Chlorine probably saved your life today
May 28, 2016 5:51 PM   Subscribe

We don't know for certain if the Gas! GAS! in Wilfred Owen's devastating poem was chlorine, but we do know that it can kill and maim in the way he described. But when his poem was written, chlorine had already begun to play a completely different, quietly heroic role, going on to save hundreds of millions of lives over the course of the 20th century. The battle to get chlorine accepted for water treatment was understandably dramatic given its known killing power. In 1908, John Leal, in almost complete secrecy, without any permission from government authorities (and no notice to the general public)... decided to add chlorine to the Jersey City reservoirs.

He wasn't the first to put chlorine in drinking water. Among others, Sims Woodhead fought the 1897 typhoid epidemic in Maidstone with a maverick one-off flushing of the water mains with chloride of lime.

Enslow and Wolman finally, a couple of years after Wilfred Owen wrote Dulce et Decorum Est, "devised a precise formula to use in chlorinating city water supplies. The pair analyzed all the relevant factors, including acidity, bacteria, purity, as well as factors related to taste. Their method provided the first rigorous scientific standards by which chlorination could be uniformly and safely controlled."

As a result, cholera, typhoid fever and many other waterborne illnesses have been virtually eliminated from the developed world. Chlorinated clean water was responsible for nearly half of the total mortality reduction in major cities, three-quarters of the infant mortality reduction, and nearly two-thirds of the child mortality reduction.

Being able to turn on the tap without risking a major illness is a daily economic advantage. We do not need to remember to add Chlorin to the water supply every morning or risk having our life devastated, a persistent poverty trap. Any failure of the water treatment system is both a scandal (previously) and an immediate health crisis. "The Walkerton Public Utilities Commission operators engaged in a host of improper operating practices, including failing to use adequate doses of chlorine..."

But for most of the 20th century, scientists didn't actually know how chlorine killed pathogens. Recent work has shown that the near-neutral charge of hypochlorous acid allows it to invade cells and hypochlorite inside cells causes proteins to clump together - and we have also learned that "our own immune cells produce hypochlorite as a first line of defense to kill invading microbes". In other words, the water treatment part of our extended phenotype shares some mechanisms with the bacteria-fighting part of our actual phenotype.

In its celebration of the year 2000, (the aptly named, for our purposes) Life magazine declared that the filtration of drinking water (plus the use of chlorine) is probably the most significant public health advance of the millennium.
posted by clawsoon (40 comments total) 83 users marked this as a favorite
 
As someone who once worked in a water plant where massive truckloads of chlorine arrived every month, this is relevant to my interests. The care that must be taken with concentrated chlorine is pretty extraordinary, because if a tank begins to leak, people will faint and perish before they have the chance to take any action.

I've heard that the plant where I used to work is converting to onsite bleach generation to replace the chlorine, and a lot of people are unhappy about this.

-goes to research differences between bleach and chlorine-
posted by ELF Radio at 6:50 PM on May 28, 2016 [4 favorites]


It's not the poison it's the dose!
posted by sammyo at 7:08 PM on May 28, 2016 [3 favorites]


It's not the poison it's the dose!
Is there a master list somewhere of "ways in which we administer weak poisons or pathogens which cure or prevent more serious illnesses"? Or two lists, one for the successful treatments and one for the counterproductive ones?

This is the second time in as many days that Metafilter had me wondering that. Giving malaria to AIDS victims may have been a monstrously bad idea... but when we gave malaria to syphilis victims it cured most of them and earned a Nobel Prize. Chemotherapy is probably the most famous tightrope walk between "not enough of this won't kill your disease" and "too much of this will kill you". Mercury compounds were used for centuries despite those categories often overlapping. Even vaccines sort of fit the pattern, although the reduction in vaccine danger is qualitative, not just quantitative.
posted by roystgnr at 7:46 PM on May 28, 2016 [21 favorites]


Today's Safety Tip: Do not pour liquid bleach into a vessel which contains dried residue from Miracle-Gro solution.


"Surely the bubbling sound gave it away?"
"No."
"The faint brown mist in the container as you began to fill it from the tap?"
"No."
"Then it must have been the sensation of inhaling steel wool whilst simultaneously having your eyes sandblasted?"
"Bingo."

posted by Johnny Wallflower at 8:04 PM on May 28, 2016 [32 favorites]


God help us if the anti-flouride crowd realizes that there's chlorine in the water too.
posted by TrialByMedia at 8:29 PM on May 28, 2016 [36 favorites]


I only use homeopathic water sanitizers at very low doses.
posted by benzenedream at 8:41 PM on May 28, 2016 [3 favorites]


I love Sam West.

Yeah, Owen doesn't mention it but all indicators led to Chlorine gas.

I love Sam West.
posted by clavdivs at 8:43 PM on May 28, 2016 [1 favorite]


"ways in which we administer weak poisons or pathogens which cure or prevent more serious illnesses"? Or two lists, one for the successful treatments and one for the counterproductive ones?

Antiobiotics get to go on both lists.
posted by the agents of KAOS at 9:38 PM on May 28, 2016 [4 favorites]


Is there a master list somewhere of "ways in which we administer weak poisons or pathogens which cure or prevent more serious illnesses"? Or two lists, one for the successful treatments and one for the counterproductive ones?

There is no medication that is not toxic at a big enough dose.
posted by aubilenon at 12:49 AM on May 29, 2016 [6 favorites]


wrong, there is no ld50 for puppy smooches
posted by poffin boffin at 12:59 AM on May 29, 2016 [44 favorites]


The first time drinking water was continuously disinfected by chlorine was in 1902, in Middelkerke, Belgium. In 1905 chlorine was added to the water supply in Lincoln (UK). And in 1906 Nice (France) started purifying water with ozone.
posted by blub at 1:24 AM on May 29, 2016 [2 favorites]


Is there a master list somewhere of "ways in which we administer weak poisons or pathogens which cure or prevent more serious illnesses"? Or two lists, one for the successful treatments and one for the counterproductive ones?

Most plant foods have some low level toxicity as well. These are their defenses against predators and infection. Given the health benefits of plant consumption one has to wonder if they function as either very low level chemotherapy or as microbiome management via anti-bacterial toxicity rather than simply by being "not meat".
posted by srboisvert at 5:26 AM on May 29, 2016 [4 favorites]


Chlorination is not universal, even in the developed world. In the 1980s, I lived for a year in the town of North Andover, Massachusetts. I did not know it when I moved there, but N. Andover was the last place in MA that got its municipal water from a surface lake and pumped it into homes with no treatment at all. I arrived in the winter. In the early summer, the water in the toilet turned a bright fluorescent green. That lasted for several weeks, until the algae in the lake died, at which time the water in the toilet turned tea-brown. Some of the algae bloom may have been a result of the McMansions that had been built with lawns sloping down to the water-supply lake, and the chemicals used to keep the grass healthy. In the fall, I learned from the Boston Globe that the town had been ordered by the state to begin chlorination of the water due to a Giardia infestation. I had long since been buying bottled water, and soon moved out. The next year, the town began work on a water-treatment plant.

There are also a lot of people who have well water, and they don't all live in far rural areas.
posted by Kirth Gerson at 5:44 AM on May 29, 2016 [9 favorites]


wrong, there is no ld50 for puppy smooches

Is when they've been eating le poop.
posted by ROU_Xenophobe at 5:48 AM on May 29, 2016 [7 favorites]


Kirth Gerson: N. Andover was the last place in MA that got its municipal water from a surface lake and pumped it into homes with no treatment at all.

From a surface lake with no treatment?? Did the town council open each meeting with a round of Russian roulette, too?
posted by clawsoon at 6:01 AM on May 29, 2016 [14 favorites]


Did the town council open each meeting with a round of Russian roulette, too?

I never attended any Selectmans' meetings, but the evidence of their priorities is all over town: The regional trash incinerator. The regional wastewater treatment plant. The regional airport. The other regional trash incinerator. The aforementioned McMansions on the shore of the water supply. Along with a couple of chemical plants and possibly the worst Chinese restaurant ever (apparently employing no Asian people), and I was glad to get out of there.
posted by Kirth Gerson at 6:19 AM on May 29, 2016 [4 favorites]


blub: The first time drinking water was continuously disinfected by chlorine was in 1902, in Middelkerke, Belgium.

I'd love to know more about the story in Middelkerke. I see that they were some kind of resort or health spa; did they advertise the chlorination as a Health Miracle!(TM), or did they quietly put it in place as a safety measure?
posted by clawsoon at 7:18 AM on May 29, 2016 [1 favorite]


It's like the homeopathy of water. I know it isn't, but I wanted to type it
posted by A189Nut at 8:08 AM on May 29, 2016


When I applied to do marketing work for my current employer they said, well you know we design water and wastewater treatment plants, some people think that's boring or gross. To which I replied, well they are wrong, without these things people die, they are what make life better. In doing this work I have come to feel awe for just how much engineering and innovation goes into turning sewage back into water safe to discharge into lakes. Now we've started working on reuse systems that skip that step and purify it to potability.
posted by emjaybee at 8:53 AM on May 29, 2016 [24 favorites]


God help us if the anti-flouride crowd

Wait, there's flour in the water? But I'm gluten free. I can only drink the water if it's spelt flour.

(Or if it's spelt fluoride, obviously. I love my strong teeth and less-damaged than they'd otherwise be bones. I wasn't joking about the cœliac disease.)
posted by ambrosen at 9:27 AM on May 29, 2016 [5 favorites]


I can only drink the water if it's spelt flour.

That's a terrible way to spell "water."
posted by ROU_Xenophobe at 10:02 AM on May 29, 2016 [13 favorites]


The people of Pompeii had great teeth because of naturally-occurring fluoride in their water. AND LOOK WHAT HAPPENED TO THEM!!
posted by clawsoon at 10:10 AM on May 29, 2016 [11 favorites]


I'm down with chlorination of water for all the purposes noted above. However, D.C. gets a bit carried away, and I'll bring my hand to my face hours after showering and think, Huh, I didn't swim in a pool today, did I? In certain places I've lived, it's gotten to where I have to buy a chlorine filter for the showerhead.
posted by the sobsister at 10:15 AM on May 29, 2016 [2 favorites]


The problem in Pompeii was more silicon and iron.
posted by maryr at 10:19 AM on May 29, 2016 [3 favorites]


If chlorination is done right, you hardly taste or smell it at all. The stuff that you smell is the stuff that's superfluous and sits around without any dirt to bind themselves to. So if it smells, there's too much of it being used.
posted by Too-Ticky at 10:23 AM on May 29, 2016 [3 favorites]


I heard Michael McGuire (author of The Chlorine Revolution) talk at an American Water Works Association conference about the history of chlorine for disinfection of potable water, and it was very eye-opening.

In general, people have no perception of how delicate the chemical balance is when it comes to potable water supply. The Washington, DC, lead-in-drinking-water issues in the early 2000s (which presaged the current problems in Flint, MI) were as a result of a switch from free chlorine to chloramine as a disinfection residual (i.e. the amount of disinfectant that is sent out in to the distribution system AFTER the treatment plant to continue to kill/inactivate pathogens in the pipes). That in itself was a response to bacteriological contamination back in the mid-1990s, when it was determined the free chlorine residual wasn't as effective, leading to several boil water alerts. This inadvertently caused a double whammy on the lead pipes: the passivating effect of the free chlorine on the pure lead was lost, and also the addition of ammonia depressed the pH to make the water more corrosive. The corrosion inhibitor that was initially selected was not effective enough, so lead started leaching into the water. The switch to an orthophosphate-based inhibitor was the final solution, but that impacts the treatment on the other end, as the wastewater treatment plant has to remove more phosphorus so as to not worsen the water quality issues in the Chesapeake Bay.

Why don't we just add more chlorine to begin with? Well, apart from it being a poison itself (it's actually killing living things we don't want to consume to make us sick), it can also react with organic material in the water (that naturally occurs in the rivers and lakes that provide the source water) to form disinfection by-products like trihalomethanes and haloacetic acids, which are carcinogens.

So pick your poison (literally): chlorine poisoning, lead poisoning, or cancer? The fact that we DON'T all get sick or die from drinking our public water supply is down to the dedicated and professional workers who look out for these issues every day, the true heroes of public sanitation. Unfortunately, like any civil engineering situation, we only really ever appreciate how important a role they play in our lives until something goes wrong, or someone turns a blind eye. Just ask the residents of Flint.
posted by ccalgreen at 10:25 AM on May 29, 2016 [33 favorites]


But I'm gluten free. I can only drink the water if it's spelt flour.

Total derail, but spelt has gluten in it.
posted by aubilenon at 10:34 AM on May 29, 2016 [5 favorites]


emjaybee: In doing this work I have come to feel awe for just how much engineering and innovation goes into turning sewage back into water safe to discharge into lakes. Now we've started working on reuse systems that skip that step and purify it to potability.

My immediate worry would be that you'd get large numbers of treatment-resistant organisms a lot faster with a closed loop. When you send them out into the lake, they at least have to compete in a completely different environment where resistance slows them down instead of being a benefit. Is this not a problem, or is it a problem that we've figured out how to deal with?
posted by clawsoon at 11:17 AM on May 29, 2016 [1 favorite]


I'd love to know more about the story in Middelkerke
Me too! I searched quite a bit to find more information, but couldn’t find any details. The person who designed the system was Maurice Duyk. He doesn’t have a Wikipedia page (not even in Dutch). It surprised me that there is so little information about this. It's mentioned in a few textbooks as a factoid, and that's it.
posted by blub at 11:33 AM on May 29, 2016 [1 favorite]


Clawsoon as a non-engineer I can't answer your question but there is a lot of literature out there about potable reuse that might. .of course it might be behind paywalls. A lot of details don't get put into marketing materials but instead are discussed in meetings and presentations.
posted by emjaybee at 12:12 PM on May 29, 2016 [1 favorite]


Quinoater.
posted by wobh at 1:48 PM on May 29, 2016 [2 favorites]


...precious bodily fluids...
posted by goatdog at 3:26 PM on May 29, 2016 [1 favorite]


God help us if the anti-flouride crowd realizes that there's chlorine in the water too.
If we weren't using chlorine or Cl by-products for water purification yet, these and or similar folks would likely keep it from being used at all.
posted by milnews.ca at 5:31 PM on May 29, 2016 [1 favorite]


And it's worth knowing that the chlorine industry is large (US $8 billion & 11 million tons annually) and would very much like you to use more of its products.
posted by sneebler at 6:11 PM on May 29, 2016 [1 favorite]


This is an excellent post.
posted by Sleeper at 12:36 AM on May 30, 2016 [3 favorites]


My immediate worry would be that you'd get large numbers of treatment-resistant organisms a lot faster with a closed loop. When you send them out into the lake, they at least have to compete in a completely different environment where resistance slows them down instead of being a benefit. Is this not a problem, or is it a problem that we've figured out how to deal with?

The real risk of a closed loop system is that if there is an error or a breakdown, the untreated water would be immediately reintroduced to the drinking water system, whereas there is at least a dilution process between when the upstream town releases untreated sewage and the downstream town pumps in river water to purify. (Which is what almost everyone drinks whose water does not come from deep aquifers or from the top of a watershed.)

It's not something that would worry me as long as the system is well-designed and -operated, and the current wastewater treatment process in many places is pretty flawed and could be improved with a fully or partially closed loop system that ensured better quality treatment.
posted by Dip Flash at 5:27 AM on June 1, 2016 [1 favorite]


One time we moved to a new place in the Sacramento area, and we found that the water there tasted like chlorine and made everyone sick. So we called the water utility, and they sent someone to check, and he explained that the reason we all got sick was because there wasn't enough chlorine, and they were now going to remedy that.

We started buying filtered water.
posted by reprise the theme song and roll the credits at 12:36 PM on June 7, 2016 [1 favorite]


reprise the..., it's possible that what you were tasting were organic chlorine compounds resulting from chlorine reacting with stuff it kills, and that what the tests showed was that there was extra stuff to kill (that was making you sick) and no residual free chlorine left to kill it.

This would most likely be caused by too much stuff growing in the pipes on the way to your house, with some of that stuff making you sick. Unless they were bullshitting you or did the tests wrong, the extra chlorine would've been intended to kill that stuff in the pipes.
posted by clawsoon at 1:55 PM on June 7, 2016 [2 favorites]


That makes alot of sense clawsoon. When I had a house with a pool I learned that a pool that smells like chlorine is actually a dirty pool because of the way chlorine breaks down fighting stuff in the pool.
posted by LizBoBiz at 3:31 PM on June 7, 2016 [1 favorite]


(And that's why my BiL put in a salt water pool.)
posted by wenestvedt at 6:43 AM on June 10, 2016


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