Environmental Engineering Reference
In-Depth Information
studies on the blood can be used for assessing the total body burden data of pesticides in
the occupationally exposed and unexposed populations.
15.5.3 Pakistan
In 1976, epidemic organophosphate insecticide poisoning due to malathion occurred
among 7500 field workers in the Pakistan malaria control program. In July, the peak month
of the epidemic, it was estimated that there were about 2800 cases. In field studies, low
red-cell cholinesterase activities were associated with the signs and symptoms of organo-
phosphate insecticide intoxication. Toxicity was seen with three different formulations of
the insecticide and was greatest with the products containing increased amounts of iso-
malathion, a toxic malathion degradation product. Poor work practices, which had devel-
oped when DDT was the primary insecticide for malaria control, resulted in excessive skin
contact with and percutaneous absorption of the pesticide. Airborne malathion concentra-
tions were very low. Implementation of good work practices and proscription of use of the
two pesticide formulations most contaminated with isomalathion halted the epidemic in
September. An extensive training program and surveillance system for pesticide toxicity
preceded the 1977 spraying operations (Baker et al. 1978).
OCP residues were monitored in the samples of human blood (N = 32) obtained from
concerned volunteers suspecting oral, dermal, or inhalation exposure to endosulfan and
heptachlor, either environmentally or occupationally, either recently or in the recent past
of Multan Division, (Pakistan) during 1995-1996. Residues of endosulfan were found to be
higher when compared to heptachlor in all the samples. Concentration of endosulfan resi-
dues in the blood in the population of Multan and Mailsi regions ranged between 58.13-
90.29 and 60.13-82.14 g/kg, respectively, while heptachlor ranged between 0.37-12.978 and
1.23-9.997 g/kg, respectively (Ansari et al. 1997).
Ahmad et al. 2002 have documented nonoccupational pesticide exposure accidents due
to pesticides left on commercial foods, home germicides, toilet cleaners, termiticides, and
suicides. The same situation has already been recognized that people living in agricul-
tural areas may have significant public health consequences by nonoccupational exposure
(Simcox et al. 1995).
Bunggush and Anwar (2000) reported the results of pesticide poisoning survey from
72 medical centers in Pakistan. A total of 408 cases were recorded. Of these, 165 (40.4%)
were accidental and 243 (59.6%) were suicidal. The total number of deaths due to suicidal
poisoning was 63 (26%).
Tariq et al. (2007) introduced an integrated picture of pesticide exposure to humans,
animals, plants, waters, soils/sediments, and the atmosphere in Pakistan. They reported
that in some areas of Punjab and Sindh, groundwater has been found contaminated due
to pesticide use. There is considerable evidence that farmers have overused and misused
the pesticides especially in cotton-growing areas. It is evident from the biological monitor-
ing studies that farmers are at a higher risk for acute and chronic health effects associated
with pesticides due to occupational exposure. Furthermore, the intensive use of pesticides
(higher sprays more than the recommended dose) in cotton-growing areas involves a spe-
cial risk to the field workers and pickers, in addition to unacceptable residue concentra-
tion in cottonseed oils and cakes. The authors reported that data limitations are still the
major obstacle toward establishing clear environmental trends in Pakistan. They suggest
that reliable monitoring, assessment, and reporting procedures should be implemented
in accordance with appropriate environmental policies, laws, and regulations, in order to
minimize the pesticide exposure.
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