What is pesticide?

Pesticides are chemicals designed to kill or control undesirable organisms. Unlike other toxic chemicals, pesticides are deliberately dispersed over large areas of the rural and urban environment. They are used within agriculture and forestry to kill pests and weeds, on roads and railways to prevent weed growth and by industry to protect manufactured products.

Pesticides can be classified according to the types of pest organism they are designed to attack; insecticides work against insects, herbicides against weeds, fungicides against fungi, and rodenticides against rodents. Pesticides come in different physical forms such as liquids, powders, or granules.

Pesticides Usage

The global business in pesticide sales gained momentum in the second half of the twentieth century. The number of active ingredients approved for use has increased from some dozens in the late 1950s to around eight hundred in the 1990s, and those active ingredients may be formulated in thousands of different products. As a rule of thumb, pesticide use has doubled every ten years since the early 1950s.

Agrochemical usage by world areas 2000

Area % (Total $29.2 billion)

Western Europe 19.8%

Eastern Europe 2.7%

East Asia 27.5%

North America 29.1%

South America 14.9%Rest of World 6.0%
(Source: International Greenpeace)

Pesticide use in Cambodia

A CEDAC survey conducted in 2000 showed that of 933 farmers surveyed, 67 % used pesticides. Of these 44% began using them in the 1980s with the rest beginning in the 1990s. Insecticides and rodenticides (rat poison) are, by far, the most commonly used pesticides in Cambodia. Herbicide use is not yet common but practices in other countries in the region suggest that usage is likely to increase.Herbicides are already available on Cambodian markets –many of them with glyphosate or 2.4-D as active ingredients. Although fungicide use is extremely rare,products can easily be found. Pesticides are used in greater volumes on vegetables (e.g.72 litres or kg per hectare per year) than rice (1 litre or kg per hectare per year).

An IRRI report showed that, depending on the province, 40-100 % of dry season and 8-50% of wet season rice farmers use pesticides.

Surveys of Cambodian markets reveal that most pesticides come from Vietnam and Thailand (c.21% and c.69% respectively in Kandal Province). Other products are manufactured elsewhere (China, Japan, India, United Kingdom), but formulated and packaged in Thailand or Vietnam.

Some pesticides on sale in Cambodia are banned in their country of origin. 42 of 241 products available in 2000 were banned in Vietnam, whilst another  are banned in Thailand. This has led to fears that Cambodia is becoming a dumping ground for unwanted and dangerous pesticides. (By Environmental Justice Foundation).

Human Exposure

Humans are exposed to pesticides in a number of ways. Those occupationally engaged in pesticide production or application will receive the highest exposures. In more developed countries training in pesticide application and modern equipment used for pesticide application reduce the exposure levels of workers. In developing countries where training may be minimal and application equipment substandard workers receive much higher exposures. Most frequently farm workers apply pesticides without wearing protective clothing and using knapsack sprayers which may be leaking. The incidence of acute poisonings is high.Pesticides and HealthMany pesticides are toxic and since their first use it has been known that they present a risk to human health. In China, many of the pesticides used are highly toxic and this has resulted in tens of thousands of users suffering the effects of pesticide poisoning which is sometimes fatal. Other users may suffer from long term health impacts as a result exposure to pesticides.

Chronic Effects

As well as the acute, or short term adverse effects of pesticides, there is the possibility of longer term effects on health. These effects may occur following acute exposure. Alternatively, long-term exposure to low levels of pesticides may result in health impacts.

Acute Risks

The most obvious effects on human health are acute poisonings which occur during or shortly after an exposure to a pesticide. Such incidents are common in developing countries where regulations may be less strict, where there is insufficient capacity for enforcing regulations, or where farmers have insufficient access to training, application equipment and appropriate protective clothing. (Source: Internation Greenpeace)

Poisoning evidence from Cambodia:

A recent (2000) report from the FAO Community IPM programme provided strong evidence of pesticide poisoning among Cambodian farmers, the majority of whom were using chemicals classed as moderately to extremely hazardous to human health(WHO classifications Ia, Ib, II). Of 210 pesticide-using farmers interviewed, 88% had experienced symptoms of poisoning (dizziness, headaches, night sweats, shortness of breath, chest pains, red eyes, unconsciousness) during or after spraying. 35% reported vomiting, a sign of moderate poisoning after spraying, whilst 5% had experienced unconsciousness, indicative of serious poisoning.

According to a CEDAC report, in1999, at least one farmer died from pesticide poisoning and several became seriously ill. In Siem Reap in 2000, seven Cambodians died and 79 became sick after eating normally nontoxic tetradontus fish. (By Environmental Justice Foundation, Death in Small Doses: Cambodia's pesticide problems and solution.)

Pesticides and the Environment

Application of pesticides to crops inevitably leads to the contamination of the environment. An amount of pesticide will be vaporised and eventually deposited again by rainfall, some pesticide will remain in the soil while some may reach surface and groundwater.Pesticides and Wildlife

The use of pesticides has undoubtedly lead to adverse impacts on many species of wildlife although it has often taken years to reach an understanding of the impacts. Adverse impacts can occur in a variety of ways such as direct contact causing death or injury, contamination of food sources or removal of food sources. Effects of pesticides on wildlife have been reported in most classes of animals including bees and other beneficial insects, birds, fish, amphibians, reptiles and mammals.

Ignorance of health risks (In case of Cambodian farmers)

According to a 1994 Government report, 82% of Cambodian farmers believed that pesticides had no effect on human health, 14% thought that sickness was possible and none envisaged a risk of death. Even when health risks are accepted, many believe that danger only exists if pesticides are ingested orally, rather than via the skin orinhalation. Said farmer Keo Chouk, 19, “If you don’t drink [the pesticide] you will never die. If you are careful, you will never have a problem”. 