Where Have All The Nasty Pesticides Gone?
(apologies to Pete Seeger for the song title reference)
The graph above shows how over the last 15 years, the use of 23 old pesticides has declined more than 97% in California. These are all pesticides that have the specific, neurotoxic mode of action called “Choline Esterase Inhibition.” They are “organophosphate” or “carbamate” insecticides – the archetypal “pesticides” that people worry about. These were actually state-of-the-art chemicals forty years ago when the goal was to get away from the environmental persistence problems with the Organochlorine pesticides like DDT. DDT was essentially non-toxic to us, but it didn’t break down and “bio-accumulated” in the food chain. The Organophosphate and Carbamate insecticides break down fairly quickly, but many are initially quite toxic to mammals and birds and they show up as low level residues in foods.
There are major differences in toxicity even between organophosphate and carbamate insecticides and there are ways to use them with minimum risk. The graph above shows how twelve other choline esterase inhibitors are still being used, but at an average of only 25% of their past volume. In previous posts I’ve discussed some of the reasons why these materials are still needed in certain circumstances.
As someone who has worked in agricultural technology for over 30 years, I have seen this and many other ways in which the safety and sustainability of farming has been advancing, but that perspective is not widespread. I’m glad that the mandatory pesticide reporting in California allows these trends to be documented.
Who Should Get the Credit?
There are actually many contributors to the continuous improvement of farming practices. There are the environmental scientists who have defined risks and issues. There are activist groups who have pressed for change. There are the regulators (EPA, California EPA) who have done and re-done the risk/benefit analysis and adjusted pesticide label requirements accordingly. Unlike financial regulation, US pesticide regulation is a relatively robust and trustworthy process. There are researchers who have developed IPM (Integrated Pest Management) techniques which help farmers control important pests with fewer and safer options. There are the major pesticide manufacturers who have spent billions of dollars over the years to discover and commercialize newer, safer and even more effective tools. Finally there are the farmers who have adapted their practices as new options become available while still producing high quality produce at a reasonable cost.
A System That Is Working
I’m not saying that farming is now “risk free” for us or for the environment, but the progress to-date is impressive, and the trend demonstrates that our current innovation and regulation environment is working very well. It is good to be able to document that because there are parties with a vested interest in having consumers believe otherwise. Some environmental groups depend on angst about pesticides for their fund raising. Some marketers of Organic are happy to fuel consumer impressions that pesticides today are just as dangerous as they were on the first “Earth Day.” With a public that is so removed from farming, it is all to easy to only heed these voices of negativity.
There are groups currently trying to define a “metric” of sustainable pesticide use, an enormously ambitious prospect because of the complexity of risk/reward across the great diversity of crops and environments involved in our food production system. The goal is to allow companies like grocery retailers to use their leverage to drive positive change. That is an appealing idea in theory, but one fraught with issues in practice. What data in this example shows is that we already have a system that is moving in the direction everyone would like to see. Maybe we should talk about that more.
Graphs created from data available on the Cal-PIP database.
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