about Brita type filters-- NO!
Jigglebelly, I don't have exact stats in my head, but years ago I checked out the alternatives because I didn't like the water where I was living. No one system does it all (refer to chart link below).
Here's some info for you:
Brita-type filters are a combo of ion exchange and carbon filter, and they do a great job removing unpleasant smells & tastes like chlorine, leaving a fresh, spring water taste.
But the most harmful contaminants will pass right on through. Brita advertises certification with the NSF, but it's
misleading in one respect: the NSF certifies that approved systems do not
add contaminants, a huge difference.
Somewhere else I saw mention of the
reverse osmosis filter systems-- that's what I used for years. Where I was living in Canada, they're considered effective for "99% of contaminants commonly found in well and tap water". However, ineffective against inorganic contaminants-- like lead.
As well, effectiveness is against 'commonly found' contaminants in Canada & US.
Filtration systems will
not remove the tiniest particles-- viral particles such as hepatitus (see info at end on biological particle size). For that, you need a water purification system-- a combination of disinfection for viruses and bacteria, and a microfilter to remove cysts containing microbes like giardia. In the US, effective microbiological water purification systems are
tested and approved by the EPA. If it does NOT have EPA certification, it's suspect.
Note, again, these purification systems remove biological contaminants. According to the chart link below, only distillation is effective in removing metal contaminants.
Obviously the chart is commercial-- it's intent is to sell those reverse osmosis systems, so it blankets all viruses and bacteria together, which is misinformation. It is informative though. The info given on this chart hasn't changed since I purchased a system in 1990.
http://www.water-filter-system.com/compare-filtrations-methods.html
Interesting to note: boiling of water is considered effective in removing bacterial/viral contaminants. It acts like the disinfection aspect of a water purification system. I suppose a 2-stage method would work: boil the water and then run it through a Brita, for biological purity
and taste. I guess the same might be true for those iodine or chlorine-type tablets-- reap the benefits and then use a Brita for better taste. Just a thought. Lots of work, though!
Here's some more info on biological contaminants. No, I'm not a fanatic... one brother is a scientist, a molecular virologist, so I get bopped over the head every once in a while. I don't call him much, otherwise I'd be a wreak.
(from: extremewater.com-- another commercial site, this one advocating those microbiological water purification systems, but this is worthwhile reading regardless)
MORE INFO on BIOLOGICAL CONTAMINANTS:
Protozoa, one-celled animals varying in size from 2 to 100 microns (one micron is one-millionth of a meter, or 0.00004 inches), live in many insects and animals, and survive in cysts (protective shells) when outside of an organism. They include Giardia lamblia and Cryptosporidium, two of the ubiquitous parasites in the United States. "In one of our studies we had over 10,000 samples from streams all across America, Alaska to Arizona, and we didn't find one without giardia" according to Chuch Hilber, professor emeritus at Colorado State University, and a parasitologist who has spent a lifetime analyzing backcountry water. When a municipal water treatment plant in Milwaukee failed in 1994, an estimated 400,000 became sick from Cryptosporidium, and 30 died. Because protozoa reproduce so rapidly inside a host organism, ingesting only a few causes disease. Symptoms include severe diarrhea, abdominal cramps, bloating, fatigue and weight loss.
Bacteria can be considerably smaller than protozoa, measuring as little as 0.2 microns. Many are symbiotic, but others cause a variety of infectious disease, including typhoid, paratyphoid, dysentery, colibacillosis and cholera. Bacteria can be present in both wild and domestic animals. Once in the water, they can survive for weeks, even longer if frozen in ice.
Viruses are the smallest agents of disease, and perhaps the most problematic. Because they are as minute as 0.004 microns, they can pass through the smallest filter. They are also widespread: according to Herbert DuPont, Chief of Internal Medicine at St. Luke's Episcopal Hospital in Houston who has spent his career studying waterborne pathogens, "Protozoa-giardia and crypto-are the number one threat, then viruses, then bacteria." Charles Gerba, the preeminent water microbiologist from the University of Arizona, agrees: "As a general rule of thumb, you can never be sure viruses aren't in your water." Waterborne viruses include hepatititus A and E, Norwalk virus, rotavirus, echovirus and poliovirus. Since there is no treatment for viruses, they are particularly dangerous, especially among immunno-compromised populations. "In developing countries, " according to Gerba, "hepatitis A and E are extremely dangerous, with hepatitis E causing 1 to 2 percent mortality in the general population, and a horrific 20 to 30 percent mortality in pregnant women."
enough already!
D
