Wednesday, August 29, 2007

Malaysia: Pesticide Poisoning

John T Arokiasamy, MPH, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur

Pesticides, insecticides and rodenticides are major agents of unintentional poisoning too, both directly as well as indirectly. In recent years, pesticides have caused numerous cases of poisoning, many of whom are children. Worldwide, an estimated half a million poisonings per year are said to be caused by exposure to agricultural pesticides. This occurs when pesticides are left in open containers in homes or in areas where children play.

The use of pesticides on commercial vegetable crops is often extensive in order to obtain higher yields and better returns. Indiscriminate, excessive spraying of stronger dosages of these chemicals are often resorted to achieve this end. In 1993, there were about 400 deaths due to pesticide poisoning from over 1400 reported cases, of which 45% were non-suicidal in nature. Ministry of Health figures based on government hospitals data revealed that in 1992, 138 cases of pesticide poisoning were unintentional in nature, mostly at work, with two deaths.

Elsewhere, reports of organophosphorous toxicity due to absorption through the skin has been reported. Organophosphates, found in pesticides, were commonly implicated in cases seen in Jordan with an annual mortality rate of about 35.3%.

It was also reported that 74% of the cases were among children less than 10 years. Aplastic anemia, pure red cell aplasia, leukemia, lymphoma and other hematologic disorders following exposure to the pesticide pentachlorophenol (PCP) has been reported, suggesting that exposure to chemicals that linger long in the environment can lead to mutagenic, hemolytic and carcinogenic effects.

Arsenic commonly found in insecticides, herbicides and industrial materials are involved in heavy metal poisonings and most commonly in children. A herbicide of importance in unintentional poisoning, resulting from accidental ingestion, is paraquat. A 9-year-old is reported to have been poisoned after using an empty bottle of paraquat for drinking water from a water tank.

Rodenticides too are known to give rise to poisoning. A superwarfarin compound (brodifacoum) used as a rodenticide resulted in a child being poisoned.

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