Stehle and Schulz compiled data from
838 studies on pesticide concentrations in surface waters globally and
determined which of these concentrations exceeded regulatory threshold limits
(RTLs) for 28 different insecticides. From this meta-analysis, the two most
striking conclusions were:
- There is no data on pesticide concentrations in surface waters near about 90% of global cropland.
- Over 50% of the measured insecticide concentrations (MICs) exceeded their respective RTLs.
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The Washington Post article
effectively communicates these two points, without ‘overselling’ the results.
In fact, the author makes sure to elucidate what is and isn’t implied by these
results. Regarding the exceedance of regulatory limits, the author explains how
this doesn’t necessarily translate directly to risk: “Just because pesticides
are toxic doesn’t mean they’ll actually pose risk – of causing a disease or
damage to the environment”. The researchers made sure to caution against
applying their risk predictions to the 90% of remaining cropland, which is also
communicated well by the Washington Post author: “That doesn’t mean that these
lands’ surface waters are tainted with pesticides, much less that the pesticide
levels are too high.”
Overall, the Washington Post article
does an adequate job of communicating the major conclusions of the study
without exaggerating the analysis, and also of explaining the researchers’
methods in simpler language. However, there were a few shortcomings of the article.
One inconsistency I found was that the article stated that the exceedances occurred
in “similar amounts” between countries with weak regulatory systems (designated
as LERQ countries in the study) and countries with strong regulatory systems
(designated as HERQ countries in the study), while the study indicated that
these amounts were significantly different (p<0.001). Still, 39.9% exceedance
in HERQ countries compared to 42.4% in LERQ countries is similar enough to be concerning.
Also the article failed to explain the challenges in assessing environmental
risk from pesticide exposure, which the study attributed to the fact that
organisms’ exposure is limited to acute amounts near the time of application
and also that organisms are exposed to a number of different pesticides
simultaneously, and the interaction effects were not accounted for. Finally,
the researchers in their analysis urge the need for better regulation of
pesticide usage, citing their results as evidence that the current regulation
schemes are not effective. This agenda is, perhaps purposefully, not included in
the Washington Post article.
I also think the article did a good job of representing the study. One thing I thought was interesting in the study is that the researchers gave a suggestion regarding efficient use of pesticides that would decrease contamination into surface water. Obviously if we don't use insecticides then pests will reduce crop yield which is bad for food security. Solutions are needed to make sure pests don't ruin crops and pesticides don't contaminate our water supply either.
ReplyDeleteThe authors of the study did mention current methods use to evaluate the pollution potential of new pesticides, but they seemed to have their doubts about the effectiveness of these methods. I agree that because food security is such a huge issue these days, it can become a heated debate. If anyone wants to learn about agroecology and the productivity of less intensive agriculture, I'd suggest a chat with Ivette Perfecto at SNRE, her research is really cool.
DeleteGreat choice of article. I agree with you that the article didn't give a future perspective and that the study enforces that we make a change to pesticide regulations and to consider more research within the area of pesticides. I think what of been nice to include in both the article and study would be the potential health problems one would face if they were exposed to one of the 28 insecticides.
ReplyDeleteI agree it would be interesting to see which of the 28 pesticides they looked at had the most potential for harm
DeleteGood article find, Marina! I think the WaPo article does an excellent job summarizing the methods, conclusions and limitations of the PNAS study -- something you rarely get in a news article.
ReplyDeleteI was interested in the time component of the PNAS article. Maybe I missed it, but did they say if they limited their search to certain years of publication? As agriculture is intensifying, it would be interesting to see if studies showed an increase in pesticide concentration over time.
The study looked at studies between 1962-2012. In the supplemental information of the PNAS article, Figure S2 gives presents the sampling date of the studies and the ratio of the found concentration to the regulatory threshold for organochlorine, organophosphate, and pyrethroid insecticides. For all three types, countries with higher environmetals regluations were in declilne, while organochlorine and organophosphates were increasing in regions with lower regulations.
DeleteOne part of the article that I personally found alarming, was the statement "Just because pesticides are toxic doesn’t mean they’ll actually pose risk — of causing a disease or damage to the environment. Creatures’ exposures to these pesticides need to be high enough as well." While it is true that exposure concentrations need to be of a certain capacity to be toxic to humans and other forms of life, the fact that many of these components can remain and accumulate in the body for extended periods of time. So, even if these toxins are minimally applied over several years time, they can still accumulate in the body and cause serious health issues not only in humans but in plant life and soil biodiversity (mentioned in PNAS), regardless of what surface water testing is telling researchers about the instantaneous concentration of toxins. Maybe I'm channeling my inner Rachel Carson, but I feel as if the author of the Post article is sidestepping an important issue.
ReplyDeleteI think that the WaPo author was trying to explain that environmental and health risk are a function of more than just toxicity, i.e. exposure concentration and duration, as you mentioned. This statement could have definitely been worded better, though.
DeleteI would have to agree with Olivia for the most part. The statement, "Just because pesticides are toxic doesn’t mean they’ll actually pose risk — of causing a disease or damage to the environment. Creatures’ exposures to these pesticides need to be high enough as well." is just alarming to me. It seems as if the article is almost discrediting the research or overall impacts of the topic. The reason for a statement like this could be that the article is trying to convey that this may or may not be an immediate health issue and the research could be further investigated or at least to tone down the severity of the subject matter. I would think that this correlates with how the Washington Post article wants to bring up the issue but not necessarily portray pesticides as a villain from farming.
ReplyDeleteWhile I don't think the Washington Post overreached on any of its claims, I think they could have made the article stronger if they had specifically mentioned the consequences of elevated pesticide levels in surface water, such as the loss of biodiversity. Also, I thought the study did a very good job of outlining why their results were likely underestimating the levels of pesticides, and therefore the stress on the environment. I don't think the Washington Post communicated this very clearly, and with some of their language may have even suggested the opposite.
ReplyDeleteSomething that I found interesting in the PNAS article was the mention that the insecticides are often present in agricultural influenced waters for only a year or so. Thus, the sampling of insecticides can be difficult. Though the PNAS article did not have a focus on this, I thought it would have been a good thing for the Washing Post article to mention.
ReplyDeleteI am wondering why the journal article presented the data of regulatory threshold level (RTL) exceedance rates rather than direct concentration data of insecticide. I feel confused since different countries may have different regulatory threshold levels. In this case, it's hard to understand what authors of the journal article actually want to tell us from the data or the above figure.
ReplyDeleteI think the news article did a good job to not over state any of the data presented. My main concern is that even with just a large collection of data, only 10% of possible area is considered. Is it possible to accurately extrapolate these results to the rest of the world?
ReplyDeleteGood read. Odd to see a news article show more restraint the original article but good on them.
ReplyDeleteGood post! I agree that the Washington Post article was very well written and accurately explained the research findings and the implications. I thought the article could have benefitted if it went into more detail on the health risks of having these different pesticides exceed the regulatory concentrations.
ReplyDeleteI think the WP article was well written and very interesting. It did not by any stretch sensationalize the original research findings. However, I agree that there were shortcomings. I found a major issue to be that they didn't go into more detail on the specific consequences and impacts of pesticides on the environment.
ReplyDeleteOverall, I agreed with you in that the Washington Post article gave a refreshingly neutral report of the study, with no agenda present. I was hoping (but this may just be the scientist in me) that they would go into more detail about the actual study that the researchers obtained information from, instead of just generalizing it as "meta-analysis". But in general I was happy that the article found a good balance between both the findings and the researcher's concerns instead of cutting information out.
ReplyDelete