The three best water filters include activated-carbon systems,
reverse-osmosis systems and distillation units. Each one will filter
specific contaminants.
Carbon filters, dating back to the ancient Greeks and Romans,
trap contaminants as the water passes through the filter. Solid-car-
bon-block filters are the most effective for this process (as opposed to
granular-carbon devices). Carbon filters remove most organic chemi-
cals, such as pesticides and herbicides, chlorine, bacteria, metals
(lead, iron, copper) and radon, but they do not remove all minerals
(so they won’t soften water), or other compounds like arsenic,
nitrates, viruses and radioactive particles. Carbon filtration usually
improves the taste of the water. Some carbon filters contain silver
nitrate to prevent bacterial build-up; these filters may have the poten-
tial to leak silver, which is toxic. Ideally, the carbon cartridge must be
replaced periodically to maintain effectiveness and normal water
flow. Small carbon-filter units for water bottles are also available,
making safer water possible when you are away from home.
Reverse osmosis has been used for large-scale projects, such as
industrial desalination of seawater. Essentially, it’s a more complex
filtration system that includes carbon. Reverse osmosis removes toxic
metals and radiation contamination, except radon, but does not
remove many organic chemicals.
Distillation, like carbon filtration, is also an ancient method of
treating water. This is the best all-around method, as it “filters” more
items than any other single device, although it is not technically a fil-
ter process (it’s more like rain water, made from evaporating water
that becomes clouds). The process involves boiling the water to be
treated, and capturing and cooling the steam, which gives you clean-
er water. Distillation removes toxic metals and radiation contamina-
tion, except radon, and also removes minerals and thus softens the
water. It may not remove all organic chemicals.
Manufacturers of these different filtering devices can provide you
with more information on which contaminants they remove as well as
proper use, installation and maintenance costs. Also, it’s well worth
testing your water again after installing a water filter to be certain it
is performing properly.
126 • IN FITNESS AND IN HEALTH