Thousands of suicides annually could be prevented from a pesticide ban
About 800,000 people die by suicide every year, according to the World Health Organization, and at least 110,000 of them die by suicide using a means that American readers might find surprising: pesticide ingestion.
This is a fairly uncommon suicide method in the US. There were only 12 pesticide suicides in the US in 2016, out of nearly 45,000 suicides total. But in poorer and more agricultural societies, pesticides make up a huge share of all suicide deaths. In China, for instance, 49 percent of suicides are suicides by pesticide; in India, the share is about 38.8 percent.
The difference boils down to how incredibly lethal certain pesticides can be. Poisoning suicide attempts are quite common the world over. A meta-analysis of 177 international studies of suicide methods found that 90 percent of attempts, on average, involved poisoning.
But not all poisons are created equal. Most people making self-poisoning attempts in the US ingest drugs, like Tylenol or sleeping pills, which are more difficult to consume in lethal quantities than pesticides are. A study of emergency rooms in eight different US states found that while 82.5 percent of attempts with firearms resulted in death, only 1.5 percent of drug/poison ingestion attempts resulted in death. Poisoning attempts are common, but frequently survived, and so most US suicides resulting in death are committed with guns.
Pesticides can be much deadlier than, say, Tylenol as a poisoning method. For comparison, a 2010 study found that 42.7 percent of people admitted to two Sri Lankan hospitals for suicide attempts involving the herbicide paraquat wound up dying. That’s a 42.7 percent fatality rate, versus the 1.5 percent fatality rate for poisonings in the US. Just as the omnipresence of guns in the US makes our suicide problem worse, the omnipresence of pesticides in South and East Asia has contributed to their suicide problem as well.
This lethality really, really matters, because suicide isn’t a rationally planned act. It’s typically quite impulsive. Many survivors say they deliberated less than a day, and sometimes for only a matter of minutes, before making an attempt. Ken Baldwin, who survived a jump off the Golden Gate Bridge, once told the New Yorker’s Tad Friend that as he was falling, he “instantly realized that everything in my life that I’d thought was unfixable was totally fixable — except for having just jumped.”
Indeed, a 2016 study that tracked 1,490 Minnesotans who were admitted to hospitals after a suicide attempt found that 94.6 percent did not die in a subsequent attempt. Put differently: The vast, vast majority of people who attempt suicide and live won’t just keep trying until they die. They’ll survive. And that means that putting small barriers between them and suicide methods can meaningfully prevent suicides.
That’s proven true in a number of cases. Suicide in the United Kingdom declined after coal stoves were phased out, removing a means of suicide by carbon monoxide that had been available in many homes. Tylenol (or acetaminophen) overdoses in England and Wales fell by 43 percent after legislation passed requiring that the medication be sold in “blister packs” where you have to pop out each individual pill; that simple switch from big bottles was enough to save lives. When the Israeli Defense Forces stopped letting soldiers bring their guns home over the weekend, suicides fell 40 percent, primarily due to a drop in firearm suicides committed on weekends.
Could limiting access to dangerous pesticides save lives? Half-measures in this direction have been tried, but they haven’t shown a lot of promise. A randomized controlled trial tested a program giving a lockable storage container for pesticides to farming households in Sri Lanka; the idea was that, just as gun safes and gun locks prevent children or unauthorized adults from using guns to hurt themselves or others, a pesticide safe could keep harmful chemicals away from severely depressed people. But it didn’t work. Pesticide suicide rates were identical between the group getting the pesticide containers and the group that got nothing.
The Sri Lanka success story
But we do know a method that does appear to work: banning particularly lethal pesticides.
There’s a lot of variation in lethality between types of pesticides. Paraquat, the herbicide mentioned before, has a 42.7 percent fatality rate, but that same study found a 2.4 percent rate for glyphosate, another widely used herbicide, and a zero percent fatality rate for one called fenoxaprop-p-ethyl. That suggests that banning particularly lethal pesticides, causing farmers to substitute for less lethal ones, is a simple way to save lives and prevent deadly suicide attempts.
Sri Lanka is perhaps the most famous case of suicides falling after a selective pesticide ban. In 1995, the country banned the import of a number of particularly dangerous pesticides, and in 1998 they banned a few more. One study estimated that the suicide rate in Sri Lanka fell by half between 1995 to 2005. A second study of another round of restrictions from 2008 to 2011 in Sri Lanka (including a ban on paraquat) estimated that suicides fell by 21 percent from 2011 to 2015.
These are big reductions. While it’s hard to know for sure if the bans caused this reduction in suicides — these aren’t randomized studies after all, and a lot else changed in Sri Lankan society over this period — a 2017 evidence review of studies in Sri Lanka but also Jordan, Bangladesh, Greece, South Korea, and Taiwan found that in every country but Greece, bans were followed by a reduction in pesticide suicides. “A worldwide ban on the use of highly hazardous pesticides is likely to prevent tens of thousands of deaths every year,” the authors conclude.
Luckily, there’s a relatively new charity that’s taken on hazardous pesticide bans as its cause. The Centre for Pesticide Suicide Prevention, founded by researchers Michael Eddleston and Leah Utyasheva with funding from the charity evaluator GiveWell, is trying to spread the success of Sri Lanka’s policy change to India and Nepal.
“CPSP plans to collect data in India and Nepal on which pesticides are most commonly used in suicide attempts, and are most likely to result in death,” GiveWell summarizes. “CPSP plans to use this data to help the governments of India and Nepal decide which pesticides to ban, with the intention of reducing suicide rates.”
Utyasheva has gone into more detail about the problem, and her group’s work, in a talk at the Effective Altruism Global conference:
And in an episode of the 80,000 Hours podcast:
I had never heard of this problem before hearing Utyasheva on that podcast. But it’s massive, and appears to be easily remediated with pretty minimal changes to government regulations. Those kinds of opportunities to save lives are rare — and we need more people like Utyasheva to seize them.
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