Pulmonary alterations associated with inhalation of occupational and environmental irritants

Many gases, vapors, or particles found in occupational and/or environmental settings can act as irritants. In the present study, sensory irritants are characterized by the stimulation of neuropeptide release from sensory nerves in the nasal mucosa, while pulmonary irritants are characterized by recruitment of PMN into bronchoalveolar airspaces, elevation of breathing frequency, and neuropeptide release from sensory fibers innervating the epithelium of the conducting airways. A review of data from our laboratory as well as results from others indicate that asphalt fume is a sensory irritant; toluene diisocyanate (TDI), methyl isocyanate, and machining fluid act as both sensory and pulmonary irritants; while cotton dust, agricultural dusts, microbial products, leather conditioner, and ozone exhibit responses characteristic of pulmonary irritants.