They came on the market initially as a cosmetic aid. Beauty experts advised their clients about the affects of chlorine on the hair and skin. Before showerhead systems came on the market, models often washed their hair in bottled water. If they are staying in a hotel, many of them still do.

Yes, chlorine dries out the hair and skin. The vapors irritate the eyes and respiratory system. They even trigger asthma attacks. But, the biggest long-term health risk is from THM exposure, chlorination byproducts.

The average dechlorinating shower filter does nothing to protect you from THMs. There are only two or three products on the market that do. One is very affordable, costing less than $70. Another is very expensive, costing over $200. Since they have the same effectiveness, I would choose the less expensive brand.

What is the long-term health risk of THM exposure? According to studies conducted in 2007, exposure to THMs in homes with chlorinated water doubles a person’s chances of developing bladder cancer. Exposure occurs in a variety of ways.

In the shower, they become gases and are inhaled. In the kitchen, when you are washing dishes by hand, the gases are again inhaled. When cooking with unfiltered water, they are again released. When you drink a glass of unfiltered water, you are ingesting them. They are present in many bottled beverages, as well.

In a bath or shower, the chemicals are absorbed through your skin, as they are if you swim in a chlorinated pool. If you live in the US, the level deemed safe by the EPA did not consider multiple areas of exposure. They were based on the assumption that your only source of exposure was through drinking and that you weighed 175 pounds.

As you can see, a dechlorinating shower filter is not the only thing that you need. You need an effective filter on your kitchen type. Just to let you know, Brita and PUR devices do NOT remove THMs or VOCs, another health hazard that exists in publicly treated supplies.

In order to make it easier for you, many companies provide product performance data, certifications from Underwriter’s Laboratory and certificates from the California Department of Health. If a company does not have those certifications or provide complete performance data before you buy, then you are probably getting a dechlorinating shower filter, but you are not getting full protection.

I believe, as do many health experts, that we can reduce the incidence of cancer in our lifetime, just by taking simple steps to limit our exposure to known carcinogens. You don’t smoke. You might eat organic food. Those are good steps to take, but limiting your exposure to THM is an excellent step, as well.

First, you sort out the avalanche of information about competing pure water appliances. I’ll do that for you here. By the time you finish reading this short article you’ll have a clear idea of the five types of pure home water systems there are.

And then you simply need to make a decision about what kind of water you want to drink. You have to do this, because these different systems all produce different pure water. Strange? Well, it’s also true — there is more than one kind of “pure”. This will become clearer in a minute.

First, then, how do we group all the different types of pure home water appliances?

I put them into just five groups.

First, and probably the most popular producer of pure home water, is the carbon filter system.

It’s well known in the industry that when you pass water through carbon it absorbs almost all the contaminants water carries. So that is the basis of these cheap, easily installed filters. Some companies add enhancements to clean out certain bacteria, but all of them will remove contaminants, including the organisms Cryptosporidium and Guardia.

At the same time they let through the essential, healthy, trace minerals like calcium and potassium that are dissolved in water. This is important, as we humans need these, and if we don’t get them from drinking water we have to rely on minerals in food — which bad cooking can remove.

Next, the ceramic filters.

They are also common and look a bit like carbon filters, but are made from the fossilized shells of microscopic algae which are molded into a filter that you can clean with a brush as dirt get stuck on the outside of the millions of tiny pores that the water is passed through. These pores are small enough to stop almost everything, while letting those essential natural minerals through. Some ceramic filters have nano-silver added to make it easier to get rid of any bacteria that clog the outside opening of the pores.

Some pure home water systems still work by distilling.

Not a good idea. When you boil water and then condense it again you literally remove everything from it. That includes all those minerals that you need. Basically, these were popular 50 years ago but are largely out of vogue now.

Reverse osmosis filters also produce pure home water.

They work on an interesting scientific principle. Water that is heavy with minerals, such as sea water, is put under pressure on one side of a special membrane barrier. By simply doing that the natural tendency of water to not creep through the barrier is reversed and it moves through to a chamber on the other side where it is collected as drinking water.

Not everything goes through, however. The minerals are left behind. The water is sterile, in effect. In submarines, these units are an excellent way of getting fresh drinking water from mineral-rich, salty sea water. However medical opinion now concedes that prolonged use of de mineralized water is not healthy. We do need the calcium and other things found in natural water supplies. So these systems are not recommended long term for you and your family.

Then finally, everything else, including bottled water, comes into the remaining group of pure home water appliances.

Some of these appliances sound like science fiction. For example, there’s a system that uses infra red energy to make water pure. That sounds plausible in itself, but the source of infra red radiation in these gadgets is often a semi-precious stone, like tourmaline. Calling something like this science fiction is generous — it sounds more like the Philosopher’s Stone of Medieval Europe.

Most of the appliances in this ‘other’ category are not suitable for home units.

And certainly bottled water is no better than untreated tap water, because the regulations governing its production require nothing more stringent than that!

So, there you have it. Practical pure home water appliances fall into four main groups. They all successfully filter out certain things. Now you just need to decide what you want left out and what you must have remaining on the other side of the filtering material. I can help you a bit further as you ponder this. My site at pure-drinkingwater.com has more information and a recommendation for the type of pure home water that’s safest for you and your kids.