It’s that time of year when the desire to put out new plants and see the resulting color and blooms is strong. So it seems strange that there could be asbestos exposure in your garden, but there are asbestos-laden products that can lead to fatal diseases if inhaled.
Vermiculite in potting soil
Because vermiculite absorbs water, thus retaining moisture and also protecting plants from fungus, it has long been a staple ingredient in potting soil. However, prior to 1990, a significant vermiculite mine was operated near Libby, Montana, an area infamous for asbestos contaminated vermiculite.
The Environmental Protection Agency (EPA) tested 38 samples of vermiculite from across the US. Asbestos was found in 17 of the 38 samples. It was also found that the presence – or quantity – of asbestos varies significantly depending on 1) what portion of the bag was tested as the bags were not homogeneous, 2) the processing facility used since there are several dust removal techniques, and 3) the amount of asbestos in the vermiculite as it differs from one mine to another.
While the EPA considers the risks to consumers as minimal, they do acknowledge a concern about occupational exposures. It is known that there is no safe level of exposure to the mineral. Asbestos is still not banned in the United States and therefore, though the percentage of asbestos may be small, it can still kill.
The EPA recommends using other materials, such as peat, sawdust, perlite, or bark. Other recommendations include:
• Use it outdoors or in a well-ventilated area
• Keep the vermiculite damp during use to avoid creating dust
• Do not bring dust into the home on clothing
Be sure to shower thoroughly after use.
A greenhouse examined
Vermiculite, while the most ubiquitous source of gardening exposure to asbestos, is not the only source. Greenhouses can also lead to exposure.
The large Lord & Burnham Greenhouse North on the campus of Fargo’s North Dakota State University (NDSU) was surveyed for asbestos content in 2007. The original greenhouse was constructed in 1950 with additions through the years.
Many materials were found to contain asbestos, including transite panels (workbenches), window glazing, window caulk, transite ceiling panels, floor tiles and mastic, autoclave insulation, hard fittings on millboard, Aircell Pipe and fiberglass insulation, concrete pillar coating, and 11 other asbestos-containing materials (ACM).
This greenhouse is not the only one with asbestos, as most would contain the same materials. Many of the materials listed for the greenhouse can also be found in homes built prior to the early 1980s. Any remodeling can disturb asbestos fibers allowing them to be inhaled. Because asbestos-containing materials such as caulking, putty, and glaze are exposed to the outdoor elements, they do break down and can make them a danger for exposure. Getting a sample tested is the safe precaution.
The consequences of asbestos exposure
Because of the microscopic fibers that can enter lungs through inhalation, they offer the possibility for acquiring an asbestos-related disease such as lung cancer, asbestosis, or the fatal mesothelioma. Always take precautions when exposed to potential asbestos materials. It can take up to 50 years for the disease to appear, creating a shocking surprise to its victim. Be safe and take care; asbestos diseases are preventable with a few cautionary steps.