The exterminators

Globally, at least three million people are poisoned by pesticides every year, of whom 20,000 people die.  That’s according to the Geneva-based World Health Organization (WHO). 

At the height of the Masagana 99 program in the Philippines during the time of the presidency of Ferdinand E. Marcos, “pesticides killed 4,000 farmers in Central Luzon alone,” reported Nicanor Perlas of the Center for Alternative Development Institute.

While most of the illnesses and deaths occur in developing countries, most of the pesticides used are imported from industrialized countries.  The companies that profit for this hazardous trade argue that pesticides help solve the “food shortage” of those exporting countries.

 One company that export pesticides to developing countries has put this in its promotional material: “Given the abundance of food in the industrial countries, it is easily forgotten that people in other parts of the world are in dire need… There can therefore be no doubt that crop protection is of crucial importance in the fight against hunger.  It is more necessary than ever before.”

Chemicals are usually the first line of defense of farmers to control pests that attack agricultural crops.  “Each year, an estimated half of the world’s critically short food supply is consumed or destroyed by insects, molds, rodents, birds, and other pests that attack foodstuffs in fields, during shipment and in storage,” wrote Jane E. Brody in “The New York Times.”

“An estimated one-third of the world’s food supply would be lost each year to weeds, insect pests, and diseases if crop protection chemicals were not used. This is enough to feed about two billion people,” said the US Agricultural Retailers Association in a statement.

In the Philippines, reports said 62% of pesticides sold are in the form of insecticides.  Of these, 46% are applied to rice and 20% to vegetables.  Insecticides had become one of the major expenses of farmers that account for about 40% of total production cost.


The Fertilizer and Pesticide Authority (FPA) defined pesticide as “any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any insects, rodents, nematodes, fungi or weeds, or any other form of life declared to be pest.”

Pesticide also refers to “any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.”

Pesticides come in two forms: synthetic or botanical.  “The synthetic organic compounds constitute the majority among the pesticides,” FPA said. “They are synthesized from oil.”  Examples include malathion and paraquat.

Botanical or “natural” pesticides, on the other hand, are extracted from vegetative parts.  Well-known examples are pyrethrum from the pyrethrum flowers, rotenone from derris roots, nicotine from tobacco leaves, and azidiracthine from the neem tree.

“Although botanicals have a natural origin,” FPA reminded, “some of these compounds can be extremely toxic for man and other vertebrates.”

There are also two types of pesticide formulation.  “Dry” formulation are products sold in dry form (as powder or granules).  This does not necessarily mean that they should also be applied on the crop in dry form. Most of the time, they need to be mixed with water before use.

“Wet” formulations are those sold in liquid form.  In general, they still need to be diluted with water before use.

Pesticides are classified according to their degree of danger.  The pesticide’s label should give a warning notice in the shape of a symbol.  Skull and crossbones on the label means that the pesticide is extremely or highly toxic.  A highly toxic pesticide may be lethal when an adult ingests less than a teaspoon.

Worldwatch Institute, based in Washington, D.C., said that the first records of pesticides come from the ancient Greeks.  Pliny the Elder compiled a list of common compounds like arsenic, sulfur, caustic soda, and olive oil used to protect crops.  The Chinese later recorded using similar substances to combat insects and fungi.  In the 19th century, European farmers commenced using heavy metals like copper sulfate and iron sulfate to fight weeds.


 For a long time, no one seemed to question the safety of pesticides.  Not until 1962, when marine biologist Rachel Carlson wrote the now classic, “Silent Spring.”  In her book, she described how pesticides cause long-term hazards to birds, fish, other wildlife, and humans, but provides only short-term gains to controlling the pests.

As a result of Carson’s book, then American President John F. Kennedy formed a science advisory committee to investigate her findings.  They were soon confirmed, and DDT (dichloro-diphenyl-trichloroethane) – which won for its discoverer, Dr. Paul Muller, a Nobel Prize – and several other pesticides were banned from the United States six years later.

 But despite a number of problems that have surfaced since what experts called as “the Era of Optimism,” pesticides use still continues.  “Farmers now apply about one pound of pesticides per year for every person on the planet, 75% of it in industrial countries,” reported Peter Weber, a researcher with the Washington-based Worldwatch Institute. 

This situation alarms scientists.  “Pesticides are like bombs being dropped in the food web creating enormous destruction,” deplored entomologist Dr. K.L. Heong, who used to work at the International Rice Research Institute (IRRI) in Los Baños, Laguna.

Unknowingly, pesticides are killing more than just the pests.  “Some pesticides harm the living organisms other than the targeted pest,” the Davao-based Technical Assistance Center for the Development of Rural and Urban Poor (TACDRUP) observed.  “Some (pesticides) travel to the food chain to bioaccumulate in higher organisms.”

Gretta Goldenman and Sarojini Rengam explained in their book, “Pesticides and You,” that pesticides concentrated even to toxic levels via the food chain. Thus, an increase feeding on plants sprayed with pesticides might be eaten by another insect which might be eaten by a bird. 

 “Traces of pesticides too small to kill the targeted pest can accumulate to levels high enough to harm species further on up the food chain,” the two authors warned.

Pesticides are also hazardous to human beings.  They can enter the human body through the mouth, lungs, digestive system, or skin, according to health experts.  Depending on the pesticide, health effects can be immediate (acute) or they can occur after years of low-level exposure.

Acute poisoning generally occurs after an accident on the skin or drinking a bottle of pesticides.  Medical doctors say the symptoms of acute poisoning occur within 24 hours: vomiting, headache, respiratory problems, heart failure, etc. 

Long-term effects of pesticides include skin disorders, damage to internal organs (liver, kidneys, lungs), increased sensitivity to pesticides and effects on the progeny, according to medical experts.


Then, there’s that problem of pesticide resistance.  “Resistance to pesticides is as natural as evolution,” Weber reminded.  

“In fact, it is natural selection in fast forward, provoked the very chemicals meant to control the pest.  Resistant strains develop particularly quickly when farmers overuse pesticides and try to eliminate pests rather than control them.  Kill 99.9 percent of the insects in a field, and the survivors are a superstrain,” he added. 

Not too many know it but pesticides are also believed to damage the ozone layer, the earth’s protective shield.  Methyl bromide, the second most widely-used pesticide in the world, is five times more destructive than the chlorofluorocarbons, according to scientists.

 Farmers spray methyl bromide onto agricultural products before shipping and storage, and also inject it into soil to kill pests.  

Between 80%-100% of the gas is subsequently released into the atmosphere, the environment pressure group Friends of the Earth reported.

 Despite the health and environmental risks, farmers are still hooked on many of the worst offenders.  Without pesticides, they claim, their costs would skyrocket, harvests would plummet, and more people would go hungry.  

It is widely assumed that for big harvests, pesticides are essential.  After all, it is noted, farmers in industrial countries apply more pesticides, lose less to pests, and reap higher yields than farmers in developing countries.


A closer look at the data, however, indicates that pesticides are not as essential as many people think, according to a study conducted by IRRI.  It looked on the effects of pesticides on rice productivity and health.  Findings of the research showed that farmers’ earnings from chemically treated crops are often greatly reduced by the cost of treating pesticide-related health problems.

“The value of the crops lost to pests is invariably lower than the expense of treating pesticide-caused ailments,” said the head of the research team.  “When health costs are factored in, the use of correct rice varieties and reliance on natural control by predators and parasites is the least expensive pest control strategy.”

Unknowingly, pests can never be obliterated.  In an article, Dr. Rodolfo P. Estigoy wrote: “Over the years, a costly war has gone on between insects and man…  Even if we pour billions of pesos worth of pesticides, we cannot totally wipe out all insect pests.”

Actually, Filipino farmers need not  use pesticides – whether natural or synthetic – to get rid of those pesky pests.  This is particularly true among farmers who grow rice, according to Dr. Heong.

All pesticides kill even those beneficial insects that are vital to the rice ecosystem, he said.  “It is always the function that matters, not where it was derived,” Dr. Heong explained.  “Be it botanically or chemically produced, if its function is to kill, then it is harmful to the whole food web in the rice ecosystem.” 

One good way to avoid using pesticides is by relying on “Bacillus thuringiensis” (Bt) to do the work.  Bt is a common soil bacterium so called because it was first isolated in the Thuringia region of Germany.  It produces a protein that paralyzes the larvae of some harmful insects.


Scientists, through genetic engineering, have taken the Bt gene responsible for the production of the insecticidal protein from the bacterium and incorporated it into the genome of plants.  As such, the plants have a built-in mechanism of protection against targeted pests.

Among the crops where Bt is introduced include corn, cotton, poplar, potato, rice, soybean, tomato, and more recently eggplant.  

“The protein produced by the plants does not get washed away, nor is it destroyed by sunlight,” said a briefing paper published by the Global Knowledge Center on Crop Biotechnology.  “The plants are protected from the insects round the clock regardless of the situation.”

“But there are other ways farmers can do to protect their crops from pests,” said Roy C. Alimoane, the director of Mindanao Baptist Rural Life Center. Among those he cites are the following: tilling (which exposes pests that live in the soil and increases soil aeration), crop rotation (it stops the build-up of microorganisms around plant roots), crop combination, and companion planting. 

To use or not to use pesticides, that is the question.  Some farmers say they will while others chorus they won’t. Former FPA administrator Francisco C. Cornejo said: “While the use of chemical pesticides in agriculture cannot be totally discontinued, minimization is probable.” G




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