How easy is it to get Mesothelioma?
Approximately 70 to 80 percent of people who get mesothelioma
have been heavily exposed to asbestos at work. Usually, the disease
shows up 35 to 50 years after exposure, so most people with it are over
the age of 65. Mostly men get the disease, but women can also get mesothelioma. It is most common in whites.
Contact with asbestos is the leading cause of
mesothelioma cancer, as nearly every patient diagnosed with this
aggressive cancer came in contact with it at some point. Mesothelioma
caused by asbestos exposure commonly occurs occupationally,
environmentally or as a result of secondhand exposure.
Mesothelioma — a cancer that most commonly attacks the lungs and abdomen
— was profoundly rare until industrial and commercial companies
expanded the use of asbestos during the 20th century. After spending
decades investigating the disease and its causes, medical researchers
identified one primary culprit: Exposure to asbestos.
Medical research studies gradually pointed to the fact that breathing in minuscule asbestos fibers starts a chain of physical and metabolic events that lead to the development of several types of cancers or an incurable breathing disorder called asbestosis.
Medical research studies gradually pointed to the fact that breathing in minuscule asbestos fibers starts a chain of physical and metabolic events that lead to the development of several types of cancers or an incurable breathing disorder called asbestosis.
In March 2009, the International Agency for Research on Cancer
reconfirmed that asbestos exposure is the leading cause for mesothelioma
and all forms of asbestos cause the disease.
Risk Factors for Mesothelioma
While exposure to asbestos is the leading cause for mesothelioma, other
elements can play a significant role in this cancer’s development.
Doctors call these elements risk factors, and they include any factors
that increase a person’s likelihood of developing cancer.
Factors that Increase the Risk of Mesothelioma:
Working at an asbestos mine or asbestos processing plant
Working in a high-risk occupational setting, such as the construction or automotive industries
Serving on military ships or facilities built with products containing asbestos
Other Factors That May Increase the Risk of Developing Mesothelioma
Apart from risk factors associated with asbestos, exposure to
minerals with similar properties to asbestos, a person's age and gender
and other elements may increase the likelihood of developing the
disease.
Where Does Asbestos Exposure Occur?
Asbestos once filled countless U.S. homes and businesses in the form
of insulation and heat-protecting materials. Throughout the massive
construction boom following World War II, it was a key element in
thousands of industrial and household products, including drywall,
wiring, glues and adhesives, ceiling tiles, cements and shingles.
Some of these asbestos products remain in old structures and are
usually harmless — as long as they're not disturbed. Workers usually
were exposed to the harmful natural mineral
while on the job, but others, including their family members, also
faced secondary exposures at home and environmental exposures in
communities that mined or processed asbestos.
Occupational Exposure
Most harmful exposures occurred at work. The risk for
asbestos-related illnesses is highest for people who worked directly
with the raw mineral or with asbestos-containing products on a daily
basis. Some of the most prevalent occurrences of asbestos exposure that cause mesothelioma were in the following occupations:
Risk Factors in Construction and Craft Jobs
Construction workers and craftspeople are most likely to experience
harmful exposures, especially while working on older homes and buildings
constructed with contaminated materials. Exposures can happen during a
renovation or demolition. If asbestos insulation is disturbed, fibers
can become airborne and contaminate anyone who inhales them.
Fast Fact: Removing asbestos is a highly
regulated endeavor, and the government fines people and businesses who
ignore the regulations. Even though the U.S. government restricted the
use of asbestos during the 1970s, workplace exposures still can occur.
Secondary Exposure
When the asbestos industry was booming, families of
workers were at great risk. Workers often came home with asbestos fibers
on their hair, work clothes and tools — exposing family members to the toxic substance and increasing their risk for related diseases.
The National Institute of Occupational Safety and Health (NIOSH)
presented a Workers' Home Contamination Study to Congress that showed
"families of asbestos-exposed workers have been at increased risk of
pleural, pericardial, or peritoneal mesothelioma, lung cancer, cancer of
the gastrointestinal tract, and nonmalignant pleural and parenchymal
abnormalities as well as asbestosis."
Environmental Exposure
Because asbestos is a naturally occurring mineral, people living near
areas of large deposits, like hilly or mountainous regions, also face
possible exposures. Minimal amounts of the mineral can fill the air in
these regions, but environmental exposure is most dangerous near
asbestos mines.
Two of the most recognized cities for asbestos exposure problems are Libby, Montana, and El Dorado Hills, California.
Libby was home to a vermiculite mine contaminated by naturally occurring asbestos. The mine, controlled by W.R. Grace & Company
and operated from 1923 to 1990, is responsible for several hundred
asbestos-related deaths. The U.S. Environmental Protection Agency (EPA)
in June 2009 declared a public health emergency at the city.
The EPA said asbestos levels in El Dorado Hills were "of concern," according to the agency's report on the 450-plus air samples gathered there in 2004.
Although asbestos mines are no longer in operation in the U.S., people living near them continue to develop mesothelioma.
Although asbestos mines are no longer in operation in the U.S., people living near them continue to develop mesothelioma.
How Does Mesothelioma Develop?
It usually takes heavy, repeated exposures to asbestos for a related
cancer to develop, but even minor exposures can be harmful. Exposure
occurs when raw asbestos is inhaled, or activities disturb materials
containing asbestos and release toxic fibers into the air.
Once inhaled, the body has a hard time getting rid of the sharp,
sometimes jagged fibers, and they build up in the lungs or abdomen over
time. Many years after the first exposure, these fibers may cause
cancerous changes. Cancer starts in mesothelial cells, which make up the protective membranes that cover our lungs, abdomen and heart.
Possible Theories for How Asbestos Fibers Cause Tumors to Develop
Inflamed cells
Fibers inflame and irritate mesothelial cells, which leads to irreversible scarring, cellular damage and cancer.Genetic changes
Fibers enter mesothelial cells and disrupt their life cycle. This can cause genetic changes that lead to cancer.Cancerous mutations
Asbestos causes the production of free radicals, molecules that damage DNA and cause healthy cells to undergo cancerous mutations.Uncontrolled Growth
The fibers can trigger the production of oncoproteins, which block genes that protect cells from growing uncontrollably and forming tumors.
The common ground of these
theories: Asbestos causes damages that change a cell's natural cycle.
Every healthy cell has genes that safeguard against cancer. Once
asbestos blocks this function, cells can divide uncontrollably,
spreading throughout the body and forming tumors. These tumors are a
patient's main source of symptoms.
The National Cancer Institute and the Mesothelioma Applied Research
Foundation in 2010 conducted a study that showed asbestos damages cells
through a process called "programmed cell necrosis." In this process, a
molecule called "high-mobility group box 1 protein" (HMGB1) triggers
chronic inflammation that causes tumor growth.
Prevention
The best way to prevent mesothelioma is to take a proactive stance on
your health. If you think a past job or home repair project exposed you
to asbestos, you should seek regular medical exams to check for signs of related diseases.
If you or a loved one has a history of asbestos exposure — especially in the workplace — don't wait for symptoms to show up. Instead, be proactive and ask your doctor. Early detection offers the best opportunity for effective treatment.
If you or a loved one has a history of asbestos exposure — especially in the workplace — don't wait for symptoms to show up. Instead, be proactive and ask your doctor. Early detection offers the best opportunity for effective treatment.
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