The Case for a Global Ban on Asbestos

Background

All forms of asbestos are now banned in 52 countries. Safer products have replaced many materials that once were made with it. Nonetheless, many countries still use, import, and export asbestos and asbestos-containing products, and in those that have banned other forms of asbestos, the so-called “controlled use” of chrysotile asbestos is often exempted from the ban. In fact, chrysotile has accounted for > 95% of all the asbestos used globally.

Objective

We examined and evaluated the literature used to support the exemption of chrysotile asbestos from the ban and how its exemption reflects the political and economic influence of the asbestos mining and manufacturing industry.

Discussion

All forms of asbestos, including chrysotile, are proven human carcinogens. All forms cause malignant mesothelioma and lung and laryngeal cancers, and may cause ovarian, gastrointestinal, and other cancers. No exposure to asbestos is without risk. Illnesses and deaths from asbestos exposure are entirely preventable.

Conclusions

All countries of the world have an obligation to their citizens to join in the international endeavor to ban the mining, manufacture, and use of all forms of asbestos. An international ban is urgently needed. There is no medical or scientific basis to exempt chrysotile from the worldwide ban of asbestos.     

Asbestos Is Still With Us: Repeat Call for a Universal Ban

Abstract

All forms of asbestos are proven human carcinogens, causing malignant mesothelioma and a host of other types of cancers. No exposure to asbestos is without risk; there is no safe threshold of exposure to asbestos. When evidence of the carcinogenicity of asbestos became incontrovertible, a worldwide ban was called for on asbestos use, mining, and manufacturing. Asbestos is now banned in 52 countries. Nonetheless, many countries still use, import, and export asbestos and asbestos-containing products; many countries that have banned other forms of asbestos still permit the use of chrysotile asbestos. This exemption has no basis in medical science, but reflects the political and economic influence of the asbestos industry. To protect the health of all people, the Collegium Ramazzini calls again on all countries of the world to join in the international endeavor to ban all forms of asbestos. An international ban on asbestos is urgently needed.     

Chrysotile asbestos is the main cause of pleural mesothelioma

In contrast to amphibole forms of asbestos, chrysotile asbestos is often claimed to be only a minor cause of malignant pleural mesothelioma, a highly fatal cancer of the lining of the thoracic cavity. In this article we examine the evidence from animal and human studies that relates to this issue. Reported data do not support widely quoted views regarding the relative inertness of chrysotile fibers in mesothelioma causation. In fact, examination of all pertinent studies makes it clear that chrysotile asbestos is similar in potency to amphibole asbestos. Since asbestos is the major cause of mesothelioma, and chrysotile constitutes 95% of all asbestos use world wide, it can be concluded that chrysotile asbestos is the main cause of pleural mesothelioma in humans. © 1996 Wiley-Liss, Inc.     

The scientific basis of a total asbestos ban

Worldwide, in the new millennium, standards for the protection of workers and the general population from as-bestos risks are not equally stringent in all countries. The present review analyzes some arguments which in recent years have been proposed as a rationale for the reconsideration of the scientific background of a total asbestos ban, such as that adopted in the European Union. The conclusion is that in order to ensure adequate protection, there is no alternative to a total ban. The evidence for carcinogenicity of chrysotile is as good as for the amphiboles, the carcinogenic potency of chrysotile is lower than that of the amphiboles, but risk estimates must also be based on extent of exposure (nowadays chrysotile represents 95% of asbestos used worldwide). The fact that induction of mesothelioma by asbestos results from the interaction of environmental exposure and genetic factors reflects a general phenomenon in carcinogenesis and does not warrant any re-consideration of the role of asbestos. The role of SV40 as yet is unclear: even assuming that current risk estimates are correct (which is debatable), this agent would interact with asbestos in only a faction of mesothelioma cases. The effectiveness of protocols suggested for "controlled use" has not been tested with a scientfiic approach: they seem hardly practicable, particularly in the countries which are currently the major consumers of asbestos.     

The hazards of chrysotile asbestos: a critical review.

Chrysotile, or "white", asbestos is the dominant form of asbestos in international commerce today. It accounts for 99% of current world asbestos production of 2 million tonnes. Chrysotile is an extremely hazardous material. Clinical and epidemiologic studies have established incontrovertibly that chrysotile causes cancer of the lung, malignant mesothelioma of the pleura and peritoneum, cancer of the larynx and certain gastrointestinal cancers. Chrysotile also causes asbestosis, a progressive fibrous disease of the lungs. Risk of these diseases increases with cumulative lifetime exposure to chrysotile and rises also with increasing time interval (latency) since first exposure. Comparative analyses have established that chrysotile is 2 to 4 times less potent than crocidolite asbestos in its ability to cause malignant mesothelioma, but of equal potency of causation of lung cancer. The International Agency for Research on Cancer of the World Health Organization has declared chrysotile asbestos a proven human carcinogen. Sales of chrysotile asbestos have virtually ended in Western Europe and North America, because of widespread recognition of its health hazards. However, asbestos sales remain strong in Japan, across Asia and in developing nations worldwide. The claim has been made that chrysotile asbestos can be used "safely" under "certain conditions" in those nations. That claim is not accurate. The Collegium Ramazzini, an international learned society in environmental and occupational medicine, has called for an immediate worldwide ban on all sales and uses of all forms of asbestos, including chrysotile. The rationale for this ban is threefold: (1) that safer substitute materials are readily available, (2) that "controlled" use of asbestos is not possible, and (3) that the health risks of asbestos are not acceptable in either the industrialized or the newly industrializing nations.     

The trend in airborne asbestos concentrations at plants manufacturing asbestos-containing products in Japan

In Japan, chrysotile is still permitted to use under the Ordinance on Prevention of Hazards due to Specified Chemical Substances. In recent years many countries have introduced a policy of prohibiting the use of asbestos, based on clinical and epidemiological studies. In light of this, it is important to evaluate the airborne asbestos concentrations in workplaces and also estimate the number of related disease cases in order to discuss the ban of asbestos use. The survey covered 528 workplaces in 145 plants and included 2795 asbestos handling workers from 1985 to 1998. These plants were belonging to the Japan Asbestos Association (JAA) as member companies. In Japan, nearly all of the asbestos using manufacturing companies are members of JAA. In our study, all of the workplaces were divided under each separate manufacturing process and classified into 3 categories of Control Classes. Of the 454/528 (86.0%) workplaces classified as Control Class 1 are improved to 376/378 (99.5%). Though in the cases of small enterprises, other factors such as a shift in product lines, and the economic recession, as well as efforts, contributed to improvements in working conditions. JAA recommended self-administered concentrations of 1.0 f/ml (compatible to <0.3 f/ml in personal exposure level) in 1991 to promote further improvements of the work environment. From this point of view, exposure limits can almost be technically achieved in Japan, and it is expected that asbestos related disease could be expected to decrease in 20 to 30 years later. This survey will become basic material for verifications whether we could control asbestos related diseases enough in such well-controlled work environment.     

Asbestos banned in Argentina

In 1997, Argentina gave priority to asbestos in its National Plan for the Sound Management of Chemicals, and it was the subject of a Technical Task Force on Occupational Cancer. After five years of public hearings in which government, workers, industry advocates, environmentalists, clinicians, scientists, and consumers participated, it was agreed that asbestos exposure is a risk factor for both workers and the general population, and that Argentina should provide to its people the same protections adopted by many developed countries. Pressure from asbestos industry groups initially delayed the inclusion of chrysotile asbestos in the proposed ban, but on January 1, 2003, the mining and import of all forms of asbestos were banned in Argentina.     

Exposing the "myth" of ABC, "anything but chrysotile": a critique of the Canadian asbestos mining industry and McGill University chrysotile studies

BACKGROUND: Beginning in the 1930s, the Canadian asbestos industry created and advanced the idea that chrysotile asbestos is safer than asbestos of other fiber types. METHODS: We critically evaluate published and unpublished studies funded by the Quebec Asbestos Mining Association (QAMA) and performed by researchers at McGill University. RESULTS: QAMA-funded researchers put forth several myths purporting that Quebec-mined chrysotile was harmless, and contended that the contamination of chrysotile with oils, tremolite, or crocidolite was the source of occupational health risk. In addition, QAMA-funded researchers manipulated data and used unsound sampling and analysis techniques to back up their contention that chrysotile was "essentially innocuous." CONCLUSIONS: These studies were used to promote the marketing and sales of asbestos, and have had a substantial effect on policy and occupational health litigation. Asbestos manufacturing companies and the Canadian government continue to use them to promote the use of asbestos in Europe and in developing countries. Am. J. Ind. Med. 44:540-557, 2003.     

Asbestos in developing countries: magnitude of risk and its practical implications

In developing countries, aggressive marketing of chrysotile asbestos continues as a result of restrictions on its use being imposed by the developed countries. In the Asian continent, China and India are emerging as the major users of asbestos. There is enough evidence to link chrysotile with pulmonary fibrosis and lung cancer in humans, even at low levels of exposure, hence the need to apply the Precautionary Principle for phasing out its use globally. Due to poor occupational health and safety systems in developing countries and difficulties in early detection of pulmonary malignancy related to asbestos, the statistics remain sketchy. This is hampering efforts to create pressure on policy makers and to counter the propaganda of the asbestos industry. The International Labour Office believes that more than 100,000 deaths a year occur from asbestos-related disease. In the view of studies published in Europe and Australia, the number of deaths due to such malignancies will peak around the year 2020 and could be anywhere between half a million to a million. That means more than a million deaths will occur in developing countries. At about the same time when asbestos-related deaths start to decrease in developed countries, their number will begin to rise in developing countries. This presents a major challenge to the international scientific community.     

Asbestos-related morbidity in India

In India, locally mined asbestos is not enough for its current needs, hence a great deal of asbestos is imported from Canada. Asbestos products manufacturers have prevailed upon the government to reduce tariffs on imported material. The efforts of the health and safety professionals who joined with nongovernmental organizations to form the Ban Asbestos Network of India (BANI) are being consistently sabotaged by the industry, using its influence and false propaganda that chrysotile asbestos can be safely used in a controlled manner. Weak legislation and lack of data are being exploited by the industry to convince policymakers that asbestos use in India has caused no major health problems. Despite this, the ban-asbestos movement has gained momentum and was able to persuade government to consider banning asbestos use. With the growing strength of the movement it is expected that asbestos manufacturers may find it increasingly difficult to manipulate the government in the future.     

How conflicted authors undermine the World Health Organization (WHO) campaign to stop all use of asbestos: spotlight on studies showing that chrysotile is carcinogenic and facilitates other non-cancer asbestos-related diseases

The silicate mineral asbestos is categorized into two main groups based on fiber structure: serpentine asbestos (chrysotile) and amphibole asbestos (crocidolite, amosite, anthophyllite, tremolite, and actinolite). Chrysotile is used in more than 2 000 applications and is especially prevalent in the construction industry. Although its use is banned or restricted in more than 52 countries, an estimated 107 000 workers die from asbestos exposure each year, and approximately 125 million workers continue to be exposed. Furthermore, ambient exposures persist to which the public is exposed, globally. Today, the primary controversies regarding the use of asbestos are the potencies of different types of asbestos, as opposed whether or not asbestos causes morbidity and mortality. The asbestos industry has promoted and funded research based on selected literature, ignoring both clinical and scientific knowledge. In this piece, we highlight a prominent example of a conflicted publication that sought to undermine the World Health Organization (WHO) campaign to stop the use of all forms of asbestos, including chrysotile asbestos. Independent and rigorous scientific data provide sufficient evidence that chrysotile asbestos, like other forms of asbestos, is a cause of asbestos-related morbidity and premature mortality     

On the release of asbestos fibers from weathered and corroded asbestos cement products

The controversy on whether weathered and corroded asbestos cement products are emitting biologically significant asbestos fiber concentrations in ambient air has not been resolved. Nor is it known if the weathered and corroded asbestos cement products release asbestos fibers which have the same carcinogenic potency as "standard" chrysotile. The purpose of this research project was to develop a method for sampling and measuring asbestos fiber emissions from solid planar surfaces (i.e., roofs and facades) consisting of asbestos cement products and to develop methods for studying the physical and chemical changes and the carcinogenic potency of the emitted fibers. Using this method asbestos fiber emissions in ambient air have been measured in the FRG during 1984/1986. The emissions of asbestos fibers longer than 5 microns were in the range 10(6) to 10(8) fibers/m2.hr. The ambient air concentrations of these asbestos fibers were for the most part less than 10(3) fibers/m3. It was shown that the emitted asbestos fibers were chemically changed and it was shown with animal experiments that their carcinogenic potency did not differ from the carcinogenicity of "standard" chrysotile fibers.     

Asbestos poisons World Trade Organization atmosphere.

In September 2000, a World Trade Organization (WTO) panel published its findings in the dispute between Canada and the European Union/France over France's ban on the import and use of chrysotile (white asbestos). The panel upheld the French ban, established that the use of chrysotile is a health risk and the idea of "controlled use" a fallacy, and used (for the first time) an exception clause in the General Agreement on Tariffs and Trade that permits trade-restrictive measures to protect human life or health. At the same time, the panel concluded that the French ban violated international trade laws by treating chrysotile products less favorably than domestically produced alternatives. Some WTO watchers believe that with asbestos as the precedent for bans on toxic substances, the regulation of other, much less well-established, toxic exposures could prove much more difficult. Now the French ban has been upheld, chrysotile producers will increasingly target developing countries. Canada is appealing the WTO decision.     

How conflicted authors undermine the World Health Organization (WHO) campaign to stop all use of asbestos: spotlight on studies showing that chrysotile is carcinogenic and facilitates other non-cancer asbestos-related diseases

Abstract

The silicate mineral asbestos is categorized into two main groups based on fiber structure: serpentine asbestos (chrysotile) and amphibole asbestos (crocidolite, amosite, anthophyllite, tremolite, and actinolite). Chrysotile is used in more than 2 000 applications and is especially prevalent in the construction industry. Although its use is banned or restricted in more than 52 countries, an estimated 107 000 workers die from asbestos exposure each year, and approximately 125 million workers continue to be exposed. Furthermore, ambient exposures persist to which the public is exposed, globally. Today, the primary controversies regarding the use of asbestos are the potencies of different types of asbestos, as opposed whether or not asbestos causes morbidity and mortality. The asbestos industry has promoted and funded research based on selected literature, ignoring both clinical and scientific knowledge. In this piece, we highlight a prominent example of a conflicted publication that sought to undermine the World Health Organization (WHO) campaign to stop the use of all forms of asbestos, including chrysotile asbestos. Independent and rigorous scientific data provide sufficient evidence that chrysotile asbestos, like other forms of asbestos, is a cause of asbestos-related morbidity and premature mortality     

Asbestos dispatches

As the global campaign to ban asbestos gathers momentum, more countries and organizations are restricting the use of chrysotile (white asbestos). Attempting to reverse the fall in global demand, asbestos stakeholders have redoubled marketing efforts in countries such as India where health and safety regulations are not strictly enforced. In the Canadian asbestos heartland, public and media awareness has grown and industry's influence has weakened. In response, chrysotile producers are pressing federal and provincial governments for mandatory increases in consumption, despite new research documenting an asbestos cancer epidemic.     

Chrysotile Asbestos in the Lungs of Persons in New York City

When inhaled, chrysotile tends to split into unit fibrils 200 to 400 Angstroms in diameter, invisible with optical microscopy. Further, it is altered chemically and physically in vivo. Therefore, attempts to identify unaltered chrysotile in the core of “asbestos bodies” have many pitfalls, especially when such attempts are limited by optical microscopy. High-magnification electron-microscopic examination of representative small samples of lung unequivocally showed chrysotile asbestos to be present in 24 of 28 consecutive New York city autopsy cases. Our data demonstrate that chrysotile fibers and fibrils are present in the lungs of New York city residents. Similar observations have been made in London. We anticipate that what is now known for New York and London will be found in other cities as well.     

Epidemiology of occupational asbestos-related diseases in China

In 1950s and 60s, asbestosis had been a major health hazard for asbestos exposed workers. In the late 1970s, lung cancers with or without asbestosis were found among asbestos workers. All cohort studies on asbestos workers and on chrysotile miners in China showed excess deaths from lung cancer. In a large scale of cohort study on asbestos workers, a synergistic effect was found between cigarette smoking and asbestos exposure in the production of lung cancer. There have been not so many cases of malignant mesotheliomas reported, so far. In the cohort of chrysotile miners, 4 cases of pleural mesothelioma were observed. In the large scale of cohort study on asbestos workers in 9 factories using only chrysotile only one case of pleural mesothelioma was detected for 10 years' observation. In another 2 cohort studies, 2 cases of peritoneal mesotheliomas were found, one in Shanghai asbestos factory where a small amount of crocidolite had been used in 1960s, and one in Anqing asbestos factory that was located near tremolite mine. Further study is needed especially for the relationship between exposure to Chinese chrysotile and malignant mesotheliomas.     

Growth changes of 3T3 cells in the presence of mineral fibers

The relationship between exposure to asbestos fibers and the development of mesothelioma or bronchial carcinoma prompted many countries to ban its use from commercial products. The biological mechanism by which asbestos induces or promotes mesothelioma or carcinoma is still unknown. In order to study the influence of fibers on the cell surface, 3T3 fibroblasts were cultured in the presence of various mineral fibers. The acute cytotoxicity produced by mineral fibers was evaluated by the trypan blue dye exclusion method; growth of 3T3 cells was measured as well as the maximum cell density at saturation. We found that growth of 3T3 cells was slower in the presence of chrysotile while light microscopy revealed an increased cellular chromogenicity and a modification of the cell-cell arrangement in the presence of this fiber. We describe an assay in which chrysotile causes an increase in the maximum cell density at saturation.     

Comparative hazards of chrysotile asbestos and its substitutes: A European perspective.

Although the use of amphibole asbestos (crocidolite and amosite) has been banned in most European countries because of its known effects on the lung and pleura, chrysotile asbestos remains in use in a number of widely used products, notably asbestos cement and friction linings in vehicle brakes and clutches. A ban on chrysotile throughout the European Union for these remaining applications is currently under consideration, but this requires confidence in the safety of substitute materials. The main substitutes for the residual uses of chrysotile are p-aramid, polyvinyl alcohol (PVA), and cellulose fibers, and it is these materials that are evaluated here. Because it critically affects both exposure concentrations and deposition in the lung, diameter is a key determinant of the intrinsic hazard of a fiber; the propensity of a material to release fibers into the air is also important. It is generally accepted that to be pathogenic to the lung or pleura, fibers must be long, thin, and durable; fiber chemistry may also be significant. These basic principles are used in a pragmatic way to form a judgement on the relative safety of the substitute materials, taking into account what is known about their hazardous properties and also the potential for uncontrolled exposures during a lifetime of use (including disposal). We conclude that chrysotile asbestos is intrinsically more hazardous than p-aramid, PVA, or cellulose fibers and that its continued use in asbestos-cement products and friction materials is not justifiable in the face of available technically adequate substitutes.     

Environmental Contamination of Chrysotile Asbestos and Its Toxic Effects on Growth and Physiological and Biochemical Parameters of <Emphasis Type="Italic">Lemna gibba</Emphasis>

Asbestos was monitored in water, sediment, and aquatic plant samples around an asbestos cement factory. Based on asbestos concentration found in aquatic plants during monitoring, and the propensity of asbestos to cause oxidative stress in animal models, laboratory experiments were conducted to assess toxicity of chrysotile asbestos on an aquatic macrophyte, duckweed (Lemna gibba). L. gibba plants were exposed to two concentrations of chrysotile asbestos (0.5 g and 5.0 g chrysotile in 5.0 l double distilled water) twice per week during a period of 28 days and cultured in medium containing 0.1 g chrysotile/L. Control plants were cultured in medium without chrysotile asbestos. Effect of chrysotile exposure on certain growth and physiological and biochemical parameters was evaluated. An inhibition effect of chrysotile exposure was found on the number of fronds, root length, and biomass. Similar alterations in contents of chlorophyll, carotenoid, total free sugar, starch, and protein were also found. Contrary to effect on these parameters, a dose- and time-dependent increase in efflux of electrolytes, lipid peroxidation, cellular hydrogen peroxide, catalase, and superoxide dismutase activity was found. The results indicate oxidative stress and phytotoxicity of chrysotile asbestos on duckweed.