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the first, the potential dermal exposure of rice farmers applying methyl
parathion (50% emulsifiable concentrate, EC) was measured at various stages
under field conditions. The applicability of the World Health Organization's
protocol (WHO 1982) in conducting the study was assessed, and the necessity
for protective clothing for rice farmers was investigated. The second exposure
study assessed the protection afforded by locally designed protective clothing
during the application of methyl parathion (50% EC) under field conditions.
The third study assessed the exposure and resulting health risk arising from
the application of monocrotophos (28.5% water-soluble concentrate, WC) to
rice under field conditions. An attempt was made to study the benefits of
"Gardman" protective clothing and high-density polyethylene (HDPE) bottles
with dispensers.
Methods
The methods used in the three studies were based on the WHO protocol for
field surveys of exposure to pesticides (WHO 1982). The three exposure
studies were conducted in rice fields in the Philippine regions of Bulacan,
Pampanga, and Laguna in the rice-growing area of the central plain of Luzon.
Study one
Forty-five farmers participated in the first methyl parathion study. They were
divided into eight groups (about six farmers per group), one for each pesticide
application activity:
Mixing and loading;
Spraying at the crop's vegetative stage (first of three replicates, RI);
Spraying at the crop's maximum tillering stage (R2);
Spraying at the crop's booting stage (R3);
Cleaning and disposal;
Day I field reentry;
Day 7 field reentry; and
All activities.
The last group represented the normal activities undertaken by rice farmers.
All groups were exposed for a minimum of I h.
The farmers wore cotton overalls, hoods, and gloves with inner patches. The
patches were analyzed for pesticide residue using gasliquid chromatography.
Samples of early-morning urine and urine collected 6 h after exposure
were analyzed for the urinary metabolite, p-nitrophenol, using spectrophotometric
methods (Kaye 1980).
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