Gases and Vapors Affecting the Respiratory System

Abstract

Respiratory effects of gases and vapors are frequent, ranging from temporary discomfort to fatal responses. Acute high‐level exposures to directly toxic agents (e.g. phosgene and chlorine gas) may be fatal, and more prolonged exposure to lower levels of irritant gases is frequent and significant. Asphyxiants prevent oxygen utilization either by displacing oxygen from the ambient air or by chemically poisoning hemoglobin or the mitochondria. Work‐related asthma includes both occupational asthma (caused by work exposures) and work‐exacerbated asthma (preexisting asthma worsened by workplace factors). Irritants and allergens adversely affect the nasal mucosa and the larynx. Gas/vapor exposures contribute to chronic obstructive pulmonary disease (COPD). Bronchiolitis obliterans, a severe disease of the small airways, develops as a late consequence of acute high‐level exposure (e.g. sulfur dioxide releases) or from more prolonged exposure to moderate levels of certain chemicals, particularly in the flavoring industry. Gas/vapor exposure may lead to malignancies of the upper airway, larynx, and lung. Industrial accidents, natural events, and chemical terrorism/warfare can lead to mass casualties. Most respiratory system disorders due to gas/vapor exposures in workplaces are preventable. Control of exposures, respiratory personal protection equipment, preparedness for potential releases, and screening for early adverse effects are essential.