Pesticide Contributions to the Ozone Problem in California
This page is under construction. Thanks to years of delays, rounds of litigation, complexities in estimating the amount of ozone formed by the volatile organic compounds (VOCs) in pesticide products, what in essence is a simple subject has become baroque. So far, this page only gives the barest outline of the present state of affairs.
The Problem
Pesticides are released in such large quantities, many tons per day, in various California air basins, that like auto exhaust and other sources of volatile organic compounds (VOCs), they are a contributor to the general problem of smog. More specifically, the volatile VOCs that are in pesticide products, sometimes as the active ingredient, and sometimes as part of the overall product formulation, are contributing to ozone formation.
The Clean Air Act
The Clean Air Act regulates ozone levels because of its ability to cause asthma and other toxic and environmental effects. For healthy adults, some of the first noticeable effects are a tightness or scratchiness in the lungs when inhaling, especially when exercising, and scratchiness in the eyes. Almost anyone who has walked in the foothills near a major urban areas in Calfornia on a smoggy day is likely to have noticed this, even if the cause was not obvious. The sources of VOCs that are a precursor to ozone formation are varied, and as a result a great variety of products and sources have been regulated, from automobile exhaust, to BBQ lighter fluid, to paints, and concentrated animal feeding operations. Although pesticides are often toxic in their own right, and their emission into the air is in some cases regulated because of that, they are also one of the many sources of VOCs, and hence a contributor to ozone formation. Many rural and suburban areas also have have high ozone levels and pesticides can be a significant part of the problem.
The Commitment
In five parts of the state that are not meeting the Clean Air Act requirements, and where pesticides are heavily used, the state committed in 1994 to reducing the total amount of pesticides released into the air by 20% relative to 1990/1991 levels.
The Reality
These commitments are far from being met in two of the five air basins:
- Ventura County, where fumigant use has been steadily increasing, instead of decreasing
- San Joaquin Valley, where pesticide use is now approximately 24 tons per day during the ozone season, far above the 16 tons per day of VOC emissions that the state committed to reach