Romeo F. Quijano, M.D.
Professor, Univ. of the Phils. College of Medicine
President, HEAL Toxics
Pesticide Action Network Philippines
The health and environmental consequences of pesticide
use are staggering, especially in Third World countries
where there are less stringent regulatory controls and
less effective implementation of whatever laws there are
to protect public health and the environment. The use
of synthetic pesticides and other chemicals results in
contamination and adulteration of food, degradation and
pollution of soil, water and air, and increased morbidity
and mortality for the exposed population.
Production of Hazardous Pesticides
The health hazards associated with pesticide
use have been known for years and the extent of harm they
cause has increased, yet, chemical companies keep on pouring
millions of tons of pesticides annually into the world’s
biosphere. In 1995, the world pesticides market has expanded
to US$30.265 billion, representing a 5% growth over the
previous year and about five-fold increase over the past
ten years. In 1997, despite increased environmental awareness
worldwide, the major pesticide companies registered hefty
profits, with sales increasing from 8% to as high as 40%.
Much of these profits come from exports of pesticides
already banned in their country of origin or pesticides
considered “likely to cause problems under conditions
of use in developing countries”. For example, more
than 344 million pounds of hazardous pesticides were exported
from US ports between 1992 and 1994, according to a report
by the Foundation for Advancement in Science and Education.
These exports included pesticides that were already banned
in the U.S. and pesticides that were “severely restricted”.
With the advent of “globalization”, more companies
based in developed countries are being attracted to locate
their active ingredient production facilities in the growing
markets in the South, particularly, here in Asia. It is
expected that the pesticide industry will continue to
“pour” millions of tons of pesticides into
this planet in the years to come.
Hazards to the Environment
Many of these pesticides being “poured”
into this planet by the pesticide industry consist of
pollutants that resist physical, biological, and chemical
degradation. They are called “persistent organic
pollutants”. They accumulate as they are taken up
in the food chain and their concentrations are increased
tremendously in certain tissues, like the liver. Their
chemical characteristics enable them to move long distances
through the atmosphere and are deposited even in areas
very far away from the actual area of application. Thus,
even the arctic seas are contaminated with these “persistent
organic pollutants”. Examples of these “persistent
organic pollutants” are DDT, endrin, lindane, endosulfan,
and many other organochlorines.
Pesticides contaminate the environment in many ways. Widespread
application of pesticides leads to drifting and contamination
of land and waterways adjacent to target fields. Pesticide
residues in soil contaminate crops subsequently grown
on the same land. Pesticides in contaminated crops used
as animal feeds eventually are found in meat and dairy
products. Pesticides in the soil eventually also contaminate
ground water, which is a source of drinking water. In
the U.S., pesticides have been found to be pervasive contaminants
in drinking water and 38% of food samples were found to
contain pesticide residues.
A consequence of environmental contamination is the widespread
killing of non-target organisms, including wildlife, cattle,
birds, fish, bees, and pest’s natural enemies. This
leads to loss of biodiversity and upsets the delicate
balance in various ecosystems in various areas. This is
made worse by the vicious cycle of pesticide-resistance.
Eventually, pesticides become ineffective because of the
inevitable emergence of resistant pests and crop losses
ensue. This leads to the creation of new and more toxic
pesticides which again eventually become ineffective because
resistance will again emerge. The effect of this vicious
cycle is the increasing number and amount of highly toxic
pesticides in our environment leading in turn to greater
loss of biodiversity and increased exposure risks to people.
Exposure and Poisoning
It has been estimated that about 25 million
people are being poisoned by pesticides annually in developing
countries. There is no segment of the population that
is sheltered from exposure to pesticides. Exposure can
occur during manufacture and formulation, transportation,
storage, mixing, application and disposal. People everywhere
affected through contamination of water, food, and air
containing pesticide residues; by pesticides drifting
from aerial spraying in plantation agriculture, from pesticides
used in houses to ward off household pests, or from washing,
bathing, or drinking water from irrigation ditches.
Most farmers in a Third World country are aware that pesticides
are hazardous but there is lack of awareness of actual
risks. The use of protective clothing is very low due
to high temperature and humidity. Pesticide handlers are
exposed heavily. Exposure of households in farming communities
occur due to spray drifts. This exposure is further enhanced
by the practice of washing the pesticide sprayers near
or in irrigation canals. Farmers also use this water source
for washing hands, feet, clothes, and for taking a bath.
The manner of disposal of pesticide left-overs and containers
also increase the risk of exposure to pesticides.
Pesticides enter the body through the skin, through breathing
or through swallowing. Entry through the skin can happen
through spills on clothing or directly on the skin, when
pesticide spray settles on the skin or soaks clothing,
when the applicator mixes pesticides with bare hands,
or when touching pesticide-laden crops or clothing. Entry
through breathing is most common in farmers who spray
pesticides or for people nearby when spraying is done.
People may not be aware that they are inhaling pesticides
because some pesticides have no smell. Swallowing pesticides
usually occur accidentally or on purpose, as in those
committing suicide. Most people actually regularly ingest
pesticides because most of the food they eat, and probably,
also the water they drink, are already contaminated with
Most pesticides are acutely toxic and can
cause death, disability, organ dysfunction, incapacitating
symptoms, and various other illnesses. Immediate effects
may include dizziness, headache, nausea and vomiting,
abdominal pain, difficulty of breathing, palpitations,
weakness, and many other symptoms which, very often, may
not be readily recognized as pesticide poisoning. Depending
on the degree and circumstances of the exposure, the health
effects may be mild, moderate or severe.
In pesticide applicators, dizziness, headache, abdominal
pain, and difficulty of breathing are a common occurrence.
People predisposed to asthma are in greater risk of developing
acute respiratory symptoms after exposure to pesticides.
Difficulty of breathing mayoccur even with very little
exposure in predisposed individuals. Weakness and tingling
sensation in the extremities are also common symptoms
observed in occupationally exposed individuals. These
symptoms occur usually upon exposure to the organophosphate
and carbamate pesticides.
Skin irritation, allergic reaction, and other skin ailments
occur when there is direct contact with the pesticide.
Fungicides and certain herbicides like paraquat are the
more likely culprits although most other pesticides can
Eye irritation and blurring of vision more commonly occur
with organophosphates and carbamates. These are usually
transient in nature but in certain instances, like with
the triphenyltin compounds or paraquat, permanent damage
to the eye leading to blindness may occur.
Certain conditions may aggravate the condition of pesticide
poisoning. Malnutrition, for example, can increase the
susceptibility to pesticide poisoning to as much as 2,000
times. Alcohol intake can mask the early symptoms of acute
poisoning and may lead to a more severe type of poisoning.
Smoking cigarettes while exposed to pesticides may also
aggravate pesticide poisoning. Simultaneous exposure to
different types of pesticides and other poisons also increase
the likelihood of adverse health effects.
Chronic Health Effects
It is not only the acute or immediate effects
that make pesticides dangerous. The adverse effects of
pesticides may manifest only after months or years of
exposure. These chronic or long-term effects may occur
even with low levels of exposure. The weight of scientific
evidence show that even low levels of exposure to pesticides
can cause serious immune and metabolic disorders, neurologic
effects, reproductive anomalies, cancer and other chronic
diseases in animals and in humans. Death rates of people
are higher in areas with high pesticide usage compared
to those living in areas with low pesticide usage. The
higher number of deaths is not only caused by a higher
rate of acute pesticide poisoning but also by a higher
rate of chronic debilitating diseases.
Recent studies have shown that certain pesticides can
disrupt the human endocrine system, which includes the
glands that control the release of hormones in our bodies.
There are also pesticides that can actually “mimic”
hormones found in the human body. Such pesticides are
commonly found in several countries of the South. In the
Philippines, for example, countrywide surveys reveal that
pesticide residues of these “hormone mimickers”,
some of which are already “banned” in developed
countries, are found in a wide range of vegetables and
fruits. One such pesticide found in food is endosulfan.
This pesticide belongs to a chemical group called “organochlorines”.
Such chemicals can “mimic” the hormones in
our bodies and have been associated with higher incidences
of breast cancer, testicular and prostate cancer, reduction
in male fertility, and defects in male sex organs.
Another pesticide belonging to this category is DDT. Residues
of this pesticide long banned in developed countries have
been found also in a number of vegetables and food products,
not only in the Philippines, but also in other countries.
In India, let me cite a survey conducted by the Punjab
Agricultural University revealing the presence of DDT
and HCH residues in wheat and maize flour and rice. Most
of the samples contain DDT residues above the legal limit.
Another study conducted by the National Institute of Nutrition,
Hyderabad, for the Consumer Education and Research Center,
Ahmedabad, showed that organochlorines were found in different
proportions in the food samples tested consisting of food
grains, milk and milk products and packaged food commodities
such as jam and coffee. Four of the pesticides tested
were present beyond the so-called “Maximum Residue
Limit” or MRL.
Women and Pesticides
Women and children are particularly vulnerable
to pesticide exposure. Most of the peasant women in the
Philippines, for example, work on farms that use pesticides
heavily such as rice, corn, sugar, vegetables, and fruit
farms. Their important role in the food production process
has been glossed over or neglected. In rice growing areas,
women spend 8-10 hours soaking in pesticide-laden fields,
weeding, transplanting, picking snails, and harvesting.
Women bathe and wash clothes in pesticide contaminated
irrigation channels. In post-harvest activities, women
get in direct contact with agricultural products contaminated
with chemical residues. The multiple roles of women often
result in overfatigue and weakened health making them
more susceptible to pesticide poisoning. A woman’s
body contains more fatty tissue than a man’s body,
thus she “stores” more pesticides in her body,
especially in breasts. When a woman gets pregnant, she
passes the pesticides to the fetus. When the baby is born,
the mother will again pass the pesticides to her baby
by breastfeeding her contaminated milk.
Pesticides are known to cause infertility, spontaneous
abortion, stillbirths, and birth defects. Certain genital
cancers may be caused by pesticides, and low sperm counts
in men have been associated with pesticide exposure. In
Third World countries, the adverse effects of pesticides
tend to occur more frequently and are likely to be more
severe because of aggravating conditions like poverty,
ignorance, malnutrition, and other social, economic and
political factors that are driven by the characteristics
of global power relations.
Adverse health effects do not only happen to people who
work with pesticides. Practically everybody has some contact
with small amounts of pesticides through contaminated
food, water, and air. Pesticide residues are found in
samples of vegetables, fruits, rice and other kinds of
food. Water samples, including those from sources of drinking
water, have been found to be contaminated also by different
kinds of pesticides. The use of pesticides in households
and yards have also been found to be associated with serious
adverse health effects. Even the use of the innocently
looking household pest strip, advertised as innocuous
by pesticide companies, have been associated with increased
incidence of childhood leukemia.
Pesticides and Cancer
One of the more serious long term effects
of pesticides on people’s health is cancer. Several
pesticides are already known to cause cancer in humans.
Others may not have direct evidence of causation but have
shown to be associated with increased cancer incidence.
Many others have been shown to cause cancer in animals
but evidence of causation in humans is non-conclusive
or lacking. Many more have not been shown to cause cancer,
mainly because they have not been studied well. Many pesticides
exhibit similarities in chemical structure and actions
as other chemicals previously shown to cause cancer. Many
other indirect evidences, for example, steroid-like effects,
production of by-products indicating cellular damage,
and disruption of intercellular communication point to
the carcinogenic effects of pesticides. Indication of
genetic damage, like mutations and chromosomal aberrations,
as well as embryotoxicity and immunotoxicity, are also
commonly associated with exposure to pesticides. Practically
all pesticides are potentially cancer producing or at
least cancer promoting. Even the so-called “Green
Label” pesticides are potentially cancer-producing.
Pesticides and Childhood Cancer
One of the more recent concerns about pesticides
is the association of childhood cancer with exposure to
pesticides at home. A study published in the American
Journal of Public Health has found elevated rates of cancer
in children exposed to pesticides in their homes and yards.
The study found a four-fold increase in the risk of soft-tissue
sarcoma, a very invasive type of cancer in children whose
yards were treated with pesticides. The investigators
also found a link between the use of pest strips containing
dichlorvos and increased incidence of childhood leukemia.
Pest strips present an exceptional health risk because
they emit a continuous vapor of the pesticide into the
household air that the residents breathe continuously.
The study also found evidence of an association between
home pest extermination and lymphomas.
It is extremely difficult to prove without doubt that
a certain chemical causes cancer in humans. Most available
data are from animal studies. Since it takes several years
for cancer to develop, the evidence of causation or association
between the use of a pesticide and cancer in humans takes
extremely long time to accumulate and gathering it involves
a tremendous amount of resources. It is therefore important
that the “precautionary principle” be applied
in the evaluation, regulation and control of pesticides.
Key elements Affecting Exposure
of People to Pesticides: Pesticide Industry and Pesticide
The use of pesticides, particularly
in Third World agriculture, was heightened during the
so-called “Green Revolution” pushed by multilateral
institutions and agricultural research agencies with close
links to transnational companies. Monocropping and use
of “high yielding varieties” which required
high inputs of chemicals practically wiped-out traditional
self-reliant ways and made most farming communities in
the Third World dependent on pesticides and global capital.
Over time, even with no serious pest attacks, farmers
increasingly applied pesticides. Sales pressures from
pesticide companies pushed pesticide consumption to grow
by leaps and bounds. Farmers usually obtained their knowledge
about pesticide use from sales agents or government technicians
highly influenced by pesticide companies. Persistent and
uncontrolled advertising and promotions created an extremely
unbalanced and biased information flow.
Despite international codes pertaining to pesticide regulation
and control, the real situation in a Third World country
is that pesticide regulation is largely ineffective. Inadequacies
in enforcement capabilities resulting from socio-economic
difficulties have encouraged pesticide companies to build
new or move existing production facilities to Third World
countries thereby facilitating exports of highly toxic
and banned pesticides. This is further compounded by non-harmonized
regulatory actions among Third World countries. The strained
and very limited human and financial resources, the weak
institutional infrastructures, the susceptibility to foreign
pressures and the lack of political will severely compromise
the formulation, implementation, monitoring and enforcement
of pesticide laws and policies.
The overwhelming profit motivation sets aside concerns
for public health and safety. Of the approximately 3,000
toxic chemicals put out yearly by chemical companies,
less than ten percent undergo thorough toxicologic evaluation.
Regulatory bodies rely mainly on data provided by the
pesticide companies which are treated as “confidential”
and not accessible to the public. Companies conceal or
distort facts exaggerate benefits, and make no mention
of adverse effects. Product labels and advertisements
hardly carry information that would warn consumers of
the health risks. Worse, many so-called “independent”
sources of information such as universities, WHO and FAO,
are also influenced, if not outrightly dictated upon by
the interests of huge transnational chemical companies.
These huge companies, in fact, have common interests with
ruling power elites and employ state mechanisms to protect
their interests and suppress critics. This and the other
factors mentioned above, objectively increase exposure
to pesticides in the Third World resulting in widespread
adverse health effects.