Is asbestos exposure a health concern?

Is Asbestos a Health Concern?

Yes, asbestos exposure is a major health concern that has been the largest single cause of occupational cancer in the United States and continues to cause significant disease and disability worldwide. 1

Primary Health Risks

Asbestos exposure causes both malignant and nonmalignant diseases with devastating consequences for morbidity and mortality:

Malignant Diseases

• Lung cancer is the most common asbestos-related malignancy, causing more deaths than mesothelioma 2
• Malignant mesothelioma (pleural or peritoneal) has an extremely poor prognosis 3
• Additional cancers including colon, larynx, and possibly gastrointestinal malignancies show elevated risk 1
• Globally, an estimated 107,000 people die annually from lung cancer, malignant mesothelioma, and asbestosis due to occupational asbestos exposure 2

Nonmalignant Diseases

• Asbestosis (interstitial pulmonary fibrosis) generally progresses slowly but causes significant disability 3
• Pleural plaques and diffuse pleural thickening 1
• Benign pleural effusions 1
• Airflow obstruction 1

Critical Exposure Characteristics

No safe threshold for asbestos exposure has been established for lung cancer and mesothelioma. 2 The cancer risk increases with cumulative exposure, with increased risk even at low levels 2.

Dose-Response Relationship

• Asbestosis is commonly associated with prolonged exposure over 10-20 years 4
• However, short intense exposures lasting several months to 1 year can be sufficient to cause disease 4
• Even 1 month of employment in high-exposure environments resulted in 20% prevalence of parenchymal opacities 20 years after exposure ceased 4
• An estimated cumulative occupational exposure of just 1 fiber/mL-year substantially raises malignant mesothelioma risk 2

Current Populations at Risk

Despite bans in many developed countries, asbestos remains a hazard in four primary settings 1:

1. Historical legacy affecting older workers who had occupational exposure decades ago 1
2. Construction and building maintenance workers - an estimated 1.3 million workers in the U.S. construction industry remain at risk 1
3. Asbestos abatement operations involving removal and replacement of insulation 1
4. Renovation and demolition of structures containing asbestos 1

High-Risk Occupations

• Construction trades, boilermakers, shipyard workers, railroad workers, and U.S. Navy veterans 3
• Workers in building and equipment maintenance who encounter asbestos insulation 1
• Passive exposure through workers carrying asbestos home on clothing historically caused elevated cancer risk, particularly mesothelioma 1

Latency Period and Long-Term Risk

The latency period between exposure and disease manifestation is typically 20 years or more, creating an ongoing epidemic of asbestos-related illness. 1, 4

• Asbestosis becomes evident only after an appreciable latency period, often two decades 4
• Many countries are experiencing an epidemic of asbestos-related disorders as the legacy of occupational exposure from the 1960s-1980s 5
• A diagnosis of nonmalignant asbestos-related disease implies a lifelong elevated risk for asbestos-related cancer 1

Smoking Interaction - Critical Caveat

The interaction between smoking and asbestos exposure substantially enhances lung cancer risk in a supra-additive manner. 1, 4 This makes smoking cessation absolutely essential for anyone with asbestos exposure 1, 3.

• Asbestos workers who cease smoking experience a dramatic drop in lung cancer risk, approaching that of nonsmokers after 30 years 2

Surveillance Recommendations

For persons with documented asbestos exposure 1, 4:

• Begin monitoring when time since initial exposure reaches 10 years 4
• Obtain baseline high-quality chest radiograph, spirometry, and single-breath diffusing capacity 1
• Continue monitoring with chest films and pulmonary function studies every 3-5 years 1, 4
• Administer influenza and pneumococcal vaccinations to patients with asbestosis or lung cancer 3

Public Health Context

While the general public faces negligible risk from environmental asbestos exposure (such as living in buildings containing sprayed asbestos) 6, occupational exposure remains a critical concern. Asbestos usage continues in many developing countries, and asbestos-related mortality and morbidity will likely continue to increase globally 5.