Health(Afya)

POISON SURVEILLANCE SYSTEM FOR PESTICIDES.



DEFINITION



The Food and Agriculture Organization (FAO) has defined pesticide as:

any substance or mixture of substances intended for preventing, destroying or controlling any pest, including vectors of human or animal disease, unwanted species of plants or animals causing harm during or otherwise interfering with the production, processing, storage, transport or marketing of food, agricultural commodities, wood and wood products or animal feedstuffs, or substances which may be administered to animals for the control of insects, arachnids or other pests in or on their bodies. The term includes substances intended for use as a plant growth regulator, defoliant, desiccant or agent for thinning fruit or preventing the premature fall of fruit. Also used as substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport.

USES

Pesticides are used to control organisms that are considered to be harmful. These organisms “pests”are harmful to useful plants and domestic animals. Pests can harm human directly or indirectly foe example by destroying stored food or buildings.

They can also kill vector the insects that transmit the diseases pathogens,for example mosquitoes which transmit malaria,filariasis and river blindness. Other vectors are tick transmit arboviruses,mites causes scabies in human and flies can cause myasis in man.

Also Pesticides can prevent sickness in humans that could be caused by moldy food or diseased produce. Herbicides can be used to clear roadside weeds, trees and brush. They can also kill invasive weeds that may cause environmental damage. Herbicides are commonly applied in ponds and lakes to control algae and plants such as water grasses that can interfere with activities like swimming and fishing and cause the water to look or smell unpleasant. Uncontrolled pests such as termites and mould can damage structures such as houses.

Pesticides are used in grocery stores and food storage facilities to manage rodents and insects that infest food such as grain. Each use of a pesticide carries some associated risk. Pesticides can save farmers' money by preventing crop losses to insects and other pests,

Indoor residual house spraying to kill mosquitoes and flies, also spraying on the wall of the houses can kill insects which have the tendency to hide in the crack along the wall,one of the method which is used to fight reduviid bugs the vectors for leishmaniasis in Southern America.

EFFECTS OF PESTICIDES

Pesticides may cause acute and delayed health effects in workers who are exposed. Pesticide exposure can cause a variety of adverse health effects, ranging from simple irritation of the skin and eyes to more severe effects such as affecting the nervous system, mimicking hormones causing reproductive problems, and also causing cancer. A 2007 systematic review found that "most studies on non-Hodgkin lymphoma and leukemia showed positive associations with pesticide exposure" and thus concluded that cosmetic use of pesticides should be decreased. Strong evidence also exists for other negative outcomes from pesticide exposure including neurological, birth defects, fetal death and neurodevelopment disoders.

Pesticide use raises a number of environmental concerns. Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, including non-target species, air, water and soil. Pesticide drift occurs when pesticides suspended in the air as particles are carried by wind to other areas, potentially contaminating them. Pesticides are one of the causes of water pollution, and some pesticides are persistent organic pollutant and contribute to soil contamination.

REGULATION AND SUVAILLANCE.

Because of their potentially negative effects on health and environment,pesticides must be judicious and limited to minimal. Negative effects can occur throughout the life cycle of pesticides ie from production,transport,storage and application to disposal.

Use of pesticides must be controlled to protect both human and environment.

One method of controlling their use is registration,which involve deciding how each pesticide formulation shall be distributed, labelled and used with maximum efficiency and minimum hazards to both human being band environment.

banning the use of highly toxic pesticides including those that are carcinogenic, mutagenic or toxic to reproduction, those that are endocrine-disrupting, and those that are persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative.[2]

Though pesticide regulations differ from country to country, pesticides and products on which they were used are traded across international borders. To deal with inconsistencies in regulations among countries,[3] delegates to a conference of the United Nations Food and Agriculture Organization adopted an International Code of Conduct on the Distribution and Use of Pesticides in 1985 to create voluntary standards of pesticide regulation for different countries. The Code was updated in 1998 and 2002.[4]The FAO claims that the code has raised awareness about pesticide hazards and decreased the number of countries without restrictions on pesticide use.

Pesticide safety education and pesticide applicator regulation are designed to protect the public from pesticides misuse, but do not eliminate all misuse.

Pesticides can be created that are targeted to a specific pest's life cycle, which can be environmentally more friendly. For example, potato cyst nematodes emerge from their protective cysts in response to a chemical excreted by potatoes; they feed on the potatoes and damage the crops. A similar chemical can be applied to fields early, before the potatoes are planted, causing the nematodes to emerge early and starve in the absence of potatoes.

In addition, applicators are being encouraged to consider alternative controls and adopt methods that reduce the use of chemical pesticides. These include removing standing water where malaria mosquitoes can breed,cultural practices such as crop rotation or using plant varieties resistant to diseases or biological control with pathogens,parasites and predators such as spiders (e.g Encarsia wasp against whitefly, Nucleopolyhedroviruses against army worms,Bacillus thuringiesis var.islaelensis against mosquitoe larvae)[4].

Banning the use of highly toxic pesticides including those that are carcinogenic, mutagenic or toxic to reproduction, those that are endocrine-disrupting, and those that are persistent, bioacumulative and toxic (PBT) or very persistent and very bioaccumulative.

 

REFERENCES.

1,2.WIKIPEDIA,http://en.wikipedia.org/wiki/Pesticide#International

3. Willson, Harold R (February 23, 1996), Pesticide Regulations. University of Minnesota.

Retrieved on 2007-10-15.