Water chlorination info
Water chlorination has been one of the major disease prevention treatments of the 20th century. While very effective, this solution has its down sides.
As per 1993 research, water chlorination produces various byproducts, such as chloroform, bromodichloromethane, chlorodibromomethane, and bromoform. The trihalomethanes, are carcinogenic in the liver, kidney, and/or intestine of rodents (From : NIH).
Conclusion of that study suggests that organic byproducts of chlorination are the chemicals of greatest concern in assessment of the carcinogenic potential of chlorinated drinking water.
Exposure to THMs can come from ingestion (e.g., drinking water), inhalation (e.g., from showering or workplace exposure), or from absorption through the skin contact (e.g., from swimming in chlorinated water or from water vapor in the air). One study funded by the Centers for Disease Control found that people had higher levels of THMs in their blood after taking a 10-minute shower than after drinking a liter of tap water. (From: CA DOE)
It really comes down to finding the smallest of the two evils: waterborne illnesses, that have plagued human civilization for centuries, vs exposing yourself to carcinogenic chemical.
Pick your poison… or use activated carbon based filters (From: EPA)