Journal of Applied Physiology, Vol 76, Issue 3 1310-1316, Copyright © 1994 by American Physiological Society
Behavioral effects of carbon monoxide: meta analyses and extrapolations
V. A. Benignus
Human Studies Division, US Environmental Protection Agency, Research Triangle Park 27711.
In the absence of reliable data, this work was performed to estimate the
dose-effects function of carboxyhemoglobin (HbCO) on behavior in humans.
Meta analysis is the quantitative analysis of the combined findings of a
number of research reports. By meta analysis, an HbCO-behavior dose-effects
function was estimated for rats and corrected for effects of hypothermia
(which accompanies acute HbCO increases in rats but not in humans). By use
of pulmonary function models and blood gas equations, equivalent HbCO
values were calculated for data in the literature on hypoxic hypoxia and
behavior. Another meta analysis was performed to fit a dose-effects
function to the equivalent HbCO data and to correct for the behavioral
effects of hypocapnia (which usually occurs during hypoxic hypoxia but not
with HbCO elevation). The two extrapolations agreed closely and indicated
that, for healthy sedentary persons, 18-25% HbCO would be required to
produce a 10% decrement in behavior. Confidence intervals are computed to
characterize the uncertainty. Frequent reports of lower-level effects are
discussed.
