Environmental and occupational exposures, which play a major role in many lung diseases as well other system disorders, are gaining increasing relevance in the modern-day industrialised and urbanised society. Air passages and skin are the primarily exposed systems to the external environment and it is natural for these two organs to bear the brunt of attack. Dr.Rajesh, reputed faculty and expert consultant in pulmonary and critical care in the Rajagiri Hospital, Kochi, explain the issue of occupational lung disorders and its treatment.
Passive exposure to tobacco smoke, automobile exhaust, construction-site chemicals and mining are important causes of environmental and occupational health hazard. A patient’s reported environmental exposures may prompt important interventions to prevent future illnesses or injuries, and work-related injuries or illnesses may require physicians to assess impairment, disability, and workers’ compensation. The situation is worsened by chemical or biological terrorism, as well as industrial disasters. This brief review attempts to narrate some of the commonly prevalent occupational lung diseases and possible preventive strategies that might be adopted.
Extent of Problem
The full extent of occupational injuries and illness is not clearly available and is difficult to measure. In the United States, the Bureau of Labour Statistics (BLS), which details statistics based on surveys of private companies, reported that there were 4,693 fatal work-related accidents (3.2 per 100,000) in 2012, and 3 million non-fatal injuries and illnesses, or 3.4 per 100 equivalent full-time workers. Over one-half of the cases reported were serious in nature that demanded days away from work, job transfer, or restricted duties at work. These figures probably underestimate the true incidence, given that many of the diseases and hazards go unreported. Similar data are lacking in our country, but given the huge population and lesser stress placed on diagnosing as well as reporting such diseases, the figures are bound to be enormous.
The intensity of the exposure is the most important factor in the development of occupational lung diseases. A doseresponse relationship between the exposure and incidence of occupational asthma has been conclusively demonstrated. Despite the known dose-response relationship, permissible exposure limits have not been established for many agents because it is unknown whether it is the intensity, duration, or cumulative dose of exposure that is most important. Intermittent short-term exposure to elevated levels of isocyanates may represent the greatest risk for the subsequent development of occupational asthma. All subjects with similar exposure intensity need not develop disease, and even those who develop do so with varying severity, thus implicating the multifactorial nature of disease causation. Genetic factors, exposure to multiple risk factors, concomitant effect of tobacco smoking, underlying lung health, etc., are determinants of the development and severity of disease in the exposed. The size of the exposed particles is the primary determinant of the site of lodging in the airway or alveoli and influence disease pattern. Particles less than 5 microns in size manage to pass to the alveoli and elicit inflammatory damage.
A variety of respiratory diseases has been implicated in the occupational setting. A detailed review of each of these may be beyond the scope of this article. The more common ones like occupational asthma, lung cancer, and asbestosis are discussed here.
(Read the full article from the November 2015 issue of Safety Messenger Magazine)