What are the 4 most common trihalomethanes?
Trihalomethanes are a group of four chemicals—chloroform, bromodichloromethane, dibromochloromethane, and bromoform—formed, along with other disinfection by-products, when chlorine or other disinfectants used to control microbial contaminants in drinking water react with naturally occurring methane, often derived from …
What are the health effects of trihalomethanes?
When people consume trihalomethanes at high levels over many years, they increase their risk of developing bladder cancer. Other health effects that may be associated with trihalomethanes include rectal and colon cancer, and adverse developmental and reproductive effects during pregnancy.
What can trihalomethanes cause?
In humans, bladder and colon cancers are linked with these THMs. Exposure to higher amounts of THMs may also cause reproductive problems and birth defects. The health risks linked with THMs in water are very small, compared to the risk of potentially deadly infectious diseases in drinking water that is not disinfected.
How do you get rid of THM in water?
For trihalomethane removal, aeration – either by diffused-air or with towers – and adsorption – either by powdered activated carbon or granular activated carbon – is effective.
What are the four THMs?
The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.
What causes THMs?
THMs are trihalomethanes, chemical compounds that can be formed when water is disinfected with chlorine. THMs occur when chlorine reacts with organic matter in water, and for this reason are more common in surface water supplies throughout Canada.
What causes high THM in water?
THMs are formed in drinking-water primarily as a result of chlorination of organic matter present in raw water supplies. The rate and degree of THM formation increase as a function of the chlorine and humic acid concentration, temperature, pH, and bromide ion concentration (Stevens et al., 1976; Amy et al., 1987).
Why are trihalomethanes bad in water?
Trihalomethanes (THMs) are the result of a reaction between the chlorine used for disinfecting tap water and natural organic matter in the water. At elevated levels, THMs have been associated with negative health effects such as cancer and adverse reproductive outcomes.
What is the suspected health risk of trihalomethanes THMs in drinking water?
The MCL for TTHM is based on potential cancer risks following a lifetime of drinking the water. TTHM are considered to be possibly carcinogenic to humans by USEPA because of evidence of carcinogenicity in experimental laboratory animals and limited evidence in people.
Do water filters remove THM?
Trihalomethanes (THMs) are among the most dangerous chemical compounds that find their way into the water supply. For example, Brita water filters and PUR water filters do not remove THMs from water. Both Aquasana and Amway water filters are proven to be effective at removing more than 99% of THMs from water.
How do you treat THM?
The easiest way to reduce or eliminate THMs in drinking water is to use a water pitcher with a carbon filter, install a tap-mounted carbon filter, or to use bottled water. When using a filter, check to verify that it is certified to remove THMs and follow replacement instructions recommended by the manufacturer.