Latency Periods for Mesothelioma
In the U.S. the use of asbestos peaked during the mid-1970s. The Environmental Working Group (EWG) estimates that, at that point, the hazardous material was present in more than 3,000 industrial and commercial products, such as insulation and fireproofing materials.
Eventually, the mineral became less prevalent once manufacturers realized they could not deny what scientists had known for years: asbestos is the principal cause of the development of malignant mesothelioma.
Scientists know that an individual’s level of asbestos exposure over time is directly related to his or her risk: the greater the exposure, the higher the likelihood of developing an asbestos-related illness. However, this latency period between contact with the mineral and the development of symptoms may be longer for some individuals than others, regardless of the level of exposure.
This led one team of researchers from Italy to measure the incidence of mesothelioma among nonagenarians.
Mesothelioma festers for decades
The EWG estimates that the latency period for asbestos-related diseases, such as mesothelioma and asbestosis, can take between 20 and 50 years. For this reason, the incidence of these illnesses in industrialized nations is expected to continue to rise for another 10 years or so.
Most people do not know they have an asbestos-related disease until they start experiencing symptoms, such as difficulty breathing. By then, an illness is likely to be in its advanced stages.
Experts from the American Cancer Society note that there is no standardized early screening approach for diagnosing mesothelioma. Doctors may recommend radiology tests to look for changes in the lungs among patients with a history of asbestos exposure, but it is not clear how effective this method is in detecting early disease.
Italian scientists study oldest patients
Researchers from Italy noted that many mesothelioma patients tend to be diagnosed between the ages of 60 and 80. Their diseases are often the result of occupational exposure, particularly if they worked in shipyards.
However, the scientists also recalled that a minority of patients are diagnosed while in their 80s or 90s. It was not immediately clear whether this was because of low asbestos exposure or late contact with the material.
In order to investigate further, the researchers reviewed the medical records of seven men and one woman, all of whom were diagnosed with mesothelioma while in their 90s. After collecting information on their employment histories, the scientists found that the latency periods within this patient group ranged from 64 to 75 years. The duration of asbestos exposure ranged from 11 to more than 40 years.
Examinations of lung tissue revealed that a low level of exposure is not the explanation for the long latency periods.
“In this group of cases, the late development of mesothelioma cannot be attributed to mild exposure to asbestos or to unusually late exposures. Very long latency periods even in people heavily exposed suggest an individual resistance to the oncogenic effects of asbestos,” the researchers wrote in the journal Tumori.
Vigilance can help protect you
At Kazan Law, we believe that vigilance is one of the most important weapons against asbestos-related diseases. The Environmental Protection Agency has many tips on how you can protect yourself from asbestos:
- Hire a professional to inspect your home for asbestos before any remodeling job, or in case parts of the house are falling apart.
- If you find asbestos in the house, inspect it without touching it. If it is intact, make sure no one and nothing disturb it.
- If you are employed in a job that may potentially expose you to asbestos, make sure you know your rights regarding protective equipment and the safety limits of asbestos fiber air concentration.