Early Scientific Reports and Policies Regarding Asbestosis
The records of asbestos use in Japan date back to ancient times. A ninth-century fairy tale, “Taketori monogatari,” describes incombustible clothes, which are now considered to have been made of asbestos (Sugiyama 1934). The industrial use of asbestos started in the late nineteenth century. Raw asbestos and asbestos products were exported from overseas to Japan in the 1880s. The first asbestos factory, which manufactured asbestos packing and other insulation materials, was founded in Osaka in 1886. Asbestos textile factories that produced the soles of Japanese socks started operating in 1907. Soon a variety of asbestos-containing textiles were being manufactured in the Osaka area (Environmental Agency 1987). At the beginning of twentieth century, the use of asbestos had extended to the construction of battleships,
the installation of military facilities, and the manufacture of underground water pipes, boilers, and brake linings.
In the 1910s and 1920s, the risk of pneumoconiosis caused by asbestos inhala- tion was frequently reported in Europe, the US, and Canada. In 1924, the term
“asbestos lung” was coined to name the pneumoconiosis caused specifically by asbestos (Cooke 1924). The UK Ministry of Interior reported that about one-fourth of the workers in their asbestos textile factories had abnormalities in their lungs.
Then in 1931, the UK government required ventilation fans to be installed in asbestos-handling factories. Shortly thereafter, the US government launched a series of epidemiological studies. In 1935, the first cases of lung cancer were reported in asbestos workers in the UK and the US. In 1938, the US Public Health Service (PHS) officially confirmed the health risk to workers in asbestos textile plants. Many medical reports linking asbestos with long cancer were published in the 1940s (Cook 1942; Greenberg 1999).
These events alerted local Japanese health officials and researchers, who then conducted surveillance in the areas where asbestos was widely processed for indus- trial use. Consequently, in 1929 the first case of asbestosis in Japan was uncovered and reported in a medical journal. In a study conducted from 1937–1940 in Osaka by Dr. Sukegawa and colleagues, asbestosis was found in 65 of 251 workers in factories that manufactured asbestos (Mizuno 2007). As raw asbestos could not be imported during World War II, many small asbestos mines were opened nation- wide, but the limited amount of asbestos ore they produced was of inferior quality.
The mines were closed soon after the war, when imports resumed. However, no actions were taken by the Japanese government until the end of World War II.
After the late 1950s, both the quantity and the use of asbestos expanded remark- ably. It was used in shipbuilding, the manufacturing of chemicals, and the plants for power generation, because of its superior durability and chemical stability. In addi- tion to water pipes, asbestos-containing slate boards and tiles became quite popular in construction, as did roof boards and wall boards. Under the new Constitution, a series of acts and regulations protected the health and safety of workers. These included the Labor Standards Law of 1947, the Compensation Law for Workers’
Accidents of 1947, and the Workplace Safety and Health Regulations of 1947. The latter, though not specifically and exclusively targeting pneumoconiosis, implicitly had its prevention as one of its aims.
In 1954, the Tokyo Labor Standards Office consulted with the Ministry of Labor (MOL) concerning the official recognition of asbestosis as an occupational disease covered by the Compensation Law. Whenever impairments possibly resulting from occupational hazards were not explicitly covered by the law, administrative adjudi- cations were sought on a case-by-case basis. The first recognized asbestos case occurred in the following year. A director at the Osaka Kosei-en National Sanatorium conducted a new health-checkup study of asbestos-handling workers in the Osaka area (Horai et al. 1957). He reported a high incidence of lung disease (especially asbestosis) among the workers.
The bureaucrats did not move quickly to protect workers. In 1955, when “the special act to prevent the impairment by silicosis (stoneman’s disease)” was placed
on the agenda, the explicit inclusion of asbestosis under the law was discussed.
Eventually, asbestos was excluded, because it was “too early.” Silica was better known at the time as a cause of pneumoconiosis than was asbestos. However, in 1956, the MOL started providing research grants to study asbestos-related health hazards, and in 1958 to create diagnostic standards for asbestosis. A 1957 study measuring airborne asbestos fibers in four factory workplaces in Sennai (Osaka) revealed that the fiber concentration exceeded 1,000 fiber/mL in the mixing process in 3 of the mills, with no official order or sanction (Horai 1959; Sera et al. 1960).
Instead, the MOL Labor Standards Bureau required employers to implement a special health-checkup program for asbestos-handling workers. In 1958, the con- struction industry began using asbestos spraying for insulation. It did not take long for this to become very popular in Japan.
In 1960, the “Pneumoconiosis Law of 1960” was adopted. Among other things, it identified asbestos as a cause of pneumoconiosis, and it set rules and regulations regarding environmental safety in the workplace, employers’ obligation to provide health checkups for their workers, and compensation for the afflicted. This was the first time that asbestos was explicitly incorporated in the list of diseases and injuries targeted by law.
Reports on Asbestosis-Induced Cancer and Associated Policies
After the initial case reports of lung cancer in asbestos-handling workers during the mid-1930s, more epidemiological studies were conducted in the UK, the US, and Europe. In the 1950s, an increased incidence of lung cancer in asbestos workers was established by research. Above all, Dr. Doll’s 1955 report confirmed the ele- vated cancer risk from asbestos. In the meantime, a special type of lung cancer, mesothelioma, was reported among workers in the UK in 1935, in Canada in 1952, and in West Germany in 1953. In 1960, mesothelioma cases were reported in the US and South Africa. A landmark article, “Asbestos Exposure and Neoplasia,” by Selikoff et al. (1964), was published in JAMA in 1964. This article thoroughly established the carcinogenic potential of asbestos. It also shows the greatly increased mortality of insulation workers exposed to asbestos, and it makes clear that an epidemic of occupational and environmental cancer was underway. In this year, the ILO held the Employment Injury Benefits Convention (C121), which required asbestosis to be compensated as an occupational injury (International Labor Organization 1964).
In the meantime, mesothelioma cases, as well as cases representing specific forms of cancer in the pleura, peritoneum, and pericardium associated almost exclusively with asbestos exposure, were sporadically reported in many countries, for example, the UK in 1935, Canada in 1952, Germany in 1953, and the US and South Africa in 1960. Asbestos as a cause of mesothelioma was confirmed by ani- mal experiments in 1969. Furthermore, it gradually became evident that the health hazards of asbestos were not confined to workers but were also present in family
members and people living near asbestos factories (LaDou 2004; Newhouse et al.
1972). In 1968, the UK Association of Industrial Hygienists revised the environ- mental standards for asbestos use. At the same time, 35 years after the first case was reported, the UK government launched a disease registration system for mesothe- lioma. Two years after that, in 1970, the government called for the voluntary cessa- tion of crosidolite imports, while the US introduced a set of federal regulations on the environmental monitoring of asbestos, the ventilation in the workplace, the use of personal protection devices, and health checkups for asbestos.
In 1960, the first case of lung cancer in asbestos workers was reported in Japan (Sera et al. 1960). Asbestos consumption was rapidly increasing. Spraying asbestos on ceilings, walls, and iron frames for construction purposes had begun in 1957 and soon became very popular. Also, the production of asbestos-containing building materials remarkably increased after 1965. Both chrysotile and amosite were used for slates and boards. The Japanese government continued to focus its efforts on preventing asbestos (pneumoconiosis). In 1968, the Labor Standards Bureau of the MOL added workplaces in which asbestos was handled to the list of venues covered by the occupational safety law. The health regulations required the instal- lation of local ventilation facilities to limit dust concentrations. The production of asbestos-containing construction materials rose steadily and remarkably from 1965 to 1975.
In 1970, an official inspection of the release into the environment of 46 hazard- ous substances revealed that only 70.3% of the 150 asbestos-handling workplaces surveyed had installed an appropriate air ventilation system. These results led the MOL to convene an expert panel. Based on the panel’s report, “the Ordinance on the Prevention of Hazards due to Specified Chemical Substances (SCS) of 1971 (SCS Ordinance of 1971, [Tokutei Kagaku-busshitsu tou Shougai Yobou Kisoku])”
was enacted. Though asbestos had not been listed as a carcinogen in the preceding report, the Ordinance included the detailed safety measures for asbestos processing, a requirement for ventilation, environmental standards for workplaces, compulsory health checkups for workers, and official inspections for manufacturers’ compli- ance with the other provisions of the ordinance. The local ambient concentration allowed for hazardous substances was defined as the permissible concentration recommended by either the Japan Society for Occupational Health (JSOH) or the American Conference of Governmental Industrial Hygienists (ACGIH). For asbes- tos, the adopted concentration was 2 mg/m3 (33 fibers/cm3).
During the discussion of this regulation in 1970, it was reported that eight asbestos-handling workers had died of lung cancer in the preceding 11 years. This report attracted the attention of experts to the risk of lung cancer caused by asbestos (Sera 1971; Sera et al. 1973). With reference to the SCS Ordinance of 1971, an MOL officer explained that asbestosis was as severe an impairment as silicosis and that a certain kind of asbestos can cause lung cancer and malignant mesothelioma in the pleura of the lung. Although the scientific evidence was yet to be forthcom- ing, asbestos was included in the regulations for the prevention of the associated health hazards. As described above, at this time asbestos was not officially treated as carcinogenic, although some considered it to be just as hazardous as silica.
However, no action was taken in response to these reports, especially as they applied to neighborhoods and the general population. The ordinance was reformu- lated only as an administrative order, in compliance with the new Occupational Safety and Health Law of 1972.
In 1972, the ILO and the WHO/IARC convened a meeting of experts in Lyon, entitled “Evaluation of the Carcinogenic Risk of Chemicals to Man.” The experts listed asbestos as a carcinogen, and several European countries introduced stricter regulations: Iceland in 1973 and Norway in 1974 banned the use of all kinds of asbestos; Sweden in 1975 prohibited the use of crocidolie (blue asbestos), and in 1972 the UK banned its import; Denmark in 1972 and the US in 1973 prohibited the spraying of asbestos. Canadian industry introduced a voluntary cessation of asbestos spraying in 1973, and at the same time the EC adopted a directive that prohibited the distribution and use of crocidolite. Finally, the ILO in 1973 adopted the Occupational Cancer Convention (C139), which recommended international standards for protection against carcinogenic substances, including asbestos; it took effect in 1974.
In Japan, some experts, bureaucrats, and politicians were already aware of the carcinogenic risk caused by various kinds of exposure to asbestos, including occu- pational, para-occupational (workers’ family), and environmental (residents in the factories’ neighborhood) exposure (Konami et al. 1974; Shishido 1986). They were also aware of the actions taken by other countries and the WHO in this regard.
Research supported by the Environmental Agency (EA) summarized the scientific reports from foreign countries. Furthermore, another EA-granted research con- firmed the elevated incidence of lung cancer among asbestos workers. In 1972, a politician from the Japan Communist Party raised this issue in the Diet, and a Director of the Public Health Bureau of the Ministry of Health and Welfare (MHW) stated that health checkups might be necessary if asbestos were shown to have detrimental health effects on neighborhood residents. In 1973, a study of residents in an area of Osaka revealed 10 lung-cancer cases among asbestosis patients, as well as the first case of peritoneal mesothelioma (Sera et al. 1973). Cases of pleural mesothelioma were increasingly publicized during the following year (Kishimoto et al. 2003). The JSOH responded by further tightening its asbestos regulations.
Shortly after the ILO convention of 1972, the MOL revised the Ordinance of 1971, setting the permissible asbestos concentration in the local air as 5 fibers/mL.
The Bureau Director mentioned that the revision was necessary because asbestos was now known to cause malignant neoplasms such as lung cancer and mesothe- lioma, and several countries were tightening their environmental standards for asbestos dust. An expert panel was again called to discuss the hazards and regula- tion of asbestos. In 1975, the SCS Ordinance was again revised. It banned the spraying of materials in which the asbestos concentration exceeded 5%, encour- aged the use of asbestos substitutes, designated other control measures, and explic- itly branded asbestos as a carcinogen.
In 1976, the Labor Standards Bureau of the MOL circulated information on asbestos hazards, including a foreign report noting an increase in the incidence of lung cancer among workers and neighborhood residents and calling for better
compliance with the revised Ordinance. The Working Environment Measurement Law of 1976 further specified that asbestos exposure levels should be reduced to less than 2 fibers/mL. Coincidentally, in the same year, the results of a local occu- pational health survey revealed that 4 relatives of workers at asbestos-handling brake factories, and 11 people living nearby, had died of lung cancer (Ebihara 1981). The IARC released a monograph documenting the risk of lung cancer and mesothelioma caused by crocidolite, amosite, and chrysotile (International Agency for Research on Cancer 1977). In 1978, 18 years after the first case report of cancer in Japan, and 5 years after the first mesothelioma case was reported there, the offi- cial standards for workers’ compensation for these cancers were institutionalized:
Asbestos-induced lung cancer and mesothelioma were identified as occupational cancers by administrative order; more than 10 years’ employment was required for lung cancer and more than 5 years for mesothelioma.
For many years, crocidolite had been used in Japan for making asbestos cement pipes and amosite had been used for making boards; both had been used for spraying.
After 1976, most of the asbestos was being used in the manufacture of boards and slates. As a result of the SCS Ordinance, more artificial (man-made) fibers, such as rock wool, were being used for spraying (rock wool containing less than 5% asbestos continued to be used for spraying until 1980). On the whole, the substitution of substances for asbestos in fact proceeded quite sluggishly, as the industry saw the substitutes as inferior in terms of their properties and costs. Also, many insisted that asbestos could be used safely if the users took sufficient caution. The major small- and medium-sized companies continued to produce asbestos-containing construction materials, because they could not afford to invest in asbestos-free products (National Diet Library 2005: p. 3). Asbestos consumption reached its peak in the mid to late 1970s (Fig. 2.1).
In Europe, West Germany banned asbestos spraying in 1979, and Norway and Denmark in principle prohibited the use of asbestos in 1980. Also in 1980, the ILO added lung cancer and mesothelioma, along with asbestosis, to its list of occupa- tional accidents and diseases eligible for compensation (Nevitt et al. 2007). Japan ratified this convention a year later.
Possible Environmental Hazards and Policies for Reassurance
Soon after the release of the IARC monograph in 1977, the US National Cancer Institute (NCI) sent warning letters on asbestos risks to all physicians nation- wide. All asbestos spraying was banned in 1979 (Nicholson et al. 1979; Baldwin et al. 1982; Stavisky 1982). The risks in school buildings appeared on the public agenda, and some states, such as New York, enacted laws to remove asbestos surfacing materials. The Environmental Protection Agency (EPA) set guidelines for clearing asbestos from school buildings. In 1980, Congress passed the Asbestos School Hazard Detection and Control Act, which required the
investigation of asbestos risks in schools, based on the premise that there was no safe level of asbestos exposure (Mossman et al. 1990). The ACGIH revised its permissible concentration level for asbestos (chrysotile 2 fibers/cm3, amosite 0.5, crocidolite 0.2).
In Japan, in 1979, soon after the institutionalization of compensation for asbes- tos-induced cancers, the EA began collecting scientific papers on the risks of air- borne carcinogens (including asbestos). Some of these papers documented an increased incidence of cancer in workers’ families and among people living near the factories. Others noted the EC’s recent determination that there was no firm evidence about the health risks of asbestos in the air. Based on these papers and the recommendation of the expert panel, the EA started an environmental measurement program in 1980. The media and politicians occasionally stressed the possible health hazards of non-occupational exposure to asbestos, such as in residences located near asbestos factories.
The EA justified its inaction by stating that it remained to be seen whether all the cancer cases with no history of occupational exposure to asbestos could or should be attributed to environmental pollution, but it reaffirmed its commitment to further research. In 1981, the Agency formed an expert panel to study factory emis- sions of asbestos, its concentration in the environment, the methods used to mea- sure and control it, and viable alternatives. The EA released the panel’s report to the national press early in 1985. It concluded that asbestos concentration in the ambient air was far below that at worksites and therefore the risk of airborne asbestos in the general environment was minimal. The panel also noted that the persistence and accumulation of asbestos in the human environment would be a problem in the future. They concluded that, therefore, the development of alternative materials was
1920 1940 1960 1980 2000
0 200 400 600 800
0 100000 200000 300000 400000
Asbestos import (left axis)
Occupational lung cancer and mesothelioma cases
cases
tons
Fig. 2.1 Asbestos import to Japan, lung cancer and mesothelioma
important, as was the development of technology to minimize the release of asbes- tos into the air, especially during demolition and waste disposal.
Regarding occupational health, the German government and asbestos industry reached a voluntary agreement in 1982 that prohibited asbestos in construction materials until 1990. In 1983, after the IARC report on the carcinogenicity of asbestos, the ILO adopted a code of practice entitled “Safety in the Use of Asbestos” that stated the obligations of both the government and employers to protect workers from asbestos (International Agency for Research on Cancer 1982). Also in 1983, the EC issued a set of directives (83/477–478/EEC) that prohibited the sale and use of crocidolite before March 1986, and the spraying of asbestos before January 1987.
Meanwhile in Japan, 11 of 427 factories nationwide were processing crocidolite and 52 were processing amosite. In 1982, doctors at a hospital in Yokosuka city began studying the pathological anatomy of 848 patients, mostly workers at mili- tary bases or engaged in shipbuilding, who had died in the previous 5 years. They found that one-third of them died from lung cancer caused by asbestos exposure (Kazan-Allen 2003; Morinaga 1989; Morinaga et al. 1982). Several clinical and epidemiological studies were further conducted (Kikuchi and Hiraga 1983;
Miyazaki 1983). Also in 1982, the JSOH recommended a lower permissible con- centration level for crocidolite (0.2 fibers/cm3). The MOL did not comply with this recommendation but instead issued a set of notices that urged local governments and employers to adopt the recommended measures for improving the work envi- ronment. In September 1986, after the EA report, the MOL issued a notice that laborers working in demolition and refurbishment must be appropriately protected from the health hazards of asbestos dust (Gunji 1987). In 1985, it was reported that 43 cases of lung cancer and 9 of the approximately 500 cases of mesothelioma deaths in Japan were compensated through the injury benefits scheme. Thirty thou- sand workers in 3,000 workplaces enrolled in special health-checkup programs for asbestos-related diseases. The MOL further reported that its inspection uncovered no asbestos factories that were processing crocidolite.
In Europe, Switzerland banned the use of asbestos. The UK banned the import of products containing crocidocite and amosite, and it followed the EC in prohibit- ing the spraying of asbestos. In 1986, the WHO’s Environmental Health Criteria (EHC53) were released. This document summarized the possible health hazards of asbestos for workers and nearby residents, but not for the general environment (World Health Organization 1986). The Japanese mass media and politicians picked up on the issue only sporadically. In July, the Japanese government ratified the ILO Asbestos Convention of 1964. When a nationwide investigation was called for, the EA argued that no epidemiological survey could detect the real extent of the health hazards to the general environment.
In 1985, the 72nd ILO Convention put the safe use of asbestos on its agenda. In June 1986, the ILO General Conference held the “Convention concerning Safety in the Use of Asbestos (C162)” and adopted the “Recommendation concerning Safety in the Use of Asbestos (R172),” which listed the main policy instruments for the safe handling and uses of asbestos, including the option of banning its use