Pesticides, why you should be worried but not about your health

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A new study in the British Journal of Nutrition (abstract)1)I was unable to gain access to the full text. Though it was unclear whether that was because it had not yet been released to the public or was behind a paywall. has lent support to the hypothesis that organically grown food is healthier than food grown conventionally (i.e. with artificial pesticides and fertilizers)2)The New York Times has a good summary. The authors report that organic food contains more antioxidants, less cadmium and fewer traces of pesticides.

Before all those dedicated organic shoppers celebrate too much, it is important to note that this is a meta-study which means they analyzed all the existing research on organic foods but did not actually collect any new data themselves. These type of studies are very important but there results are almost always controversial because the methods you select to combine all those different research projects (in this case 343) can lead to different results3)For example: selection of which studies to include, normalizing data, combing very different populations, dealing with outliers, etc.. The higher antioxidant finding is good news, though for all their frequent appearance on food packaging the science on their actual health benefits is unclear though suggestive. As for the other two… I would be shocked if they had found otherwise! It would be very disturbing if food grown without pesticides (organic) had more traces of pesticide than food grown with it.4)The same applies to the cadmium which gets to the food via the application of artificial fertilizers in conventional agriculture.

Organic food is not the solution for making us healthier

While this study adds support to the hypothesis of organic food being healthier, we should not be concluding that if only everyone switched to organic disease would disappear (or even be reduced significantly) because:
Backpack Sprayer in El Salvador
Application of pesticides by a small farmer in El Salvador. Aaron Redman

  • Other meta-studies have found contrarian results.
  • This study does not discuss (at least in the abstract) if the pesticide traces or cadmium levels found were at levels believed to present danger to human health. I don't want to consume either, but dose matters!
  • When it comes to human health pesticides are mostly a danger to farm workers, particularly in less developed contexts.
  • It would seem that exploding fertilizer plants pose a bigger threat than the consumption of residues.
  • Any impact of organic foods on health would get vastly overwhelmed by our other food choices: huge amounts of sugar, salt, oil and carbohydrates, too much meat and too few fruits and vegetables.5)One study in Briton found that people consumed only half the servings of vegetables that would be best for their health and in the USA a third of the "vegetables" we consume are potatoes!

Conventional agriculture continues to do serious harm to ecosystems

Rachael Carson's Silent Spring is remembered not for her shaky claims about cancer but for her lament that industrialized agriculture was devastating bird populations everywhere it went. Unfortunately it appears that pesticides are continuing to decimate bird populations as a new study in Nature demonstrates.6)The research article is behind a paywall but the abstract can be found here Researchers in the Netherlands found that bird populations had significantly declined in areas where contamination for a class of pesticides known as neonicotinoids was highest. They investigated other possible causes of the decline but the presence of this pesticide was by far the best predictor. This piles on to numerous other studies which are beginning to show the danger of this widely used pesticide to ecosystems. What is particularly concerning is that the authors believe that bird populations are not being harmed directly7)Which is what DDT did. By accumulating in the bodies of raptors it caused them to lay very thing egg shells which easily broke and reproduction failed, but rather by the elimination of their food supply-insects. These types of cascading effects are rampant in Sustainability problems and the damage we know about to the Earth's ecosystems from conventional agricultural techniques, continues to grow.

To go organic or not, why is that the only question?

Unfortunately when it comes to pesticides the focus continues to be on whether it is making you sick via your food. This means that there are guides to help us avoid the dirty dozen but nothing to help consumers avoid those crops whose production is doing the most ecosystem damage.8)Bananas for example are produced with probably the highest applications of pesticides and fertilizers of any food crop at a serious risk to field workers and the local ecosystems. Yet because of their thick skin, the consumer is at no risk of encountering residues of these chemicals. And thus they never appear on these types of lists. What really bugs me about this whole debate of organic versus conventional is that we are constantly asked to make a false choice between two options when in reality there is a whole spectrum of possible ways we can grow our food. For example, Integrated Pest Management is an approach where pests are not eliminated but kept at harmless levels through natural means (e.g. crop rotation) but chemicals are kept in reserve to treat a bad outbreak and avoid serious crop loss. Artificial pesticides, herbicides and fertilizers are tools which because of their damaging consequences should be used sparingly but in many situations they present significant upsides. Eliminating their use entirely (i.e. going organic) is neither Sustainable nor is it even feasible.

*Brad Plummer over at Vox has published a very good (and similar) take on the issue as well

Aaron Redman is the founder of Achieving Sustainability and what passes for an administrator in these parts. Currently he is working on his Sustainability PhD at ASU while raising a baby daughter and taking advantage of nap time to foment discussions on this here blog.

Footnotes   [ + ]

1. I was unable to gain access to the full text. Though it was unclear whether that was because it had not yet been released to the public or was behind a paywall.
2. The New York Times has a good summary.
3. For example: selection of which studies to include, normalizing data, combing very different populations, dealing with outliers, etc.
4. The same applies to the cadmium which gets to the food via the application of artificial fertilizers in conventional agriculture.
5. One study in Briton found that people consumed only half the servings of vegetables that would be best for their health and in the USA a third of the "vegetables" we consume are potatoes!
6. The research article is behind a paywall but the abstract can be found here
7. Which is what DDT did. By accumulating in the bodies of raptors it caused them to lay very thing egg shells which easily broke and reproduction failed
8. Bananas for example are produced with probably the highest applications of pesticides and fertilizers of any food crop at a serious risk to field workers and the local ecosystems. Yet because of their thick skin, the consumer is at no risk of encountering residues of these chemicals. And thus they never appear on these types of lists.
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3 thoughts on “Pesticides, why you should be worried but not about your health

    • Hi Steffan,
      Thanks for the full text of the article. I am having fun with the blog so far. Hope to see more of you on here.
      -Aaron

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