Asbestos Exposure in Landscapers and Groundskeepers

If you worked in landscaping, grounds maintenance, nursery work, or gardening, or someone in your family did, and an asbestos diagnosis has come in, you may be wondering how outdoor work could be connected. This page explains the ways landscapers can meet asbestos, how serious each one is, and what to do next.

For most landscapers, asbestos exposure is lower than in building trades like insulation or pipefitting, but it is not zero. Asbestos occurs naturally in some rock and soil, it was mixed into some older garden products, and pieces of old asbestos building materials are sometimes found in the ground. Digging, grading, tilling, and mowing over these materials can put fibers in the air.

Some landscapers also did other work over the years, such as construction, demolition, or building maintenance. Those jobs often carry clearer asbestos exposure, and we look at your whole working life.

Naturally occurring asbestos in soil and rock

Asbestos is a group of natural minerals. Where they are found in the ground, they are called naturally occurring asbestos, or NOA. See our page on asbestos minerals.

Where it is found. The U.S. Geological Survey has published maps of reported natural asbestos occurrences, with more than 300 in the eastern United States alone and others across the central and western states. California has the best-known deposits. Serpentine is California's state rock. A University of California guide reports more than 1,988 square miles of serpentinite outcrops in 42 of the state's 58 counties, especially in the Coast Ranges, the Klamath Mountains, and the Sierra foothills. It notes that most serpentinite contains naturally occurring asbestos or asbestos-like fibers, most often chrysotile, and that the health risk from these fibers in soil is unclear.

How landscape work disturbs it. The same guide explains that soil normally binds asbestos fibers into larger clumps that are hard to breathe in. Work that breaks up dry soil or exposes the rock underneath can release them. It lists rototilling, digging, jackhammering, grading, and plowing as activities to avoid when serpentine soil is dry and dusty.

El Dorado Hills, California. In October 2004, the U.S. Environmental Protection Agency simulated everyday outdoor activities in El Dorado Hills, including sports, playground play, and work in a school garden, and measured the air people breathed. In results released in May 2005, EPA reported finding asbestos fibers in almost all of more than 450 air and soil samples, mostly amphibole asbestos (tremolite and actinolite types), and found that people doing the activities breathed more asbestos than the nearby background air showed. An industry-funded consultant argued that most of the particles were not true asbestos. EPA rejected that review in 2006, and EPA said the long-term health risk could not be measured exactly.

Road gravel and fill. In Alaska, a road project used local gravel that turned out to contain asbestos. Of almost 700 air samples taken on workers, 3% were at or near the federal exposure limit, and the highest exposures were among workers such as grader operators who ground or spread the material (Perkins et al., 2008). The authors judged worker exposures measurable but low overall. Landscapers who spread crushed rock from asbestos-bearing areas could face a similar kind of exposure, usually on a smaller scale. In 2000 the California Air Resources Board barred the use of asbestos-containing serpentine rock for surfacing, including landscaping.

What this means for health. A study of mesothelioma cases in California found that the odds of mesothelioma fell by about 6% for every 10 kilometers farther a person lived from rock formations likely to contain natural asbestos, after accounting for job exposure (Pan et al., 2005). The link was clear in men but not in women. That study looked at where people lived, not at landscapers specifically. Research on natural asbestos and disease is still developing.

Vermiculite garden products

Vermiculite is a mineral that puffs up when heated. Gardeners use it to loosen soil and hold water.

• The Libby connection. EPA reports that a mine near Libby, Montana, was the source of over 70% of all vermiculite sold in the United States from 1919 to 1990, and that the vermiculite from Libby was contaminated with asbestos. See Libby Vermiculite and Zonolite.
• Sold for gardening. The federal Agency for Toxic Substances and Disease Registry (ATSDR) says vermiculite was commonly sold in gardening and hardware stores as a soil amendment, a fertilizer carrier, and an ingredient in many potting soil mixes.
• What EPA found in 2000. EPA tested 54 vermiculite garden products. Six had asbestos at a level that could pose a potential for exposure, and all five such products in the nationwide phase were straight vermiculite rather than premixed soil. EPA said the levels found did not pose a significant risk to home gardeners, but that the results raised questions about the risk to workers who use vermiculite products regularly.
• Newer products. ATSDR noted in 2003 that because the Libby mine closed in 1990, newer products are not expected to contain significant asbestos.

That concern applies most to people such as nursery, greenhouse, and landscape workers who regularly handled straight vermiculite. Older products made from Libby ore are the main concern, since newer products are not expected to contain significant asbestos.

Old asbestos debris in the ground

Older properties sometimes have pieces of asbestos-cement siding, sheeting, roofing, or pipe in the soil, left from demolition, poor construction cleanup, or dumping. Western Australia's Department of Health, which has detailed guidance on this, notes that bonded asbestos-cement fragments in soil normally present a very low public health risk, because the fibers stay locked in the cement unless it is badly damaged or weathered. It also warns that pieces should be removed promptly if they could be broken up by traffic or lawn mowers.

Mowing, trenching, and tilling can break these pieces up. A landscaper who regularly works old sites may run into them more often than a homeowner.

Who else is exposed

• Families at home. Dust can come home on shoes, clothing, tools, and pets. The University of California guide advises washing exposed clothing separately and cleaning shoes before going indoors. See take-home asbestos exposure.
• Neighbors and residents in areas with natural asbestos, especially when soil is dry and being disturbed.
• Road, grading, and construction crews who move rock and soil. See carpenters and construction workers.

The diseases

Asbestos diseases usually appear decades after exposure. That delay is called latency.

• Mesothelioma, a cancer of the lining of the lungs or abdomen. Asbestos causes most, but not all, mesothelioma. See mesothelioma.
• Lung cancer, where smoking is the leading cause and asbestos adds to the risk. See asbestos lung cancer.
• Asbestosis, lung scarring that generally follows heavier exposure. See asbestosis.
• Pleural plaques, markers of past exposure. See pleural plaques and thickening.

Protection today

The University of California and EPA guidance points to simple steps that cut exposure:

• Keep soil and vermiculite damp. Wet material releases far less dust.
• Avoid dry digging, tilling, and grading on serpentine soils, and cover bare serpentine soil with 3 to 6 inches of mulch or clean soil.
• Use premixed potting soil, or alternatives such as peat, perlite, sawdust, or bark, instead of straight vermiculite. Mix outdoors or in a well-ventilated area.
• Do not break up suspect fragments. If you find possible asbestos-cement in soil, wet it, bag it, and follow local rules for disposal, or call a licensed contractor for larger amounts.
• Keep dust out of the house and truck. Clean shoes and wash work clothes separately.

How landscaper asbestos claims work

We want to be direct about this. Claims for landscapers depend heavily on the source of the asbestos.

• Contaminated products. If the exposure came from a product, such as asbestos-contaminated vermiculite, the company that made or sold it may be responsible. W. R. Grace, which owned the Libby mine and sold Zonolite products, went through bankruptcy, and asbestos personal injury claims against it are paid by the WRG Asbestos PI Trust. See how asbestos trust claims work.
• Natural asbestos. When the only source is natural rock and soil, there is often no product maker to hold responsible. In some situations a property owner or a company that mined or supplied asbestos-bearing rock may be. These cases are fact-specific.
• Other jobs. Some people who did landscaping also worked in construction, demolition, maintenance, or the military at some point. Those jobs may support bankruptcy trust claims or lawsuits against product makers. See mesothelioma lawsuits.

Who may have a claim: a worker diagnosed with an asbestos disease, a family member exposed through the worker's clothing, or the family of a worker who has died, through a wrongful death claim where state law allows.

We reconstruct the product exposure. We ask where you worked, what products you used, and what other jobs you held, and we match that history to the products and sites known to involve asbestos. This is called product identification. If we do not see a claim, we will say so.

If you have not been diagnosed but are concerned, our free screening is a chest X-ray read by a B-reader, with a CT scan if needed. It looks for asbestos changes in the lungs. It is not a test for mesothelioma. See our free asbestos health test.