toxicological profile for malathion - Agency for Toxic Substances and ...

MALATHION 93
3. HEALTH EFFECTS
Respiratory Effects. Dyspnea and excessive secretions in the respiratory tract were observed in
cases of malathion intoxication in children by dermal application to the hair of a solution containing 50%
malathion in xylene reported by Ramu et al. (1973). No studies were located regarding respiratory effects
in humans or in animals following dermal exposure to malathion.
Hematological Effects. No studies were located regarding hematological effects in humans
following dermal exposure to malathion. No hematological alterations were reported in guinea pigs
applied 400 mg/kg/day malathion (98% pure) in acetone on a 36 cm 2 area of the skin for 30 days
(Dikshith et al. 1987). Application of up to 1,000 mg/kg/day of malathion (94% pure) 6 hours/day,
5 days/week for 3 weeks to skin of rabbits resulted in no significant alterations in hematological variables
and clinical chemistry parameters (Moreno 1989).
Hepatic Effects. Limited information on hepatic effects in humans is provided by a study of
12 agricultural workers who sprayed malathion over a period of 6 months (Grech 1965). The study was
prompted by reports of ill-defined complaints and the finding that because the workers were not wearing
the recommended protective clothing, significant dermal absorption was occurring. Serum levels of ALT,
AST, aldolase, and albumin were determined at intervals during several periods of exposure and
compared with preexposure levels and control subjects. No significant differences were observedbetween
exposed and controls subjects, but in general, mean preexposure levels of the workers were higher than
during exposure and than the control subjects. The toxicological significance of these findings is
unknown.
Unspecified mild hepatic changes were reported in guinea pigs applied 400 mg/kg/day of malathion
(98% pure) in acetone for 30 days, no alterations were seen at 200 mg/kg/day (Dikshith et al. 1987). No
gross or microscopical lesions were observed in the livers from rabbits treated dermally with up to
1,000 mg/kg/day malathion (94% pure) for 3 weeks (Moreno 1989). No further information was located
in the available literature.
Renal Effects. No studies were located regarding renal effects in humans following dermal exposure
to malathion. No gross renal alterations were reported in guinea pigs applied 400 mg/kg/day malathion
(98% pure) in acetone on a 36 cm 2 area of the skin for 30 days (Dikshith et al. 1987). No gross or
microscopical lesions were observed in the kidneys from rabbits treated dermally with up to
1,000 mg/kg/day malathion (94% pure) for 3 weeks (Moreno 1989).