Many sources of tap water within North America are treated with chlorine. Chlorine is added to water in order to eliminate various microorganisms that may cause illnesses if left untreated. However, chlorinated water may also lead to other illnesses, including trihalomethane (THM) contamination. Presently, a large debate surrounding the safety of chlorinated water is ensuing.
Trihalomethane is a type of disinfection by-product that is produced when chlorine is added to a drinking water source. Amongst other things, THM contains chloroform. The amount of THMs that can be found within a water supply vary according to seasonal changes. While a large amount of chlorine is added to water during the summer months, this amount is reduced during the wintertime. The reason for this is that natural organic matter increases when temperatures are warmer.
Since chlorine is added to water in order to reduce any kind of waste matter, chlorine levels are increased during warmer months. In addition, wells and lakes do not contain as much chlorine as rivers and other types of surface water do. Surface water tends to have a vast amount of organic waste, which is why chlorine levels are higher within this kind of water source.
Some studies have shown that a high amount of THM may increase a person's risk of cancer. These studies have revealed that people who rely solely upon chlorinated water as a main drinking source for at least 35 years may have a greater chance of developing colon or bladder cancer. In addition, THMs may also contribute to miscarriages. A recent study has shown that pregnant women who drink chlorinated water tend to have more miscarriages than those women who do not drink chlorinated water.
While these health risks are of concern to many people, the benefits of chlorine upon drinking water are enormous. In fact, most studies show that the benefits associated with chlorinated water greatly outweigh any possible THM risk. Chlorinated water prevents diseases such as cholera and typhoid fever from forming. Without chlorine, these diseases would quickly spread from household to household.
Even though some risk may be associated with chlorinated water, most governments that rely upon chlorine to treat drinking water claim that a minimal amount of THM is safe for human consumption. People who are concerned about the effects of THM may be able to reduce the amount of THM consumed by using an activated carbon filter. Water filters that contain carbon have the ability to effectively remove chlorine by-products and chlorine. While these filters will help to reduce THM levels, it is important that the instructions included on a filter package be acknowledged.