Eighty-six workers exposed to zinc phosphide (Zn3P2) pesticide were studied for 
evidence of neuropsychiatric manifestations. They were evaluated clinically, by 
electroencephalography (EEG), and, in some cases, by electromyography (EMG). All 
were males (mean age, 35.8 years; mean duration of exposure to zinc phosphide, 
11.3 years). Most presented with one (or more) neuropsychiatric symptom(s), 
including fear of poisoning, anxiety, impotence, and easy fatigue. About half 
showed evidence of neuropsychiatric signs, including hyperreflexia, 
polyneuropathy, lumber radiculopathy, and cervical myelopathy, as well as 
anxious mood, impaired attention, and psychomotor stimulation. EEG recordings 
showed abnormal findings in 17.4% of the subjects. The mean age in that group 
was 39.1 years; mean duration of exposure to Zn3P2 was 15.1 years. EMG studies 
showed evidence of partial denervation of the anterior tibial group of muscles 
and flexor digiti minimi in 2 of the 30 workers (6.7%) who underwent EMG 
examination. Serum levels of zinc (Zn) and cadmium (Ca) were significantly 
higher in exposed workers than in controls (P < 0.005). Serum copper (Cu), iron 
(Fe), phosphorus (P), and magnesium (Mg) were significantly lower in exposed 
workers than in controls. Electrophoretic pattern of globulin showed that 
gammaglobulin fraction was significantly increased (P < 0.005); alpha2 and 
beta-globulin were decreased (P < 0.005) in exposed workers. Lipoprotein pattern 
showed that the total lipids, B-lipoprotein, and B/alpha ratio were 
significantly increased (P < 0.005) in exposed workers; the alpha1 lipoprotein 
was decreased. Triglycerides and cholesterol were significantly increased (P < 
0.001), and phospholipids and phospholipid/cholesterol ratio were significantly 
decreased (P < 0.005) in exposed workers compared to controls. The study 
findings indicated that exposure to Zn3P2 not only caused mild acute and 
subacute liver cell damage, but also affected renal function and perhaps B-cells 
of the pancreas. A total of 68.6% of the exposed workers had chest symptoms; 
only 24.4% presented with chest or cardiac signs. Ventilatory functions were 
abnormal in 70% of the exposed workers; abnormal ECG findings were present in 
12.8%.