Have you ever wondered how dust exposure has impacted workers throughout history? Dust may seem a minor inconvenience today, but it has played a significant role in occupational health over the centuries. From ancient times to the modern era, understanding the historical context of dust exposure can help us appreciate the advancements in industrial hygiene and the importance of maintaining safe work environments.
In this post, we’ll take a fascinating journey through the history of dust exposure, exploring how it has been managed (or mismanaged) across different eras. We’ll delve into the health impacts workers have faced, the evolution of safety practices, and the lessons learned along the way. By the end, you’ll have a deeper appreciation for the progress made in protecting workers and the ongoing efforts to ensure safe and healthy workplaces.
What You’ll Learn
- Historical Impact of Dust Exposure: Discover how dust exposure has affected workers throughout history and the health challenges they faced.
- Evolution of Safety Practices: Learn about the development of industrial hygiene practices and how they have evolved to protect workers better.
- Lessons from the Past: Gain valuable insights from historical experiences that can inform and improve current dust management strategies.
Introduction
Airborne contaminants exist in several states. Dust (or particulate matter) is a broad category that describes solid particles suspended in the air. They may be mechanically or thermally generated and can affect different parts of the body.
Some inhaled dust is removed from the body, although a fraction will remain in the lungs without inducing a biological reaction. These are called nuisance dust, and their risk presents more as minor irritation or affecting vision. However, exposure to other dust can lead to chronic lung disorders such as lung cancer, silicosis, and bronchitis.
Looking Back in History
Dust-related diseases and ill health can be traced back to ancient times. Hippocrates identified that inhaled dust could affect health. From here, Charles Thackrah called attention to the effect of exposure to cotton and flax in the nineteenth century.
Coal mining in all countries has been associated with dusty lung disease, also known as coalworkers’ pneumoconiosis or black lung, a progressive fibrosis of the lung. The term pneumoconiosis is derived from Friedrich Albert von Zenker’s use of the term ‘pneumono koniosis’ in 1866. Its application is now restricted to those diseases where silica has some implications.
Mining, quarrying, and tunneling through rock high in quartz containing free silica content have led to silicosis. Silicosis was usually accompanied by tuberculosis. In the 1930s, silicosis had reached epidemic proportions amongst miners in gold-producing regions in Canada due to the amount of dust being generated in underground mines from drilling, blasting, and digging into lower-grade hard-rock ore bodies with high silica content (Jorgenson & Sandlos, 2021).
Stonemasons and those in the granite and stone carving industry often developed respiratory diseases. The consequence of exposure to asbestos dust is showing its full effects after latency periods of 30 to 50 years. For instance, in Italy, mortality from pleural mesothelioma continues to rise, despite asbestos being banned in 1992 (Oddone et al., 2020).
Even now, workers are exposed to dust and fibers such as sensitizing wood dust, synthetic mineral fibers, organic dust from the rural industry, and crystalline silica. Even exposure to soft paper dust from a soft tissue paper mill has been reported to cause lung function impairment (Andersson et al., 2020).
Some Definitions
From an industrial hygiene perspective, solid particles are generally categorized as dust, fiber, or fume.
- Dust is a mixture of solid materials of varying sizes. Particles usually range from 0.1 to 30 microns. Examples include cotton dust from cotton milling and wood dust from sawmilling.
- Fiber is a solid, thread-like filament with a defined length-to-width ratio. This includes asbestos, fiberglass, rock wool, and ceramic fibers.
- A fume is generated when a solid is heated until the gas is released. The gas recondenses into minute solid or liquid particles.
Dust
Dust can be described in terms of its physiological effect or the size distribution of the dust cloud. Fibrotic or fibrinogenic dust penetrates into the alveolar region of the lung and damages these cells, causing scarring or fibrosis. Fibrotic dust elicits this action deep in the lung because of its exceptionally small size and, in some cases, its composition (e.g., free silica).
This is why fibrotic dust is respirable, meaning it enters the respiratory zone of the lungs. Some examples of fibrotic dust include asbestos and crystalline silica, such as quartz or cristobalite.
Toxic dust affects the lungs or other body systems. These outcomes might be an immunological response (e.g., exposure to sensitizing wood like western red cedar or organic dust) or a direct effect on an organ or system (e.g., slaked lime, calcium hydroxide, burning the skin, or eyes).
Size Distributions of Dust
Occupational dust is classified according to its size and chemical composition. Dust clouds do not exist uniquely as one size but as a range of compositions. This is called the size distribution. There are three size distributions of occupational significance:
- Respirable dust
- Inspirable (inhalable) dust
- Total dust.
Respirable dust consists of tiny particles that can penetrate into the alveolar region of the lung and show an effect here. This includes:
- Crystalline silica (e.g., quartz, cristobalite, tridymite) generated during quarrying, mining, or sandblasting
- Asbestos (e.g., chrysotile, crocidolite, amosite) is used in brake linings, textiles, and lagging due to its thermal insulation properties
- Vanadium dust or fume, resulting from use as an alloy for strengthened steel and more recently in trial tests of vanadium batteries
Inspirable (inhalable) dust includes examples such as:
- Birch of beech timber used for housing construction and finishing
- Cement dust from cement plants (Adeyanju & Okeke, 2019) and concreting work
- Metal dust, such as zinc oxide from grinding galvanized steel.
Total dust has little industrial hygiene significance and should not be monitored in the workplace except where the distribution of the dust cloud is sought.
Summary
Dust and particulate are industrial hygiene hazards that may risk workers’ health. They are categorized according to their aerodynamic equivalent diameter and are known as either respirable or inspirable (inhalable) dust. Different air sampling techniques are used for respirable and inspirable dust.
Helpful Resources
- 5 Types of Industrial Dust Blog Post, by Megan Tranter
- Basics of Industrial Hygiene, by Debra Nims
Bibliography
Adeyanju, E., & Okeke, C. A. (2019). Exposure effect to cement dust pollution: a mini review. SN Applied Sciences, 1, 1572. https://link.springer.com/article/10.1007/s42452-019-1583-0
Andersson, E., Sällsten, G., Lohman, S., Neitzel, R., & Torén, K. (2020). Lung function and paper dust exposure among workers in a soft tissue paper mill. International Archives of Occupational and Environmental Health, 93, 105-110. https://link.springer.com/article/10.1007/s00420-019-01469-6
Jorgenson, M., & Sandlos, J. (2021, March). Dust versus Dust: Aluminum Therapy and Silicosis in the Canadian and Global Mining Industries. Canadian Historical Review, 102(1), 1-26. https://utpjournals.press/doi/abs/10.3138/chr-2019-0049
Oddone, E., Bollon, J., Rubina Nava, C., Bugani, M., Consonni, D., Marinaccio, A., Magnani, C., & Barone-Adesi, F. (2020). Predictions of Mortality from Pleural Mesothelioma in Italy After the Ban of Asbestos Use. International Journal of Environmental Research and Public Health, 17(2), 607. https://www.mdpi.com/1660-4601/17/2/607
