The CDC is currently monitoring the occurrence of occupational respiratory disease and occupational lung disease in an effort to identify their cause and increase prevention of both.
There are many different diseases that can be caused by occupational irritants or substances. These include diseases of the respiratory units, diseases of the lungs and diseases of the airways. The skin (including eyes and nose) and lungs (including the airways leading to them) are the first organs to be exposed to environmental irritants. These organs are most susceptible to deposition of airborne particles. The lungs receive air via the trachea (or windpipe). The airways, which conduct air, are covered in cells with tiny projectiles called cilia. Mingled among these cells are mucus producing cells. The mucus producing cells work to cover the cilia creating a fluid barrier. The cilia cells then work in an undulating pattern to move forward in the airway and clear any dangerous dust or particles from the body. This is the body’s defense system that works to decrease the amount of dangerous substances in the body. The nose can also work as a filter to eliminate dangerous particles from entering and lodging in soft body tissue. The tiny cilia hairs protect the internal nasal passageways by trapping and filtering unwanted substances. The cilia move rhythmically to rid the nose and respiratory tract of foreign particles by pushing them toward the nostrils or pharynx. The particles are then either blown out through the nose or flushed through the body’s waste system.
Airborne particles come in many forms. They can be released as dust, vapors, gases or mists. These different forms are treated differently within the body. Vapors and gases can cause deprivation of oxygen to bodily tissues. They can also cause severe irritation to the airways and lungs and damage surrounding tissues. Dusts are the solid particles that can be found in the air while mists are liquid droplets that have become airborne. When either of these types of particles come into contact with an airway they begin the process of deposition. Gravity, airstream changes, collision with other particles and the general size and shape of the particle itself will determine when and where the particle will become deposited within the airway or lung. Some are immediately lodged into soft tissue while fluids carry other particles to surrounding tissue. Some of these particles are flushed out of the body through the body’s waste system. Others are filtered by special “scavenger cells” that render particles harmless. The mucus produced by cells in the body cover small particles and allows them to be coughed out. However, sometimes the body cannot fight off the harmful particles and disease develops.