Category: Asbestos Exposure

Enlisting the Body’s Immune System to Fight Mesothelioma and Asbestos Disease

• Nancy Meredith
• Asbestos Exposure, Cancer, Mesothelioma, Research, Treatments

Mesothelioma, a cancer of the lining of the lung and abdomen, suppresses the normal immune system response designed to ward off disease. Scientists have been trying to understand the mechanics of the immune suppression process to develop more effective therapies for mesothelioma, an aggressive form of cancer.

One promising treatment is immunotherapy that enlists the body’s natural defense system to shrink cancerous tumors. A number of immunotherapies are currently being tested in clinical trials. Mesothelioma is among the cancers that appear to be responsive to immunotherapy, researchers say. But the failure of immunotherapies to stop the growth of malignant mesothelioma tumors suggests that the immune suppression process is complex and involves multiple targets.

In an article published in the journal Immunology and Cell Biology, researchers at Harvard University investigate the roles of three factors affecting the immune response: regulatory T cells, intratumoural transforming growth factor (TGF)-â and the protein cytotoxic T lymphocyte-associated antigen-4, which plays a regulatory role in the immune system.

The researchers say that immunotherapy treatments targeting multiple regulators simultaneously appear to be more effective than focusing on one regulator protein that is suppressing immune response. They report that a triple treatment involving all three immune system factors led to long-term shrinkage of tumors and residual resistance to cancer cells if tumors reappeared.

“These data suggest that clinical application of immunotherapies against tumors may be improved by simultaneously targeting multiple mechanisms of immune suppression,” said lead investigator Haydn T. Kissick in a summary of the research.

Mesothelioma is caused by exposure to asbestos fibers. When a person breathes asbestos dust, the microscopic asbestos fibers can penetrate deep in the lungs and cause inflammation and eventually disease.

Approximately 2,500 to 3,000 people a year in the United States receive a diagnosis of malignant mesothelioma. Many victims of mesothelioma are older workers, retired workers and veterans who were exposed to asbestos decades ago in a workplace. The symptoms of mesothelioma typically take 20 years to 40 years to appear, but the disease is aggressive once it appears.

McGill Reviews Research After Questions Raised About Links to Asbestos Industry

• Nancy Meredith
• Asbestos Exposure, Research

The dean of Medicine at McGill University said in a statement Thursday that the prestigious Canadian research university will conduct a preliminary inquiry into accusations that a McGill researcher had allowed his research to be influenced by the asbestos industry. Canada remains one of the world’s leading producers of asbestos, a mineral fiber that causes serious respiratory diseases including lung cancer and mesothelioma, a cancer of the lining of the lungs and abdomen.

Dr. David Eidelman, vice principal of health affairs and dean of medicine at McGill, said a review was being undertaken to ensure that the research of Prof. J. Corbett McDonald, who is now retired, was conducted according to rigorous scientific standards. “The allegations in the media … are very serious and must be address,” Eidelman said in the statement.

A documentary last week on the CBC, Canada’s national public television and radio network, outlined how an institute established by the Quebec Asbestos Mining Association paid McGill Prof. Corbett McDonald and other researchers at least $1 million between 1966 and 1972 for research on the health effects of chrysotile asbestos. In the documentary, Professor David Eidelman of Brown University, claimed that some of the researchers altered the literature to minimize or misrepresent the health effects of chrysotile asbestos. The documentary suggested the research was still being cited by the asbestos industry and Canadian government to support Canada’s continued involvement in asbestos mining.

According to McGill University, Prof. Corbett McDonald and colleagues began in 1966 to investigate the mortality rates of approximately 11,000 Quebec miners and millers of chrysotile, a type of asbestos fiber. Asbestos exposure remains an occupational hazard for many workers. The researchers published their findings in articles in peer reviewed scientific journals from 1971 to 1998. The researchers acknowledged in the journal articles that the research was funded in part by the Institute of Occupational and Environmental Health of the Quebec Asbestos Mining Association.

In the research, McDonald demonstrated that asbestos is a carcinogen linked to lung cancer and mesothelioma. But the research also suggested that the health risks of chrysotile asbestos could be greatly minimized by reducing exposure and that chrysotile asbestos —the type of asbestos mined in Canada—was significantly safer than other types of asbestos.

Eidelman said it is true that Prof. McDonald drew different conclusions about the possible safe use of chrysotile asbestos than most scientists do today. “Holding scientific views that are different from those of the majority does not constitute research misconduct,” Eidelman said.

Eidelman said the outcome of the preliminary review conducted by a Canada Research Chair would determine whether there is a need for further investigation.

Rise in Asbestos Use in U.S. Increases Urgency to Ban Cancer Causing Fiber

• Nancy Meredith
• Asbestos Exposure, Mesothelioma

The president of the Asbestos Disease Awareness Organization said that she was appalled by a recent U.S. government report showing a dramatic increase in asbestos imports into the United State in 2011. Asbestos, a mineral fiber, is a cause of cancer in humans, including mesothelioma, a cancer of the lining of the lung and abdominal cavity. Many nations have banned asbestos because it’s toxic, but the United States still allows the import of raw asbestos and asbestos-containing products.

Linda Reinstein, co-founder and president of the ADAO, an advocacy group, said the asbestos industry had argued for years that importation and exposure to asbestos have been gradually decreasing, but the new report shows that simply isn’t accurate.

According to the 2012 United State Geological Survey of mineral commodities, U.S. industries consumed 1,100 metric tons of asbestos from January through July 2011, compared to 820 metric tons during the same period in 2010. The difference represents a 34 percent increase in consumption, Reinstein said.

The U.S. Geological Survey report estimated that roofing felt materials account for about 60 percent of U.S. consumption of asbestos. The chlorine manufacturing industry, which utilizes asbestos diaphragms in the manufacturing of industrial chemicals, accounted for about 30 percent of asbestos consumption, the report said. The United States still has asbestos diaphragm cell plants.

The use of asbestos creates an occupational hazard of asbestos exposure. Asbestos exposure in the chlorine industry arises form the transport and storage of sacks of raw asbestos. Cutting open and empty sacks of asbestos and transferring asbestos into slurry mixing tanks and handling empty bags can cause additional exposures, according to testimony presented by environmental consultant Barry Castlemen to a U.S. Senate committee. The handling and storage of asbestos diaphragms presents another possible source of asbestos exposure, he said.

More than 30 years ago, the International Agency for Research on Cancer declared asbestos a human carcinogen, yet workplace exposure continues throughout the United States.

Reinstein called on Congress and the president to prohibit the importation of raw asbestos and asbestos-containing products. “I have lost my husband, Alan, to mesothelioma, a disease caused by asbestos exposure,” Reinstein said in a prepared statement. “Nothing can bring him or the hundreds of thousands of other victims back to life, but we can begin by aggressively preventing exposure thus eliminating deadly diseases.”

Approximately 3,000 people in the U.S. are diagnosed with mesothelioma each year. Most are older workers, retired workers and veterans who had workplace exposure to asbestos. Most people diagnosed with mesothelioma do not notice any symptoms of the disease for 20 years to 40 years after exposure.

For more information about mesothelioma, click here.

Elevated Rate of Lung Cancer Among Carolina Textile Workers Exposed to Asbestos, Study Says

• Nancy Meredith
• Asbestos Exposure, Mesothelioma

Researchers report that textile workers in North Carolina and South Carolina who were exposed to asbestos had significantly increased incidence of lung cancer. Asbestos, a mineral fiber used in thousands of products from building materials to textiles, is associated with serious respiratory diseases including asbestosis, a scarring of the lung, lung cancer and mesothelioma, a cancer of the lining of the lung and abdomen.

In the new study published in January issue of the journal Occupational and Environmental Medicine, researchers tracked the status of more than  6,100 textile workers who had been employed at four Carolina textile mills that previously used asbestos in manufacturing. From the 1950s through the early 1970s, textile plants converted chrysotile asbestos, typically imported from Canada, and cotton fibers into yarn and woven materials. That created an occupational hazard of asbestos exposure for unsuspecting textile workers, who typically did not wear any breathing protection.

The researchers, based at the University of Nebraska, Duke University and the University of North Carolina, reported a significantly elevated rate of death from lung cancer among the textile workers as compared to the general population. They determined that 3,356 of the textile workers employed in the mills had died as of 2003, and a disproportionate number had died of lung cancer, according to death certificate data.

The researchers also found a strong correlation between the increased mortality rate of lung cancer and the workers’ cumulative occupational exposure to asbestos. The cumulative exposure to asbestos varied considerably among the four plants. Exposure to asbestos usually occurs by breathing air in workplaces contaminated with microscopic asbestos fibers or swallowing asbestos fibers. Typically, workers do not experience symptoms of mesothelioma or other asbestos disease  for 20 years to 40 years after exposure to asbestos.

Another study published last year in the journal Lung Cancer found that textile workers in China who were exposed to asbestos had an increased risk of dying of lung cancer, mesothelioma and all forms of cancer. The trend was most pronounced among textile workers who had a high exposure to asbestos and also were smokers.

For more information about mesothelioma click here.

Families of Asbestos Workers At Risk of Mesothelioma From Exposure At Home

• Nancy Meredith
• Asbestos Exposure, Cancer, Mesothelioma

A report in a British newspaper describes the terrible legacy of asbestos disease that families of asbestos workers face. Asbestos is associated with scarring of the lungs and mesothelioma, an aggressive cancer of the lining of the lung and abdomen.

According to a  Jan. 17 article in the Yorkshire Post,  eight adult children of Kora Leah, who was a foreman at Cape Asbestos in Hebben Bridge, Yorkshire, have been diagnosed with asbestos-related disease. The family has lost two siblings in recent months to mesothelioma.

When Marjorie King, one of Leah’s daughters died last July at age 67, a tumor was found on her right lung and asbestos particles were discovered in her lung tissue. Deputy Coroner Paul Marks concluded after an inquest that she died of mesothelioma.

Her sister, Maureen McGeogh, 73, of West Yorkshire, recalled that she and her siblings would play with their father when he returned home from work with his clothes still covered in asbestos dust. “I remember my mother shaking his overalls and dust going everywhere,” McGeogh recalled.

She said the children sometimes accompanied their father to work on Sunday and would play in the piles of dust. They were unaware of the danger of the asbestos dust.

Of the other siblings, Gerald, 78, has pleural plaques and emphysema while Cedric, 74, Rosalind, 71, Raymond, 69 and Glynn, 64, all have scarred lungs. Because of their secondhand exposure to asbestos they are at higher risk of developing mesothelioma.

The father Kora Leah died of lung cancer in 1958, 10 years after leaving Cape Asbestos, according to the newspaper.

According to the National Cancer Institute, there is evidence that family members of workers heavily exposed to asbestos face an increased risk of developing mesothelioma. The risk results from exposure to asbestos brought into the home on clothing, shoes, skin and hair.

When asbestos fibers get inhaled, they get trapped in the lung and remain there for a long time. The symptoms of mesothelioma typically appear 30 years to 50 years after initial exposure to asbestos. Possible signs of mesothelioma include shortness of breath and pain under the rib cage, pain or tightening of the chest, and a persistent cough that gets worse over time. It’s important to check with a doctor if you develop any of these symptoms and inform the doctor of any known exposure to asbestos.