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Age did not appear to be an important factor except for the occurrence of
certain respiratory conditions and anemia that affected younger workers
(under 40 years) exposed to pesticides. Abnormal ECGs, although significantly
more frequent among the younger rural exposed workers, were also
associated with older workers (over 40 years) in the urban exposed group.
The clinical laboratory investigations, including the hepatorenal function
tests, were also reviewed in relation to the presence of bilharzia in the pesticide
workers. Comparison with the control groups suggested that bilharzial infestation
was associated with significantly more severe functional changes, particularly
among the rural pesticide workers.
Discussion
Of special interest in this study was the significantly more frequent occurrence
of neurologic, psychiatric, and liver disorders among the workers exposed to
pesticides (Albert 1976; Gupta et al. 1978; Amr et al. 1984a,b,c; El Samra et al.
1984). The high prevalence of polyneuropathy supports two hypotheses: that
organophosphates can produce delayed neuropathy and that prolonged low
exposure to these substances can induce nervous-system symptoms (Lotti et
al. 1984). However, chronic and cumulative effects of other compounds used
in pesticide formulation cannot be excluded. Sridhar (1986) postulated that
changes in the concentration of trace elements in people exposed to pesticides
might explain the observed neuromuscular changes. The neurobehavioural
symptoms and signs in the exposed workers seemed to be related to duration
of exposure.
Behavioural effects are now a recognized outcome of exposure to many
industrial and environmental chemicals, especially pesticides (Weiss 1988)
and the EEG changes observed in both exposed groups corroborate this. EEC
abnormalities, which are destructive or irritative in nature (Klimmer 1969;
Mannaloni 1960; El Samra et al. 1984; Savage et al. 1988), might reflect toxic
encephalopathy, cerebral anorexia, brain edema and osmotic permeability, or
metabolic disturbances prevailing among pesticide-exposed workers.
Chronic liver pathology, found by examination and confirmed by abdominal
ultrasonography and liver-function tests, was a common, but not unexpected,
finding, as liver problems are common in Egyptians (Amr et al. 1984a,b,c;
Kundiev et al. 1986; Moses 1989). Impaired liver function was confirmed in
90% of rural and 86% of urban workers. Establishing conclusive correlations
between liver function and pesticide exposure is confounded by the high
prevalence of bi1iarzia and hepatitis.
Liver injury results in failure or delay in the body's detoxification mechanism
causing earlier development of cumulative pesticide effects. Subnormal metabolism
and elimination of neurotoxins, pesticides, and their metabolites is
evident among susceptible and sensitive subjects (Couri and Milks 1982).
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