California Environmental Protection Agency: Department of
Pesticide Regulation
Results
and Discussion
Executive
Summary
California
spends more than $48 million each year for the nation's
most comprehensive program to regulate pesticide use. Under
this program:
- A
pesticide's safety and efficacy is scientifically evaluated
before it can be used.
- All
agricultural pesticide use must be reported.
- Pesticide
specialists enforce restrictions to ensure safe use of
pesticides in the workplace and elsewhere.
- Domestic
and imported produce is sampled and tested for traces
of pesticide residue.
Annually,
only a small fraction of the samples violated established
standards. Since the standards include a safety margin,
illegal residues rarely present a health risk, according
to leading scientific experts.
There
are two elements in the Department of Pesticide Regulation's
(DPR) residue testing program: Marketplace Surveillance
and Priority Pesticide. In 1995, there were 7,706 samples
taken. Recent findings are consistent with those from previous
years. There are few violative residues, and pesticide detections
in produce are generally well below the allowable levels.
Marketplace
Surveillance Program
There
were 5,502 samples taken throughout the channels of trade:
at seaports and other points of entry into the State, packing
sites, wholesale, and retail outlets. All samples are tested
with multi-residue screens capable of detecting more than
200 pesticides and breakdown products. No residue were detected
in 64.6 percent of the samples. Residues within tolerance
(the legal limits set by the U.S. Environmental Protection
Agency) were found in about 33.7 percent. The majority of
these samples had residues at less than 10 percent of the
tolerance level. There were 1.64 percent of the samples
with an illegal residue. This consisted of 0.31 percent
with residues over the tolerance level; and 1.33 percent
with residues of a pesticide not registered for the crop.
Priority
Pesticide Program
In
this program, DPR concentrates monitoring on pesticides
of special health interest. Only crops known to have been
treated with a targeted pesticide are sampled. Because the
crop is known to have been treated, DPR obtains accurate
residue data on which to base estimates of dietary exposure
and evaluate preharvest intervals (the time between pesticide
application and before crop harvest). Analyses were completed
on 2,204 samples. Twenty-three pesticide active ingredients applied to 43 different commodities were sampled in 1995.
Even though 100 percent of the samples had been treated,
only 14 percent contained detectable residues. A majority
of the samples (85.9 percent) contained no detectable residues.
There were four samples (0.18 percent) with residues over
the tolerance level.
Residues
In Fresh Produce
1995 Monitoring Program
Results
and Discussion
The
Department of Pesticide Regulation (DPR) has the primary
responsibility for regulating all aspects of pesticide sales
and use to protect the public health and the environment.
DPR's
mission is to evaluate and mitigate impacts of pesticide
use, maintain the safety of the pesticide workplace, ensure
product effectiveness, and encourage the development and
use of reduced-risk pest control practices while recognizing
the need for pest management in a healthy economy.
The
results of DPR pesticide residue monitoring each year correspond
to the findings of 30 years of extensive monitoring. Residues
above established tolerance levels are rarely found. Violations
more commonly involve commodities that contain traces of
pesticides not registered for the commodity on which they
are found. Most illegal residues are below 1 parts per million
(ppm) and are the result of residual traces of pesticides
in soil, or drift from adjacent applications, an not from
direct misuse.
DPR's
two residue monitoring programs are Marketplace Surveillance
and Priority Pesticide. In 1995, there were 7,706 samples
taken in these two monitoring programs. County agricultural
commissioners, under contract to DPR, collect all the Priority
Pesticide Program samples. DPR staff in four field offices
collect most of the Marketplace Surveillance Program samples,
with assistance from the county agricultural commissioners.
Marketplace
Surveillance Program
There
were 5,502 samples collected in the Marketplace Surveillance
Program in 1995. Routine Marketplace Surveillance samples
are collected throughout the channels of tradeBBat packing
sites, seaports and border stations, and wholesale and retail
markets. All samples were tested with multi-residue screens.
In addition, selected samples were also analyzed for non-screenable
pesticides of enforcement concern.
In
1995, 132 different commodities were sampled in the Marketplace
Surveillance Program. Many were major production commodities
such as potatoes, oranges, and grapes, although many specialty
fruits and vegetables were sampled as well.
In
1995, findings in the Marketplace Surveillance Program included:
- No
residues were detected in 64.6 percent of the samples.
- Residues
at less than 50 percent of the tolerance level were detected
in 32.8 percent of the samples.
- Residues
from 50 to 100 percent of the tolerance were detected
in 0.96 percent of the samples.
- Illegal
residues were found in 1.64 percent of samples. Of these,
0.31 percent had residues that were over the tolerance
level, and 1.33 percent had residues of a pesticide not
authorized for use on the commodity. In most of the latter
situations, residues detected were well below what would
be allowed for the same pesticide on other crops. These
illegal residues are usually caused by leftover pesticides
in the soil or by pesticides drifting on the commodity
when applied to a nearby field.
Sampling
in the Marketplace Surveillance Program is not designed
to produce data that are statistically representative of
the overall residue situation for a particular pesticide,
commodity, or place of origin. It should be noted that the
percentage of samples with detectable residues is the average
for all samples. Certain commodities may have a higher percentage
of residues within tolerance because of post-harvest applications
or applications made close to harvest, while o her commodities
rarely contain detectable residues due to the nature of
pest populations and crop production practices. In DPR's
surveillance sampling, some bias may be incurred because
sampling is weighted toward such factors as patterns of
pesticide use; relative number and volume of pesticides
typically used to produce a commodity; relative dietary
importance of the commodity; past monitoring results; and
knowledge of local pesticide use. Therefore, the results
may be biased toward finding produce more likely to contain
illegal residues than if samples were collected in a true
statistically random fashion. In addition, the number of
samples of a given commodity analyzed for a particular pesticide
each year may not be sufficient to draw specific conclusions
about the residue situation for the whole volume of that
commodity in commerce.
DPR
targets imported commodities at points of entry into California
and samples foreign produce at wholesale and retail markets.
Produce grown outside California represented about 40 percent
of the sample: 10.3 percent from other states and 29.7 percent
from foreign countries. The most frequently sampled countries
of origin were Mexico, with 1,273 samples and Chile, with
128 samples, reflecting the volume and variety of commodities
imported to California from those nations, especially during
the winter months.
DPR's
Pesticide Enforcement Branch continued to target imported
peppers (such as Serrano, Anaheim, and yellow bell) and
melons (cantaloupe and honeydew), and added papaya and kale
to the list for surveillance based on U.S. Food and Drug
Administration (FDA) referrals and a history of illegal
residue problems in the past. This resulted in a higher
proportion of these commodities being sampled.
The
proportion of illegal residues found in produce of foreign
origin was 3 percent in 1995, up from 2.83 percent in 1994.
The increase in detected illegal residues in produce imported
from foreign countries is a result of the targeted enforcement
strategies of DPR and FDA.
Priority
Pesticide Program
In
the Priority Pesticide Program, DPR concentrates monitoring
on pesticides of special health interest. In this program,
samples are taken only of crops that are known to have been
treated with a targeted pesticide. Because the crop is known
to have been treated, DPR obtains accurate residue data
on which to base estimates of dietary exposure.
The
pesticides and commodities to be targeted in the Priority
Pesticide Program are selected in a coordinated effort by
DPR's Medical Toxicology and Pesticide Enforcement Branches.
The primary focus of the program is on pesticides of known
toxicological concern. DPR considers factors, including
the amount of pesticide used on California crop acreage,
and the dietary significance of those commodities. Working
under contract to DPR, county agricultural commissioners
collect samples of the targeted commodities.
In
1995, findings in the Priority Pesticide Program included:
- Analyses
were completed on 2,204 samples in the Priority Pesticide
Program.
- Twenty-three
pesticide active ingredients applied to 43 different commodities
were sampled in 1995.
- Although
100 percent of the samples were treated, residues were
found in only 14 percent. Four of the 2,204 samples (0.18
percent) contained illegal residues over tolerance.
- Chemicals
analyzed: Insecticides acephate, carbaryl, diazinon,
dicofol, dimethoate, endosulfan, methamidophos, methomyl,
mevinphos, naled, oxamyl, phosmet and propargite. Herbicides
2,4-D, chlorthal-dimethyl, and simazine. Fungicides
benomyl, captan, chlorothanlonil, mancozeb, maneb, thiabendazole,
and triadimefon.
Regulatory
Program History
California's
pesticide regulatory program had its beginnings in 1902,
when the first state law regulating pesticide product quality
was passed. That bill was limited to one productBBcopper
acetoarsenite, an arsenic-based chemical better known as
"Paris Green." In 1910, Congress passed an omnibus pesticide
product quality law and one year later, the California Legislature
followed suit. The state took its next step in 1921, when
the Legislature began a program requiring that all pesticides
manufactured and sold within the state be registered with
the Director of Agriculture. Though the intent of this law,
like earlier ones, was to protect consumers from misbranded
or adulterated products, it also allowed the Director to
cancel the registration of any chemical that was dangerous
to animals or to public health, even when used properly.
This law was one of the first attempts to use the pesticide
registration process to protect the environment and the
public from potentially harmful effects of pesticides.
The
State's pesticide regulators (then part of the State Department
of Agriculture) began analyzing small quantities of produce
for pesticide residues in 1926. This was after the U.S.
Bureau of Chemistry established the pesticide tolerances,
setting allowable residue levels for arsenic on apples and
pears in interstate commerce and for export.
In
1927, there was a public outcry over excessive arsenic residues
detected in some fruits and vegetables, and the British
government threatened an embargo against American-grown
fruit. The California Legislature responded by passing the
Spray Residue Act. It created a program to control residues
of arsenic-based sprays on fruits and vegetables. There
were only about 30 pesticide active ingredients in use at
the time. Many were arsenical compounds, and arsenic was
then considered the major pesticide residue of health concern.
The
new law established a monitoring program designed not only
to safeguard the consumer against harmful residue levels,
but also to promote marketing of California products. The
goal was to ensure that no shipments of California fruit
were confiscated because of excess residues. The Department
had both a regulatory program designed to monitor compliance
with the law, and a program to provide certification to
growers. The latter was a voluntary, fee-based program that
allowed growers to obtain state certification that their
crops were free from arsenic residue. Without such certification,
growers often found it impossible to export fruit. The service
was phased out by the 1940s.
As
part of its regulatory monitoring program, Department inspectors
made daily visits to wholesale and retail markets in Los
Angeles, San Diego, and San Francisco. Samples were sent
to Department laboratories in these cities for analysis.
Throughout the 1930s, the spray residue program was expanded
to include sampling for residues of lead, fluorine and copper.
The number of samples also grew from 1,675 samples in 1931
to 3,779 in 1938. With the introduction of many new synthetic pesticides in the late 1940s, residue sampling expanded
to test for DDT and other newly introduced organic compounds.
During
the 1980s, the Department added three new programs to complement
marketplace surveillance. They included a program to test
raw produce destined for processing, another to sample crops
before harvesting, and the most significant to target sampling
of commodities known to have been treated with pesticides
of health concern. This new program was designed to provide
data needed for accurate assessments of dietary risk.
In
addition to adding new programs, the number of pesticides
for which routine tests were done increased. In 1988, residue
program chemists were using multi-residue analytical methods
(called screens) that could detect 108 pesticide active
ingredients, metabolites, and breakdown products; by 1991,
that number had increased to more than 200. The results
are usually available within eight hours.
Findings
and Their Significance
The
validity of any sampling program lies in its design and
in its ability to replicate the results. Over the past decade,
even as the number of samples varied, the findings have
been consistent from year to year. Most residues are below
detectable limits. Residues that are found are usually at
levels that are measured at a fraction of a part per million
(ppm). Less than one percent of samples have residues over
the allowable levels established by the U.S. Environmental
Protection Agency (U.S. EPA). These levels are called "tolerances."
A tolerance is the highest residue level of the particular
pesticide that is legally allowed on the particular commodity.
A tolerance is set by U.S. EPA for regulatory purposes and
is established at a level that incorporates a margin of
safety, and usually assumes a lifetime of consumption of
the commodity at the maximum allowable residue level.
While
the goal of DPR's regulatory program is to ensure that all
food is in compliance with pesticide safety standards that
include a safety margin, an occasional produce item slightly
above tolerance should not automatically be considered a
health hazard. The results from years of DPR residue monitoring
document the safety of produce grown and consumed in California.
The
effectiveness of DPR's monitoring program is enhanced by
the Department's formal cooperative agreement with FDA,
which has an extensive nationwide produce monitoring program.
DPR and FDA staff meet regularly to plan sampling strategies
that complement rather than duplicate the other. The two
agencies share monitoring results and cooperate on investigations.
This cooperative agreement leads to a more comprehensive
understanding of the incidence of pesticide residues in
the food supply.
Enforcement
and Compliance Options
DPR,
working with the county agricultural commissioners, has
wide-ranging authority to deal with violators of pesticide
laws and regulations. Enforcement options include administrative
actions; criminal and civil actions; and crop quarantine,
crop abatement, and crop seizure. Administrative actions
can be taken by the Department or the county agricultural
commissioner to refuse, revoke or suspend the right of a
pest control business to apply pesticides, or a far er to
use certain pesticides. The Department and the commissioners
also have the authority to levy agricultural civil penalties
to enforce certain pesticide regulations, including those
prohibiting the packing, shipping or selling of produce
containing illegal pesticide residues.
Criminal
or civil actions may also be taken, with fines ranging from
a minimum of $500 up to $50,000. Criminal and civil proceedings
are considered for repetitive or intentional violations,
or violations that have created a hazard to human health
or the environment.
Crop
quarantine, crop abatement, and crop seizure are additional
tools in the enforcement arsenal. The Department may quarantine
and hold any lot of produce domestic or imported that contains
pesticide residues over the tolerance levels. DPR may also
quarantine produce suspected of containing illegal residues.
The produce is then tested, and should illegal residues
be present, the quarantine is maintained. The owner of the
produce has the option of reconditioning the produce to
remove the illegal residues. If the illegal residues cannot
be removed, the produce must be destroyed. Should an illegal
residue be found on a crop in the field, the Department
can prohibit harvest and, in some cases, order the crop
destroyed.
The
Department investigates every case of illegal residue detected
in its residue monitoring programs. Enforcement staff interview
shippers and packers to determine where the produce was
grown. If the produce came from out of state, the produce
remains under quarantine and information is forwarded to
the FDA for further enforcement action. If the produce was
grown within California, enforcement staff interview growers,
pest control applicators, and others to learn how the pr
duce was contaminated before determining appropriate enforcement
action.
Enhancements
in Analytical Technology
California's
participation in the U.S. Department of Agriculture's Pesticide
Data Program (USDA's PDP) helped give rise to significant
enhancements of the multi-residue screens that can simultaneously
detect a number of pesticides. These analytical tools are
particularly useful for testing the large numbers of samples
in the Marketplace Surveillance Program, whose pesticide
treatment history is not usually known at the time of sampling.
The screens now used b DPR can detect a total of more than
200 pesticides, metabolites, and breakdown products at exceedingly
low levels.
The
focus of USDA's PDP is gathering comprehensive data on minute
traces of residues. To do this, multi-residue methods were
enhanced to be sensitive to residue levels of well under
100 parts per billion. Some of these analytical advances
are being used to analyze samples taken in DPR's monitoring
programs, making it possible to detect smaller levels of
residues.
Beginning
in 1991 and continuing through 1995, this has resulted in
an increased percentage of samples with detectable residues.
The increase in detected residues does not mean there is
more risk; minute traces of pesticides in food are to be
expected, and are not considered significant health threats.
As the chart on page 12 indicates, much of the increase
in detectable residues has been at levels that are 10 percent
or less of the tolerance level.
Between
1987 and 1990, the percentage of samples with detectable
residues varied little, averaging 21 percent. Samples that
had detected residues at 10 percent or less of the tolerance
level also held steady, between 12 and 13 percent each year.
Samples with residues between 50 and 100 percent of tolerance
were about 1 percent each year.
In
1991, as technology made possible the routine detection
of lower residue levels, the percentage of samples with
detectable residues increased to 25 percent. Much of the
increase was in lower-level residues: the percentage of
residues at 10 percent or less of tolerance jumped to 16
percent, while residues at 50 to 100 percent of tolerance
continued a slight decline to 0.8 percent.
In
1995, the percentage of samples with detectable residues
remained at 34 percent. The percentage of detections at
10 percent or less of tolerance was 24 percent. The percentage
of residues at 50 to 100 percent of tolerance was below
1 percent.
Year |
Total
Samples |
Percentage
of Samples with Detectable Residues |
Percentage
of Samples at
0-10% of Tolerance |
Percentage
of Samples at 50-100% of Tolerance |
1987 |
7,010 |
20% |
12% |
1.1% |
1988 |
9,232 |
22% |
13% |
1.1% |
1989 |
9,403 |
22% |
13% |
0.9% |
1990 |
8,278 |
20% |
12% |
0.7% |
1991 |
7,446 |
25% |
16% |
0.8% |
1992 |
7,319 |
31% |
21% |
0.8% |
1993 |
6,066 |
34% |
23% |
1.3% |
1994 |
5,588 |
34% |
23% |
1.3% |
1995 |
5,502 |
34% |
24% |
0.96% |
To
detect pesticides not picked up by the multi-residue screens,
single-residue methods or selective screens are used. A
single-residue method generally detects one pesticide; a
selective screen measures a small number of chemically related
pesticides, such as the phenylurea herbicides. These types
of methods are more resource-intensive per residue, and
may require as much time to do as a multi-residue screen.
These analytical methods can generally detect levels well
belo tolerance values. The minimum level of detection in
the screens may vary from 0.02 to 0.2 ppm; for individual
analyses, the minimum level of detection may vary from about
0.005 to 1 ppm. These variations may be caused by the particular
commodity being tested, the sample size, and by other factors.
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NASD Review: 04/2002
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