Chemicals

Pesticides, health and environment

Monday, March-26-2007 

By Dr Aftab Turabi

March 26 2007: PAKISTAN has basically an agrarian background and agriculture is mainstay of our economy. About 70 per cent of its population depends directly or indirectly on agriculture and approximately 68 per cent of its industries are agro-based. Pakistan possesses high potentialities to grow almost all types of tropical and sub-tropical field and garden crops in abundance. Cotton, wheat, paddy, sugarcane are the major crops of the country other than the fruit and vegetables.

Use of pesticides is increasing day by day. Around 45 multinational companies in association with local agents by way of import, and other 13 local pesticide manufacturing plants are meeting the pesticide requirements of the country. As the use of pesticide in controlling pests to avoid crop losses is increasing, number of pesticide toxicity cases also increasing so there is immense need to develop other methods for adequate plant protection.

Impact of Pesticide on Health: In course of struggle between mankind on one side and insects, pathogenic organisms and weeds on the other, the newly developed chemical pesticide gave hope that the ultimate weapon had been found and these being poisonous substances were found to be quite dangerous if not handled carefully and cautiously.

Pesticides however, can be categorised in groups in view of their chemicals properties, which dictate relevant sets of precautionary measures for safety and curative treatments against their injurious effects of different types and intensities.

Some of the classical members of following groups are used in Pakistan: Chlorinated Hydrocarbon Pesticide: (1) Aldrin, (2) BHC (lindane/gammexane), (3) Chlordane, (4) DDT, (5) Dieldrin, (6) Endrin, (7) Heptachlor, (8) Thiodane.

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Organophosphate Group: (1) Ethion, (2) Usathion, (3) Arathion, (4) Thimet, (5) Imecron, (6) Formathion, (7) Azodrin, (8) Nexion, (9) Arbicron, (10) Diptrex, (11) Diazinon, (12) Imidan, (13) Lebaycid, (14) Malathion, (15) Methyl Parathion, (16) Metasystox, (17) Phosdrin 18) Sumithion, (19) Nexagan, (20) Disyton / Solvirex.

Pesticides industry: Presently, the basic manufacturing facilities for pesticides do not exist in the country. However there were two manufacturing units for the production of Dichloro Diphenyl Trichloro Ethane (DDT) and Benzene Hexa Chloride (BHC) in Pakistan, located at Kala Shah Kaku (Punjab) and Nowshera (NWFP). The total installed capacity of these two units for DDT and BHC were 2,020 and 2,310 MTPY respectively. These units are closed for last many years because both pesticides have been banned for use in Pakistan. The problems need to be addressed by the state as officially banned pesticides are still available in the local market.

Pesticides used at present are either organic or inorganic in nature. Organic group contains natural plant oils, nicotine and pakerthsun as natural pesticides. It also contains synthetic pesticides as compound of chlorine like DDT, BHC and endrin, aldrin, dialdrin, heptachlor etc. Twenty four pesticides, including above compounds, have been banned in Pakistan.

Since pesticides were subsidised ( their imports till 1979), 75 per cent share was passed to private sector while the government retained remaining 25 per cent. However, since February 1985, all subsidies were withdrawn and private sector was fully made responsible for imports, distribution and sales of pesticides throughout Pakistan except Balochistan province. Pesticides were imported under generic names from 1991. By the year 2000, the local formulation exceeded the imported pesticides several times.

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Production capacity: Presently, the installed capacity for the formulation of various types of pesticides is more than the local requirement. There are about 40 companies involved in the formulation of pesticides. The local formulation product includes liquid pesticides, powder and granules that contribute 67 per cent in the local market. Most of the raw materials including active ingredients as well pesticides in finish form are being imported. The sector growth rate is three per cent.

Imports of pesticides: Liquid pesticides account for 95 per cent of the total consumption. Remaining five per cent are powder, dust for granules. Insecticides account for 88 per cent, herbicides 11 per cent and fungicides one per cent of the total pesticides used for plant protection. Additional quantities of pesticides are used for public health and household.

Future Prospects: This sector lacks production of base chemicals. Few ingredients are produced in Pakistan especially base chemicals used in the pesticides for the protection of cotton crop. Around one billion dollar (Rs60 billion) is spent on the cotton crop and others every year from sowing to harvesting. The share of plant protection for the cotton crop is 33 per cent or $ 0.33 billion. This shows the importance and need for local pesticides industry.

Ill effects of pesticides on health and environment.: Due to extensive use of pesticides there is an extensive need of: risk identification. After determining and identifying the risk factors and its impact on health and environment we have to plan to search appropriate measures for reduction in the use of pesticide without affecting the crop quantity and quality;safe use and handling of pesticides; development of appropriate alternative methodology; study of acute and chronic effects of pesticides on health and environment.

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During the past decade, the public has grown concerned about agricultural pesticides use. Exposure to pesticides, even at low doses, is associated with a wide variety of health effects, and these compounds are now commonly found throughout our environment. Despite some important advances, federal pesticides regulatory programmes have failed to prevent an overall increase in pesticides use, risks, and reliance. This not only threatens public health and the environment, but it puts farmer?s livelihood in jeopardy. Farmers using the pesticides that are legal and safe and also effective for crop production, later come to know that they are discovered to be hazardous.

In the long run, both farmers and public will be the best protected by a fundamental restructuring of pesticide policies and agricultural and education programmes to minimise pesticide use and rely instead on non-chemical, biologically-based methods that prevent pest problem. A wide variety of alternative agricultural tools are available to reduce pesticide use and reliance, including those used in integrated Pest Management (IPM) and sustainable organic farming system.

Various alternative pest management techniques are: Scouting and monitoring for pest and natural enemy population levels; precision pesticides application equipment; rotating crops and planting cover crops; switching to biologically-based pest control products: conservation tillage, irrigation management, and soil-building.

Courtesy The DAWN

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