Objectives The original objectives of this research contract were to establish a program for the evaluation of the possible effects of selected sulfate salt inhalation upon human cardiopulmonary function. The first phase was to evaluate the effects of selected neutral and acid sulfates likely to be present in the atmosphere and found to be irritants in experimental animals. Later phases plan to focus on the interaction effects of other atmospheric covariables (eg@ relative humidity@ NO2@ O3@ SO2 nitrate and hydrocarbon aerosols) with sulfate aerosols under controlled conditions. In the first phase of this contract@ we originally proposed to expose single human volunteers@ via a face mask@ to acute doses of selected sulfate aerosols. During this initial phase@ the high capacity aerosol generator and real time mass concentration and particle size monitoring systems were being developed and installed in our human exposure chamber by our subcontractor@ Environmental Research and Technology Inc. (ERT). Because of the demonstrated capability of our prototype high-capacity generator@ developed by ERT under CAPM-20-74@ in maintaining a fairly stable ammonium sulfate aerosol in the chamber@ we decided to proceed with exposures of groups of 5 normals@ sensitives and asthmatic subjects to ammonium sulfate aerosol. The aerosol mass concentration of 100 ??/m3 was the ammonium sulfate equivalent to 2 hour peak ambient concentrations of sulfate aerosol measured in the Los Angeles Basin. This level was determined to be safe for 2 hour exposures of humans based on squirrel monkey exposures to 25 times this concentration under the CAPM-20-74 contract@ which showed small aerosol-induced effects.
API 27-30839-1977 history
1977API 27-30839-1977 FINAL REPORT - EFFECTS OF SULPHATE AEROSOLS UPON HUMAN CARDIOPULMONARY FUNCTION