Town collects the water on his rooftop and through a filtration system stores it in six drums on his balcony.

The water he drinks is kept in a copper vessel. He says: “We have nature’s biggest gift in the form of rainwater but unfortunately we don’t use it. I can’t describe in words the taste and benefits of rainwater.”