Naturally Occurring Asbestos Linked To Lung Cancer

The study - the largest to examine the question - will be published this fall in the American Journal of Respiratory and Critical Care Medicine.

Exposure to asbestos in the workplace, particularly in shipyards, has long been recognized as a risk factor for mesothelioma, a rare form of cancer affecting the lining of the lung. But in the new study, researchers found a consistent and dose-dependent association between mesothelioma and residential proximity to ultramafic rock, the predominant source of naturally occurring asbestos.

"Our findings indicate that the risks from exposure to naturally occurring asbestos, while low, are real and should be taken seriously," said Marc Schenker, professor and chair of the UC Davis Department of Public Health Sciences and the study's senior author. "This study provides important supportive evidence that naturally occurring asbestos causes mesothelioma - and public efforts should now shift to understanding the risk and how we can protect people from this preventable malignancy."

To put the mesothelioma risk in perspective, the disease kills about the same number of Americans each year as passive smoking. About 2,500 people a year die from mesothelioma in the United States, according to National Institute of Occupational Safety and Health statistics. About 3,000 deaths a year are attributed to exposure to secondhand tobacco smoke, according to U.S. Environmental Protection Agency statistics.

Ultramafic rock is distributed throughout the Sierra Nevada, Coast Ranges and Klamath Mountains in Northern and Central California, and has been a source of increasing concern as new housing developments cut through these areas. Of most concern are the areas of ultramafic rock associated with tremolite asbestos.

In their ambitious study, Schenker and his colleagues used California Cancer Registry data to identify 2,908 cases of malignant mesothelioma diagnosed between 1988 and 1997 in adults ages 35 and older. In most cases, the registry also provided occupational history. As a control group, an equal number of age- and gender-matched pancreatic cancer cases was selected (since pancreatic cancer has no known association to asbestos exposure). For both the mesothelioma and pancreatic cancer cases, the researchers employed sophisticated geographic information system mapping to pinpoint home or street addresses for every diagnosed individual. A map from the California Department of Conservation, Division of Mines and Geology, served as the reference for ultramafic rock deposits. Finally, statistical adjustments were made for sex, occupational asbestos exposure and age at diagnosis.

The researchers found that the risk of developing malignant mesothelioma was directly related to residential proximity to a source of ultramafic rock. Specifically, the odds of having mesothelioma fell by 6.3 percent for every 10 kilometers (about 6.2 miles) farther a person lived from the nearest asbestos source. The association was strongest in men, but was also seen in women. No such association showed up in the pancreatic cancer group. The study was not designed to determine the "ground zero" risk for those living closest to an asbestos source - only to test for a relationship between proximity and risk.

"This is very creative, painstaking epidemiology," said Jerrold L. Abraham, professor and director of environmental and occupational pathology at SUNY Upstate Medical University in Syracuse, New York, and a leading authority on mesothelioma. "The UC Davis researchers have shown a significant association between living near deposits of naturally occurring asbestos and mesothelioma. This is the strongest evidence possible without conducting one-on-one interviews with each diagnosed mesothelioma patient or his or her family."

Laurel Beckett, professor and vice chair of the UC Davis Department of Public Health Sciences and a study co-author, said the findings are important. "We showed that breathing asbestos in your community is not magically different from breathing asbestos in an industrial setting. It would have been a surprise to find otherwise."

Similarly, she said, it was no real surprise to scientists when passive smoking was found to cause lung cancer. "Like smoking, exposure to asbestos appears to be very dose-dependent," Beckett said. "Day-in, day-out occupational exposures are more dangerous than intermittent exposures in the community. But the more you can do to reduce your personal exposure, the safer you will be."

While the overall mesothelioma rate was about one case per 100,000 people per year in the California study, the rate varied markedly by gender and age. For white males, the rate was 2.29 cases per 100,000. For white females, it was 0.49. People over age 60 had ten times the rate of those ages 40 to 59.

Worldwide, epidemiological studies of mesothelioma have found occupational causes for most but not all cases of the disease. In some undeveloped areas of the world, including parts of Greece and Turkey, mesothelioma cases have been linked to use of naturally occurring asbestos in household materials such as whitewash. The UC Davis study suggests naturally occurring asbestos also causes mesothelioma in developed countries, through incidental, non-occupational exposures.

California has required statewide cancer reporting since 1985 and established the California Cancer Registry in 1988. One of the largest cancer databases in the world, the registry is responsible for collecting cancer incidence and mortality statistics for more than one tenth of the United States population. An estimated 98.9 percent of all mesothelioma cases diagnosed in California are reported to the registry.

The registry's size enabled researchers to identify an association that might not have been apparent in a smaller study.

Needed now are field studies to more accurately characterize determinants of exposure to asbestos fibers among residents in areas with naturally occurring asbestos, Schenker said. In addition, he said more must be learned about the types and size of fibers in asbestos deposits, the types of human activities that disturb asbestos fibers and the determinants of cancer risk in exposed populations.

"Because mesothelioma takes 20 to 30 years to develop, what we learn today will allow us to protect Californians from this preventable cancer decades into the future," Schenker said.

Asbestos Contamination: Health Impacts Of One Of The Nation's Largest Environmental Disasters

Researchers at Mount Sinai School of Medicine, leading a team of investigators from four institutions, are now launching three investigations into disease pathology in the town and to determine recommended cleanup efforts.

The Principal Investigator of the project is Stephen Levin, MD, Associate Professor of Preventive Medicine at Mount Sinai School of Medicine and a nationally known expert in occupational medicine and asbestos-related diseases who has also served as PI of the nationwide World Trade Center Medical Monitoring & Treatment Program, coordinated by Mount Sinai since 2002.

"The asbestos-related disease in Libby is far more aggressive and rapidly progressive than what's seen in most asbestos-exposed workers, with high rates of cancers and severe effects on respiratory function," said Dr. Levin. "For that reason alone, the health problems in Libby are important to study and understand."

The first of the three programs will focus on particular risks of exposure to Libby asbestos during childhood, when lungs are still developing and maturing. This research may determine the level of environmental cleanup necessary in Libby to protect children, who are a particularly sensitive target population.

A second study will compare lung scarring among Libby residents who were exposed to asbestos only in their environment (and not at their place of employment) with lung scarring seen in workers with historically long-term, heavy exposure to common commercial forms of asbestos. Researchers hope to discover why Libby residents have advanced rates of lung scarring. They will also investigate the mechanism for asbestos-related scar formation and approaches to preventing scar formation after exposure has already occurred.

The third investigation will examine the relationships between autoimmune disorders, autoimmune antibody abnormalities, and CT-scan evidence of scarring lung disease in the context of exposure to Libby asbestos. Auto-immune disorders such as rheumatoid arthritis and lupus have been found to occur more frequently in Libby, and antibody levels to the body's own tissues are found in Libby residents more frequently and at higher concentrations.

Mount Sinai researchers will collaborate on the research effort, to be known as the Libby Epidemiology Research Program, with Libby's Center for Asbestos Related Disease (CARD), investigators from the University of Montana and Idaho State University, and a national scientific advisory group. The research will be supported by a grant of over $4.8 million from the Agency for Toxic Substances and Disease Registry (ATSDR) of the federal Center for Disease Control and Prevention.

The crisis in Libby, a mining town whose history has been shaped by vermiculite-producing corporations since the 1920s, is the result of community-wide occupational and environmental exposure to Libby's naturally occurring vermiculite, contaminated with asbestos and asbestos-like silicate fibers up to 26% by weight.

Health effects have been detected not just in mine and processing plant workers, area lumber mill workers and loggers (from asbestos dusting of forests) and their families, but also among other Libby residents and their children. Many were exposed through ambient air or to mine tailings and other contaminated materials provided to the town by mining companies for the construction of ball fields, school running tracks, playgrounds, public buildings and facilities, as well as for private gardens and house and business insulation.

There is evidence that even relatively low-level exposures to Libby asbestos can cause serious scarring lung diseases, which markedly impair respiratory function, as well as asbestos-related cancers like lung cancer and mesothelioma, which occur at higher rates among the Libby population than elsewhere in the United States.

The health crisis potentially extends far beyond the borders of Libby, since millions of homes and businesses in North America have used vermiculite from Libby as attic insulation, fireproofing and soil conditioner. The ore from Libby was shipped by rail to 49 plant locations throughout North America and the Caribbean for processing, exposing many more workers and communities to the hazardous dust.

CARD Director Brad Black, MD, said, "The pattern of asbestos disease caused by exposure to Libby amphibole asbestos has led to excessive morbidity and mortality for the Libby population, and has been exceedingly challenging for the medical community. The severity of nonmalignant pulmonary disease in non-occupational exposure has been very unusual, raising question as to the potency of the unique amphibole mixture. We look forward to working with Dr. Levin and Mount Sinai to find some of these answers."

Asbestos Disease Projections Too Low

The analysis by Dr Mark Clements, from the National Centre for Epidemiology and Population Health, and colleagues shows that the peak number of cases of mesothelioma, a deadly cancer caused by asbestos, will occur four years later and the future total incidence may be in excess of 35 per cent higher than existing models would have predicted. The pattern for mesothelioma reflects changes in asbestos exposure and therefore reflects predictions for all asbestos-related diseases, Dr Clements said.

These early results have important implications for asbestos-related disease liability schemes, Dr Clements said, although more detailed work is needed to properly integrate other factors related to the actuarial implications.

According to the research, an existing model developed by the auditing firm KPMG gave the peak of mesothelioma cases as occurring in 2010, with 3530 cases in New South Wales men. However, Dr Clements said their own epidemiological model showed that the peak could occur as late as 2017 and see 6430 cases of the deadly disease in NSW men.

“There is reasonable evidence that the peak of mesothelioma incidence is later than 2010. This has far reaching consequences for actuarial predictions, where the number of cases out to 2060 may be in excess of 35 per cent higher than the number predicted by KPMG’s model,” he said.

“It is unclear why the two models give different results. The KPMG modeling may have been influenced by a common belief that peak incidence would be in 2010; in contrast, our epidemiological model is able to predict the peak for incidence.

“Although these results have implications for liability, there are several steps between predicting mesothelioma incidence and calculating liability,” he said. “Moreover, modelling would be required for other asbestos-related diseases.

“I can’t speculate as to the revised level of liability. However based on our modelling of future mesothelioma incidence it’s worrying that the liability may have been substantially under-estimated,” Dr Clements said.

Dr Clements presented this paper at the Accident Compensation Seminar, hosted by the Institute of Actuaries of Australia.

Workers Exposed To Libby Vermiculite Ore Have High Rate Of Chest Wall Abnormalities

Researchers examined recent chest X-rays of 236 people who worked at a plant in Marysville, Ohio, that until 1980 used vermiculite ore mined in Libby, Mont., that contained asbestos fibers.

Of the 236 workers tested, 62 (26.3 percent) showed pleural plaques, or scarring of the chest wall lining. The occurrence was as high as 44.1 percent in workers with the largest and heaviest exposure to the vermiculite ore. The percentage of workers with pleural plaques was 5.1 percent in those with the lowest levels of exposure.

Pleural plaques are usually considered markers of previous exposure to asbestos fibers. Because of the previous exposure to asbestos, there is a potential increased risk for other asbestos-related lung changes, including scar tissue within the lungs and certain types of cancer such as mesothelioma.

Preliminary results of the study were presented in San Diego May 24, 2005, at the annual International Conference of the American Thoracic Society.

"Our study shows that cumulative exposure to vermiculite from Libby is associated with a significant increase in pleural changes," said study leader James Lockey, MD, professor of occupational and pulmonary medicine at the University of Cincinnati College of Medicine.

"There is clearly a relationship with increasing exposure, but the pleural changes also were seen in the low-exposed workers," said co-author Amy Rohs, MD, a fellow in occupational and pulmonary medicine at University of Cincinnati.

About 0.2 percent of the general population with minimal history of exposure to respiratory hazards shows signs of pleural plaques, Dr. Lockey noted. "I was surprised at the significant increase in overall pleural changes in this working population from 2 percent in 1980 to 26 percent, based on these preliminary results," he added.

"The public health implications of these preliminary findings are important in view of the national distribution of the Libby vermiculite ore," the authors concluded.

Until 1990, more than 200 sites around the country received shipments of vermiculite from the Libby mine.

Vermiculite is a group of minerals with a flaky, mica-like structure. Vermiculite ore from Libby has been shown to contain high levels of asbestos, which could have become airborne and inhaled when used in manufacturing. Vermiculite is widely used in a variety of applications, including insulation, packing materials, construction materials and gardening products. The Libby mine closed in 1990 and vermiculite ore used now comes from other sources and is not known to contain asbestos.

The X-rays were taken during the past two years, and each was reviewed independently by three board-certified radiologists. Spirometry tests, which measure lung function, and health histories also were taken. Although these were not assessed for this study, they will be reported later when the complete study findings are reviewed and published.

The workers were among a group of 513 employees at the Ohio plant exposed to vermiculite and who took part in a 1980 study. Of these 513 workers, 433 (84 percent) are currently alive. That original study, published by Dr. Lockey in the June 1984 issue of American Review of Respiratory Disease, initially showed that exposure to vermiculite containing asbestos fibers could cause pleural plaques.

How Asbestos Fibers Trigger Cancer In Human Cells

Though any clinical application is years away, the researchers hope their findings could aid in drug development efforts targeting illnesses caused by excessive exposure to asbestos, including the deadly cancer called mesothelioma.

The researchers use atomic force microscopy to observe how a single asbestos fiber binds with a specific receptor protein on cell surfaces. They suspect that at least one of the more lethal forms of asbestos triggers a cascade of events inside cells that eventually lead to illness, sometimes decades later.

The conditions most commonly associated with long-term exposure to airborne asbestos are lung cancer; asbestosis, a chronic respiratory disease; and mesothelioma, a cancer that forms in the membrane lining most internal organs of the body, including the lungs.

Eric Taylor, a doctoral candidate in earth sciences at Ohio State and a coauthor of the study, describes atomic force microscopy as “Braille on a molecular level,” meaning it allows scientists to feel and observe what’s happening on molecular surfaces.

“We’re looking at what molecules are involved in the chain of events when the fiber touches the cell. Does the binding occur over minutes, or hours? And what processes are triggered?” said Taylor, who presented the research at the American Geophysical Union meeting in San Francisco.

Asbestos comprises six different minerals that naturally occur in both fragment and fibrous forms. Because of its high durability and heat resistance, the fibrous form has been used in many manufacturing products since the late 1800s. Though its use is now highly regulated, asbestos is still present in many materials. The U.S. Department of Labor estimates that 1.3 million employees face significant asbestos exposure on the job. Environmental exposure is also possible because asbestos is a naturally occurring mineral in soils and exposed bedrock.

Crocidolite, or blue asbestos, is part of the amphibole group of asbestos minerals, which were banned in most of the Western world by the mid-1980s. Before that, they were used in such products as ceiling tiles and thermal insulation.

Ohio State researchers have focused so far on the crocidolite form of asbestos, but eventually hope to study how all six forms of asbestos interact with certain proteins on cell surfaces. Some forms of asbestos can dissolve in the lungs if they are inhaled, but others are believed to essentially “stick” to cells, especially at high concentrations, and eventually cause lung diseases.

“For the first time, this will give us data on biological activity that should help policymakers determine which forms of asbestos are the most dangerous,” said Steven Lower, associate professor of earth sciences at Ohio State and a coauthor on the study.

“The hypothesis we’re testing is that binding of cell surface receptors to asbestos fibers triggers a signal event, which initiates the cancer,” said Lower, also a faculty member in the School of Environment and Natural Resources. “There seems to be something intrinsic about certain types of asbestos, blue asbestos in particular, that elicits a unique signal, and it triggers inflammation, the formation of pre-malignant cells and, ultimately, cancer.”

The first protein to be studied is epidermal growth factor receptor, which is present on the surface of every human cell. Understanding the intricacies of the binding process between the mineral and one or more proteins will provide an index of the biological activity of a particular type of asbestos, and might lead the researchers to figure out how to prevent or undo that interaction, Lower said.

Taylor said the driving motivation behind the research is the potential to find a way to intervene and prevent illness even after someone is exposed to asbestos. Mesothelioma symptoms don’t typically appear until 30 to 50 years after exposure. After diagnosis, however, the cancer is difficult to control, and there is no cure.

This work is supported by the National Science Foundation.

Taylor and Lower conducted the research with Ann Wylie of the University of Maryland and Brooke Mossman of the University of Vermont.

Mesothelioma Cancer - You Deserve Compensation

The mesothelioma is a dreaded cancer affecting the mesothelium of lungs, abdomen, and heart. The causative factor determined is the asbestos exposure that leads to death in several workers related to asbestos industry every year. The sad part is that the appearance of the symptoms occurs at very late stage after around 3 to 4 decades of asbestos exposure. That's the reason why there is so much difficulty in diagnosing mesothelioma cancer in early stages.

No doubt the employers who made this exposure for these workers are guilty. It is employers' duty to protect their employees at any cost while they work for them and give them hefty profits. Failing to do this is an offense and horrific suffering of mesothelioma certainly demands huge compensation from these careless employers. However, due to lots of years elapsed between exposure and occurrence of symptoms, the sufferer and his family needs an expert lawyer who can seek compensation from the guilty employers.

What can be done to seek compensation?

• Firstly taking a decision to approach a mesothelioma attorney is very crucial. Yes, in the tricky times while juggling between hospital visits, bearing terrible pains, breathlessness, and hiring a legal support system may sound weird. Even the relatives are in fizzy as to what to do. But as is said mesothelioma patient needs quite a lot financial support to go through the huge investigation schedules, treatment patterns, and clinical trials. So, decide first to seek justice and everything else will run smoothly.

• Today mesothelioma attorney is a special faculty altogether and one can secure help from lawyers even online.

• The patient and/or his relative can consult the attorney online and call him to know the status of his case. In cases where the causative factor can be traced perfectly, there are very few hurdles in securing compensation.

• The mesothelioma lawyers will tell you the procedures and he will work on your behalf. Most patients can get compensation by completing legal work online itself and they need not visit courts.

• Just giving all the information correctly and as accurately as possible helps one get through the case easily and no doubt the compensations got are huge.

Apart from legal help the mesothelioma cancer patients need a psychological counseling too. Going through this tragedy is certainly not easy. But with apt support system, the journey becomes bit easy. Also the patients' nutritional needs should be maintained in order to improve treatment compliance.

It is rightly said that mesothelioma must be handled with utmost care while considering all these points and only then this life battle may be won. Even if the patient dies, the family can file a lawsuit for the compensation, because it is the family that undergoes huge financial and mental burden due to the entire scenario. Hope, we understand fast the effectiveness of preventive attitude while working enthusiastically during our tenure and our employers understand the importance of employee safety, so that we will never have to see the day when we will lie helplessly struggling with mesothelioma!

How Lung Cancer Affects Other Organs and Body Parts

Every human being wants to be fit and health till the time they live. But, with population increasing and competition rising, people are adopting unfair means to reach higher position and earn more money. This is not only affecting their health but also harming the society. The stress of work is making them to adopt short comfort intakes be it cigarette smoking, alcohol intake, life staking steroids, drugs and so on.

The rate at which people are dying is on rising scale. Due these habits, people are getting affected by the most dreadful disease named "Lung Cancer". The lung cancer survival rate is basically low as this disease spreads at a faster rate compared to other cancers.

Today, we have many lung cancer treatment centers that are exclusively specialized in curing this ailment. Research has shown that Lung cancer is counted under the most life-threatening disease as the cancer in the lungs spreads typically at the high ratio than other cancers like kidney cancer, skin cancer, prostate cancer and so on. The most particular body organs that are affected by this cancer are liver, brains, adrenal glands and bone.

And, to know this, one of the best ways is assessing the extent to which the lungs are being affected, known as lung cancer staging. Through this examination we can know the stage of the cancer that a person is affected. It helps in curing the disease easily to an extent. Many methods are available for conducting this test.

Most of the nations both developed and under developed have hospitals that conduct the lung cancer surgery. But, the pitfall here is, not every patient is fit for this operation. Some of the limiting factors or reasons are the stage of cancer, the number of cells affected and the place of cancer.

The Author "Tom Schavo" is an expert Health adviser who worked for several multinational Companies. Although a professional with rich experience, he quit his position in these companies to finally open up his own Health consulting forum. He also provides free advise on all the latest health developments in market and runs a site on Health Care