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

The agricultural sector has by far the largest occupational labour force:
70% of Thailand's 23.2 million workers (Thailand, Department of Health
1988).
Pesticide use is considered to be the greatest occupational health hazard
to agricultural workers - this is the consensus of officials interviewed
in the Ministry of Public Health's Occupational Health Division and
Occupational Health faculties at two major Thai universities.
The educational materials about pesticides used by Thai medical schools
were believed to be inadequate by curriculum committee members.
To emphasize population health and promote critical thinking among medical
students, several criteria were included in the conceptual design of the educational
package:
The model would incorporate national health statistics and surveys
about pesticides. Students would be encouraged to assess the strengths
and weaknesses of this data. For example, the students would be asked
to assess the limitations of pesticide-related mortality data collected at
district hospitals for estimating community morbidity or to contrast
hospital data with figures derived from the Ministry of Labour's compensation
statistics (estimates of pesticide-related mortality rates differ
by a factor of 70).
The module would depict a community-based management strategy,
arising from a field investigation at a farm where a poisoning incident
had occurred. This would be presented along with a conventional
medical "work-up" and treatment of a poisoned individual. The aim
was to encourage the students to think in a practical way about the
feasibility of community surveys and investigations and about the
opportunities they have to promote useful preventive strategies.
The module would apply basic principles of clinical epidemiology to
pesticide-related health issues, including: evaluating the effectiveness
of a screening test for plasma cholinesterase inhibition by calculation of
sensitivity and specificity; appreciating the problems inherent in establishing
a case definition of pesticide poisoning, and how different diagnostic
criteria lead to discrepancies in morbidity rates; and identifying
factors that affect the selection of an appropriate denominator, particularly
stressing the concept of an at-risk population.
Many aspects of the health effects resulting from pesticide use require careful
evaluation: the variability in clinical presentation; the range of toxicities and
routes of exposures; and the appropriateness and reliability of laboratory aids
in diagnosis. Illustrating the complexities of the problem might challenge
students to pursue learning in a self-directed manner rather than relying on
an approach based on simplistic assumptions.
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