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

Obstructive = FVC>80% of the predicted value; FEV.o/FVC < 75%; and
RV > 80% of the predicted value; and
Normal = FVC 80% of the predicted value; FEV1.o/FVC 75%; RV
80-120% of the predicted value; and TLC 80-120% of the predicted
value.
Based on an exposure-to-paraquat score obtained from the questionnaire,
blood and urine samples were collected during December 1986 and March
1987 from 603 paraquat users. The concentration of paraquat in these samples
was then determined.
During the paraquat spraying period1 December 1986 to March 1987, air in the
breathing zone of 14 workers was collected and the concentration of paraquat
measured. Sampling was done with the aid of personal sampling pumps that
passed the air over collection filters. Paraquat was extracted from the filters
and concentrations determined by the National Institute of Occupational
Safety and Health analytical method S294: paraquat (NIOSH 1979). Samples
were analyzed for paraquat content at the National Institute of Health, Bogota,
with a 10% external control carried out in the laboratory of toxicology of the
University of Laval, Quebec, Canada.
Because data were generated from a random sample of the population, it is
possible to compare the group of people that displays the outcome of interest
(disease) with the group that does not, according to the presence or absence
of exposure to paraquat in a 2 x 2 table. The estimate of the risk of exposed
people relative to unexposed people is the cross product of the entries in this
table. It represents a relative risk or odds ratio, for which variances, standard
errors, confidence limits, and significance tests (chi squared) were calculated.
Results
Of the 5 483 people interviewed, 61.2% (3 357 people) lived in the rural area
of Carmen de Viboral and 38.8% (2 126 people) in the municipality. By age
distribution the largest group consisted of people 15-44 years of age, followed
by those under 15 years. In general, 11.3% of the population was found to be
illiterate; 18.7% of this group consisted of men who lived in the rural area. Of
the rural working population, 86.3% worked in agriculture or with cattle and
2.4% performed activities related to the production of ceramics. In the township,
the corresponding proportions for these two groups of activities were
26.0% and 13.6%, respectively.
Of the population interviewed, 11.0% (603 people) used paraquat: 4.4% (94
people) of the urban population and 15.2% (509 people) of the population in
the rural area. The distribution of paraquat users by age and level of exposure
(high and low) was determined by the questionnaire (Table 1).
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