epidemiology mesothelioma

Understanding Mesothelioma

Mesothelioma is a rare type of cancer caused by asbestos exposure that affects the lining surrounding internal organs in the body. There are three types of mesothelioma. The most common, accounting for about 70% of cases, is pleural mesothelioma that affects the lining surrounding the lungs and internal chest cavity. Mesothelioma can also affect the peritoneum (the lining of the abdominal cavity) and the pericardium (the lining surrounding the heart). 

Mesothelioma is not lung cancer. Lung cancer affects the inside of the actual lung, while mesothelioma affects the lining that surrounds the lungs or other internal organs. Mesothelioma is caused by exposure to asbestos, a naturally occurring compound that was used in many construction materials and consumer products in the 1940s through 1970s. People may have been exposed to asbestos at work, during military service, at home, and at school. 

Symptoms of mesothelioma are similar to those presented from other more common diseases and may not appear until decades after exposure. If you know you have been exposed to asbestos and are experiencing symptoms, seek medical care and tell your doctor about your asbestos exposure. Your doctor will conduct physical exams and tests to rule out more common illnesses like tuberculosis, and will not diagnose mesothelioma until biopsy results and pathology reports conclusively show the cancer. Treatment options will be discussed and determined with you.

living with mesothelioma

Job Discrimination Protection for Cancer Patients

The Family and Medical Leave Act (FMLA) and the Americans with Disabilities Act (ADA) offer protection against discrimination on the job. You are protected against discrimination from your employer under the Americans with Disabilities Act. The act also emphasizes that, if necessary, you should be provided “reasonable accommodations” in order to continue with your job.

Under the Family and Medical Leave Act, you are allowed to take unpaid leaves of up to 12 weeks without losing your job in case of a serious medical condition. Apart from this, your state may have specific laws to protect against employment discrimination.

For queries related to your specific situation, you need to talk to someone in your organization’s human resources (HR) department. In case your organization does not have an HR department, you can consult a lawyer about your concerns or contact the local chapter of the American Cancer Society.

At times, people with cancer find it difficult to deal with co-workers who may be prejudiced against cancer patients. These co-workers may have false beliefs such as cancer patients vomit 24 hours, a cancer diagnosis implies sure death, or it may be contagious and any contact with the person with cancer should be avoided. Some individuals also fear that chemotherapy make cancer patients shed type of sweat, urine or stool. These individuals may avoid shaking hands with you or sharing the same bathroom. There was an incident wherein an employer had asked an young patient (an employee) to use a different bathroom. The primary reason for these false beliefs is that most people do not have much knowledge on cancer.

However, there have also been co-workers who have demonstrated unbelievable support such as arranging transportation, accompanying the patient to the health center, helping with cooking, and even preparing cooking for the doctors and nurses. These individuals are just co-workers and not friends or family members. Some patients who possess dynamic personalities have organized lunch meetings in order to discuss their experiences with cancer, talk about their plans and try to clear up prejudices.

Apart from coping up with their diagnosis, side effects of treatments such as chemotherapy, the changes occurring in the family and social life, and financial strain, cancer patients should also think about the possibility of losing their job and the security that comes with it.

Your cancer diagnosis may confirm to the definition of disability, as provided by the Americans with Disabilities Act (ADA). A federal law, the ADA provides protection against discrimination based on any type of disability in the workforce. The law has described “disability” as a physical or mental impairment which significantly restricts one or more basic life activities, a proper record of such an impairment, or considered to have such an impairment.

Explicit conditions and ailments have not been defined, but cancer is normally considered a disability in case the disease itself or the treatment side effects limit your ability to perform basic life activities, for instance, walking, caring for yourself, concentrating, or interacting with others.

Cancer survivors who may be experiencing long-term effects of cancer or its treatment, for instance severe depression, loss of cognitive function or fatigue can also be considered to have a disability. However, cancer may not be treated as a disability in case the effects are not long-term or permanent.

There are a lot of alternative options that employees with serious health complication can use. These include short and long-term disability insurance, the Family and Medical Leave Act and variable work schedules. The HR department in your organization can provide you additional information or help you in obtaining the necessary accommodations you may need. To know more about the Americans with Disabilities Act, you can call the ADA Information Line at 1-800-514-0301.

epidemiology mesothelioma

Cancer Clusters

When beginning to learn about cancer clusters it is important to know the facts about cancer itself.  Cancer is the growth and spread of abnormal cells in the body and if left untreated it can often result in death.  There are more than 100 types of the disease and it can attack any part of the body.  

One out of every four adult deaths in the United States can be traced to some form of cancer and according to the National Institute of Health over 1,437,180 new cases of cancer are projected to occur in the United States in 2008. 

Cancer is the leading cause of death in children between the ages of one and 14 and more than 8,000 new cases are expected to be diagnosed this year.   

The most common forms of cancer affecting men are lung, stomach, liver, colorectal and esophagus.  The most common cancers faced by women are breast, lung, stomach, liver, colorectal and cervical.   

Tobacco smoke is the leading cause of cancer and is the single most preventable cause of the disease in the world.  It is estimated that over 30% of all cancer could be avoided by not smoking, eating a healthy diet and participating in daily exercise.   

Early detection and treatment are critical in the management of cancer and it is estimated that one third of all cases could be cured with early treatment.   

Asbestos hazards

Toxic Effects of Asbestos

The toxic effects of asbestos are not due to its chemical make-up, but its structural features: fibers.

Chrysotile is 90% of the world’s asbestos production.

Amosite appears to be the culprit. 5-10% amphiboles which are rod forms associated with malignant mesothelioma even when chrysotile is present.

Chyrsotile breaks down in the body much faster than amphiboles. There is an association between malignant mesothelioma and chrysotile when chrysotile is present at 400 times the lung burden of amosite.

One interesting thing is that animals are affected differently from humans to asbestos fibers. Chrysotile appears to be a more potent inducer of mesothelioma than amphibole fibers. The two types of asbestos break down at similar rates in rodents.

Interestingly, other fibers such as fiberglass are carcinogens in rats but not in humans. Researchers speculate that fiber types may differ in their ability to catalyze reactions between iron ions and oxygen. This reaction could cause free radicals that lead to lipid peroxidation, a fibrosis response, DNA damage, and mutations and cancer.

Asbestos hazards epidemiology

Asbestos Toxicology

There is some understanding of the etioloy, but the basis for mesothelioma formation is unknown.

Asbestos is inert in natural rock form. For it to be hazardous, it must be turned into fine flakes of dust that can be inhaled. So there is a risk in mining, milling, and abatement activities with friability.

Respirators make effective safety devices. However, dust and fibers go home on the clothing of workers. Self exposure, family exposure: there is a ten times increased risk of mesothelioma in women who live with asbestos workers.

Science has shown that the hazard depends on particle size.

Length of fibers: 2 microns: asbestosis

5 microns: mesothelioma, asbestosis

10 microns: bronchogenic lung cancers associated with cigarette smoking and asbestosis.


Over 3 microns: no mesothelioma

Less than 0.5 microns: mesothelioma

cancer treatment living with mesothelioma

Get medical advice

Individuals that experience symptoms associated with occupational diseases should seek medical advice as soon as they notice symptoms. The sooner these types of diseases are diagnosed and treated the better the prognosis is for patients.

There are doctors who specialize in occupational medicine but they are very rare. Of the 800,000 physicians in the United States only 10,000 of them specialize in occupational medicine.

The first point of contact for most individuals is the family physician. This physician should do a thorough screening and can assist patients in recognizing the possibility of an occupational illness. Providing the physician with information about workplace irritants will help attain an accurate diagnosis.

Individuals should also consult the “materials supervisor” at the workplace. This person should be able to give detailed information via a “materials safety data sheet” about the types of toxic compounds found at the work site.

Occupational illnesses tend to be diagnosed infrequently however, they are responsible for approximately 860,000 illnesses annually. These illnesses lead to 60,300 deaths in the United States every year. Detecting, diagnosing and treating these diseases in the earliest stages may increase the chance of reversal and/or survival.

It is also important to be aware of dangerous substances prior to beginning a job and to ensure that proper protection is available. Prevention is the best means to avoid lung and respiratory disease and proper equipment may keep workers safe from dangerous airborne particles. Respirators, proper ventilation and other types of equipment should be provided on the job.

occupational safety

Common Occupational Lung and Respiratory Diseases Defined

Exposure to workplace irritants can lead to a vast array of diseases. These diseases may last only as long as the exposure continues or may be chronic conditions that last a lifetime. Certain lung and respiratory illnesses that are caused by occupational exposure to chemicals, dangerous fibers or other substances can cause fatal diseases that currently have no known cure.

Many occupations hold greater risks for exposure due to the location, surrounding environment or nature of the required tasks. It was previously thought that only individuals such as coal miners were exposed to irritants that cause lung disease. This is no longer considered valid as individuals in other industries have been diagnosed with similar illnesses.

Several of the most well know lung diseases associated with occupational exposure are asbestosis, mesothelioma and lung cancer. These diseases were once very rare but have increased as the population of those who were exposed to asbestos on the job ages. Adult onset asthma is also on the rise and many researchers believe this is due to workplace irritants. Other lung and respiratory illnesses have increased in frequency due to the latency period of the disease.

The aging population that is now becoming ill from past workplace exposures is providing valuable information on other dangerous substances.


Asbestosis is a chronic condition of the lung. This disease develops slowly and often causes suffers to experience shortness of breath and chest pain. Many individuals can no longer live an ordinary life as the tolerance for physical activity decreases. Asbestosis is caused by inhalation of asbestos fibers. These fibers, which lodge into the lining of the lungs cause scarring. This scar tissue prevents the lung from properly inflating causing difficulty breathing. When the exposure to asbestos ends the disease does not progress further. Not every person that is exposed to asbestos gets asbestosis. Researchers believe genetics may play a role. There is no effective treatment for asbestosis and the disease progresses slowly. The occurrence of this disease is difficult to ascertain however, the American Academy of Family Physicians sites 20,000 hospital discharges with this diagnosis in the year 2000.

epidemiology occupational safety


In the United States occupational lung disease is the number one cause of on-the-job illness. This disease tops the list both in frequency and severity yet is, in almost every case, preventable. Over 20 percent of men worldwide have been exposed to some type of dangerous occupational irritant that may cause cancer and 5 to 20 percent of women have experienced similar types of exposure.

Occupational asthma is the most common occupational lung disease in the U.S. and approximately 15-23 percent of all new asthma cases are caused by occupational irritants. Individuals who already suffer from asthma may experience increasing severity of symptoms due to workplace exposures.

According to the American Lung Association the cost associated with occupational illnesses is estimated to be over $45 billion per year. Additional indirect costs may make that number climb as high as $229 billion annually.

Ethnicity of employees also seems to play a part in the statistics of occupational disease. In 2005 African American employees held approximately 30 percent of the 70,000 U.S. textile jobs. These individuals were 80 percent more likely to die from byssinosis, a chronic lung disease caused by dust produced in textile factories, than their Caucasian counterparts. Hispanics are the most likely ethnic group to work in high-risk occupations while those of Asian descent are least likely to hold a job that involves dangerous exposure.

Asbestos hazards occupational safety

Preventing lung diseases

Preventing occupational lung and respiratory diseases is the most significant way to reduce the number of deaths from these illnesses. The most effective way to prevent these diseases is to avoid inhaling the substances that cause them. Limiting or eliminating exposure to these irritants is the only way to decrease their effects on the body. Some preventive measures recommended by the National Heart, Lung and Blood Institute (NHLBI) include:

  • Wear protective gear such as facemasks, respirators, or other garments that will prevent inhalation of dangerous airborne particles.
  • Follow specific government guidelines in removal or repair of
    dangerous substances such asbestos.
  • Do not smoke cigarettes as the use of tobacco can increase
    the risk of developing lung and respiratory disease.
  • Make routine visits to your physician to have lung function evaluated
    with spirometry.
  • Become familiar with any dangerous substances that may be present in the workplace and know the risks associated with them.

The lungs and the tissue leading to them are the body’s first organs to come into contact with outside air. The lungs are susceptible to many irritants due to the constant breathing in and out. The particles in the air can cause damage and leave individuals permanently disable and sometimes lead to death. The diseases caused by these particles are almost entirely preventable. Using the measures listed above as well as following workplace guidelines may help worker’s avoid these life-changing diseases.

Government agencies also help in the prevention of occupational disease by posing regulations on workplace safety. In 1970 the government established laws that created two national health agencies. The first, the National Institute for Occupational Safety and Health (NIOSH), was formed to oversee and research safety in workplace activities. This agency was established within the U.S. department of Health and Human Services. The second agency was established within the U.S. Department of Labor. The Occupational Safety and Health Administration (OSHA) was designed to set government standards for health and safety in the workplace and also enforce these standards.

NIOSH has created the National Occupational Research Agenda (NORA) which is a comprehensive list of areas that address workplace dangers. This agenda explores toxicology, identifies emerging technology dangers and evaluates how the combinations of substances in the workplace may effect workers. The reports garnered from this research may help to provide insight into new and dangerous substance as they arise.

Occupational irritants are found worldwide and the knowledge of their danger has helped to decrease the occurrence of disease in many industrialized nations. These developed countries such as the United States have begun major prevention programs. Unfortunately, less developed nations are just beginning to see the effects of imported, dangerous materials. It is the hope of world organizations such as the World Health Organization and the International Labor Office to begin prevention programs worldwide to help stop these diseases.

occupational safety

Occupational diseases

Occupational diseases are those illnesses that occur due to exposure to irritants in the workplace. Occupational illnesses may occur instantaneously due to exposure to toxic chemicals or fumes or may take years to develop due to long-term exposure. Many individuals today are faced with respiratory disease such as adult asthma, chronic obstructive pulmonary disease (COPD) and emphysema. These diseases are life changing and can often be fatal. According to the Center for Disease Control and Prevention (CDC) many of these airway and lung diseases are being contracted on the job. The CDC states that almost 30 percent of adult asthma and COPD may be caused by irritants in the workplace. Over 20 million American workers may be exposed to these dangerous substances each year. In addition to respiratory diseases, individuals may also be exposed to substances that cause lung diseases, such as malignant mesothelioma, obstructive lung disease, lung cancer and a host of other serious illnesses. The American Lung Association cites occupational lung disease as the number one cause of workplace illness. Not all occupational diseases lead to death but a significant amount greatly diminish quality of life.

Many jobs require employees to work in close proximity to dangerous substances. These substances include asbestos and coal dust, which are well known to cause respiratory and/or lung diseases. In addition to these substances, there are many lesser-known irritants that can also be harmful after long-term exposure. Even short-term exposure to some gases or fumes can have long lasting and damaging effects.