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

At the end of each day's operations, the protective garments were washed with
detergent and water using a standard procedure and dried overnight.
Assessment of protection
Permeation was derived by measuring the amount of methamidophos found
on the protective and sampling garments. Methamidophos was extracted
from the garments using methanol for cotton and ethyl acetate for Kleenguard
and Tyvek. The extracts were subjected to analysis by high-performance liquid
chromatography (HPLC) using an ultraviolet detector for the determination
of methamidophos. The results were corrected for losses of methamidophos
through exposure to light, storage, and transit.
The permeation value, expressed as a percentage, was the amount of
methamidophos found on a sampling garment, divided by the total amount
found on the protective and sampling garments. Permeation data for each
group were compared using Student's t-test after exclusion of outlying values
(Tukey 1977).
Evaluation of comfort, thermal comfort, and durability was achieved through
the use of a detailed questionnaire and from observations made by the study
team.
Health surveillance
The workers were given a medical examination I day before the start of the
prestudy and were kept under medical surveillance during both phases of the
study. Blood samples were collected at regular intervals to test for cholinesterase
activity Measurement was carried out in situ using the tintometer method.
Results
Total working time on the 1st day of the prestudy was about 4 h. As the study
proceeded, work rate increased. On the last day of the main study, working
time had decreased to about 2.5 h. Because spray equipment broke down
frequently, one person was employed full-time to look after the equipment
and ensure continuity of spraying.
Over the 9-day study period, shade temperatures during work ranged from
26 to 33C. Relative humidity, measured on 3 days, was 52-81%. Wind speed
was low, with gusts of up to I rn/s recorded occasionally.
During the prestudy, all 20 workers said that they felt comfortable when
working in the Kleenguard protective garments (Table 1). By contrast, 11 of
the 20 workers said that the Tyvek garments were uncomfortable and this was
reinforced by responses to questions about problems during spraying; 10 of
the 16 sprayers complained that the material stuck to the skin and caused the
189