Inhalation of dusts, fumes, and organic substances at the workplace can cause a number of pulmonary syndromes.1–4 The lung parenchyma and airways, as well as the pleura, can be affected by inhalation of foreign substances. This chapter discusses reactions of the large airways to inhalation of toxic substances present in the workplace. Lung parenchymal and pleural reactions, as well as obliterative bronchiolitis in response to inhaled materials, are discussed elsewhere in this text. Occupational airway disease can manifest itself as chronic bronchitis with variable airway hyperreactivity (industrial bronchitis or asthma-like syndrome), or with asthma accompanied by persistent hyperreactivity of the airways (occupational asthma). Some occupational exposures can cause both industrial bronchitis and asthma whereas others cause only one or the other. Cotton dust is the most common cause of industrial bronchitis without occupational asthma. Grain dust can cause both industrial bronchitis and asthma. In this chapter, general and specific issues regarding industrial bronchitis and occupational asthma are discussed.
Two important causes of industrial bronchitis - byssinosis and grain dust exposure - are discussed below.
Adverse pulmonary reactions in cotton workers have been recognized for more than 100 years. In 1831, Kay5 described chest tightness and fever that commonly occurred on Monday after workers had been off work over the weekend. It was because of this observation that the term Monday morning fever was coined. The term byssinosis was proposed by the French physician Proust6 and is derived from the Greek word meaning linen or fine flax. Over the years, as cotton mills appeared in more and more countries, the association of chronic bronchitis with cotton dust exposure was confirmed.
There is no doubt that recurrent exposure to cotton dust causes acute and chronic bronchitis. In a prospective study, 16% of cotton mill workers in South Carolina developed symptoms of chronic bronchitis,7 as compared to only 1% of appropriate controls in the region. A very recent study8 of textile workers in Pakistan confirmed this finding; 16.7% of workers complained of frequent cough and 26.6% of workers had frequent phlegm production. Another recent study of cotton textile workers in China9 found that the frequency of symptoms of byssinosis increased from 7.6% at baseline to 15.3% after 15 years of working in the textile mill. In this latter study, airway flow rates decreased significantly over time in textile workers when compared to silk workers. The appearance of symptoms during work or worsening of pulmonary function tests during the work shift predicted this accelerated loss of pulmonary function. The association between the length of time working in a textile mill and the onset of symptoms was also confirmed in the study from Pakistan.
Overall textile employment has dropped over the past few years but there are ...