Fact: Chlorine is harmful.

Chlorine is used to treat tap water. It kills disease-causing contaminants before they reach your home. The problem? It’s downright dangerous in high doses. And it can react with naturally occurring organic compounds to create hazardous by-products. After all, chlorine can be linked to cancer, heart disease, and even death.
The rationale for chlorine: The health risks from its by-products are far less intense than the health risks associated with microorganisms it destroys. That’s a fancy way of saying chlorine is a necessary evil. The issue is chlorine levels vary based on all kinds of factors: source, temperature, season, location, etc. And despite regulations, we continue to have problems...
Tap water in Wrangell, Alaska, was found to be contaminated with chemicals that occur when chlorine interacts with naturally-occurring organic compounds in water. Officials were forced to urge locals who were elderly, pregnant, or had health problems to avoid the tap water unless using a filter. Some cities, like Delray, Florida, reportedly failed to complete their daily chlorine tests. What are they hiding? Meanwhile, in New Zealand, one city has taken steps to move away from chlorine entirely.
A necessary evil? Perhaps. Though the regulations could probably use a second look. Harmless? Absolutely not.