More than 20 million U.S. workers are exposed to substances that can cause airway disease, according to NIOSH. Nearly 30 percent of chronic obstructive pulmonary disease (COPD) and adult asthma cases may be attributable to occupational exposure. Nearly nine million workers are occupationally-exposed to known sensitizers and irritants associated with asthma, according to NIOSH. Occupational asthma is now that most frequent occupational respiratory disease diagnosis among patients visiting occupational medical clinics. Many workers are unaware that pre-existing asthma may be worsened by the work environment.
Occupational agents such as coal dust, grain dust and cotton dust have been shown in studies to cause COPD. Investigations of particulate exposure in the general environment, where exposure levels are far lower than found in the workplace, suggest that COPD can result from generally dusty conditions. Workers with lung diseases from other causes are especially vulnerable to occupational respiratory hazards. Cigarettes are the primary cause of pulmonary disease in the U.S., but many occupational exposures both by themselves or in combination with smoking are known to cause COPD.