The volumetric incidence of atmospheric allergens: III. Rate of fall of pollen grains in still air

Abstract

Abstract This paper stresses the need of a standardized method of sampling, counting, and volumetric conversion of data for air-borne allergens. As a result of five seasons of experimentation with various gravity sampling devices controlled by parallel volumetric tests, the following proposals are submitted: 1.1. The basic index of atmospheric contamination in a given community should depend on aerobiologic data secured from air samples taken on the unobstructed top of a tall downtown building. 2.2. A practicable gravity sampling device (slide shelter) is pictured and described, and suggested as a tentative standard device. It has been used in a number of places during the past season and has been carefully rated as to the average proportion of ragweed pollen which it recovers from a cubic yard of air. 3.3. A method of volumetric conversion of pollen and fungus spore counts is submitted with definite factors for about 40 pollens and one fungus spore. Two sets of conversion factors are listed so that counting may be done on the basis of 1 sq. cm. of slide area or on 3.6 sq. centimeters.