Allergen and irritant exposure and exposure-repsonse relationships.

Abstract

Exposure to allergens and irritants is a complex phenomenom. Especially the particulate nature of many natural allergens in combination with the low exposure creates remarkable phenomena. Many allergens appear to be potent sensitizers in the nanograms per cubic meter air range. Evidence exists that workers can be sensitized even after exposure to a low number of particles. With exposure in the low nanogram range, the repiratory tract is exposed to distinct exposure quanta of a few particles, which lead to high local concentrations of allergenic molecules. With gaseous exposure, a more equal exposure over the large surface area of the respiratory organ is to be expected. These phenomena may have mechanistic and biological implications, but certainly determine exposure assessment approaches, the interpretation of exposure measurements and the evaluation of exposure-response relation-ships.