Trihalomethanes are formed as a by-product predominantly when chlorine is used to disinfect drinking water . They are generally referred to as disinfection by-products . They result from the reaction of chlorine or bromine with organic matter present in the water being treated. (

Are Trihalomethanes harmful to my health?


….. At elevated levels, THMs have been associated with negative health effects such as cancer and adverse reproductive outcomes. Now a study by government and academic researchers adds to previous evidence that dermal absorption and inhalation of THMs associated with everyday tap water use can result in significantly higher blood THM concentrations than simply drinking the water does [EHP 113:863–870]. The results of this exposure assessment study could serve as a guide for future epidemiologic investigations exploring the potential connection between THMs in tap water and adverse health effects. (1)

…… The researchers recruited seven healthy participants aged 21–30 years to spend two 24-hour periods (usually one week apart) in one of two study residences. The study residences were typical ranch-style homes, one located in North Carolina, the other in Texas. The North Carolina house was served with a water supply higher in THMs than that of the Texas house.

Over the total two days, each participant performed 14 activities using tap water. These included drinking a hot beverage prepared with tap water (THM-free bottled water was consumed except when drinking was part of a test activity), washing their hands, showering, washing dishes both by hand and in a dishwasher, and washing clothes in a washing machine. The water use activities were rigidly scheduled and controlled for exposure time and water temperature.

The team took baseline measurements of the THMs in ambient indoor air, cold tap water, and subjects’ blood and exhaled breath just before and just after each activity. The ratio between pre- and post-activity measurements illustrated the impact of each activity on participants’ blood and exhaled breath THM concentrations; twofold or greater deviation from baseline was established as meaningful.

Relatively high pre- to postactivity ratios were observed for several of the activities. For example, blood concentrations rose 5- to 15-fold as a result of showering in the North Carolina participants, and rose approximately 5-fold in the Texas subjects. The results confirm that showering and bathing are important sources of THM exposure; they also provide evidence that other THM exposure scenarios, such as washing dishes by hand and being exposed to a cohabitant’s shower steam, may also be important. (1)


Other articles on this topic:

How can trihalomethanes be removed from the water?

The use of carbon filters will remove trihalomethanes from your water.

What Carbon Filters Remove

Carbon filters are very effective at removing a number of deleterious chemicals, reports the Home Water Purifiers and Filters site. These include chlorine, benzene, radon, solvents trihalomethane compounds, volatile organic chemicals such as pesticides and herbicides and hundreds of other man-made chemicals that may come into contact with tap water as it proceeds through the system. In addition, filters remove bad tastes and odors from the water. (

For trihalomethane removal, aeration ……. adsorption – either by powdered activated carbon or granular activated carbon – is effective. (

We have developed a product that will remove trihalomethanes from your water.  This product will also soften your water.

Dynamic duel: whole house carbon filtration and water softener (all in one package):

Boyett’s portable exchange tank soft water cures eczema or psoriasis

Portable Exchange Tank Service

Please contact me for rental information on these products.

text is best 602.291.4157

office (480) 969-7251

P.S We specialize in providing water softeners to Gilbert Az.


Posted by Hayden Boyett’s family water treatment 12.06.18