Determination of Airborne Cadmium in Environmental Tobacco Smoke by Instrumental Neutron Activation Analysis with a Compton Suppression System

Concentrations of cadmium, a toxic trace element, were measured in the indoor air of several public places where environmental tobacco smoke was present. Particulate-phase cadmium concentrations were determined by analyzing air filter samples using epithermal instrumental neutron activation analysis in conjunction with a Compton suppression γ-ray detection system, in which the detection limit for cadmium was reduced to a few nanograms per filter. A cascade impactor and a personal filter sampler were used to collect the indoor suspended particulate matter for size-fractionated mass as well as total mass, respectively. Results show that where environmental tobacco smoke is present, cadmium concentrations are significantly higher than background and that about 80% of the cadmium found in indoor airborne particulate matter is associated with particles with aerodynamic diameters less than 1.8 μm. In one instance, airborne cadmium concentrations in a music club were found to be 38 ng/m³, which is at least 30 times higher than background.