New Scientific Findings Are Changing Pesticide Regulation
Comments by Dr. J.P. Myers, Director, W. Alton Jones Foundation
to Pesticide Inspectors in EPA Region III.
16 October 1996
The world of pesticide regulation and inspection will undergo significant change over the next several years.
The Delaney Clause is gone. It's been replaced by a health and science based standard that ultimately will be much more enforceable and far more challenging to current practices and current chemicals. Implementing this new law will lead to much greater food and worker safety than had been in common practice under the old FIFRA. This new law will have wide-ranging impacts on your industry, agricultural and non-agricultural alike.
A number of commonly used pesticides, I predict, will be removed from the market. Here are a few which deserve the closest scrutiny:
As suburbia further encroaches upon agricultural lands, you will see more and more debate over pesticide exposure. And while this might seem to be an infringement upon the rights of farmers to use their land as they have always done, it is a problem arising because some landowners want the ability to sell off pieces of land to developers while simultaneously using what remains of their land in traditional ways. When traditional use puts their new neighbors at risk to pesticide exposure, they will learn they can't have it both ways.
Related to this, pesticide drift and volatilization will become one of the hot regulatory issues. I know from my 4 years service on the Virginia Pest Control Board that no matter how well intentioned, private applicators violate drift regulations regularly. And that's before you begin worrying about volatilization.
Why do I think this is going to happen?
I believe we are entering into a new era of scientific awareness about the health risks of pesticide use. And this new understanding has already led to a dramatic shift in the underpinnings of national food safety laws, most obviously in the 1996 Food Safety Act passed in Congress and signed by the President this summer. The most fundamental switch has been to moved toward child-based standards.
This switch goes deeper and more widely than the Food Safety Act.
And as Carol Browner announced just last month:
An awareness of children's unique susceptibility and exposure to toxic threats must guide every action we take to protect public health and the environment.
Thus the Administration pledged to update federal regulations for toxic substances to ensure that the rules better protect the health of infants and children
The book I published with Theo Colborn and Dianne Dumanoski this spring,Our Stolen Future 1, lays out the scientific bases for these changes. I am pleased to see it is already having a national, indeed, international impact on managing risk.<
The bottom line is this:
The types of effects they have include:
Those of you who follow this issue will know that our book was attacked by some sectors of industry—even, I might add, while other parts of the chemical industry issued statements stating to the effect: "we respect the science."
Let me offer a few observations about those criticisms.
Some of them were outrageous distortions which if you had read the book would have seemed almost humorous, except for their tone and intent.
Some of them were alternative interpretations of existing data. Reasonable people can disagree on matters of scientific substance.
Some of them were wishful thinking combined with a procrustean approach to science.
Procrustes, as you may recall, was the Greek inn keeper who greeted his guests with a measuring stick. His inn had beds of only one size. If his guests were too tall to fit the bed, he cut off a section of their legs. If they were too short, he put them in a rack and stretched them out. We had many disciples of Procrustes reading the book and decrying its contents because it failed to meet their preconceptions.
The sperm count story was and remains the best example of this.
The book reviewed the evidence available before we went to press that human sperm count was declining. This question had been raised by a paper 2 analyzing data from around the world. The authors of this paper had concluded that on average sperm count had declined by 40% over 5 decades, worldwide.
Scientists investigating this trend showed 3 that some synthetic compounds in use in agriculture and industry were capable of reducing adult sperm count, if the male in question had been exposed in the womb to small doses of these compounds. An elaborate, biologically plausible hypothesis was developed that identified the mechanisms and agents at work, and subsequent laboratory tests presented data consistent with these mechanisms. 4
Several European studies also confirmed the sperm count results for specific places in Europe. 5 They also showed that the declines were not uniform. For example, in London the declines were greatest in particular water utility areas and in the Nordic countries the declines were least in rural, nonagricultural areas.
Just after Our Stolen Future came out, two American studies were released purporting to show that in 4 American cities no declines had taken place. 6
That's quite plausible. It's not inconsistent with there being declines elsewhere. The press, nonetheless, perhaps gently pushed by a few spinmeisters from vested interests, treated these results as invalidating the entire trend.
A closer look at these studies showed them to be severely flawed. In particular, data from three of the four cities examined were from samples from men volunteering for vasectomies. We know from other work that men volunteering for vasectomies represent a biased sample of the population at large. Hence the flawed studies may not tell us anything about what is really happening in the United States.
That didn't stop the critics, who have chosen to ignore these scientific failings.
In Our Stolen Future we were quite open about the uncertainties. In fact, one of our major recommendations was that there be more research on the issue. Fortunately, that is happening, and the results that have come in since we published the book have simply added ammunition to the case.
Let me give you some examples:
The striking thing about McLachlan's new findings isn't the existence of synergistic effects, but their reported magnitude and their unpredictability. Using individual small doses of the estrogenic pesticides dieldrin, toxaphene, endosulfan, and chlordane produced little, if any, effect, but when two chemicals were combined, the response was powerfully enhanced. If further experiments confirm these findings, this study will undoubtedly have profound implications for the regulation of chemicals, which are now reviewed individually.
According to the data, higher rates of birth defects occur not only in the children of farmers, who are directly exposed to the chemicals at work, but also in the children of families living in predominantly agricultural regions in the state where fungicides and chlorophenoxy herbicides are most heavily used. Children conceived in the spring, when these herbicides are routinely applied, are at particular risk of birth defects, the study found. In another intriguing finding, the researchers noted that birth defects occur at a much higher rate in the male offspring of farmers and than in the normal population.
Anyone here who worries about the adequacy of federal standards in risk assessment and the regulatory fascination with the 1 in a million threshold should look at this paper.
This study found that birth anomalies increase by 1.5 per hundred births comparing the lowest risk group with the highest risk group. That increase is four orders of magnitude greater than the 1 in a million standard, and the low risk group was not a zero baseline, because it is impossible to find a control group where there has been zero exposure.
While scientists are exploring a number of theories including parasites as well as viral and bacterial disease, pesticides and synthetic chemicals are leading suspects, especially given what is known about the crucial role of hormones in guiding metamorphosis from tadpole to frog.
As the Jacobson's note, the high levels of PCBs carried by these women were not that high. They"were similar to or slightly above the general population level in the United States," whose contamination can come from many sources other than Great Lakes fish.
The bottom line here is that science is showing the problems to be more widespread and immediate, not less. It is confirming the hypotheses advanced in the book, not refuting them. And this science will not end.
In particular, I expect there to be dramatic new discoveries on the impacts of low-dose exposures, findings that will challenge one of the most fundamental assumptions of risk assessment, that of the standard dose-response curve. 11 We should also expect scientists to continue discovering new and unexpected sources of exposure, not just from pesticides, but from other materials in modern commerce.
All of this means that your jobs are going to be more challenging, more important, and more crucial. Rest assured that the public is going to be looking to you for better protection and better help. I hope that our legislatures at the state and the federal level have the wisdom to give you the resources to do the job effectively.
2 E Carlsen, A Giwercman, N Keiding, N Skakkebaek
"Evidence for Decreasing Quality of Semen During Past 50 Years"
British Medical Journal 305:609-613, 1992.
3 Sharpe, RM, JS Fisher, MM Millar, S Jobling,
and JP Sumpter. 1995. Gestational and Lactational Exposure of Rats to
Xenoestrogens Results in Reduced Testicular Size and Sperm
Production. Environmental Health Perspectives, Vol. 103(12):
4 Two references
5 Seven references
7 Repetto, R and S.S. Baliga. 1996. Pesticides and the
Immune System: The Public Health Risks. World Resources Institute.
8 Arnold, SF,
DM Klotz, BM Collins, PM Vonier, LJ Guillette Jr., JA McLachlan. 1996
Synergistic Activation of Estrogen
Receptor with Combinations of Environmental Chemicals. Science 272:
9 Garry, VF, D Schreinemachers, ME Harkins, and J Griffith.
Pesticide Appliers, Biocides, and Birth
Defects in Rural Minnesota. 1996. Environmental Health Perspectives,
Vol. 104(4) 394-399.
10 Jacobson, JL and SW Jacobsen. 1996. Intellectual
Impairment in Children Exposed to Polychlorinated Biphenyls in Utero.
The New England Journal of Medicine 335(11): 783-789.
11 See Chapter 10, pp. 169-170, Our Stolen