|
Items in cart [0] |
Questions? Call 888-624-8373 |
| Copyright © 2009. National Academy of Sciences. All rights reserved. Terms of Use and Privacy Statement |
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 17
1
Introduction
The modern increase in pesticide use demonstrates how technological
advancements can be beneficial and harmful at the same time. Effectively
used, pesticides can kill or control pests, including weeds, insects, fungi,
bacteria, and rodents. As a result, chemical pest control has won a central
place in modern agriculture, contributing to the dramatic increases in crop
yields achieved in recent decades for most major field, fruit, and vegeta-
ble crops. The production systems for most crops in most regions of the
United States are dependent on at least one pesticide, and often several
some for weed control, some to control insect pests, and others for the
control of a variety of plant diseases. The amount of pesticide use varies
by region, however. Oats in the northern plains require little or no
pesticide use, whereas vegetables in humid regions of the South may
require 20 or more pesticide applications in a single growing season.
The focus of this study is limited to pesticide use on food crops.
Although pesticides help protect food crops from insect pests, weeds, and
diseases, most are potentially dangerous substances whose use requires
careful control. They work because they are toxic to target organisms or
otherwise disrupt natural processes necessary for the organisms' sur-
vival. Some are toxic only to target pests and pose little threat to other life
forms, including humans. Many, however, are capable of harming
nontarget species.
Pesticides are dispersed widely to treat crops, pastureland, and har-
vested fruits and vegetables. Consequently, most pesticide applications
result in some contact with nontarget crops and organisms as well as
17
OCR for page 18
I ~ REGULATING PESTICIDES IN FOOD
applicators (persons who apply pesticides), farm workers, food handlers,
and ultimately food consumers. Drinking water is also an increasingly
significant source of human exposure to pesticides. All of these routes of
exposure present concerns, but this study is limited to dietary exposure
from oncogenic residues in food and to the process designed to control
this route of exposure.
FIFRA AND THE FDC ACT
The societal response to the dual nature of pesticides has been the
development of a comprehensive regulatory system that seeks to make
possible the beneficial use of pesticides while minimizing their public
health and environmental risks. The current system originated with
enactment of the 1947 Federal Insecticide, Fungicide and Rodenticide Act
(FIFRA). The system now is defined by a comprehensively amended
FIFRA and for pesticides likely to appear on human foods- by various
provisions of the Federal Food, Drug and Cosmetic (FDC) Act. The basic
goals of these statutes are to allow only those pesticide uses that (1) do not
have "unreasonable adverse effects" on human health or the environ-
ment and (2) have benefits outweighing whatever risks might exist. These
goals are easy to state but difficult to implement. Complex issues and
scientific uncertainties arise in estimating risks and benefits of pesticide
uses. There is no simple, widely accepted method for balancing risks and
benefits. Moreover, the avoidance of unsafe residues requires not only an
operational definition of safety but a costly and complex system for
monitoring and enforcement. The responsibility for deciding which pes-
ticides may be used and what residues can be tolerated lies with the
Environmental Protection Agency (EPA).
The EPA performs two main tasks. First, under FIFRA, the EPA
decides what pesticide uses can be registered or approved in the United
States. A single pesticide may have many potential uses. For example,
the insecticide dimethoate is used to control a variety of pests on nearly
30 different crops, including cotton, tomatoes, and corn. In this report, a
pesticide use refers to the application of a pesticide on a particular crop.
The EPA registers each use under a statutory standard that requires
balancing of benefits of a pesticide use against its potential risks to human
health and the environment.
The EPA's second main task and the focus of this study is the
establishment of legal limits (tolerances) specifying the amount of pesti-
cide residue that can be present in or on foods sold in interstate
commerce. The EPA performs this function under the authority of the
FDC Act. It is a huge administrative task. A single pesticide intended for
use on a single crop is likely to leave residues on the raw agricultural
OCR for page 19
INTRODUCTION 19
TABLE 1-1 Section 408 and 409 Food Tolerances
Listed in the CFR
Type of
Pesticide
Number
Section 408
Section 409
Insecticides 3,654 63
Herbicides 2,462 39
Fungicides 1,256 20
Total 7,372 122
NOTE: This table does not include feed-additive tolerances listed
in the CFR.
commodity. It can also find its way into numerous processed food and
animal products. Moreover, most pesticides are used on several crops.
On the basis of field testing to measure residue levels, the EPA
establishes tolerances to cover all expected residues on food. Over 8,500
food tolerances for all pesticides are currently listed in the Code of
Federal Regulations (CFR). Approximately 8,350 of these tolerances are
for residues on raw commodities (promulgated under section 408) and
about 150 for residues known to concentrate in processed foods (promul-
gated under section 4091. Table 1-1 shows the number of tolerances issued
for insecticides, herbicides, and fungicides, which are the major classes of
pesticides.
The EPA's tolerance-setting task is made complicated by divergences
between FIFRA and the FDC Act. Most notably, some legal standards
within the FDC Act apply to pesticide residues present in or on raw
commodities and some apply to pesticide residues in processed foods. In
deciding whether to establish a raw agricultural commodity tolerance for
a fresh food such as tomatoes, the EPA is authorized to balance the
benefits of using the pesticide to produce a crop against the potential
human health effects of any residue that would result a process similar
to that undertaken when the pesticide is considered for registration under
FIFRA. ~
Some processed foods contain higher levels of residues than allowed by
the raw commodity tolerance because residues concentrate during pro-
cessing. An example is the fungicide benomyl, which concentrates in
processed tomato products. This phenomenon can have important regu-
latory implications because the FDC Act does not allow the EPA to
consider the benefits of a pesticide's use in setting tolerances for residues
that concentrate in processed foods. Tolerances for such residues are
instead set under the same risk-only standard that governs intentional
food additives: a residue must be proven safe.2
OCR for page 20
20 REGULATING PESTICIDES IN FOOD
THE DELANEY CLAUSE AND THE PURPOSE OF THIS REPORT
The regulatory consequences of residue concentration in processed
food are profound if a pesticide has been found to induce cancer in
experiments on animals. Such a residue, or food additive for legal
purposes, is subject to the FDC Act's most famous provision the
Delaney Clause. The EPA has interpreted the Delaney Clause as gener-
ally prohibiting the establishment of any processed-food tolerances for an
oncogenic pesticide (a pesticide capable of inducing tumors), regardless
of whether or to what extent its residue is judged to pose a hazard to
human health. It is this policy that has occasioned the current study.
The objectives of this study are to describe and, to the greatest extent
possible, estimate the consequences for public health and agricultural
innovation of these dichotomous standards for setting pesticide toler-
ances. The EPA's request for this study followed its recognition that the
procedures necessary to implement the two standards had grown exceed-
ingly complex and sometimes produced results that were difficult to
reconcile scientifically. Moreover, the agency realized that an increasing
number of regulatory decisions would hinge on its policies for dealing
with oncogenic residues in processed foods as the results of new residue
chemistry and chronic toxicity studies became available as part of its
ongoing pesticide reregistration process.
In describing the need for the study, EPA officials anticipated that
application of the Delaney Clause could have a major impact on pesticide
availability. Agricultural producers could face high costs if they were
forced to adjust cropping patterns and pest control methods. In addition,
the agency emphasized a potential paradox. Adherence to the strict
standard of the Delaney Clause in establishing new tolerances could
preclude commercial introduction of potentially lower-risk pesticides.
These lower-risk pesticides would then be stopped from replacing older,
potentially more hazardous compounds that have not been fully tested or,
if tested, have not been brought into compliance with all current statutory
requirements. The EPA was also concerned that actions dictated by the
law's preoccupation with oncogenicity might make it more difficult to
address other health and environmental hazards.
The EPA asked the National Research Council's Board on Agriculture to
study the current system for tolerance setting, especially as affected by the
Delaney Clause. The agency also asked the board to evaluate the clause's
impact on the EPA's ability to accomplish the central goals of pesticide
regulation enunciated by Congress: permitting beneficial uses of pesticides while
me zing public health and environmental risks. The board appointed the
Committee on Scientific and Regulatory Issues Underlying Pesticide Use
Patterns and Agricultural Innovation to respond to these questions.
OCR for page 21
INTRODUCTION 21
THE COMMITTEE'S TASKS
The committee began by developing an analytical framework and a data
base to assess the impact of the current system (and possible alternatives) on
the future availability of pesticides and on human exposure to oncogenic
pesticide residues. As explained in Appendix B. the committee, with the
EPA's cooperation, assembled an extensive database. This data base covers
289 registered pesticide active ingredients currently used on food crops by
· Tolerance levels.
· Crop use,
· The likely need for processed food tolerances (because residues tend
to concentrate),
· Potential human exposure based on average dietary consumption patterns,
· Regulatory status and history, and
· Toxicological properties.
The committee carried out a series of analyses using the data base.
From the results, the committee estimated the effects of different regula-
tory strategies across all registered pesticides. Based on risk assessment
and other analytic methods routinely used by the EPA, this data base
analysis has yielded approximate answers to such general questions as-
· How large is the potential human oncogenic risk from pesticides in the diet?
· What pesticides pose the most significant risks?
· What crops account for the greatest exposure and largest risks?
· What general conclusions can be drawn regarding the characteristics
of the most hazardous and least hazardous pesticides?
The committee's report of data responsive to these questions, primarily in
Chapter 3, must be interpreted with great caution. It is especially important to
note that only estimated cancer risks and no other human health risks were
assessed. Further, estimates of oncogenic risks are derived using methods
designed to identify conservative upper bounds on potential human risk. The
estimates presumably overstate true human risk. But with these caveats the
analysis provides some important insights, which are described below.
The potential impact of the Delaney Clause on the availability of
pesticides and human exposure to oncogenic pesticides is explored in
Chapters 4 and 5. In these chapters, four scenarios, or theoretical policy
constructs, were evaluated to determine which approach or approaches to
tolerance setting will maximize the availability of useful pesticides while
minimizing public health and environmental risks.
Throughout the study, the committee has been impressed by the complex-
ity of the tasks that Congress has delegated to the EPA. The committee has
come to appreciate the sometimes perplexing scientific and administrative
OCR for page 22
22 REGULATING PESTICIDES IN FOOD
issues posed by each regulatory decision. Before the agency can sanction a
new chemical use or restrict or eliminate an old nsk, it must assemble and
evaluate large amounts of scientific and economic data. It must deal with an
array of sometimes competing considerations. It must pay attention to
consistency among decisions, especially when far-reaching impacts on the
public health, environment, and economy are potentially at stake. It must
regularly incorporate scientific advances in risk assessments. In spite of
scientific advances and an exponential increase in data that must be
evaluated in estimating risks and benefits of pesticide use, the EPA shoulders
these complex tasks with budget constraints and limited resources that have
shrunk considerably since 1980.
A major part of the EPA's difficulty in reaching and defending regula-
tory decisions is caused by the law itself rather than the amount or
complexity of data. By statute, the propensity of a pesticide residue to
concentrate in processed food has been made the linchpin for determining
which of two quite different statutory standards applies to the tolerance-
setting decision. For oncogenic pesticides that do concentrate, the
agency's exercise of scientific judgment is curtailed because the Delaney
Clause purports to demand not only zero risk but zero exposure. As a
result, agency resources have been diverted toward inquiries regarding
the fact and extent of concentration, which may often be insignificant in
terms of public health protection, but of great consequence in practice.
The committee began the study with the understanding that the Delaney
Clause could have substantial impacts on the pesticide program, but was
unsure of how to characterize or measure the impacts. The report's
analyses shed new light on these impacts.
The committee hopes that this study will provide a framework for policymak-
ers In the EPA, the Congress, and elsewhere to malice infonnedjudgments about
whether the current system for tolerance setting should be changed. The
committee offers some general conclusions concerning the desirability of charge
and suggests how the prospective consequences of alternative policies should be
analyzed. If further refined, the analytical framework and data base used herein
may help clarify whether strict adherence to the Delaney Clause contributes to
or detracts from achievement of Congress' goals.
NOTES
1. "In establishing any such regulation [raw agricultural commodity tolerance] the Admin-
istrator shall give appropriate consideration . . . (1) to the necessity for the production of
an adequate, wholesome, and economical food supply." 21 USC § 346(b).
2. "No such regulation [food additive tolerance] shall issue if a fair evaluation of the data
before the Secretary fails to establish that the proposed use of the food additive under the
conditions of use to be specified in the regulation, will be safe." 21 USC § 348(C)(3)(A).
Representative terms from entire chapter:
processed foods
