Environmental Engineering Reference
In-Depth Information
as a prototype for the types of toxicological properties that may exist for many
other organochlorine insecticides (Cullen and Hill
2006
; Lauwerys
1996
).
Organophosphorus and organochlorine chemicals adversely affect the functions of
the central nervous system, though they do so by different mechanisms. Behavioral
dificulties have been experienced by aerial applicators following their exposures
to certain pesticides (Dille and Smith
1963, 1964
; Lewis et al.
1972
; Smith et al.
1968
; Wood et al.
1971
). Symptoms of such exposures have included anxiety,
uneasiness, depression with weeping, dizziness, emotional liability, frequent and
severe disagreement with family members and coworkers, and being unable to
perform familiar tasks. These effects were reported during medical evaluations of
two agricultural pilots actively engaged in the aerial application of organophospho-
rus (methyl parathion) or organochlorine insecticides (DDT, toxaphene, endrin,
and dieldrin) (Dille and Smith
1963, 1964
).
Toxicological evaluation of postmortem samples from pilots killed while engaged
in aerial application revealed that blood cholinesterase levels in 44 of 104 pilots
(Laceield et al.
1975
) and 77 of 130 pilots (Laceield et al.
1978
) were below the
normal range. This suggests a problem of acute and/or chronic toxicity from expo-
sure to the organophosphorus pesticides these pilots were applying. Reduced plasma
cholinesterase levels were found in two agriculture pilots who were involved in
nonfatal aviation accidents (Dille and Morris
1966, 1967
). The types of accidents
and poisonings that have occurred as a result of aerial applications have been docu-
mented (Dille and Mohler
1968
; Dille and Morris
1966, 1967
). Aerial application-
related precautions, signs, and symptoms of pesticide poisonings, and their
treatments have also been summarized in the literature to help protect agricultural
pilots (Dille and Mohler
1968
; Mohler and Harper
1966
). Among the precautions
suggested is a key one that points out the need for better educational efforts designed
to reduce accidents in this sector of agricultural activity.
Aerial spraying programs are also used to help manage insect infestations of
large tracts of forest. In this area, extensive studies have been conducted on the
toxicity of forest insecticides (fenitrothion and aminocarb), the technology of aerial
spraying, the development of less hazardous formulations, and the quantitation of
off-target drift of aerosolized insecticides (Ecobichon
1990
). These studies resulted
in improved pesticide application techniques, and they have fostered the establish-
ment of regulations to implement buffer zones around human habitation for certain
types of aircraft that apply different formulations of forest insecticides.
2.3
Exposure to Multiagricultural Chemicals and Organic
Solvents/Surfactants
If proper safety and precautionary measures are not observed, there is a clear poten-
tial for aerial applicators, associated personnel, and aircraft accident investigators to
be exposed to multiple agricultural chemicals and the solvents/surfactants in their
commercial spray preparations. Such exposure may result in poisonings and could
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