and Integrated Pest Management - part - usaid

OCCUPATIONAL FIDPOSURE OF SPRAY WORKERS 411
indicated more clearly the extent of exposure on the various parts of the body
experienced by the operators. The percentage exposure of the legs to the whole
body was significantly higher for the SD operators (86.12%) Comparcd to that of
knapsack sprayer operators (58.68%). The hands of mixers were the most
contaminated part of the body while the backs of operators handling the knapsack
sprayer were more contaminated than those using the SD sprayers. Inhalation
exposure contributed negligibly to the total exposure of the three groups of
operators.
DISCUSSION
The total spray volume per hour exposure experienced by operators using
the two types of sprayers were not significantly different. lowever, it is
pertinent to note that in practice the concentrations of pesticide spray solutions
used in SD sprayers are often 4 to 8 times higher than those with the knapsack
sprayers. Since hazard is a function of toxicity and degree of exposure it would
therefore be more hazardous to use a SD sprayer than a knapsack sprayer under
tie conditions described.
The high percentage of spray solution falling on the legs and thighs of spray
operators using knapsack sprayers was also shown in an exposure study carried
out in the United Kingdom to determine the total and regional potential dermal
and respiratory exposure of agricultural workers during the application of 2,4-D
with five types of application cquipmcnt typically used in the country (13onsall
1985). The tendency of operators to walk through the spray mists before the
droplets settled on the target and also to walk into the sprayed areas, particularly
where foliage was thick, contributed to the, higher exposure in tie leg region.
Since hazard to spray operators can be reduced if exposure can be minimized,
it is clear that for both types of sprayers, operat')rs should wear proper boots
which cover as much of the legs as possible. These boots should be made of
rubber or other suitable materials and be comrfortable for hot and humid
conditions. They should also be suitable for walking through the undulating
terrain which is common in the plantations. An alternative to these boots would
perhaps be the use of leggings made from suitable malerials which can prevent
penetration of the pesticide spray solutions. k,-sults of this study indicated that
through the use of proper footwear more than 58% for knapsack and 86% for the
SD sprayer of the total exposure of spray solution to operators could be reduced.
This would mean that if good safety standards could be achieved, then the use of
SD sprayers might be acceptable for the more toxic pesticides. Presently
however,there is a lack of such suitable protective clothing for spray operators
working in the tropics. In view of this it may be prudent for spray operators to
adopt clean working practices and good personal hygiene, and maintain their
equipment well.
It was observed that contamination of the back of the spray operators'
clothing was due mainly to loose capping and spillage of spray solution during
refilling. Hence, proper design of equipment which would minimize spillage
during refilling should be encouraged. It may also be wise for the spray operator
to wipe off any spillage before starting to spray. In addition, a piece of plastic