ASBESTOS-RELATED PULMONARY DISEASES
Asbestos-related pulmonary diseases are a group of diseases that are associated with exposure to asbestos with subsequent development of a clinical condition attributed to the exposure. This document is an attempt to provide a brief overview of asbestos and the mechanism of its effects in humans, an overview of the more common asbestos-related pulmonary diseases, diagnostic considerations in individuals alleging asbestos-related pulmonary diseases, and application of the information to the Ohio Workers' Compensation System.
OVERVIEW OF ASBESTOS
Physical Properties and Effects in Humans
Asbestos is a term applied to a family of naturally occurring, flexible, silicate minerals that are resistant to heat and many chemicals.[1] The properties of relative heat and chemical resistance has lead to widespread use in the 20th Century of asbestos in many processes and products including insulation materials, building materials such as vinyl asbestos floor tile, linings of furnaces, filtration systems, asbestos cement products, and as spray products for acoustical, thermal, or fireproofing purposes. Therefore, asbestos is commonly found throughout the work and non-work environments. Identification of asbestos fibers in samples of lung tissue, lung lavage samples or sputum, documents past exposure, but not necessarily the source of the exposure or whether asbestos-related disease is present. While individuals with asbestos-related disease may have higher concentrations of fibers in tissue samples, there is considerable overlap and laboratory variation so that asbestos fiber count has limited usefulness.
Once inhaled, the body attempts to remove fibers by several pathways including mucociliary transport through the airways, the lymphatic system, or through degradation of the fibers by macrophages. The fundamental disease process is the induction of inflammation resulting in fibrosis and/or cancer of the lung and pleural space. The fibrosis process is the result of the inflammatory reaction and repair processes by the body’s defense system to remove asbestos fibers. These reactions lead to permanent scarring and fibrosis. The cancer processes are the result of damage to target cells with genetic mutations through a variety of molecular injuries.
[1] Begin R, Samet GM, and Shaikh RA: “Asbestos” in Harber P,
There is a latency period of several years between initial exposure and onset of clinical disease. The latency period is variable. Individuals who are no longer occupationally exposed to asbestos may develop asbestos-related diseases years after their removal from occupational exposure. Current OSHA regulations and industrial processes have tried to limit exposure by substitution of other materials, monitoring with limits on the concentration of fibers permitted per cc of air in the workplace, use of personal protective equipment when exposed to asbestos fibers in significant concentrations, and required periodic medical monitoring of exposed workers for asbestos-related diseases.
Mesothelioma and Children
Mesothelioma and Children
When people think of mesothelioma, they typically picture an older adult who has been exposed to asbestos. Yet this disease can, in rare cases, also strike children. Because the prognosis is poor, doctors need to carefully diagnose mesothelioma in their youngest patients.
Doctors don’t know what causes mesothelioma in children. Although a high number of adults with the disease have a history of asbestos exposure, this isn’t the case in children. “The latent period of asbestos exposure in mesothelioma patients can be many years,” explains Cesar A. Moran, MD, professor of Pathology in the Department of Pathology at MD Anderson Cancer Center in
Dr. Moran and his colleagues recently published a study in the journal, Histopathology, in which they looked at the cases of eight children with mesothelioma. All of the children had cancer in the abdominal cavity lining (peritoneal mesothelioma). Most adults with the disease have pleural mesothelioma, which affects the lining of the lung.
Because this cancer is so rare in children, it can be challenging to diagnose. “For most physicians, the diagnosis of mesothelioma [in children] is low on the list,” Dr. Moran says. Children with mesothelioma tend to complain of the same symptoms: pain, bloating, and fluid build-up in the abdomen. Moran says that it is important to rule out other types of lesions in this location before making an unequivocal diagnosis of mesothelioma in a child.
In this study, all of the children had a biopsy (removing a sample of tissue for examination) to determine the type and severity of their cancer. Diagnosing mesothelioma also typically involves radiological scans of the abdomen, as well as immunohistochemical studies, in which the cells are examined to look for specific cancer markers. “You have to do immunohistochemical tests to make sure you aren’t dealing with another tumor that has metastasized [spread] into the peritoneum,” according to Dr. Moran.
Treating mesothelioma presents another challenge to doctors. No standard therapy exists, even for adults with the disease. Surgery and chemotherapy may be used in adult patients. Similar treatments may be tried in children, but regardless of which treatment is used, the outlook is generally poor.
Currently there is very limited research on peritoneal mesothelioma in children to guide doctors in diagnosis and treatment, and what little research does exist is conflicting. Because this cancer is so rare in children, additional research should be done in adult patients to learn more about this disease, says Dr. Moran. “From adults, we can make more meaningful conclusions, and the results may be applied to the pediatric population,” he says.
Source:Moran CA, Albores-Saavedra J, Suster S. Primary peritoneal mesotheliomas in children: a clinicopathological and immunohistochemical study of eight cases. Histopathology. 2008;52:824-830.
Is there any treatment that may help?
The initial most helpful treatment is that which deals with symptoms. Removing fluid from around the lung can help to relieve breathlessness. Firstly the fluid may be drained either by drawing off fluid or inserting a small drainage tube. However the fluid often reaccumulates and the chest physician or surgeon may perform a procedure called a ‘Pleurodesis’ This is an attempt to stick the lung surface to the chest wall by inserting sterile talc into the pleural space. This may be done by a surgeon using ‘key hole surgery’ otherwise called VATS - Video Assisted Thoracoscopic
Surgery.
How is Mesothelioma diagnosed?
What causes Mesothelioma?
Mesothelioma
What is Mesothelioma?
This is about the disease itself and is written in a ‘question and answer’ format to answer the most common questions asked about mesothelioma. I’m sure there are many more which are beyond the scope of this small booklet, but further sources of
information and advice are listed in part
Mesothelioma (also known as ‘diffuse’ or ‘malignant’ Mesothelioma) is a form of cancer, which affects the thin membranes which line the chest (pleural mesothelioma). Less commonly it can affect the linings of the abdomen (peritoneal mesothelioma). It may also surround the organs found within these cavities for example the heart, lung and intestines.
Pleural Mesothelioma
The pleural lining has two layers - an inner (visceral) layer which lines the lung and an outer (parietal) layer which lines the chest wall. The pleura produce fluid to lubricate the space between the two layers allowing the layers to slide comfortably over each other as we breathe.Pleural Mesothelioma causes the pleura to thicken. This may make it press on the lung or attach itself to the chest wall. Fluid, sometimes several litres, can collect between the two layers and cause
breathlessness. This is known as a Pleural effusion
Peritoneal Mesothelioma
The peritoneum also has two layers, the inner (visceral) layer which is next to the abdominal organs and the outer (parietal) layer which lines the abdominal wall. Peritoneal Mesothelioma causes the peritoneum to thicken and fluid to collect in the abdomen, this collection of fluid is called ascites and causes the abdomen to swell. Peritoneal Mesothelioma is much less common than Pleural Mesothelioma.
Asbestos in Older Homes
Asbestos in Older Homes
Asbestos has been a growing concern for city governments and the owners of public buildings for some time. In recent years, concerns about asbestos have become a growing issue among the owners of single family homes. These are some of the questions most commonly asked of asbestos abatement companies by the owners of private homes, and their best answers.
- How likely is my home to contain asbestos?
If your home was built after 1980, the chances that it contains asbestos or any materials that have asbestos added to them is very small. If your home was built or underwent major renovations between World War I and 1980, there’s a very good chance that there are materials in your home that contain asbestos.
- How dangerous is asbestos in my home?
While asbestos is a known carcinogen, it is only dangerous in the form of tiny airborne fibers. Asbestos is a mineral that easily separates into tiny fibers that are light enough to float in the air. Those fibers were often mixed into things like paint, cement and wood pulp to help make them fire resistant and increase their insulating properties. As long as those materials are in good repair, the chance of them releasing asbestos fibers is very small, and there is little health risk in living with them.
- Why is asbestos dangerous?
Breathing in asbestos fibers increases your risk of developing lung cancer, causes asbestosis – scarring of the lungs – and may lead to the development of mesothelioma, a rare cancer that is only found in people who were exposed to asbestos. For additional resources please see the resources at Asbestos.com
- When is asbestos dangerous to me or my family?
Asbestos containing materials can become dangerous to your family’s health when they are damaged or disturbed enough to release fibers of asbestos into the air.
- How can I tell if something in my home contains asbestos?
The only way to know for sure that a material in your home contains asbestos is to have it examined by a professional. It’s nearly impossible to identify asbestos by visual examination alone unless you have the experience and knowledge to identify specific brands and types of materials by sight. Even then, most professionals rely on a microscopic examination to determine whether a material contains asbestos.
If you suspect that something in your home is made of asbestos, you have two choices: you can assume that it contains asbestos and take the same precautions you would if you were certain that it did, or you can have it tested by a professional asbestos surveyor. Testing is not very expensive, and it could set your mind at east.
- Where might I find asbestos in my home?
Asbestos was used in thousands of different products that were used in home construction and consumer products. Among the most common places to find asbestos are:
- roofing and siding shingles made with asbestos cement
- insulation in homes built between 1930 and 1950
- textured paints used for decorative ceiling and wall coatings (banned in 1977)
- pipe insulation and caulking
- furnace or water heater blankets may contain asbestos
- the floor and walls under and behind stoves, fireplaces and heaters may be protected with asbestos containing millboard, asbestos paper or cement sheets containing asbestos
- the door gaskets in oil or coal furnaces may contain asbestos
- joint compound used to seal wallboard may contain asbestos
- resilient floor tiles or sheet vinyl flooring may have been made with or backed with asbestos containing materials
- decorative plaster treatments on walls and ceilings may contain asbestos
completed download here
