Biomedical Engineering Reference
In-Depth Information
Methanol exposure produced significant increases in blood and urine
methanol concentration. No changes in plasma formate were observed.
Most of the neurobehavioral endpoints were unaffected by exposure to
methanol; however, statistically significant effects and trends were
found for a cluster of variables, including the latency of the P200
component of event-related potentials, performance on the Sternberg
memory task, and subjective measures of fatigue and concentration.
The changes in neurobehavioral effects were small and did not exceed
the normal range. The effects were judged not to be related to methanol
exposure at 200 ppm in this limited study (Cook et al., 1991).
In a later study with 26 subjects (random double blind study with
subjects who served as their own control) were exposed to 200 ppm
methanol or water vapor for 4 hours to evaluate potential changes in
urinary and serum formate levels as a result of methanol exposure at the
TLV. Urinary and serum formate levels as well as folic acid levels were
measured at various times during exposure. No difference was found in
serum formate at any time between control and exposed individuals.
Only a slight nonsignificant increase in urinary formate was noted at
4 hours. Serum and urinary formate levels were found to be of no value
as a biological marker of methanol exposure up to 200 ppm methanol
(D'Alessandro et al., 1994).
In what appeared to be the same study, 26 subjects (random double
blind study with subjects who served as their own control) were exposed
to 200 ppm methanol or water vapor for 4 hours to evaluate potential
neurobehavioral effects of methanol. Exposure to methanol increased
serum concentration and urinary excretions of methanol, but did not
affect serum formate, visual, neuropsychological, or neurobehavioral
tests. No significant treatment-related effects were reported (Chuwers
et al., 1995).
In a study by the same group methanol serum and urinary levels of
methanol were evaluated in a random double blind study with 22
subjects exposed to 200 ppm methanol for 4 hours. Methanol was
rapidly absorbed by inhalation (absorption rate constant
ΒΌ
0.87
0.6 hours
1
). At the end of the exposure period serum methanol con-
centration rose from the beginning level of 0.9
0.6 to 6.5
2.7mg/l as
did urinary methanol excretion, but serum formate levels (11.2mg/l)
