Biomedical Engineering Reference
In-Depth Information
One female monkey was exposed per level (except two monkeys
were used at 5000 ppm). Parameters evaluated were effects on vision,
clinical signs, hematology, histopathology, clinical chemistry, and
survival. The results demonstrated that the monkeys tolerated
3000 ppm methanol after a few days, based on physiological and
clinical signs, but higher levels of methanol exposure resulted in
reduced movement, weak knees, vomiting, and dyspnea. The two
monkeys exposed at 5000 ppm were sacrificed or died on day 14 or
15. Monkeys exposed at higher level were also sacrificed. Body weight
was decreased in monkey exposed to 10,000 ppm. Monkeys exposed to
5000 ppm methanol and higher had reduced blood pH (acidosis),
decreased feed consumption, body temperature, increased lipid levels,
and nervous system effects. Blood methanol was 5250mg/l and blood
formic acid was 1210mg/l in the 5000 ppm monkey. The lower dose
animals had blood methanol levels of approximately 80mg/l and blood
formic acid levels of 30mg/l. No effects on clinical chemistry, but slight
changes in the central nervous system (hyperplasia of reactive astro-
cytes in the basal ganglion) were noted in animal exposed at 3000 ppm
methanol. Fatty degeneration of liver, degeneration of basal ganglion,
and other nervous system effects were seen in a dose-related manner at
monkey exposed at 3000 ppm and higher, but no effects on lung,
thyroid, trachea, GI tract, pancreas, spleen, urinary tract, and female
organs. In the monkeys exposed at 7000 ppmmethanol and higher, ECG
showed cardiovascular effects, increase in alkaline phosphatase, and an
increase in white blood cells. Body weight decrease was observed in
monkeys exposed at 10,000 ppm methanol. No effect on water con-
sumption, protein, GOT, GPT, A/G ratio of urobilinogen, and bilirubin
was noted. No treatment-related effects were noted in retina, optic
nerve, corpus geniculatum, and calcarinus. The NOAEL was 3000 ppm
and the LOAEL was 5000 ppm.
This study is a follow-up to the earlier pilot inhalation study in
monkeys conducted by NEDO (1986, 1987). In this study, monkeys
were exposed by inhalation to 1000, 2000, 3000, or 5000 ppm methanol
for 21 hours per day (NEDO, 1986; NEDO, 1987). This study had no
control group. Three female monkeys were exposed at each level.
Monkeys were exposed to methanol for 12 days at 5000 ppm, 20 days at
