ENVIRONMENTAL
AND ECONOMIC COSTS OF THE
APPLICATION OF PESTICIDES PRIMARILY IN THE UNITED STATES
David Pimentel
College of Agriculture and Life Sciences,
Cornell University, Ithaca, NY 14853-0901
Abstract: An obvious need for an updated and
comprehensive study prompted this investigation of the complex of environmental
costs resulting from the nation’s dependence on pesticides. Included in this assessment of an estimated
$10 billion in environmental and societal damages are analyses of: pesticide
impacts on public health; livestock and livestock product losses; increased
control expenses resulting from pesticide-related destruction of natural enemies
and from the development of pesticide resistance in pests; crop pollination
problems and honeybee losses; crop and crop product losses; bird, fish, and
other wildlife losses; and governmental expenditures to reduce the
environmental and social costs of the recommended application of pesticides.
The major economic and environmental losses due to the
application of pesticides in the U.S. were: public health, $1.1 billion per
year, pesticide resistance in pests; $1.5 billion; crop losses caused by
pesticides, $1.4 billion; bird losses due to pesticides, $2.2 billion; and
groundwater contamination, $2.0 billion.
Key words: agriculture, costs, crops, environment,
livestock, natural resources, pesticide, pesticide resistance, public health.
1. Introduction
Worldwide, about 3 billion kg of pesticides are applied each
year with a purchase price of nearly $40 billion per year (Pan-UK, 2003). In the U.S., approximately 500 million kg of
more than 600 different pesticide types are applied annually at a cost of $10
billion (Pimentel and Greiner, 1997).
Despite the widespread application of pesticides in the
United States at recommended dosages, pests (insects, plant pathogens, and
weeds) destroy 37% of all potential crops (Pimentel, 1997). Insects destroy 13%, plant pathogens 12%, and
weeds 12%. In general, each dollar
invested in pesticide control returns about $4 in protected crops (Pimentel,
1997).
Although pesticides are generally profitable in agriculture,
their use does not always decrease crop losses.
For example, despite the more than 10-fold increase in insecticide
(organochlorines, organophosphates, and carbamates) use in the United States from
1945 to 2000, total crop losses from insect damage have nearly doubled from 7%
to 13% (Pimentel et al., 1991). This rise in crop losses to insects is, in
part, caused by changes in agricultural practices. For instance, the replacement of corn-crop
rotations with the continuous production of corn on more than half of the corn
acreage has nearly resulted in an increase in corn losses to insects from about
3.5% to 12% despite a more than 1,000-fold increase in insecticide
(organophosphate) use in corn production (Pimentel et al., 1991). Corn today is
the largest user of insecticides of any crop in the United States.
Most benefits of pesticides are based on the direct crop
returns. Such assessments do not include
the indirect environment and economic costs associated with the recommended
application of pesticides in crops. To
facilitate the development and implementation of a scientifically sound policy
of pesticide use, these environmental and economic costs must be examined. For several decades, the U.S. Environmental
Protection Agency pointed out the need for such a benefit/cost and risk
investigation (EPA, 1977). Thus far,
only a few scientific papers on this complex and difficult subject have been
published.
2. Public health effects
2.1. Acute Poisonings
Human pesticide poisonings and illnesses are clearly the
highest price paid for all pesticide use. The total number of pesticide
poisonings in the United States is estimated to be 300,000 per year (EPA,
1992). Worldwide, the application of 3 million metric tons of pesticides
results in more than 26 million cases of non-fatal pesticide poisonings (Richter,
2002). Of all the pesticide poisonings,
about 3 million cases are hospitalized and there are approximately 220,000
fatalities and about 750,000 chronic illnesses every year (Hart and Pimentel,
2002).
2.2. Cancer and
Other Chronic Effects
Ample evidence exists concerning the carcinogenic threat
related to the use of pesticides. These
major types of chronic health effects of pesticides include neurological
effects, respiratory and reproductive effects, and cancer. There is some evidence that pesticides can
cause sensory disturbances as well as cognitive effects such as memory loss,
language problems, and learning impairment (Hart and Pimentel, 2002). The malady, organophosphate induced delayed
poly-neuropathy (OPIDP), is well documented and includes irreversible
neurological damage.
In addition to neurological effects, pesticides can have
adverse effects on the respiratory and reproductive systems. For example, 15% of a group of professional
pesticide applicators suffered asthma, chronic sinusitis, and/or chronic
bronchitis (Weiner and Worth, 1972).
Studies have also linked pesticides with reproductive effects. For example, some pesticides have been found
to cause testicular dysfunction or sterility (Colburn, et al. 1996). Sperm counts in males in Europe and the
United States, for example, declined by about 50% between 1938 and 1990
(Carlsen et al., 1992). Currently, there
is evidence that human sperm counts continue to decrease by about 2% per year
(Pimentel and Hart, 2001).
U.S. data indicate that 18% of all insecticides and 90% of
all fungicides are carcinogenic (NAS, 1987).
Several studies have shown that the risks of certain types of cancers
are higher in some people, such as farm workers and pesticide applicators, who
are often exposed to pesticides (Pimentel and Hart, 2001). Certain pesticides
have been shown to induce tumors in laboratory animals and there is some
evidence that suggest similar effects occur in humans (Colburn et al., 1996).
A UFW (2003) study of the cancer registry in California
analyzed the incidence of cancer among Latino farm workers and reported that
per year, if everyone in the U.S. had a similar rate of incidence, there would
be 83,000 cases of cancer associated with pesticides in the U.S. The incidence of cancer in the U.S.
population due to pesticides ranges from about 10,000 to 15,000 cases per year
(Pimentel et al., 1997).
Many pesticides are also estrogenic – they mimic or interact
with the hormone estrogen – linking them to increase in breast cancer among some
women. The breast cancer rate rose from
1 in 20 in 1960 to 1 in 8 in 1995 (Colburn et al., 1996). As expected, there was a significant
increase in pesticide use during that time period. Pesticides that interfere with the body’s
endocrine – hormonal – system can also have reproductive, immunological, or
developmental effects (McCarthy, 1993).
While endocrine disrupting pesticides may appear less dangerous because
hormonal effects rarely result in acute poisonings, their effects on
reproduction and development may prove to have far-reaching consequences
(Colburn et al., 1996).
The negative health effects of
pesticides can be far more significant in children than adults, for several
reasons. First, children have higher
metabolic rates than adults, and their ability to activate, detoxify, and
excrete toxic pesticides differs from adults.
Also, children consume more food than adults and thus can consume more
pesticides per unit weight than adults.
This problem is particularly significant for children because their
brains are more than 5 times larger in proportion to their body weight than
adult brains, making cholinesterase even more vital. In a California study, 40% of the children
working in agricultural fields had blood cholinesterase levels below normal, a
strong indication of organophosphate and carbamate pesticide poisoning (Repetto
and Baliga, 1996). According to the EPA, babies and toddlers are 10 times more
at risk for cancer than adults (Hebert, 2003).
Although no one can place a precise
monetary value on a human life, the economic “costs” of human pesticide
poisonings have been estimated (Table 1).
For our assessment, we use the EPA standard of $3.7 million per human
life (Kaiser, 2003). Available estimates suggest that human pesticide poisonings
and related illnesses in the United States cost about $1 billion per year
(Pimentel and Greiner, 1997).
The majority of foods purchased in super markets have
detectable levels of pesticide residues.
For instance, of several thousand samples of food, the overall the
assessment in 8 fruits and 12 vegetables is that 73% have pesticide residues
(Baker et al., 2003). In 5 crops (apples, peaches, pears, strawberries and
celery) pesticide residues were found in 90% of the crops. Of interest is the fact that 37 different
pesticides were detected in apples (Groth et al., 1999).
Up to 5% of the foods tested in 1997 contained pesticide
residues that were above the FDA tolerance levels. Although these foods violated the U.S.
tolerance of pesticide residues in foods, these same foods were consumed by the
public. This is because the food samples
were analyzed after the foods were sold in the super markets.
3. Domestic animal poisonings and contaminated
products
In addition to pesticide problems that affect humans,
several thousand domestic animals are accidentally poisoned by pesticides each
year, with dogs and cats representing the largest number (Table 2). For example, of 250,000 poison cases
involving animals, a large percentage of the cases were related to pesticides
(National Animal Poison Control Center, 2003).
Poisonings of dogs and cats are common.
This is not surprising because dogs and cats usually wander freely about
the home and farm and therefore have greater opportunity to come into contact
with pesticides than other domesticated animals.
The best estimates indicate that about 20% of the total
monetary value of animal production, or about $4.2 billion, is lost to all
animal illnesses, including pesticide poisonings. It is reported that 0.5% of
animal illnesses and 0.04% of all animal deaths reported to a veterinary
diagnostic laboratory were due to pesticide toxicosis. Thus, $21.3 and $8.8 million, respectively,
are lost to pesticide poisonings (Table 2).
This estimate is considered low because it is based only on
poisonings reported to veterinarians.
Many animal deaths that occur in the home and on farms go undiagnosed
and unreported. In addition, many are
attributed to other factors than pesticides.
Also, when a farm animal poisoning occurs and little can be done for the
animal, the farmer seldom calls a veterinarian but, rather either waits for the
animal to recover or destroys it. Such
cases are usually unreported.
Additional economic losses occur when meat, milk, and eggs
are contaminated with pesticide. In the
United States, all animals slaughtered for human consumption, if shipped
interstate, and all imported meat and poultry, must be inspected by the USDA. This is to insure that the meat and products
are wholesome, properly labeled, and do not present a health hazard.
Pesticide residues are searched for in animals and their
products. However, of the more than 600
pesticides in use now, the National Residue Program (NRP) only searches for about
40 different pesticides, which have been determined by FDA, EPA, and FSIS to be
of public health concern. While the
monitoring program records the number and type of violations, there might be
little cost to the animal industry because the meat and other products are
sometimes sold and consumed by the public
before the test results are available.
For example, about 3% of the chicken with illegal pesticide residues are
sold in the market (NAS, 1987).
In addition to animal carcasses, pesticide-contaminated milk
cannot be sold and must be disposed of.
In some instances, these losses are substantial. For example, in Oahu, Hawaii, in 1982, 80% of
the milk supply, worth more than $8.5 million, was condemned by the public
health officials because it had been contaminated with the insecticide
heptachlor (Baker et al., 2003). This
incident had immediate and far-reaching effects on the entire milk industry on
the island.
4. Destruction of beneficial natural predators and
parasites
In both natural and agricultural ecosystems, many species,
especially predators and parasites, control or help control plant feeding
arthropod populations. Indeed, these
natural beneficial species make it possible for ecosystems to remain “green.” With the parasites and predators keeping
plant feeding populations at low levels, only a relatively small amount of
plant biomass is removed each growing season by arthropods (Hairston et al.,
1960: Pimentel, 1988).
Like pest populations, beneficial natural enemies and
biodiversity (predators and parasites) are adversely affected by pesticides
(Pimentel et al., 1993a). For example,
the following pests have reached outbreak levels in cotton and apple crops
after the natural enemies were destroyed by pesticides: cotton = cotton bollworm, tobacco budworm,
cotton aphid, spider mites, and cotton loopers; apples = European red mite,
red-banded leaf roller, San Jose scale, oyster shell scale, rosy apple aphid,
wooly apple aphid, white apple aphid, two-spotted spider mite, and apple rust
mite. Major pest outbreaks have also
occurred in other crops. Also, because
parasitic and predaceous insects often have complex searching and attack
behaviors, sub-lethal insecticide dosages may alter this behavior and in this
way disrupt effective biological controls.
Fungicides also can contribute to pest outbreaks when they
reduce fungal pathogens that are naturally parasitic on many insects. For example, the use of benomyl reduces
populations of entomopathogenic fungi, resulting in increased survival of velvet
bean caterpillars and cabbage loppers in soybeans. This eventually leads to reduced soybean
yields.
When outbreaks of secondary pests occur because their
natural enemies are destroyed by pesticides, additional and sometimes more
expensive pesticide treatments have to be made in efforts to sustain crop
yields. This raises the overall costs
and contributes to pesticide-related problems.
An estimated $520 million can be attributed to costs of
additional pesticide application and increased crop losses, both of which
follow the destruction of natural enemies by various pesticides applied to
crops (Table 3).
As in the United States, natural enemies are being adversely
affected by pesticides worldwide.
Although no reliable estimate is available concerning the impact of this
in terms of increased pesticide use and/or reduced crop yields, general
observations by entomologists indicate that the impact of loss of natural
enemies is severe where pesticides are heavily used in many parts of the world.
For example, from 1980 to 1985 insecticide use in rice production in Indonesia
drastically increased (Oka, 1991). This
caused the destruction of beneficial natural enemies of the brown plant hopper
and this pest population exploded. Rice
yield decreased to the extent that rice had to be imported into Indonesia. The estimated cost of rice loss in just a
2-year period was $1.5 billion (FAO, 1988).
After this incident, Dr. I.N. Oka, who had previously
developed a successful low-insecticide program for rice pests in Indonesia, was
consulted by the Indonesian President Suharto’s staff to determine what should
be done to rectify the situation. Oka’s
advice was to substantially reduce insecticide use and return to a sound
‘treat-when-necessary” program that protected the natural enemies. Following Oka’s advice, President Suharto
mandated in 1986 on television that 57 of 64 pesticides would be withdrawn from
use on rice and sound pest management practices implemented. Pesticide subsidies were also reduced to
zero. By 1991, pesticide applications
had been reduced by 65% and rice yields increased 12%.
Dr. Rosen (Hebrew University of Jerusalem, PC. 1991)
estimates that natural enemies account for up to 90% of the control of pests’
species in agroecosystems. I estimate that
at least 50% of the control of pest species is due to natural enemies. Pesticides provide an additional control,
while the remaining 40% is due to host-plant resistance in agroecosystems
(Pimentel, 1988).
Parasites, predators and host-plant resistance are estimated
to account for about 80% of the nonchemical control of pest arthropods and
plant pathogens in crops (Pimentel et al., 1991). Many cultural controls, such as crop
rotations, soil and water management, fertilizer management, planting time, crop-plant
density, trap crops, polyculture, and others provide additional pest
control. Together these non-pesticide
controls can be used to effectively reduce U.S. pesticide use by more than 50%
without any reduction in crop yields or cosmetic standards (Pimentel et al.,
1993a).
5. Pesticide resistance in pests
In addition to destroying natural enemy populations, the
extensive use of pesticides has often resulted in the development and evolution
of pesticide resistance in insect pests, plant pathogens, and weeds. An early report by the United Nations
Environmental Program (UNEP, 1979) suggested that pesticide resistance ranked
as one of the top 4 environmental problems of the world. About 520 insect and mite species, a total of
nearly 150 plant pathogen species, and about 273 weeds species are now resistant
to pesticides (Stuart, 2003).
Increased pesticide resistance in pest populations
frequently results in the need for several additional applications of the
commonly used pesticides to maintain crop yields. These additional pesticide applications
compound the problem by increasing environmental selection for resistance. Despite efforts to deal with the pesticide
resistance problem, it continues to increase and spread to other species. A striking example of pesticide resistance
occurred in northeastern Mexico and the Lower Rio Grande of Texas (NAS,
1975). Over time extremely high
pesticide resistance had developed in the tobacco budworm population on cotton. Finally, approximately 285,000 ha of cotton
had to be abandoned, because the insecticides were totally ineffective because
of the extreme resistance in the budworm.
The economic and social impact on these Texan and Mexican farmers’
dependent on cotton was devastating.
The study by Carrasco-Tauber (1989) indicates the extent of
costs associated with pesticide resistance.
They reported a yearly loss of $45 to $120 per ha to pesticide
resistance in California cotton. A total
of 4.2 million hectares of cotton were harvested in 1984; thus, assuming a loss
of $82.50 per hectare, approximately $348 million of the California cotton crop
was lost to resistance. Since $3.6
billion of U.S. cotton was harvested in 1984 (USBC, 1990), the loss due to
resistance for that year was approximately 10%.
Assuming a 10% loss in other major crops that receive heavy pesticide
treatments in the United States, crop losses due to pesticide resistance are
estimated to be about $1.5 billion per year.
Furthermore, efforts to control resistant Heliothus
spp. (corn ear worm) exact a cost on other crops when large, uncontrolled
populations of Heliothus and other pests disperse onto other crops. In addition, the cotton aphid and the
whitefly exploded as secondary cotton pests because of their resistance and
their natural enemies’ exposure to high concentrations of insecticides.
The total external cost attributed to the development of
pesticide resistance is estimated to range between 10% to 25% of current
pesticide treatment costs (Harper and Zilberman, 1990), or more than $1.5
billion each year in the United States. In other words, at least 10% of
pesticide used in the U.S. is applied just to combat increased resistance that
has developed in several pest species.
Although the costs of pesticide resistance are high in the
United States, the costs in tropical developing countries are significantly
greater, because pesticides are not only used to control agricultural pests,
but are also vital for the control of arthropod disease vectors. One of the major costs of resistance in
tropical countries is associated with malaria control. By 1985, the incidence of malaria in India
after early pesticide use declined to about 2 million cases from a peak of 70
million cases. However, because
mosquitoes developed resistance to pesticides, as did malarial parasites to
drugs, the incidence of malaria in India has now exploded to about 60 million
cases per year (Malaria, 2000). Problems are occurring not only in India but
also in the rest of Asia, Africa, and South America. The total number of
malaria cases in the world is now 2.4 billion (WHO, 1997).
6. Honeybee and wild bee poisonings and reduced
pollination
Honeybees and wild bees are vital for pollination of fruits,
vegetable, and other crops. Bees are
essential to the production of about one-third of U.S. and world crops. Their benefits to U.S. agriculture are
estimated to be about $40 billion per year (Pimentel et al., 1997). Because most insecticides used in agriculture
are toxic to bees, pesticides have a major impact on both honeybee and wild bee
populations. D. Mayer (Washington State
University, PC, 1990) estimates that approximately 20% of all honeybee colonies
are adversely affected by pesticides. He
includes the approximately 5% of U.S. honeybee colonies that are killed outright
or die during winter because of pesticide exposure. Mayer calculates that the direct annual loss
reaches $13.3 million per year (Table 4).
Another 15% of the honeybee colonies either are seriously weakened by
pesticides or suffer losses when apiculturists have to move colonies to avoid
pesticide damage.
According to Mayer, the yearly estimated loss from partial
honeybee kills, reduced honey production, plus the cost of moving colonies
totals about $25.3 million per year.
Also, as a result of heavy pesticide use on certain crops, beekeepers
are excluded from 4 to 6 million ha of otherwise suitable apiary locations,
according to Mayer. He estimates the
yearly loss in potential honey production in these regions is about $27 million
each year (Table 4).
In addition to these direct losses caused by the damage to
honeybees and honey production, many crops are lost because of the lack of
pollination. In California, for example,
approximately 1 million colonies of honeybees are rented annually at $55 per
colony to augment the natural pollination of almonds, alfalfa, melons, and
other fruits and vegetables (Burgett, 2000).
Since California produces nearly half of our bee-pollinated crops, the
total cost for honeybee rental for the entire country is estimated at $40
million per year. Of this cost, I
estimate that at least one-tenth or $4 million is attributed to the effects of
pesticides (Table 4).
Estimates of annual agricultural losses due to the reduction
in pollination caused by pesticides may be as high as $4 billion per year (J.
Lockwood, University of Wyoming, PC. 1990).
For most crops, both yield and quality are enhanced by effective
pollination. Several investigators have
demonstrated that for various cotton varieties, effective pollination by honeybees
resulted in yield increases from 20% to 30%.
Mussen (1990) emphasizes that poor pollination will not only
reduce crop yields, but equally important, it will reduce the quality of some
crops, such as melon and fruits. In
experiments with melons, E.L. Atkins (University of California [Davis], PC
1990) reported that with adequate pollination melon yields increased 10% and
melon quality was raised 25% as measured by the dollar value of the melon crop.
Based on the analysis of honeybee and related pollination
losses from wild bees caused by pesticides, pollination losses attributed to
pesticides are estimated to represent about 10% of pollinated crops and have a
yearly cost of about $210 million per year (Table 4). Clearly, the available evidence confirms that
the yearly cost of direct honeybee losses, together with reduced yields
resulting from poor pollination, are significant.
7. Crop and crop product losses
Basically, pesticides are applied to protect crops from
pests in order to increase yields, but sometimes the crops are damaged by the
pesticide treatments. This occurs when
(1) the recommended dosages suppress crop growth, development, and yield; (2)
pesticides drift from the targeted crop to damage adjacent crops; (3) residual
herbicides either prevent chemical-sensitive crops from being planted; and/or
(4) excessive pesticide residue accumulates on crops, necessitating the
destruction of the harvest. Crop losses
translate into financial losses for growers, distributors, wholesalers, transporters,
retailers, food processors, and others.
Potential profits as well as investments are lost. The costs of crop losses increase when the
related costs of investigations, regulation, insurance, and litigation are
added to the equation. Ultimately the
consumer pays for these losses in higher market place prices.
Data on crop losses due to pesticides are difficult to
obtain. Many losses are never reported
to the state and federal agencies because the parties settle privately
(Pimentel et al., 1993a).
Damage to crops may occur even when recommended dosages of
herbicides and insecticides are applied to crops under normal environmental
conditions. Recommended dosages of
insecticides used on crops have been reported to suppress growth and yield in
both cotton and strawberry crops (ICAITI, 1977; Reddy et al., 1987; Trumbel et
al., 1988). The increase in
susceptibility of some crops to insects and diseases following normal use of
2,4-D and other herbicides has been demonstrated (Oka and Pimentel, 1976; Pimentel,
1994). Furthermore, when weather and/or
soil conditions are inappropriate for pesticide application, herbicide
treatments may cause yield reductions ranging from 2% to 50% (Pimentel et al.,
1993a).
Crops are lost when pesticides drift from the target crops
to non-target crops located as much as several miles downwind (Barnes et al.,
1987). Drift occurs with most methods of
pesticide application including both ground and aerial equipment; the potential
problem is greatest when pesticides are applied by aircraft. With aircraft from 50% to 75% of the
pesticide applied never reaches the target acre (Akesson and Yates, 1984;
Mazariegos, 1985; Pimentel, et al., 1993a).
In contrast, 10% to 35% of the pesticide applied with ground application
equipment misses the target area (Hall, 1991).
The most serious drift problems are caused by “speed sprayers” and ultra-low
volume (ULV) equipment, because relatively concentrated pesticide is
applied. The concentrated pesticide has
to be broken into small droplets to achieve adequate coverage.
Crop injury and subsequent loss due to drift are
particularly common in areas planted with diverse crops. For example, in southwest Texas in 1983 and
1984, nearly $20 million in cotton was destroyed from drifting 2,4-D herbicide
when adjacent wheat fields were aerially sprayed with the herbicide (Hanner,
1984). Because of the drift problem,
most commercial applicators carry insurance that costs about $245 million per
year (Pimentel et al., 1993a).
When residues of some herbicides persist in the soil, crops
planted in rotation are sometimes injured.
This has happened with a corn and soybean rotation. When atrazine or Sceptor herbicides were used
in corn, the soybean crop planted after was seriously damaged by the herbicides
that persist in the soil. This problem
also has environmental problems associated.
For example, if the herbicide treatment prevents another crop from being
grown, soil erosion may be intensified (Pimentel et al., 1993a).
An average 0.1% loss in annual U.S. production of corn,
soybeans, cotton, and wheat, which together account for about 90% of the
herbicides and insecticides used in U.S. agriculture, was valued at $35.3
million in 1987 (NAS, 1989). Assuming
that only one-third of the incidents involving crop losses due to pesticides
are reported to authorities, the total value of all crop lost because of
pesticides could be as high as 3 times this amount, or $106 million annually.
However, this $106 million does not take into account other
crop losses, nor does it include major events such as the large-scale losses
that have occurred in one season in Iowa ($25 to $30 million), in Texas ($20
million), and in California’s aldicarb /watermelon crisis ($8 million)
(Pimentel et al., 1993a). These recurrent losses alone represent an average of
$30 million per year, raising the estimated average crop loss value from the
use of pesticides to approximately $136 million each year.
Additional losses are incurred when food crops are disposed
of because they exceed the FDA and EPA regulatory tolerances for pesticide
residue levels. Assuming that all the
crops and crop products that exceed the FDA and EPA regulatory tolerances
(reported to be 1% to 5%) were disposed of as required by law, then about $1
billion in crops would be destroyed because of excessive pesticide
contamination.
Special investigations and testing for pesticide
contamination are estimated to cost the nation more than $10 million each year
(Pimentel et al., 1993a).
8. Ground and surface water contamination
Certain pesticides applied at recommended dosages to crops
eventually end up in ground and surface waters.
The 3 most common pesticides found in groundwater are aldicarb,
alachlor, and atrazine (Cornell, 2003).
Estimates are that nearly one-half of the groundwater and well water in
the United States is or has the potential to be contaminated (Holmes et al.,
1988; USGS, 1996). EPA (1990) reported
that 10% of community wells and 4% of rural domestic wells have detectable
levels of at least one pesticide of the 127 pesticides tested in a national
survey. Estimated costs to sample and
monitor well and groundwater for pesticide residues costs $1,100 per well per
year (USGS, 1995). With 16 million wells
in the U.S., the cost of monitoring all the wells for pesticides would cost
$17.7 billion per year (Well-Owner, 2003).
Two major concerns about ground water contamination with
pesticides are that about one-half the human population obtains its water from
wells and once groundwater is contaminated, the pesticide residues remain for
long periods of time. Not only are there
extremely few microbes present in groundwater to degrade the pesticides, but
the groundwater recharge rate is less than 1% per year (CEQ, 1980).
Monitoring pesticides in groundwater is only a portion of
the total cost of groundwater contamination.
There is also the high cost of cleanup.
For instance, at the Rocky Mountain Arsenal near Denver, Colorado, the
removal of pesticides from the groundwater and soil was estimated to cost
approximately $2 billion. If all
pesticide-contaminated groundwater were to be cleared of pesticides before
human consumption, the cost would be about $500 million per year. Note the cleanup process requires a water
survey to target the contaminated water for cleanup. Thus, addition the monitoring and cleaning
costs, the total cost regarding pesticide-polluted groundwater is estimated to
be about $2 billion annually. The $17.7
billion figure shows how impossible it would be to expect the public to pay for
pesticide-free well water.
9. Fishery losses
Pesticides are washed into aquatic ecosystems by water
runoff and soil erosion. About 13 t/ ha/ yr. are washed and/or
blown from pesticide-treated cropland into adjacent locations including rivers
and lakes (Unnevehr et al., 2003).
Pesticides also can drift during application and contaminate aquatic
systems. Some soluble pesticides are
easily leached into streams and lakes.
Once in aquatic ecosystems, pesticides cause fishery losses
in several ways. These include high
pesticide concentrations in water that directly kill fish; low doses that may
kill highly susceptible fish fry; or the elimination of essential fish foods,
like insects and other invertebrates. In
addition, because government safety restrictions ban the catching or sale of
fish contaminated with pesticide residues, such fish are unmarketable and are
an economic loss.
Only 6 to 14 million fish are reported killed by pesticides
each year (Pimentel et al., 1993a).
However, this is an underestimate because fish kills cannot be
investigated quickly enough to determine accurately the cause of the kill. Also, if the fish are in fast-moving waters
in rivers, the pesticides are diluted and/or the pesticides cannot be
identified. Many fish sink to the bottom
and cannot be counted.
The best estimate for the value of a fish is $10. This is based on EPA fining Coors Beer $10
per fish when they polluted a river (Barometer, 1991). Thus, the estimate of the value of fish
killed each year is only $10 to $24 million per year. This is an under estimate and I estimate $100
million per year minimum.
10. Wild birds and mammals
Wild birds and mammals are damaged and destroyed by
pesticides and these animals make excellent “indicator species”. Deleterious effects on wildlife include death
from the direct exposure to pesticides or secondary poisonings from consuming
contaminated food; reduced survival, growth, and reproductive rates from
exposure to sub-lethal dosages; and habitat reduction through the elimination
of food resources and refuges. In the
United States, approximately 3 kg of pesticide is applied per hectare on about
160 million hectares of cropland each year (Pimentel et al., 1993a). With such
heavy dosages of pesticides applied, it is expected that wildlife would be
significantly impacted.
The full extent of bird and mammal kills is difficult to
determine because birds and mammals are often secretive, camouflaged, highly
mobile, and live in dense grass, shrubs, and trees. Typical field studies of the effects of
pesticides often obtain extremely low estimates of bird and mammal mortality
(Mineau et al., 1999). This is because
bird and small mammal carcasses disappear quickly, well before the dead birds
and small mammals can be found and counted.
Even when known numbers of bird carcasses were placed in identified
locations in the field, from 62% to 92% of the animals disappeared overnight
due to vertebrate and invertebrate scavengers (Balcomb, 1986). Then in addition, field studies seldom
account for birds that die a distance from the treated areas. Finally, birds often hide and die in
inconspicuous locations.
Nevertheless, many bird kills caused by pesticides have been
reported. For instance, 1,200 Canada
geese were killed in one wheat field that was sprayed with a 2:1 mixture of
parathion and methyl parathion at a rate of 0.8 kg/ha (White et al.,
1982). Carbofuran applied to alfalfa
killed more than 5,000 ducks and geese in five incidents, while the same
chemical applied to vegetable crops killed 1,400 ducks in a single application
(Flickinger et al., 1980, 1991).
Carbofuran is estimated to kill 1 to 2 million birds each year (EPA,
1989). Another pesticide, diazinon,
applied to three golf courses killed 700 Atlantic brant geese of the wintering
population of just 2,500 birds (Stone and Gradoni, 1985).
EPA reports that there are 1100 documented cases of bird
kills each year in the United States (ABCBirds, 2003). Birds are not only killed in the U.S. but
they are killed as they migrate from North America to South America. For example, more than 4,000 carcasses of
Swainson’s hawks were reported poisoned by pesticides in late 1995 and early
1996 in farm fields of Argentina (CWS, 2003).
Although it was not possible to know the total kill, conservatively it
was estimated to be more than 20,000 hawks.
Several studies report that the use of some herbicides has a
negative impact on some young birds. Since the weeds would have harbored some
insects in the crops, their nearly total elimination by herbicides is
devastating to particular bird populations (Potts, 1986; R. Beiswenger,
University of Wyoming, PC. 1990). This
has led to significant reductions in the grey partridge in the United Kingdom
and in the common pheasant in the United States. In the case of the partridge, population
levels have decreased more than 77% because the partridge chicks (also pheasant
chicks) depend on insects to supply them with needed protein for their
development and survival.
Frequently the form of a pesticide influences its toxicity
to wildlife (Hardy, 1990). For example,
treated seed and insecticide granules, including carbofuran, fensulfothion,
fonofos, and phorate, are particularly toxic to birds. Estimates are that from 0.23 to 1.5 birds
per hectare were killed in Canada, while in the United States the estimates of
kill ranged from 0.25 to 8.9 birds killed per hectare per year by the
pesticides (Mineau, 1988).
Pesticides also adversely affect the reproductive potential
of many birds and mammals. Exposure of birds, especially predatory birds, to
chlorinated insecticides has caused reproductive failure, sometimes attributed
to eggshell thinning (Elliot et al., 1988).
Most the affected predatory birds, like the bald eagle and peregrine
falcon, have recovered since the banning of DDT and most other chlorinated
insecticides in the U.S. (Unnevehr et al., 2002). Although the U.S. and most other developed
countries have banned DDT and other chlorinated insecticides, other countries,
such as India and China, are still producing, exporting, and using DDT (Asia
Times, 2001).
Habitat alteration and destruction can be expected to reduce
mammal and bird populations. For
example, when glyphosate (Roundup) was applied to forest clear cuts to
eliminate low-growing vegetation, like shrubs and small trees, the southern
red-backed vole population was greatly reduced because its food source and
cover were practically eliminated (D’Anieri et al., 1987). Similar effects from herbicides have been
reported on other mammals. Overall, the
impacts of pesticides on mammal populations have been inadequately
investigated.
Although the gross values for wildlife are not available,
expenditures involving wildlife made by humans are one measure of the monetary
value. Nonconsumptive users of wildlife
spent an estimated $14.3 billion on their sport (USFWS, 1988). Yearly, U.S. bird watchers spend an estimated
$600 million on their sport and an additional $500 million on birdseed, or a
total of $1.1 billion (USFWS, 1988). For bird watching, the estimated cost is
about 40¢ per bird. The money spent by
hunters to harvest 5 million game birds was $1.1 billion, or approximately $216
per bird (USFWS, 1988). In addition, the
estimated cost of replacing a bird of an affected species to the wild, as in
the case of the Exxon Valdez oil spill, was $800 per bird (Dobbins, 1986).
If it is assumed that the damages that pesticides inflict on
birds occur primarily on the 160 million ha of cropland that receive the most
pesticide, and the bird population is estimated to be 4.4 birds per ha of
cropland (Boutin et al., 1999), then 720 million birds are directly exposed to
pesticides. Also, if it is conservatively estimated that only 10% of the bird
population is killed by the pesticide treatments, it follows that the total
number of birds killed is 72 million birds.
Note this estimate is at the lower range of the range of 0.25 to 8.9
birds killed per hectare per year mentioned earlier.
The American Bald Eagle and other predatory birds suffered
high mortalities because of DDT and other chlorinated insecticides. The Bald eagle population declined primarily
because of pesticides and was placed on the endangered species list. After DDT and the other chlorinated
insecticides were banned in 1972, it took nearly 30 years for the bird
populations to recover. The American
Bald Eagle was recently removed from the endangered species list (Millar,
1995).
I assumed a value of a bird to be about $30 based on the
information presented, plus the fact that the cost of a fish is about $10, even
a 1-inch fish. Thus, the total economic
impact of pesticides on birds is estimated to be $2.1 billion per year. This estimate does not include the birds
killed due to the death of one of the parents and in turn the deaths of the
nestlings. It also does not include
nestlings killed because they were fed contaminated arthropods and other foods.
11. Microbes and invertebrates
Pesticides easily find their way into soils, where they may
be toxic to arthropods, earthworms, fungi, bacteria, and protozoa. Small organisms are vital to ecosystems
because they dominate both the structure and function of ecosystems (Pimentel
et al., 1992).
For example, an estimated 4.5 tons per hectare of fungi and
bacteria exist in the upper 15 cm of soil. They, with the arthropods, make up
95% of all species and 98% of the biomass (excluding vascular plants). The microbes are essential to proper
functioning in the ecosystem, because they break down organic matter, enabling
the vital chemical elements to be recycled (Atlas and Bartha, 1987; Pimentel et
al., 1997). Equally important is their
ability to “fix” nitrogen, making it available to plants and ecosystems
(Pimentel et al., 1997).
Earthworms and insects aid in bringing new soil to the
surface at a rate of up to 200 tons/ha per year (Pimentel et al., 1993a). This action improves soil formation and
structure for plant growth and makes various nutrients more available for
absorption by plants. The holes (up to
10,000 holes per square meter) in the soil made by earthworms and insects also
facilitate the percolation of water into the soil (Edwards and Lofty, 1982).
Insecticides, fungicides, and herbicides reduce species
diversity in the soil as well as the total biomass of these biota. Stringer and Lyons (1974) reported that where
earthworms had been killed by pesticides, the leaves of apple trees accumulated
on the surface of the soil and increased the incidence of scab in the
orchards. Apple scab, a disease carried
over from season to season on fallen leaves, is commonly treated with
fungicides. Some fungicides,
insecticides, and herbicides are toxic to earthworms, which would otherwise
remove and recycle the fallen leaves.
On golf courses and other lawns, the destruction of
earthworms by pesticides results in the accumulation of dead grass or thatch in
the turf (Potter and Braman, 1991). To
remove this thatch special equipment must be used and it is expensive.
Although these microbes and invertebrates are essential to
the vital structure and function of both natural and agricultural ecosystems,
it is impossible to place a money value on the damage caused by pesticides to
this large group of organisms. To date,
no relevant quantitative data on the value of microbe and invertebrate
destruction by pesticides are available.
12. Government funds for pesticide pollution control
A major environmental cost associated with all pesticide use
is the cost of carrying out state and federal regulatory actions, as well as
pesticide-monitoring programs needed to control pesticide pollution. Specifically, these funds are spent to reduce
the hazards of pesticides and to protect the integrity of the environment and
public health.
About $10 million is spent each year by state and federal
governments to train and register pesticide applicators. Also, more than $60 million is spent each
year by the EPA to register and reregister pesticides. In addition, about $400 million is spent to
monitor pesticide contamination of fruits, vegetables, grains, meat, milk, water,
and other items for pesticide contamination.
Thus, at least $470 million is invested by state and federal
governmental organizations.
Although enormous amounts of government funds are being
spent to reduce pesticide pollution, many costs of pesticides are not taken
into account. Also, many serious
environmental and social problems remain to be corrected by improved government
policies.
13. Ethical and moral issues
Although pesticides provide about $40 billion per year in
saved U.S. crops, the data of this analysis suggest that the environmental and
social costs of pesticides to the nation total approximately $10 billion. From
a strictly cost/benefit approach, it appears that pesticide use is
beneficial. However, the nature of the
environmental and public health costs of pesticides has other trade-offs
involving environmental quality and public health.
One of these issues concerns the importance of public health
vs. pest control. For example, assuming
that pesticide-induced cancers number more than 10,000 cases per year and that
pesticides return a net agricultural benefit of $32 billion per year, each case
of cancer is “worth” $3.2 million in pest control. In other words, for every $3.2 million in
pesticide benefits, one person falls victim to cancer. Social mechanisms and market economics
provide these ratios, but they ignore basic ethics and values.
In addition, pesticide pollution of the global environment
raises numerous other ethical questions.
The environmental insult of pesticides has the potential to demonstrably
disrupt entire ecosystems. All through
history, humans have felt justified in removing forests, draining wetlands, and
constructing highways and housing in various habitats. L. White (1967) has blamed the environmental
crisis on religious teachings of mastery over nature. Whatever the origin, pesticides exemplify
this attempt at mastery, and even a noneconomic analysis would question its
justification. There is a clear need for
a careful and comprehensive assessment of the environmental impacts of
pesticides on agriculture and natural ecosystems.
In addition to the ethical status of ecological concerns are
questions of economic distribution of costs.
Although farmers spend about $10 billion per year for pesticides, little
of the pollution costs that result are borne by them or the pesticide producing
chemical companies. Rather, most of the
costs are borne off-site by public illnesses and environmental destruction. Standards of social justice suggest that a
more equitable allocation of responsibility is desirable.
These ethical issues do not have easy answers. Strong arguments can be made to support
pesticide use based on social and economic benefits. However, evidence of these benefits should
not cover up the public health and environmental problems. One goal should be to maximize the benefits
while at the same time minimizing the health, environmental and social
costs. A recent investigation pointed
out that U.S. pesticide use could be reduced by one-half without any reduction
in crop yields (Pimentel et al., 1993 b).
The judicious use of pesticides could reduce the environmental and
social costs, while it benefits farmers economically in the short-term and
supports sustainability of agriculture in the long-term.
Public concern over pesticide pollution confirms a national
trend toward environmental values. Media
emphasis on the issues and problems caused by pesticides has contributed to a
heightened public awareness of ecological concerns. This awareness is encouraging research in
sustainable agriculture and in nonchemical pest management.
Granted, substituting nonchemical pest controls in U.S.
agriculture would be a major undertaking and would not be without its
costs. The direct and indirect benefits
and costs of implementation of a policy to reduce pesticide use should be
researched in detail. Ideally, such a
program should both enhance social equitability and promote public
understanding of how to better protect public health and the environment, while
abundant, safe food is supplied.
Clearly, it is essential that the environmental and social costs and
benefits of pesticide use be considered when future pest control programs are
being considered and developed. Such
costs and benefits should be given ethical and moral scrutiny before policies
are implemented, so that sound, sustainable pest management practices are
available to benefit farmers, society, and the environment.
14. Conclusion 2003, 10 Times Worst 2016
An investment of about $10 billion in pesticide control each
year saves approximately $40 billion in U.S. crops, based on direct costs and
benefits. However, the indirect costs of
pesticide use to the environment and public health need to be balanced against
these benefits. Based on the available
data, the environmental and public health costs of recommended pesticide use
total more than $9 billion each year (Table 6).
Users of pesticides pay directly only about $3 billion, which includes
problems arising from pesticide resistance and destruction of natural
enemies. Society eventually pays this $3
billion plus the remaining $9 billion in environmental and public health costs
(Table 6).
Our assessment of the environmental and health problems
associated with pesticides was made more difficult by the complexity of the
issues and the scarcity of data. For
example, what is an acceptable monetary value for a human life lost or a cancer
illness due to pesticides? Equally difficult is placing a monetary value on
killed wild birds and other wildlife; on the dearth of invertebrates, or
microbes lost; or on the price of contaminated food and groundwater.
In addition to the costs that cannot be accurately measured,
there are many costs that were not included in the $12 billion figure. If the full environmental, public health and
social costs could be measured as a whole, the total cost might be nearly
double the $12 billion figure. Such a
complete and long-term cost/benefit analysis of pesticide use would reduce the
perceived profitability of pesticides.
The efforts of many scientists to devise ways to reduce
pesticide use in crop production while still maintaining crop yields have
helped but a great deal more needs to be done.
Sweden, for example, has reduced pesticide use by 68% without reducing
crop yields and/or the cosmetic standards (PCC, 2002). At the same time, public pesticide poisonings
have been reduced 77%. It would be
helpful, if the United States adopted a similar goal to that of Sweden. Unfortunately,
with some groups in the U.S., IPM is being used as a means of justifying
pesticide use.
Table 1. Estimated economic costs of human pesticide
poisonings and other pesticide related illnesses in the United States each
year.
____________________________________________________________________
Human health effects from pesticides Total costs ($)
____________________________________________________________________
Cost of hospitalized
poisonings
5000a x 3 days @
$2,000/day 30,000,000
Cost of outpatient
treated poisonings
30,000c x $1,000b 30,000,000
Lost work due to
poisonings
5,000a
workers x 5 days x $80 2,000,000
Pesticide cancers
10,000c x $100,000/
case 1,000,000,000
Cost of fatalities
45 accidental fatalities x
$3.7 million 166,500,000
TOTAL 1,228,500,000
____________________________________________________________________
a Estimated.
b Includes hospitalization, foregone earnings,
and transportation.
c See text for details.
Table 2. Estimated domestic animal pesticide poisonings in
the United States.
Livestock
|
Number x 1000
|
$ per head
|
Number ille
|
$ cost per poisoning
|
$ cost of poisonings
|
Number deathsd
|
$ cost of deaths x 1,000g
|
Total $ x 1,000
|
Cattle
|
99,000a
|
607a
|
100
|
121.40
|
12,140
|
8
|
4,856
|
16,996
|
Dairy cattle
|
10,000a
|
900a
|
10
|
180.00
|
1,800
|
1
|
900
|
2,700
|
Dogs
|
55,000c
|
125h
|
55
|
25.00
|
1,375
|
4
|
500
|
1,875
|
Horses
|
11,000b
|
1,000c
|
11
|
200.00
|
2,200
|
1
|
1,000
|
3,200
|
Cats
|
63,000c
|
20h
|
60
|
4.00
|
240
|
4
|
80
|
320
|
Swine
|
53,000a
|
66.30a
|
53
|
13.26
|
703
|
4
|
265
|
968
|
Chickens
|
8,000,000a
|
2.50a
|
6000
|
.40
|
2,400
|
500
|
1,250
|
3,650
|
Turkeys
|
280,000a
|
10c
|
280
|
2.00
|
560
|
25
|
250
|
810
|
Sheep
|
11,000a
|
82.40a
|
11
|
16.48
|
181
|
1
|
82
|
263
|
TOTAL
|
8,582,000
|
|
|
|
21,599
|
|
|
30,782
|
a USDA (1989a).
b FAO (1986)
c USBC (1990)
d Based on a 0.008% mortality rate (see text).
e Based on a 0.1% illness rate (see text).
f Based on each animal illness costing 20% of
total production value of that animal.
g The death of the animal equals the total value
for that animal.
h Estimated.
Table 3. Losses due to the destruction of beneficial natural enemies in
U.S. crops ($ millions).
_________________________________________________________________
Crops Total
expenditures Amount of
added
for
insect control control
costs with pesticides a
__________________________________________________________________
Cotton 320 160
Tobacco 5 1
Potatoes 31 8
Peanuts 18 2
Tomatoes 11 2
Onions 1 0.2
Apples 43 11
Cherries 2 1
Peaches 12 2
Grapes 3 1
Oranges 8 2
Grapefruit 5 1
Lemons 1 0.2
Nuts 160 16
Other 500
50
__________________________________________________________________
TOTAL $1,120 $257.4 ($520)b
__________________________________________________________________
a Pimentel et al. (1991)
b Because the added
pesticide treatments do not provide as effective control as the
natural enemies, we estimate that at least an additional $260 million in
crops are lost
to pests. Thus the total loss due to the destruction of natural enemies
is estimated to
be at least $520 million per year.
Table 4. Estimated honeybee
losses and pollination losses from
honeybees and wild bees
___________________________________________________
Colony losses from pesticides $13.3 million/year
Honey and wax losses $25.3
million/year
Loss of potential honey
production $27.0
million/year
Bee rental for pollination $ 8.0
million/year
Pollination losses $210.0 million/year
___________________________________________________
TOTAL $283.6 million / year
Table 5. Estimated loss of crops and trees due to the use of pesticides.
________________________________________________________
Impacts Total
Costs
(in
millions of dollars)
________________________________________________________
Crop losses 136
Crop applicator insurance 245
Crops destroyed because of excess
Pesticide contamination 1,000
Governmental investigations
and testing 10
TOTAL $1,391
Table 6. Total estimated environmental and social costs from pesticide in the United States.
_____________________________________________________________________
Costs Millions of $/year
_____________________________________________________________________
Public health impacts 1,140
Domestic animals deaths and contaminations 30
Loss of natural enemies 520
Cost of pesticide resistance 1,500
Honeybee and pollination losses 334
Crop losses 1,391
Fishery losses 100
Bird losses 2,160
contamination 2,000
Government regulations to prevent damage 470
TOTAL 9,645
___________________________________________________________
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