Lack of correlation between PM10 measurements and upper respiratory tract dose.
Ann Occup Hyg, Inhaled Particles VIII 1997 Jan; 41(Suppl 1):14-18
A size-selective air intake that has a 50% cut point at 10 microm (PM1O) was developed to monitor those ambient air particulate concentrations that might cause lung disease. The underlying assumption in establishing the current U.S. ambient air monitoring system was that PM1O samples would provide equal protection regard- less of the size distribution of the particulate matter. The size fraction, PM1O, is based on the aerodynamic diameter of particles that are capable of penetrating to, but not necessarily depositing in, the thoracic region of the respiratory system. Epidemiologic studies suggest that exposure to particulate air pollution may cause increased mortality and morbidity from respiratory and cardiovascular disease (Pope et aI, 1996). Epidemiological studies seek a dose-response relationship to understand the etiology of disease. These analyses seek to find the relationship between particulate air pollution and mortality. However, questions about the usefulness of the PM1O estimates have emerged. Previous results suggested that there was a questionable relationship between particulate dose and the PM1O measurement. For occupational environments, McCawley (1993) showed that there is a bias in the relationship between exposure (penetration) and dose (deposition) due to the variations in size distribution in occupational environments. The amount of bias associated with the use of the penetration criteria is dependent upon the particle size distribution. Since deposition is a measurement of dose and as such is the quantity of particulate crossing the physical boundaries of the person and entering the tissue, deposition should relate more directly to response than should measurements such as PM1O which only measure penetration.
Air-samples; Air-sampling; Air-quality-monitoring; Air-quality-measurement; Air-quality; Lung-irritants; Lung-disease; Lung-disorders; Respiratory-system-disorders; Air-contamination; Cardiovascular-disease; Cardiovascular-function; Mortality-data; Mortality-rates
Annals of Occupational Hygiene, Inhaled Particles VIII