cleared by mucociliary actions, the less soluble amphibole fibers are more toxic and reach the deep part of the lungs (Bhandari et al., 2022; Lazarus & Philip, 2011). At-risk populations include individuals working in asbestos insulation environments, shipyards, asbestos textile works, mines, and mills (Suvatne & Browning, 2011); work- ers in the aerospace industry; bystanders exposed as electricians, masons, and painters; and community members exposed from road surfaces, playgrounds, landfills, and chemi- cal paints (Nations & Lazarus, 2011). Now that the use of asbestos is banned in many countries, community exposure to asbestos is becoming an issue of public health signifi- cance (Emmett, 2021). It is worth noting that banning the use of asbestos does not remove asbestos already present in communities and people could be exposed through various sce- narios and activities. The latency period for asbestosis, which is the time between initial exposure to asbestos and disease diagnosis, is critical for most occu- pational lung diseases (Huh et al., 2022). The latency period for asbestiosis is between 20 to 30 years (Lazarus & Philip, 2011) and an average of 40 years for most asbestos-related diseases such as asbestiosis and mesothe- lioma (Świątkowska et al., 2016; Teta et al., 2008). This latency period makes early diag- nosis challenging and underscores the impor- tance of protecting workers against exposure. Furthermore, in a review by Lanphear and Buncher (1992), disease resulting from expo- sure to asbestos had a median latency period of 32 years. This long latency period creates an additional health burden for workers as they advance in age, in addition to other age-related health challenges. Even with the ban and clo- sure of most asbestos-associated industries, workers still face the risk of asbestos-related diseases. Therefore, providing a medical examination to exposed workers would lead to early diagnoses and better management and outcomes (Świątkowska et al., 2016). Patients with asbestosis present clinically with symptoms such as progressive dyspnea on exertion, dry cough, and chest pain or tightness as the disease progresses. A physi- cal examination shows the presence of end- inspiratory crackles at the base of the lungs and reduced lung function test with severe fibrosis. Diagnosis is by evidence of pleural plaques and pulmonary fibrosis by radio-
TABLE 1
Occupational Exposure Limits for Common Respiratory Hazards
Hazard
Permissible Exposure Level 8-hr TWA: 0.1 f/cc 8-hr TWA: 50 μg/m 3
Action Level
Other Limits
Standard or Agency
Asbestos
Excursion limit: 1.0 f/cc per 30 min Employers in the construction industry can use Table 1 as outlined in 29 C.F.R. 1926.1153 using wet methods, time limits, and respirators
29 C.F.R. 1910.1001 29 C.F.R. 1926.1153 29 C.F.R. 1910.1053 29 C.F.R. 1910.1000
8-hr TWA: 25 μg/m 3
Silica
Coal dust
2.4 mg/m 3 SiO 2 + 2 (resp.)
Table Z-3: Mineral dusts (Occupational Safety and Health Administration, n.d.-a) Mine Safety and Health Administration
Respirable coal mine dust
1.5 mg/m 3
Cotton dust and operations
29 C.F.R. 1910.143
100 μg/m 3
Lint-free respirable cotton dust (e.g., yarn manufacturing, cotton washing operations) Lower-grade washed cotton (e.g., textile mill waste house operations, yarn manufacturing) Lint-free respirable cotton dust (i.e., slashing, weaving operations)
200 μg/m 3
250 μg/m 3
500 μg/m 3
375 μg/m 3
750 μg/m 3
Note. f/cc = fiber per cubic centimeter; resp. = respirable; SiO 2 = silica dioxide; TWA = time weighted average.
Methods We conducted an extensive literature search on the current information and knowledge on occupational lung disease, regulations, and strategies for protecting workers from exposure to hazardous materials and particles. Data from the Occupational Safety and Health Administration (OSHA) and Mine Safety and Health Administration (MSHA) for exposure limits are summarized in Table 1.
Results and Discussion
Asbestosis Asbestosis is a chronic interstitial lung condi- tion caused by prolonged exposure to high con- centrations of asbestos fibers (American Lung Association, 2024; Bhandari et al., 2022). The toxicity of asbestos depends on the category or form inhaled. While the more soluble serpen- tine fibers settle in the upper airways and are
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November 2024 • Journal of Environmental Health
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