If you’ve tried everything and still can’t pin down the cause of your problems, give some thought to the water you’re drinking – and cooking with, and brushing your teeth with. Tap water is likely to contain chemicals that are deliberately added (chlorine or fluoride), plus industrial wastes and agricultural chemicals (like formaldehyde) that inevitably seep into local water supplies.

And that goes for wheels, springs, rivers or reservoirs, too. (incidentally, if you find you are allergic to fluoride – only a few people are – you’ll also have to avoid fluoride in toothpaste, vitamin supplements and dental treatments). As a vehicle for so many substances – even in amounts of well bellow so called toxic levels – tap water has been known to aggravate allergy in highly sensitive people.

William J. Rea, M.D., a cardiovascular (heart) doctor in Dallas, Texas, specializing in environmentally triggered reactions, has seen a whole slow of symptoms squarely to something in the water – everything from hay fever, post nasal drip, bronchitis and asthma to mouth pain, mouth ulcers, nausea, diarrhea, bloating, and urinary problems, among others.

We hope you aren’t that sensitive. But water is certainly some thing to take into account when trying to solve unexplained problems. The ideal methods is testing for water allergy is to fast for two days in a controlled setting – a hospital unit free airborne contamination – and then sample various water such as tap water, bottled water and so on to determine which do and which don’t cause problems.

For home testing, you can start by substituting bottled spring water for tap water for four or five days and see if your symptoms subside. Be sure to buy bottled water in glass containers, not plastic, with leaches chemicals into the water. Even that precaution may be in vain, however.

”Bottled spring water is transported in plastic lined trucks and stored in plastic vats, then bottled in glass.” says Dr. Rea. So if symptoms persist, switch to another brand until you find one you can tolerate. In Dr. Rea’s experience, Spring House and Mountain Valley water are the best tolerated by water sensitive people, followed by Perrier and Evian.

Others brands didn’t fare too well with his patients, but that doesn’t mean they won’t be okay for you. Ultimately, the bottled water you tolerate will depend on your own individual sensitivity. And, of course, cost and convenience are big factors.

”We try to encourage people to drink the least expensive water they can tolerate, because they have to not only drink it, but cook their food in it and wash in it.” says Sue Herbig, R.N., assistant to Dr. Rea and general manager of the Ecology Unit at Carrolton Community Hospital in Carrolton, Texas, a small community near Dallas.

Of course, anything you can do to purify your tap water is likely to be cheaper in the long run than going through stockpiles of bottled water daily. For some people, ousting allergenic substances from their tap water is as easy as boiling it for 30 minutes or storing it in an uncovered glass pitcher in the refrigerator overnight to allow the volatile chemicals to escape.

Others will have to look into home water treatment equipment. Running your tap water through ordinary charcoal filters won’t do the job unless the charcoal with some other purification material, such as activated carbon. In fact, you might as well skip the charcoal and just use the carbon.

Activated carbon is charcoal that’s been specially treated with heat and steam in the absence of oxygen so that particles cling to it like a pollution magnet; water that passes through it is as clean as mountain dew. Studies show that activated carbon filters effectively remove chlorine, industrial chemicals and some patricides, as well as bad taste and odors.

Of course, a carbon filter must be replaced every 3 week or 20 gallons of water (whichever come first) to avoid recontamination. The best activated carbon filters come in double canisters that are installed below the sink and then attached to a separate faucet that bypasses the existing water line. They’re more expensive the the small filters that look up to your faucet. But if you have a water problem, they’re worth it.

Table bellow shows the most efficient brands and types of home water treatment units, based on test of 30 activated carbon models conducted by the Environmental Protection Agency in July 1980. none, as you can see, are 100 percent efficient. But they’re the best of their kind available (see appendix for addresses of suppliers).

Dr. Rea says that some water sensitive people do equally well on distilled water. Distilled water is heated until it turns to stream, and then recondensed into water. Presumably, the chemicals and other debris are left behind. In truth, only ”fractional” water distillers actually get rid of all objectionable particles.

Water distillers have several drawbacks. They require a lot of water and they’re hard to keep clean. If you decide you want a water distiller anyway, look for one that’s easy to maintain. Once your tap water has been filtered or distilled, store it in clean, glass containers in the refrigerator.

Or you can buy bottled distilled water – just make sure it’s been ”fractionally” distilled. If you are indeed allergic to something in your water, the most practical arrangement of all probably would be to purify your tap water and drink bottled water away from home. Effective activated carbon water treatment units

Unit Name	Type	Average Reduction
		THM (%)*	NPTOC (%)+
Continental Water Filter Model 350	Line-bypass	99	87
Everpure Model QC4-THM	Line-bypass	99	55
Aquacell Bacteriostatic Water Treatment Unit	Faucet-bypass	86	23
Hurley Town And Country	Line-bypass	69	31
Seagull IV		70	30

Source: Adapted from “Fact Sheet/Update: Home Water Treatment Units, “by the Criteria and Standards Division (Washington, D.C.: Office of Drinking Water, Environmental Protection Agency, July, 1980).
* Thrihalomethanes (byproducts of chlorine). Most common water pollutants.
+ Non Purgeable Total Organic Carbon. A general indicator of contamination.