"Drinking around three litres of pure still filtered water a day makes
a vital contribution to health."
Emma Mitchell, the Guardian, 7 September 2002

Emma Mitchell is a "natural health therapist" who, in her column
for the Guardian, "Ask Emma", gives advice on how to live a healthier
life. Emma is usually pretty sensible, and her advice to drink more water is
in line with recommendations from most health experts.

Emma, however, has a thing about the need for water to be filtered. No mention
of H2O is complete without the qualifying word "filtered" attached.
So, in her 5 July column, she advises someone who suffers from acne that it
is likely she does "not drink enough filtered water". A few paragraphs
later, she advises that, if eating soya beans, to "first soak in filtered
water for at least eight hours".

One of the benefits of drinking more filtered water, according to Emma, is
that "it helps eliminate toxins". This is probably why she thinks
the water ought to be filtered: unfiltered tap water contains more toxins, so
is not as healthy as the filtered alternative.

I don’t disagree with any of this, but I do suspect that filtering water provides
such an insignificant health benefit that to think one ought to do it for the
sake of one’s own health is akin to thinking one can increase one’s life expectancy
by exercising for 91 minutes per week rather than 90.

Certainly the British
Drinking Water Inspectorate thinks so. They insist that "All public
water supplies in England and Wales are safe to drink and there is no need to
install additional treatment within the home as a health protection measure."
And they claim strict controls on levels of pesticides mean "additional
filtration is not required". Last year, 99.87% of water samples met legal
standards and none of those that failed posed a health risk.

The Consumer
Association also concluded in its report that tap water, filtered or unfiltered,
often tasted better than bottled water, and that no water source contained unsafe
levels of bacteria.

In the US, it seems that tap water quality is more variable. But even the Natural
Resources Defense Council, which campaigns for better quality tap water,
thinks that it is usually unnecessary to filter water. They recommend buying
a filter only "if you know you have a tap water quality or taste problem,
or want to take extra precautions".

Such is the insignificance of the health benefits of filtered water that not
even water filter companies make strong claims for them. The UK market leader
Brita,
for example, focuses instead on the general benefits of drinking water and only
on the taste improvements it claims its filters provide. It also openly acknowledges
that its cartridges cannot remove nitrates, reassuring us that "Water companies
have to comply with the standards set down in the E.C. water quality regulations."
But if these standards are good enough for what the filters can’t remove, then
surely they are good enough for what they can.

To think, therefore, that one really owes it to one’s heath to bother to filter
tap water when the tapped supply is perfectly decent is to get things out of
proportion. Unfortunately, such losses of proportion are all too common, as
we are generally very bad at assessing risks and tend to worry far too much
about things that are of little importance or which we have no control over
and ignore the basics of diet and exercise that really can affect both life
expectancy and quality of life. Ironically, paranoia about issues such as drinking
water may fuel the kind of stress which really might finish you off prematurely.

Arguably, this isn’t just an intellectual and prudential mistake but a moral
one. To worry about the infinitesimally small increase in risk to one’s health
drinking unfiltered water represents when one billion people do not access to
safe water and when a child dies every fifteen seconds from water related diseases
looks like moral myopia at its most narcissistic. That is why when I returned last year
from a trip to East Africa, where young children were frequently seen
carrying jerry cans for miles, I threw my water filter out in disgust.

But there’s a coda: I soon retrieved it when I discovered that in my flat,
unfiltered water just doesn’t taste nice. Which goes to show how because one
reason for doing something might be bad, there might be another good reason
for doing exactly the same thing anyway.