Physiological damping of exposure variability during brief periods.
Rappaport SM; Spear RC
Ann Occup Hyg 1988; 32(1):21-33
A theoretical analysis was presented of the reduction in the variability of exposure to chemicals over short periods of time because of delayed accumulation in the tissues (physiological damping). A first order autoregressive model was used to describe the time course of short term exposure. Physiological damping was measured by a transmission factor, defined as the ratio of the coefficients of variation of burden and exposure. Since some chemicals were not intrinsically toxic, but were activated to toxic species by metabolism, transmission factors were determined in terms of the burden of metabolite associated with exposure to the parent chemical. Transmission of variability of exposure to the body was decreased as the biological half times of elimination and metabolism increased and was enhanced as the autocorrelation of a series of inhaled air concentrations increased. The authors conclude that since autocorrelation is linked to the air exchange rate, the hygienist might be justified in increasing the amount of general ventilation and turbulence in the workplace rather than in focusing exclusively upon the amount of toxicant emitted.
NIOSH-Publication; NIOSH-Grant; Grants-other; Analytical-methods; Toxic-materials; Mathematical-models; Exposure-limits; Analytical-models; Exposure-levels; Toxic-gases
Biomedical & Environ Hlth Scis University of California School of Public Health Berkeley, CA 94720
Other Occupational Concerns; Grants-other
Annals of Occupational Hygiene
University of California Berkeley, Berkeley, California