Non-Occupational Exposure to Asbestos
Although mesothelioma results primarily from occupational exposure, there are instances of patients developing the disease even though they weren’t employed in jobs that exposed them to asbestos.
Levels of asbestos fibers are always present in the ambient air that is the air that is all around us that we normally breathe. Some studies have shown that on average, the level of asbestos fibers can be as high as 0.005 fibers per cubic centimeter in urban areas. Fiber levels tend to be lower in the suburbs, generally between 0.003 to 0.004 fibers per cubic centimeter.
Studying Non-Occupational Exposure helps Researchers Understand the Nature of Mesothelioma
It is just as important to study non-occupational exposure to asbestos as it is to study worker exposure because mesothelioma cases that result from non-occupational exposure actually give researchers a clearer picture of what amount of fibers produces a response, meaning development of the disease. That’s because work exposure-induced mesothelioma develops when the patient is an adult and has been around an especially high concentration of fibers. Also, the majority of these workers are male. In order for researchers to understand how the disease affects both sexes and at what exposure level, they have to study non-work related cases of mesothelioma.
Scientists are very interested in observing what happens when individuals are exposed to natural sources of asbestos because the exposure can start during childhood and continue throughout the person’s lifetime, and it can occur 24 hours a day, seven days a week. The evidence that results from these observations provides data about the way in which early exposure affects cancer risk, how both sexes are affected by exposure, and whether or not different types of asbestos fibers have different effects on individuals.
How are Individuals Non-Occupationally Exposed to Asbestos?
There are a number of ways an individual can be exposed to air that contains asbestos fibers:
- Mining- Mine workers aren’t the only ones exposed to asbestos fibers. People who live near mining or manufacturing locations that are associated with material that contains tremolite asbestos may be exposed to high levels of asbestos in the air they breathe.
Building Materials – There are a number of different types of building
materials, such as insulation, ceiling or floor tiles, and cement pipes
that contain amphibole asbestos. Many buildings constructed before 1981
are assumed to have been built using these asbestos containing materials.
Homeowners that do maintenance, repair, or remodeling work on houses containing these products have the possibility of being exposed to high amphibole levels. The exposure occurs when the asbestos-containing materials are moved, causing them to release fibers into the air. If the materials remain untouched, the exposure level is minimal.
- Gardening Supplies – The majority of the vermiculite supply came from Libby, Montana, which had a natural deposit of asbestos. This meant that the vermiculite was contaminated with asbestos. The contaminated vermiculite that was sold in gardening supply stores was used to improve the quality of soil or as a fertilizer carrier. It was also a component in potting soil mixtures. The Libby mine closed in 1990, so the current vermiculite supply is assumed not to be contaminated.