Aeroallergens (pollens) are airborne materials which elicit a hypersensitivity response in susceptible individuals. The two major responses exhibited are allergic rhinitis and bronchial asthma. The pollens of wind-pollinated plants are the most important of the aeroallergens, and ragweed pollen is commonly found in this group. Ragweed pollen is the cause of more than 90 percent of pollinosis in this country. Other aeroallergens include molds, house dust, danders, and a miscellaneous group of insecticides, cosmetics, paints, and vegetable fibers. Most of the aeroallergen investigations have been concerned with ragweed. Pollen counts are taken daily in many local areas throughout the country. These counts are used as guidelines for anticipating and understanding the incidence of pollinosis in a given area rather than as standards. Local programs of ragweed eradication generally have met with little success in controlling pollen concentrations. The pollen can be windborne for many miles, and therefore pollen entering a city from the outside usually is sufficient to cause pollinosis in the susceptible population. The gravity slide method has been accepted as the standard procedure for pollen sampling by the Pollen Survey Committee of the American Academy of Allergy. (Author)

Prepared for the National Air Pollution Control Administration, Consumer Protection & Environmental Health Service, Department of Health, Education, and Welfare (Contract No. PH-22-68-25). Includes bibliographical references (pages 56-65). Microfiche.