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There seems to be increasing concern about a substance called chloramine that is widely used as a disinfectant in drinking water around the world. It’s promoted as having a number of advantages over chlorine, which has been the disinfection of choice for most of the world for the last 100 years.

Chloramine has been used for 80 years in the US, but like any substance, we’re still learning more about it. Last week, two researchers published an article in the journal Science about potential health effects from chloramines. It got picked up by NPR, then reported on the blog TreeHugger, and re-posted at Alternet. I subscribe to their water channel in my RSS reader, and the content is highly variable—some of their reporting misses the mark, as I felt this piece did.

Unfortunately, they missed the happy drinking water quality story last week: Congress amended the Safe Drinking Water Act to limit the amount of lead in pipes and fixtures.

Here’s my comment on the chloramines story:

This is an extremely interesting and important topic, but this article misses the mark. Rather than contributing to public understanding of the issue, I only see fear-mongering.

Both chlorine and chloramine are toxic at high doses, and thus are regulated by the EPA. But, according the Centers for Disease Control, water disinfection with these chemicals has saved more lives than any drug ever invented. There are potential risks with these chemicals, which is why our water systems are highly regulated and professionally-managed. There seem to be more downsides to chlorine, hence the movement by many water suppliers to chloramine.

First, chlorine is often transported as chlorine gas, which could cause a problem if a rail car derails or is attacked. There was chatter about this after 9/11, but no one mentions it much these days. Chloramine is made from less hazardous materials.

Chloramine does not impart a taste or odor to water the way chlorine does. This seems to be one of the top factors why consumers choose expensive and environmentally-unfriendly bottled water over perfectly safe and ridiculously cheap tap water.

As noted, chlorine can cause the creation of so-called disinfection byproducts, the most famous of which are trihalomethanes, a suspected carcinogen. EPA is increasingly clamping down on these byproducts, prompting many water suppliers to look at alternatives.

Lastly, disinfectants are only effective at keeping disease-causing bacteria and viruses from growing in drinking water while the dose or “residual” is above a certain concentration, and stays that way until it reaches your home. Chloramine has a longer-lasting residual, which means safer drinking water.

Chloramine has been certified as safe by the US EPA, many states’ Departments of Public Health, and the National Sanitation Foundation.

We DO need ongoing research on the long-term consequences of using any chemicals, looking at impacts to human health and the environment. Sedlak and von Gunten’s article is an important contribution, but it does not mean that we should abandon chloramine.

Keep calm and carry on.