Why do communities (in the US) treat our tap water with chlorine?

Question

Chlorine and flouride are both toxic chemicals so why do they dump it in our drinking water? My tap water smells like a swimming pool and drinking it makes my throat burn! Those levels of chemicals in the water are deadly. Why can't they treat city water through reverse osmosis or something that removes bacteria and such without dumping sh*t in there that is going to have adverse health effects and is harmful to the environment? Does this make sense to anyone else?

Answer 1

It's cost effective is likely the main reason, besides the significant public health concern.



When chlorine treatment was introduced in the early 1900's diseases like typhoid, cholera, and dysentery were commonly carried in drinking water and chlorination effectively eliminated them. BUT:

I quote:

"... the July [1992] issue of the American Journal of Public Health, researchers found that people who regularly drink tap water containing high levels of chlorinated hydrocarbons have a greater risk of developing bladder and rectal cancers than people who drink unchlorinated water. The study estimates that about 9% of all bladder and 18% of all rectal cancer cases are associated with long-term consumption of these hydrocarbons. This amounts to over 20,000 new cases each year!"



European water treatment has largely shifted to ozone and filtration, and they have found it works. Plus the chlorine residuals are about 10 times less than in US water.



Your question is timely for me because my public water company just sent me a letter announcing that the drinking water was above regulatory limits for trihalomethanes-and this is caused by chlorination. Dibromochloromethane is associated with cancer risk of one per million at 0.6 micrograms per liter. That's about the same as 6 parts per billion. Not terrible odds at 1 per million, but I don't like that ppb since the smallest I can measure in the lab is probably about 3 parts per billion. In other words, it’s barely measurable.



Anything like water that one consumes in large quantities daily for year after year deserves some attention. I am often the first to dismiss the latest crazy report about something else that will kill me, but with water it is statistically different. I see no choice but to filter drinking water. What else can you do?



Fluoride? Well, you probably get a fair amount in your toothpaste. It’s normally kept around 1 ppm in drinking water so I doubt it is really that much of a problem. I suspect that using fluoride cuts down on the amount of chlorine needed so it may not always add to costs of treatment.

Answer 2

When public health scientists discovered that there was a lot of (sh*t) bacteria in the water supply, reverse osmosis hadnt been invented yet, and distillation was too expensive. It still is too expensive and would add greenhouse gas emissions too. Anyway, to avoid many diseases, chlorine was the best option 100 years ago. It's not just the USA that does this.

..

Flourine has been proven to improve strength of kid's

tooth enamel, reducing work for dentists. Lately there's

been a controversy about correlations between increased consumption of bottled water (generally without flourine) and increases in tooth decay problems.

...

Hmmm I know it tastes bad, but you and your family are likely much healthier than you would be with all the different water-borne illnesses you now don't get.

Answer 3

Chlorine is used to kill bacteria and other harmful living organisms in the water. While clorine is harmful, it is less harmful than the disease germs that are there.



Technology has made it possible to foul our water supply and still live failrly normal healthy lives.



Some of the worst disease outbreaks in history were due to unsanitary water supplies. Chlorine prevents most of those from occuring in large populations today.