Impact of - IDL-BNC @ IDRC - International Development Research ...

In Thailand, research on the effects of pesticide exposure have generally
concentrated on acetylcholinesterase inhibition. Efforts have been made by
the Department of Medical Sciences (Sinhaseni 1990) to estimate average
normal values for plasma cholinesterase levels in Thai people. Researchers
have found a range of 1 500-4 000 milliunits (Ellman's method), with significant
differences between males (2 760 ± 712 milliunits) and females (2 516 ±
665 milliunits). The Shell Company (Thailand) has supported a surveillance
program measuring blood cholinesterase levels in farmers in various areas
and at special functions such as agricultural fairs. The Occupational Health
Division, Ministry of Public Health, under the Green Esarn Project, has developed
and distributed paper-strip cholinesterase test kits to village health-care
personnel. About 300 tests per village in six provinces were conducted in 1990.
An integrated knowledge, attitudes, and practices (KAP) survey incorporating
clinical investigations as well as cholinesterase studies is currently being
conducted by a multidisciplinary team from Chulalongkorn University. The
project involves 150 vegetable farmers in Bang Bua Thong, near Bangkok. In
a survey of 658 agriculturalists (150 families), the most common complaints
were weakness (61%), dizziness (47%), headache (39%), shortness of breath
(35%), poor memory (34%), and nausea or vomiting (33%) (Suwanabun et al.
1986).
Assessment of pesticide exposure has been carried out by local scientists as
well as international teams (Working Group 1989; Shell Thailand 1989). Perhaps
the most comprehensive field study was that conducted by Tuinman and
Eadsforth (1987) on exposure and health effects after application of phosdrin
formulations on vegetable farms in Thailand. No health effects were observed
in any of the workers and it was recommended that attention be paid to the
packaging of the concentrate to minimize the possibility of contamination of
hands during preparation of formulations.
Tongsakul and Punepan (1988) conducted an exposure-assessment study
using high-volume spray dye to compare exposure of the different parts of
operators' bodies when spraying crops of different heights using a knapsack
mistblower. Sinhaseni and Tesprateep (1988) similarly conducted an assessment
of exposure to endosulfan by gardeners who sprayed large trees.
The pesticide application research team in the Entomology and Zoology
Division, Department of Agriculture, is responsible for providing information
related to pesticide-application technology in Thailand. Various types of
lever-operated knapsack sprayers are currently being evaluated. In addition,
the Division of Plant Protection Services operates pesticide clinics; they gather
farmers' and government-owned out-of-service equipment for repair by six
rotating units. These units also offer training in equipment repair.
There have been at least 16 KAP studies of Thai farmers. They have revealed
that farmers usually do not use protective apparel according to guidelines
(Working Group 1989). The studies have emphasized the importance of
40