Faucet FiltersAdvice for people with severely compromised immune systems
Some people may wish to take special precautions with the water they drink. In particular, people with immune systems that are weakened by AIDS, chemotherapy or transplant medications are more vulnerable to microbial contaminants in drinking water such as Cryptosporidium.
Cryptosporidium is a microscopic
parasite that lives in the intestine of
infected animals and humans. It
passes in the stool in its dormant
oocyst form.The oocyst is protected
by an outer shell that allows it
to survive outside the body for
long periods of time and makes it
very resistant to chlorine-based
disinfectants. It occurs mainly in
surface water sources, such as
lakes,streams and rivers.In healthy
adults,Cryptosporidium can cause illness,
but for people with weakened
immune systems, it can cause
severe illness and even death.
Those who wish to take extra measures to avoid waterborne cryptosporidiosis can bring their drinking water to a boil for a full minute. Boiling water is the most effective way of killing Cryptosporidium.As an alternative to boiling water, people may take the following measures:
Use a point-of-use filter
Consider using point-of-use (personal use, end-of-tap, under sink) filters that remove particles one micrometer or less in diameter. Filters that use reverse osmosis, those labeled as “absolute one micron filters,” or those labeled as certified by an American National Standards Institute (ANSI) - accredited organization to ANSI/NSF Standard 53 for “Cyst Removal” provide the greatest assurance of removing Cryptosporidium. As with all filters, follow the manufacturer’s instructions for filter use and replacement.
Use bottled water
Check the label or call the bottler
to find out how bottled water is
treated. The following bottled
water treatments protect against
Cryptosporidium: reverse osmosis,
distillation, ultraviolet light,or filtration
with an absolute one micron
filter. Bottled waters derived from
protected well and spring water
sources are less likely to be contaminated
by Cryptosporidium than
those containing untreated municipal
drinking water from less protected
sources such as rivers and
lakes.
Those who choose to take these precautions should remember that they can be exposed to waterborne pathogens through water used for brushing teeth, making ice cubes, and washing fruits and vegetables – not just through water they drink.