Mesothelioma Center Presentation Recap: Farmworkers and Asbestos


As part of The Mesothelioma Center’s ongoing Community Partnership Program, I recently presented information to Michigan state and federal agency members regarding asbestos exposure risks for farm workers.

The Michigan Department of Health and Human Services represents agricultural interests that provide services to migrant and seasonal farmworkers, nonprofits and educational institutions, research groups and representatives of grower interests.

It was the perfect opportunity to spread awareness of asbestos products and exposure risks plaguing agricultural workers across the U.S.

Sources of Agricultural Asbestos Exposure

Asbestos exposure risks present themselves in many forms, both artificially and naturally. Asbestos remains hidden in older farming equipment, buildings and even soil. Farmers risk exposure that could lead to deadly mesothelioma cancer without proper training and awareness. 

There are six naturally occurring minerals that scientists classify as asbestos. They belong to two main categories: amphibole and serpentine. 

Amphibole asbestos is straight and needle-like with jagged edges. Serpentine asbestos is curly and consists of chrysotile-type asbestos, also known as “white asbestos.” These fibers were used in manufacturing thousands of products throughout the 20th century due to their resistance to heat, electricity and corrosion. 

One of the main concerns regarding asbestos exposure is its tendency to contaminate other minerals in proximity. Vermiculite is a natural mineral that is not dangerous to human health in its pure form. However, asbestos has contaminated vermiculite used in potting soils, fireproofing materials and brake linings. 

Contaminated vermiculite products include:

  • Animal feed
  • Fertilizer
  • Pesticides
  • Potting mix
  • Root cuttings
  • Seed encapsulation
  • Seed germination
  • Soil conditioner
  • Sowing composts

Because asbestos was so prominent in older buildings and machinery, there are many hidden sources of asbestos exposure, including naturally formed asbestos in the soil.

Other sources of asbestos exposure include:

  • Animal husbandry
  • Contaminated soil in areas of naturally occurring asbestos
  • Digging up asbestos-laden soil
  • Machinery parts
  • Aftermarket brakes, brake linings and gaskets
  • Older farm buildings
  • Secondary exposure

Naturally occurring asbestos is prominent in areas with a mining history, such as Michigan, Washington, Nevada, Arizona and California. 

Asbestos in Farming Equipment and Machinery

Asbestos was particularly useful in farming equipment because it provided insulation and protection from fire. Manufacturers used asbestos in gaskets to prevent fires, as a spray-on coating for insulation and in clutches used on tractors. 

Asbestos-containing insulation panels and hood liners were applied near engines and between seats and heat sources to retain heat. Brakes and brake linings used in tractors and other equipment may still contain asbestos, even new products.

As with residential homes built before the 1980s, asbestos was a standard construction material. On older farms, asbestos may still be present in residential and farming structures. 

Farm building materials that may contain asbestos include:

  • Building Partitions: Walls and partitions inside farm structures were made of asbestos to limit fire damage.
  • Cement: Many products, including roofing materials, historically incorporated asbestos cement. For example, Leekproof Asbestos Plastic Roof Cement was marketed to farmers as a patching material and roofing adhesive.
  • Roofing Sheets: Corrugated asbestos cement sheets were used as a roofing material on various farm buildings.
  • Shingles: Asbestos cement shingles were used on farmhouse roofs to prevent fire damage.
  • Siding: Asbestos cement siding was applied to the sides of farmhouses and other farm buildings.

Many prominent manufacturers of asbestos products for home goods and residential construction also produced asbestos-containing products for farmers. These manufacturers include:

  • Dana Corporation: Dana manufactured asbestos-containing automotive parts. It sold asbestos gaskets to John Deere for use on tractors.
  • DeWitt Products: DeWitt made Liquid Asbestos Roof Coating, and the product label recommended it for use on barns.
  • John Deere: John Deere used asbestos parts on its tractors, including asbestos gaskets and brakes. The company never manufactured asbestos products. It outsourced them to other companies and installed them during the manufacturing process.
  • W.R. Grace: Grace’s Zonolite brand of vermiculite products was used by farmers for horticultural and insulation purposes.
  • Johns Manville: JM made a wide range of asbestos products used in farm buildings, including corrugated transite cement siding and roofing, insulation materials, wallboard and shingles. Old advertising materials show that JM directly marketed its asbestos building products to farmers as inexpensive and reliable construction materials. JM also made asbestos brake linings and clutch facings for farm tractors.
  • Midwest Products of Illinois: This company made Leekproof Asbestos Plastic Roof Cement and marketed it directly to farmers.

Knowing the sources of asbestos exposure can significantly reduce the risk of developing an asbestos-related illness. 

Avoiding and Preventing Asbestos Exposure

The best way to prevent asbestos exposure is to be aware of the risks and avoid direct contact. Be wary of older buildings, equipment and vehicles. Although most asbestos manufacturing ended in the late 1980s, many older building products and farming equipment still contain asbestos.

Never try to remove asbestos on your own. Most types of asbestos are friable and break easily when disturbed. Instead, consult an asbestos abatement specialist who can perform testing and safely remove asbestos.

If you’re aware of asbestos in your work environment, wear appropriate protective clothing such as boots, coveralls and gloves. Only properly fitted NIOSH-approved N100 or P100 respirators can protect against airborne asbestos fibers. 

You can wet or cover asbestos-related debris to minimize dust if there is friable asbestos in your environment. If you’ve been exposed to asbestos, get in touch with your doctor as soon as possible. They can update your medical history in case you develop symptoms later.

It’s also essential to consider secondary asbestos exposure as a risk to others besides yourself. Secondary exposure occurs when workers carry asbestos fibers on their bodies, clothes, hair or equipment. You can avoid secondary exposure by thoroughly showering and washing after being in an area with asbestos to remove any dust and fibers that could become airborne.

It is recommended to properly dispose of your clothes or wear disposable coveralls when handling asbestos materials. Never wash clothes covered in asbestos dust because tiny fibers interwoven into the fabric can lead to exposure for you and your family.

Secondary asbestos exposure is just as dangerous as primary exposure. Any amount of asbestos exposure can cause serious health problems. Repeat, long-term secondary exposure causes the same diseases and cancers as direct exposure, including mesothelioma.

Asbestos-Related Illnesses and Treatment

The most common asbestos-related disease is mesothelioma. Mesothelioma cancer is characterized by malignant tumors that develop in the mesothelium, a layer of protective tissue that covers several organs in the chest and abdomen.

Pleural mesothelioma develops in the protective lining around the lungs and accounts for 75% of all mesothelioma cases. Signs of asbestos exposure usually include pleural thickening or scarring.

Peritoneal mesothelioma forms in the abdomen and accounts for 10% to 20% of all cases.

The average life expectancy after diagnosis is about one year for pleural mesothelioma and around five years for peritoneal mesothelioma.

Common pleural mesothelioma symptoms include dry cough, shortness of breath, chest pain, fever and fatigue. Misdiagnosis is frequent due to mild or vague symptoms.

Symptoms can take 20 to 60 years to develop, making diagnosis difficult before cancer reaches later stages. Symptoms of mesothelioma are treatable, but the cancer is incurable.

Important Considerations Regarding Mesothelioma Treatment

  • If you have a known history of asbestos exposure, inform your doctor or health care provider so they can perform diagnostic tests for an earlier asbestos disease diagnosis.
  • After a diagnosis, obtaining a second opinion with a mesothelioma specialist provides the best access to more treatment options, including experimental clinical trial therapies.
  • Treatment options such as surgery, chemotherapy, radiation and immunotherapy have helped patients live for years after their diagnoses.
  • Surgery is beneficial for patients with early disease. Other treatments, such as chemotherapy, immunotherapy and radiation, can add several months to survival.

Asbestos is also a direct cause of lung cancer which, unlike mesothelioma, develops directly within the lungs. Smoking exponentially increases this risk. Asbestosis is a chronic respiratory illness like pulmonary fibrosis that is also caused by asbestos exposure.

Research has linked asbestos exposure with laryngeal and ovarian cancer. Noncancerous asbestos diseases include effusions (fluid buildup), inflammation and thickening of the pleura, atelectasis and COPD.

Resources and Support for Farmers Exposed to Asbestos

Research is uncovering new ways to diagnose and treat asbestos-related illnesses every day. Clinical research trials provide access to the latest treatments at reduced costs. 

Farmers diagnosed with an asbestos illness also have access to financial support through government assistance programs, charity networks or asbestos-specific legal compensation. 

Caregiver and family support groups and resources are also available to help deal with the complexities of treatment and grief after losing a loved one. 

With increased awareness of how asbestos impacts farmers and agricultural workers, we can lower the rate of mesothelioma and asbestos-related diseases. 

Thanks to efforts such as those of the Michigan Department of Health and Human Services and The Mesothelioma Center’s Community Partnership Program, we can shine a light on asbestos risks by taking that step to raise awareness and save lives through education.