varied exposure to environmental lung stresses—occupational and non-occupational—including cigarette smoke, air pollution, various allergens, and occupational gases, fibers, and particulates. The role of cardiac and other nonpulmonary systemic conditions is also important is assessing lung function. A large number of specific occupational lung diseases have been documented; they are beyond the scope of this report. In addition, the aging lung is susceptible to increasing risk of infection, due at least in part to structural and immune alterations, increasing the importance of immunization programs for older workers and others (Petty, 1998). Less clearly understood is the impact of ongoing pulmonary occupational exposures on existing or developing lung conditions such as chronic obstructive pulmonary disease and emphysema, and the effect of well-established occupational pulmonary pathogens when exposure begins at a later age. These exposures and related medical conditions may have an effect on general human function and hence on work capacity. The net impact on the older worker will depend on the job demands and environment, as well as on individual clinical illnesses or disorders, exercise, and other hygienic habits.
Bone anatomy and function are not often related to occupational conditions and the older worker, but they have an important role. For example, bone may be a repository for occupational exposures, such as heavy metals and certain chemicals. Synergy of bone structure with marrow activity may be important for immune and hematological status (Compston, 2002). Older persons have decreasing bone density and increased rates of traumatic fractures; this is particularly more common among postmenopausal women than in men (Riggs, 2002), but fracture rates also vary by ethnicity and other risk factors. Lower bone density may be a risk factor for degenerative arthritis (Sowers, 2001), the leading cause of disability among older persons within industrialized countries. Poor quality maxillary and mandibular bone may lead to the need for more dental prostheses and may contribute to poorer nutritional status, leading to other health problems (Bryant and Zarb, 2002).
In job situations where the risk of falls and other unintentional injury is high, older workers will likely sustain more fractures for a given amount of trauma, due to age-related increases in bone fragility and architectural changes (Seeman, 2002). Several approaches to preventing age-related osteoporosis, other bone loss, and fractures are possible, including increasing calcium and vitamin D intake, maintaining an active exercise program, and screening and treatment for osteoporosis. The emphasis on bone health is not often prominent in worker health promotion programs, but with an increasing number of older workers, this may become more important.