Pesticides are Complicated

I finally finished Pesticide Biotransformation and Disposition (you can see the few public notes I made, usually while riding the bus, here). It’s really more of a reference work but it’s given me a better grasp of the breadth of the question. As a side-effect, I’m even more annoyed at the simplification from anti-pesticide groups that dominates public perception of pesticides.

After reading this book, it seems all of the following are basically true:

  • All pesticides are harmful to some creature, at some dose. Otherwise we wouldn’t call them pesticides — but that doesn’t necessarily mean they are harmful to humans.
  • Pesticides are just chemicals and many chemicals that aren’t thought of as pesticides have similar classes of behavior.
  • Many pesticides aren’t harmful to humans at low doses.
  • Some are.
  • Some pesticides will cause a harmful effect in some humans at one dose that others won’t be affected by (due to genetics, age and other considerations).
  • Some pesticides will increase harmful activity of another pesticide.
  • Some pesticides will inhibit harmful activity of another pesticide.
  • Some pesticides will decrease production of chemicals in your body that you need.
  • Some pesticides will increase production of chemicals in your body that you need.
  • Either could be harmful, sometimes depending on how old you are, your genetics, etc.
  • Sometimes the pesticide itself directly causes harm. Sometimes the pesticide reacts with something in the body and the by-product causes harm.
  • Various chemicals that react with pesticides are produced at varying levels in different parts of the body so a pesticide may be harmful in one part of the body but easily made harmless elsewhere.
  • A pesticide could have an effect in an animal that doesn’t happen in humans1
  • How often you’re exposed can matter a lot.
  • How a pesticide enters the body can change how it might affect you.
  • Commonly used house-hold products (e.g. sunscreen) can increase skin absorption of some pesticides. Clothing can also affect how pesticides are absorbed.

And a lot I’ve forgotten. That’s why I bought the book. Out-of-brain memory.

My own emotional reaction is interesting. On one hand, I realize that I’ve been a bit cavalier in my beliefs about the likely non-harm from pesticides2 and feel a bit foolish (I cringe to re-read some older blog posts). On the other hand, anti-pesticide groups and individuals tend to conflate all risks from all pesticides into one big pile of “BAD”3. Having a slightly more clear idea how complicated it is, the fear-mongering about pesticides annoys me even more. It’s hard to have rational risk discussions about whether harm from a particular pesticide is worth it for the benefits4 when at least some consider any risk too high5.

I don’t know what the answer is but at least I have a reference to research further on particular pesticides as they come up instead of assuming they’ll behave just like another one I’m more familiar with. 🙂


  1. A good example here is a nasal cancer in rats from repeated exposure to alachlor which doesn’t appear to be likely in humans because rats metabolize the pesticide into a pre-cursor to the actually carcinogenic compound at rates much higher than humans do.
  2. At doses I’m likely to experience — which is near nothing for currently applied ones since we don’t often use pesticides in the home and most food products actually have very little — my risk is still probably pretty small. But probably not as small as I like to think, especially when considering DDT and by-products are still heavily part of our environment.
  3. Studies about occupational studies are too often used to make claims about the superiority of organic food. Or the harms of long-banned pesticides such as DDT are used to make claims about other pesticides thought to be safer.
  4. Relatedly, there is a problem of attention. Which pesticides get attention (research into safety, environmental effects, etc.) is driven by public and private interests and concerns. The current concerns with neonicotinoid pesticides and EFSA’s recent report on them make me wonder if any useful, widely-used pesticides would survive scrutiny. Are other pesticides seen as safe simply because we haven’t looked hard enough for risks?
  5. There is also the problem that many non-experts believe that anything that hurts insects must be dangerous to humans.

Comments suck right? So why do you have them?

A study is going to be published that supposedly shows stories with uncivil comments below them results in people being less informed. That’s the gist. The sad part are news and blog sites posting about this study, including noting people shouldn’t read comments, on sites that have comments on every story! As an example, Mother Jones published a piece on it that concluded:

To be sure, we all retain the option of not reading the comments. Which, in light of the latest research, is looking smarter than ever.

Mother Jones makes little effort to moderate their comments (beyond automated spam flagging that disqus supports). They also do not encourage their authors to engage with the comments. Their comment threads are full of people making uncivil claims, full of falsehoods and otherwise not very useful (though I’ve had some good discussions there). The sad part is their own piece on this research had no self-reflection about what Mother Jones could do to make their comment threads better.

Of course, poor comment threads are not limited to Mother Jones, nor were they alone in publishing a story about this study while having comments on their site. Most versions of the story I saw go by were for sites I know have comment sections. I know comments can be civil and actually add to discussions and my understanding of the topic (see Scalzi’s blog, Metafilter and Biofortified for a few examples). But having a good comment section is work. Authors and site owners have to actively read comments and either remove off-topic (or uncivil) comments or respond to them regularly to create the kind of atmosphere that encourages everyone to make useful (or at least not harmful) comments.

The response to this study shouldn’t have been: now we all have proof no one should read comments! It should have been: why do so many sites allow comments when they clearly aren’t willing to invest in making them worthwhile?

Taking People at Face Value

A lot of discussion is happening about whether the labels “anti-science” or “science denier” are accurate (or fair). Keith Kloor blogs about it regularly. A sprawling twitter conversation about denialism (and whether or not scientists are actually mostly Democrats or not and why) reminded me of why I don’t think it’s a helpful frame (never mind accurate). Simply put: we should take people at face value. Good argument requires a charitable outlook and most people making seemingly unscientific arguments believe they aren’t. Avoiding uncharitable assumptions makes for more fair and genuine arguments — and we’re far more likely to agree on something.

I recently came across a blog with a great term: steelmanning. The idea is the opposite of a strawman. Steelmanning is arguing against the strongest possible version you can imagine. Yes, this might mean you have to put yourself in their position (this might make your skin crawl at first). A follow-up post argued for greater charity in argument. The gist is that we should argue from a place that sees the best version of our opponent’s position and doesn’t assume awful things about them. A charitable steelman form of argument makes us better people: we aren’t denigrating anyone’s positions (or values) and we’re forced to make good arguments for our own side because we’re really seeing the other side.

I’ve long held the idea that I should take people at face value. I’ve realized from these blogs that part of what I mean by that phrase is that I should assume people are like me. I think I’m saying what I mean (no matter how confusing I speak) and I obviously don’t think it’s awful or evil! So I should likewise assume that people are earnest when they say something and no matter how awful it sounds to me, they probably don’t see it that way. I should try to understand what they mean. Sadly, it’s easy to fall into a trap of dismissing someone broadly, ignoring their argument or dismissing them because “they really just believe X and that’s awful”. In the end, it’s just exhausting and makes me angry. I need to step out of conversations when I realize I no longer have the ability to see someone charitably (or at least with good humor!)

How does this apply to labels like “anti-science” and “science denier”? Well, obviously, given the high value our society puts on science and evidence, claiming your opponent is “anti-science” is simply not charitable. If someone says science (and evidence) is important and that’s why they believe (or don’t believe) something, that’s great! Take them at their word. It’s no good to say that because they cherry-pick evidence that supports their position — or discount inconvenient evidence — that this means they “deny science”. People in general don’t realize it when they are processing information in an extremely skewed way. It’s going to be hard enough to help them see more evidence without implicitly or explicitly dismissing them as “anti-science”. Worse, by short-circuiting the argument with “just more anti-science crap”, we’re likely going to miss the real argument they are trying to make. For a lot of topics this is going to come down to values and not necessarily facts, even if the arguments being made seem to be about facts.

Argue against the best version of a position you disagree with. Don’t assume something they wouldn’t say of themselves. “Anti-science” is just one flavor of dismissing your opponent for reasons they would feel slighted for and make them not take you seriously. I’m probably quite guilty of painting “anti-science” on someone I’m arguing with (certainly in my head, though hopefully not explicitly too often). Hopefully writing a blog about the importance of charity in argument will remind me to do better. I probably need to carry around a button to remind me. 🙂

The Life You Can Save

In the spirit of the New Year, I am about to post something awkward. Normally people don’t talk about charitable giving. It’s not really considered polite to talk about it. It looks like you’re seeking praise. The act itself is supposed to be its own reward.

But here it is: I took the Life You Can Save pledge a few months ago. The pledge is to give at least a particular percentage (usually 1% or 5%) of one’s income to help those in the greatest need. Here’s why I’m talking about it.

I first encountered The Life You Can Save when I read the book by book by Peter Singer a few years ago. I came away convinced I should be doing something. Unlike previous times when I thought about this question, I didn’t shut the idea down and dismiss it as nothing I can really do (and all the aid groups are corrupt anyway, right?). So I started giving more money, primarily to a couple international charities I trusted and that Singer thought were effective (primarily Oxfam and Doctors Without Borders). For the last few years I’ve been giving a bit more and over the last year I came to realize I could honestly take the pledge (automatic debiting helps a lot).

But this post isn’t why charitable giving or why the kind of charitable giving Singer would recommend: you can read the book (or the website or even just a short opinion article) and decide for yourself. This post is why one would talk (or blog) about it. This seems pretty arrogant, doesn’t it? There are two reasons why Singer recommends taking a public pledge:

  • Talking about it publicly changes the culture of giving. People tend to think that others like them aren’t giving because no one talks about it. It’s easy to not give yourself because you think your peers aren’t either.
  • A public pledge makes it more likely you’ll keep it. My hook of tying this to the New Year actually made it easier to finish this blog post (after months sitting as a draft). I’ve already publicly signed the pledge on his website, but this is a bit more personal isn’t it?

So here I am.

This post isn’t a plea to you to go change your behavior. It’s an announcement of my own behavior, as weird as that is. Obviously I hope some people who aren’t already giving will have a look at the Life You Can Save (or if you already give, taking the pledge). This post is about letting you know it’s normal and more common than you think.