move to the right menu  move to the main contents



Jump menu


Home > Supreme Court of Japan


2001 (Ju) 1760

2004.04.27
2001 (Ju) 1760
Minshu Vol. 58, No. 4
Judgment upon the case in which the failure of the Minister of International Trade and Industry to exercise the authority to enforce safety regulations under the Mine Safety Law in order to prevent the outbreak of pneumoconiosis in coal mines was judged to be illegal under Article 1, para. 1 of the Law Concerning State Liability for Compensation
Case to seek damages and restitution against a provisional execution under Article 260, para. 2 of the Code of Civil Procedure
Judgment of the Third Petty Bench, dismissed
Fukuoka High Court, Judgment of July 19, 2001
1. Where people engaging in work in the dusty environment in coal mines have contracted pneumoconiosis due to inhalation of dust, given the facts that, in light of the serious conditions of coal workers suffering pneumoconiosis and the changes in medical knowledge on pneumoconiosis, the Pneumoconiosis Law was enacted, which broadly defines pneumoconiosis so that the law would be applicable to cases where pneumoconiosis was caused due to inhalation of mineral dust such as coal dust, and by that time, it became obvious engineering knowledge that it would be possible to prevent the generation of dust, the cause of pneumoconiosis, very successfully by using wet-type rock drills and there were no special obstacles to the use of wet-type rock drills in all coal mines in the same manner as in metal mines but the Minister of International Trade and Industry failed to amend, by the time of enactment of the said law, ministerial ordinances under the Mine Safety Law and to require the use of wet-type rock drills as a general safety regulation, the failure of the Minister of International Trade and Industry to exercise the authority to implement safety regulations including the authority to amend ministerial ordinances under the Mine Safety Law immediately after the enactment of the Pneumoconiosis Law shall be deemed to be illegal for the purpose of the application of Article 1, para. 1 of the Law Concerning State Liability for Compensation.
2. The period of extinctive prescription set forth in the second part of Article 724 of the Civil Code shall start from the time when all or part of damage has arisen from an unlawful act if the damage, due to its nature, arises after a considerable period of time has passed since the termination of the act of causing the damage.
(Concerning 1) Article 1, para. 1 of the Law Concerning State Liability for Compensation, Articles 1 and 4 of the Mine Safety Law, Article 30 of the Mine Safety Law before amendment by Law No. 105 of 1962, Article 2, para. 1 sub-para. 1 of the Pneumoconiosis Law before amendment by Law No. 76 of 1977, Article 284-2 of the Safety Regulations on Coal Mines before amendment by Ministry of International Trade and Industry Ordinance No. 74 of 1986

Article 1, para. 1 of the Law Concerning State Liability for Compensation
When a governmental official who is in a position to exercise the public authority of the State or of a public body has, in the course of performing his duties, illegally caused damage to another person either intentionally or negligently, the State or the public body concerned shall be liable to compensate such damage.

Article 1 of the Mine Safety Law
(Purpose of the law)
The purpose of this law is to prevent harm to mine workers and prevent mine pollution as well as to promote the rational development of mineral resources.

Article 4 of the Mine Safety Law
(Obligations of the mining right owner)
The mining right owner shall take necessary measures to:
(1) Prevent rockfall, collapse, burst of water, gush of gas, explosion of gas or coal dust, spontaneous fire or mine fire;
(2) Prevent harm or mine pollution, which arise from the treatment of gas, dust, waste rock, slag, mine water, wastewater, and metallurgical smoke;
(3) Prevent harm arising from the handling of machinery, equipment (excluding hygienic protective equipment; hereinafter the same), or explosives and other materials, power, and fire;
(4) Ensure ventilation and establish rescue bodies;
(5) Protect mineral resources;
(6) Maintain machinery, equipment, buildings, and structures;
(7) Prevent mine pollution due to excavation of land and take other safety measures.

Article 30 of the Mine Safety Law before amendment by Law No. 105 of 1962
(Delegation to ministerial ordinances)
Except as otherwise provided in Articles 6 to 10, Article 12, Article 13, Article 15 to 17, Article 19, Article 23, and the preceding two articles, measures to be taken by the mining right owner under Article 4 and matters to be observed by technical personnel for safety protection and other mine workers under Article 5 shall be prescribed by ministerial ordinances.

Article 2, para. 1, sub-para. 1 of the Pneumoconiosis Law before amendment by Law No. 76 of 1977
(Definitions)
1. Each of the following terms used in this law shall have the meaning as defined in the relevant subparagraph.
(i) "Pneumoconiosis" means pneumoconiosis caused by inhalation of mineral dust (hereinafter referred to as "dust") and pulmonary tuberculosis complicated by pneumoconiosis.

Article 284-2 of the Safety Regulations on Coal Mines before amendment by Ministry of International Trade and Industry Ordinance No. 74 of 1986
(Silicic acid areas)
1. In an area designated by the Minister of International Trade and Industry as an area that has a large quantity of free silicic acid contained in bedrock at the mining site (hereinafter referred to as "silicic acid area"), water must be sprayed on and around such bedrock before drilling.
2. Percussive rock drills to be used in a silicic acid area must be wet-type drills.
3. In any of the following cases, it shall be allowable not to comply with the provisions of the preceding two paragraphs, if it is permitted by the Director of the Bureau of Mine Safety and Inspection or the Director of the Department of Mine Safety and Inspection:
(i) Where the surface to be drilled is always covered with water from springs, which is regarded as being as effective as or more effective than using a wet-type percussive rock drills in preventing dust;
(ii) Where a machine, piece of equipment, or apparatus, which is regarded as being as effective as or more effective than a wet-type percussive rock drill in preventing dust, is used.
4. Where a percussive rock drill is used in a silicic acid area (excluding cases where percussive rock drills other than wet-type drills are used with the permission of the Director of the Bureau of Mine Safety and Inspection or the Director of the Department of Mine Safety and Inspection under the preceding paragraph), a necessary amount of water must be supplied to the rock drill in order to reduce the amount of dust scattered to the level separately notified, unless there are special circumstances and the permission of the Director of the Department of Mine Safety and Inspection is obtained.
5. Where a percussive rock drill is used in a silicic acid area (excluding cases where percussive rock drills other than wet-type drills are used with the permission of the Director of the Bureau of Mine Safety and Inspection or the Director of the Department of Mine Safety and Inspection under Paragraph 3), water distribution pipes must be provided in order to supply necessary water to the rock drill, unless it is extremely difficult to provide water distribution pipes and appropriate measures have been taken, as permitted by the Director of the Bureau of Mine Safety and Inspection or the Director of the Department of Mine Safety and Inspection, to supply necessary water to prevent dust.

(Concerning 2) Article 724 of the Civil Code

Article 724 of the Civil Code
The right to demand compensation for the damage which has arisen from an unlawful act shall lapse by prescription if not exercised within three years from the time when the injured party or his legal representative became aware of such damage and of the identity of the person who caused it, and the same shall apply if twenty years have elapsed from the time when the unlawful act was committed.
This jokoku appeal shall be dismissed.
The jokoku appellant shall bear the whole cost of the jokoku appeal.
I. Outline of the case
1. The jokoku appellees are the persons who claim to have contracted pneumoconiosis due to having engaged in dusty work in coal mines located in the Chikuho region (the persons indicated in the section of the names of deceased employees in the "List of Plaintiffs and Their Inheritance" in Tables 1-5 attached to the judgment of the first instance as Plaintiff Numbers (original numbers) 104-106, 115, 118, 138, 150, 155, 161, 162, 165, 166, 170, 172, 184, 190, 195, 210, 212, 215, 229, 313, 316, 319, 323, 324, 328, 332, 408, and 414, the persons indicated in the "List of Parties Concerned" in Exhibit 1 attached to the judgment of the second instance as Numbers 109, 112, 113, 117, 136, 146, 175, 189, 216, 217, 306, 314, 322, and 403, and the persons indicated in the section of the persons to be succeeded in the "List of Inheritance" in Exhibit 4 attached to the judgment of the second instance as Original Numbers 148, 149, 177, 218, 219, and 226; hereinafter referred to as the "Former Employees") or their successors. This is a case brought by the jokoku appellees to seek damages from the jokoku appellant under Article 1, para. 1 of the Law Concerning State Liability for Compensation, on the ground that the failure of the jokoku appellant to exercise the authority to enforce regulations under the Mine Safety Law in order to prevent the outbreak and deterioration of pneumoconiosis in coal mines is illegal.

2. The outlines of the facts legally determined by the judgment of the second instance and of related laws and ordinances are as follows.
(1) Article 2, para. 1, sub-para. 1 of the Pneumoconiosis Law defines pneumoconiosis as "diseases consisting mainly of fibrotic changes in the lungs due to inhalation of dust." Among such diseases, the one caused by inhalation of dust that contains free silicic acid is called "silicosis," and as explained later, attention before the enactment of the Pneumoconiosis Law was given exclusively to silicosis caused by inhalation of dust containing free silicic acid in metal mines.
Pneumoconiosis is caused by dust that is inhaled into the lung cells and that develops fibrotic changes in lymph glands and alveoli over a long period of time, thereby causing pneumoconiosis nodules or blocked small blood vessels, and the clinic picture of pneumoconiosis is characterized by the progression of the disease such as a fusion of enlarged pneumoconiosis nodules even after the end of exposure to dust (progressiveness) and the unavailability of methods to cure fibrotic changes or emphysematous changes completely (irreversibility). Pneumoconiosis is often with a delayed onset, taking time to cause symptoms, at the shortest two or three years, generally five to ten years or more, or at the longest 30 years or more, after the start of the exposure to dust, and it is often the case that symptoms appear after a considerable period of time has passed since the end of the exposure to dust. Diseased persons notice symptoms such as coughing, sputum, shortage of breath, and dyspnea, and if these symptoms become worsen exceedingly, diseased persons would suffer prostration due to respiratory failure or cardiopulmonary function disorder, and might suffer complications such as pulmonary tuberculosis complicated by pneumoconiosis and finally result in death.
(2) The outline of laws and ordinances concerning pneumoconiosis is as follows.
(a) The Pneumoconiosis Law promulgated on March 31, 1960, aims at contributing to the maintenance of workers' health, etc. by proper preventive means, supervision of health, and any other necessary measures against pneumoconiosis (Article 1), obliges the employer to take proper measures for preventing pneumoconiosis (Article 5), prescribes the classifications for supervision of health (No. I to IV) to be required for workers engaged in dusty work based on the result of a medical examination on pneumoconiosis, and requires the employer to decide what work should be assigned to each worker by giving consideration to the classifications to which each worker belongs (Article 4 and Articles 21 to 23). The Pneumoconiosis Law was under the jurisdiction of the Ministry of Labour, as the "Special Law for Protection of Persons who Suffer Silicosis or Damage on the Spinal Cord by External Injury" (Law No. 91 of 1955, abolished by Law No. 29 of 1960; hereinafter referred to as "Special Law on Silicosis"), which was abolished along with the enactment of the Pneumoconiosis Law.
(b) The Mine Safety Law promulgated on May 16, 1949, aims at preventing harm to coal workers, etc. (Article 1) and requires the mining right owner to take necessary measures to prevent harm or mine pollution, which arise from the treatment of dust, etc. (Article 4, sub-para. 2). According to the delegation under Article 30 of the said law, regulations such as the Safety Regulations on Metal Mines, Etc. (Ministry of International Trade and Industry (MITI) Ordinance No. 33 of 1949) and the Safety Regulations on Coal Mines (MITI Ordinance No. 34 of 1949) provide for specific safety measures to be taken by the mining right owner pursuant to Article 4 of the said law. The Safety Regulations on Metal Mines, Etc. provide for safety measures for mining for the purpose of mining mineral resources other than coal, lignite, and petroleum, or in other words, mining in metal mines, etc., and the Safety Regulations on Coal Mines provide for safety measures for coal mining and lignite mining. The Mine Safety Law and these Safety Regulations are legal grounds for the regulation of dust prevention measures to be taken by the mining right owner to prevent mine workers from contracting pneumoconiosis.
(3) The following is an outline of the Japanese government's coal policy in the postwar period before 1965 or thereabouts.
During the war, many coal mines in Japan were devastated by forced production of coal due to shortages of resources. Based on the recognition that the increase in coal production was the most important task for Japan's postwar economic recovery, the government, under the cabinet decision to adopt the emergency coal production policy in October 1945, vigorously promoted a policy for increasing coal production by what is known as the prioritized production system. According to the Mine Safety Law enacted in May 1949, mine safety administration was placed under the jurisdiction of the Ministry of International Trade and Industry (former Ministry of Commerce and Industry) as mentioned in (2)(b) above, which was out of consideration of the need to increase coal production.
Subsequently, due to the increase in import of fuel oil and other energy resources, a great depression occurred in coal industry in 1953 and 1954. To respond to this, the government decided to rationalize coal production by concentrating production in high-efficiency mines while supporting the closure of low-efficiency mines. The Coal Mining Industry Rationalization Temporary Measures Law was enacted in July 1955, and in light of the necessity for thorough rationalization of coal production to compete with fuel oil, the government gave specific instructions on rationalization to companies under the law. In 1963, implementation of the first coal policy was started with the aim of rationalizing the coal-mining industry by "taking a wide range of measures while recognizing that coal would not countervail against fuel oil and giving consideration to avoiding social conflicts that would be caused by the collapse of the coal mining industry." The government formulated several coal policies afterward.
Thus, the government vigorously promoted increasing coal production as one of the postwar national policies, and also had a strong influence on matters concerning the management of coal industry after the policy changeover to rationalization.
(4) The following is an outline of the advances in medical knowledge on pneumoconiosis in the postwar period until 1964.
(a) Until the beginning of the Showa era (1926), among occupational diseases affecting mine workers that were caused by inhalation of dust, only silicosis in metal mines was seen as a problem. Silicosis is a chronic disease consisting of fibrotic changes in the lungs due to the inhalation over a long period of time of dust that contains a large amount of free silicic acid in metal mines, and it was already well known at that time that diseased persons would suffer symptoms such as dyspnea and pulmonary emphysema and might suffer cardiopulmonary function disorder or pulmonary tuberculosis complicated with this disease and finally result in death. On the other hand, pneumoconiosis, which coal miners contracted in coal mines, was often called "coal miner's lung disease," and it was regarded as causing not so many symptoms, most of which were regarded as not very serious. Therefore, pneumoconiosis was not seriously recognized among the public as a severe occupational disease, and some people even claimed that coal dust was effective in preventing silicosis and pulmonary tuberculosis. Subsequently, by around 1935, the existence of silicosis sufferers in coal mines was pointed out and workshops were held to underline the necessity of dust prevention measures. However, as Japan was soon put on a war footing, no major progress was made in medical knowledge on pneumoconiosis.
(b) After the war, a movement was launched, mainly in metal mines, for the establishment of a special law on silicosis, with the aim of eradicating silicosis. The Metal Mines Reconstruction Conference consisting of mine operators submitted a proposal to the Speakers of the House of Representatives and the House of Councilors on measures to prevent silicosis, thus advancing the movement. The Ministry of Labour presented a silicosis bill to the Silicosis Council in 1950 and Diet members submitted another silicosis bill to the Diet in 1953, but neither bill was enacted. The first special law on silicosis was finally established as the Special Law on Silicosis, which was promulgated on July 29, 1955. Article 2, para. 1, sub-para. 1 of the Special Law on Silicosis defined silicosis as "a disease consisting of fibrotic changes in the lungs due to inhalation of free silicic acid or dust that contains free silicic dust, and pulmonary tuberculosis complicated with it." As obviously shown by this definition, this law was applicable to silicosis caused by inhalation of dust that contained free silicic acid, and was intended to prevent the progression of this disease (Article 1).
(c) In October 1948, the Ministry of Labour conducted, as a national administrative organization, the first nationwide medical examination on silicosis, which revealed the fact that there were also a number of silicosis sufferers in coal mines. The Ministry of Labour also conducted, from September 1955 to March 1957, the medical examination on silicosis that was of the largest scale at home and abroad, targeting 12,981 business facilities and their 339,450 workers, of which 144,247 were coal workers. As a result of this medical examination, by around 1959, it became obvious that 38,738 workers were diagnosed as having silicosis, and among them, 11,747 were coal workers (about 30% of all workers so diagnosed).
(d) As for medical knowledge on the pneumoconiosis suffered by coal workers, it was pointed out in a number of theses published in medical journals since about 1955, that the condition of pneumoconiosis in coal mines could not be disregarded based on the results of surveys on coal workers suffering pneumoconiosis, and that there was no difference in dusts in terms of harmful effect and all kinds of dust had harmful effects if they were inhaled over a long period of time. Furthermore, an experiment conducted on animals revealed that serious nodules due to fibrotic changes were found in the lungs of rats that inhaled coal dust over a long period of time. Thus, it became increasingly obvious medical knowledge that inhalation of coal dust over a long period of time would lead to contraction of pneumoconiosis.
(e) The Minister of Labour, in June 1958, consulted with the Silicosis Council about the necessity of amendment of the Special Law on Silicosis, and the Council established a medical working group in charge of discussing this issue from a medical professional perspective. In September 1959, the medical working group announced the "Opinion on the Medical Problems Concerning Pneumoconiosis," stating the following: "as a result of the recent autopsies, various kinds of pneumoconiosis have been identified such as pneumoconiosis due asbestos, pyrophyllite, aluminum, and diatomite, and any of these kinds of pneumoconiosis would cause cardiopulmonary function disorder if it became serious; therefore, it is necessary to prevent harm due to all kinds of dust and monitor those workers' health." This opinion affirmed, in light of the medical knowledge on pneumoconiosis at that time, the possibility and risk of suffering pneumoconiosis due to inhalation of any kinds of dust including coal dust, and pointed out the seriousness of health hazards in the case where pneumoconiosis became worse. It also stated the necessity of preventing not only damage due to dust that contained free silicic acid, the cause of silicosis, but also damage due to all kinds of dust, and monitoring those workers' health.
(f) As the actual situations regarding coal workers suffering pneumoconiosis became obvious and the medical working group announced the above opinion, as discussed above, the need to fundamentally review the conventional measures concerning pneumoconiosis, which were only applicable to silicosis, was recognized. According to the report compiled by the Silicosis Council based on the above opinion of the medical working group, the government submitted a pneumoconiosis bill to the Diet in December 1959. Through deliberations at the Diet, the bill was passed and promulgated on March 31 and was enforced on April 1, 1960.
The initial Pneumoconiosis Law defined pneumoconiosis as "pneumoconiosis caused by inhalation of mineral dust and pulmonary tuberculosis complicated by pneumoconiosis" (Article 2, para. 1, sub-para. 1). This law thus broadly defined pneumoconiosis, including not only silicosis due to inhalation of dust that contained free silicic acid but also other kinds of pneumoconiosis due to inhalation of mineral dust such as coal dust, so that the law would also be applicable to such a broad scope of pneumoconiosis. Upon the adoption of the Pneumoconiosis Law, the Committee on Social and Labour Affairs of the House of Councilors adopted an additional resolution that stated that, "for the enforcement of the Pneumoconiosis Law, the government should place primary emphasis on preventive measures and give appropriate guidance on labour and health affairs in general."
(5) When the pneumoconiosis bill was submitted to the Diet in 1959, the regulations for dust prevention provided by the Safety Regulations on Coal Mines under the delegation under Article 30 of the Mine Safety Law were as below.
With regard to dust prevention in coal mining and lignite mining, the Regulations only provided general safety regulations as follows: "At worksites in mining pits where rocks are mined, conveyed, and broken, if a large amount of dust would be scattered due to such mining, conveying, and breaking of rocks, appropriate measures shall be taken to prevent the scattering of dust, by, for example, installing dust prevention apparatus and spraying water on rooks, unless antidust masks that satisfy the standards separately notified are used" (Article 284 of the Safety Regulations on Coal Mines before amendment by MITI Ordinance No. 115 of 1979). On the other hand, tightened regulations were applicable to "silicic acid areas," areas designated by the Minister of International Trade and Industry as areas that have a large quantity of free silicic acid contained in bedrock at the mining site, and it was provided that in such areas, water must be sprayed on and around such bedrock before drilling and percussive rock drills to be used in a silicic acid area must be wet-type drills (Article 284-2 of the Safety Regulations on Coal Mines before amendment by MITI Ordinance No. 74 of 1986). These tightened safety regulations only applicable to silicic acid areas where a large quantity of free silicic acid was contained in bedrock at the mining site had been introduced upon the amendment of the Safety Regulations on Coal Mines in August 1950.
Similar regulations were also introduced to the Safety Regulations on Metal Mines, Etc. at the same time. However, upon the amendment of the Safety Regulations on Metal Mines, Etc. in September 1952, the tightened regulations requiring spraying of water before drilling and the use of wet-type rock percussive rock drills were regarded as general safety regulations that should be applicable to all worksites in metal mining pits, and thus the designation of silicic acid areas was abolished under the amended Safety Regulations on Metal Mines, Etc. On the other hand, the designation of silicic acid areas was maintained in coal mines even after the amendment of the Safety Regulations on Metal Mines, Etc., and subsequently, even after the results of the medical examination targeting coal workers and the opinion of the medical working group were published and then the Pneumoconiosis Law was established based on the report by the Silicosis Council in March 1960, the designation of silicic acid areas continued to exist and tightened regulations were not applicable to areas other than the designated areas. The regulations requiring spraying of water before drilling and the use of wet-type rock percussive rock drills were not adopted as general safety regulations until November 1986.
(6) Dust prevention measures to be taken to prevent pneumoconiosis include preventing the generation, scattering, and inhalation of dust, and in particular, preventing the generation of dust was regarded as key measure. By 1955, it became obvious engineering knowledge that it would be possible to prevent the generation of dust, the cause of pneumoconiosis, very successfully by using wet-type rock drills. Also by that time, light handheld wet-type rock drills were put into practical use, and by 1960 at the latest, there were no special obstacles to the use of wet-type rock drills in all coal mines. In metal mines, after the amendment of the Safety Regulations on Metal Mines, Etc. in September 1952, rapid progress was made in the laying of water distribution pipes and the use of wet-type rock drills: the rate of use of wet-type rock drills came to 99.7% by 1954, and water distribution pipes were laid in all metal mines by 1958.
On the other hand, according to the survey on coral mines conducted in 1961, in the Kyushu area, the rate of use of wet-type rock drills was only 18.7% in large coal mines and 5.9% in medium and small coal mines, falling significantly behind the rate in metal mines. Among others, in mining pits other than those designated as silicic acid areas (the former referred to as "non-designated pits" and the latter referred to as "designated pits"), wet-type percussive rock drills were not widely used, and the number of non-designated pits where water was sprayed on rocks only accounted for about one-third of the number of such sites in designated pits. Thus, the rate of use of wet-type rock drills and the rate of implementation of water spraying were exceedingly low in non-designated pits. In the Kyushu area, mining pits that had been designated by 1960 only accounted for 3.6% of all mining pits, and the designation criteria (the content of free silicic acid at 40% in 1956 and the content of free silicic acid at 30% in 1959, etc.) were not based on any medical knowledge on the tolerance of dust and therefore they were unreasonable as criteria for ensuring that the exposure of coal workers to dust in non-designated pits would be below a tolerable level in terms of health effects. When viewing the measures actually implemented as a whole at the stages of generation, scattering, and inhalation of dust, it was impossible to say that they were appropriate measures to prevent pneumoconiosis in coal mines, because dust collectors, which had been regarded as achieving almost the same effect as wet-type rock drills in 1960, were not diffused widely, the rate of use of antidust masks was low, and pneumoconiosis education for developing understanding among coal workers of the need to wear such masks was insufficient.

3. The court of the second instance pointed out that the jokoku appellant should have reviewed the Safety Regulations on Coal Mines upon the enactment of the Pneumoconiosis Law in March 1960, and should have either abolished the designation of silicic acid areas or at least amend the designation criteria, or should have required that measures be taken to prevent the generation and scattering of dust, regardless whether the pit was a designated pit or a non-designated pit, for example by using wet-type percussive rock drills, and therefore the failure of the jokoku appellant to take any of these measures at that time should be deemed to be extremely unreasonable. The court also stated that the instruction and supervision provided by the jokoku appellant for taking the dust prevention measures applicable for both designated pits and non-designated pits was insufficient to eliminate such unreasonableness. On these grounds, the court of the second instance judged the jokoku appellant's failure to exercise the authority to enforce safety regulations to be regarded as illegal for the purpose of the application of Article 1, para. 1 of the Law Concerning State Liability for Compensation, and also held the jokoku appellant liable to pay compensation for up to one-third of the damage suffered by each Former Employee who had engaged in dusty work in April 1960 and afterwards and had contracted pneumoconiosis, excluding those who had had no complication and had been classified as No. II and III.

II. Concerning Grounds 2 and 3 for the petition for accepting the jokoku appeal argued by the attorney for jokoku appeal TSUZUKI Hiroshi and 27 other attorneys
1. It is appropriate to construe that if the failure of national officials or officials of public bodies to exercise the authority to enforce safety regulations is deemed to be beyond the allowable limits and therefore extremely unreasonable in light of the purport and purpose of the laws and ordinances that are the basis of the authority and the nature of the authority as well as specific circumstances concerned, such failure is illegal, in relation to people who have suffered damage due to the failure, for the purpose of the application of Article 1, para. 1 of the Law Concerning State Liability for Compensation (See 1986(O)No. 1152, judgment of the Second Petty Bench of the Supreme Court of November 24, 1989, Minshu Vol. 43, No. 10, at 1169; 1989(O)No. 1260, judgment of the Second Petty Bench of the Supreme Court of June 23, 1995, Minshu Vol. 49, No. 6, at 1600).
In this case, the Mine Safety Law aims to prevent harm to mine workers (Article 1), and it provides that measures to prevent accidents at mining work shall only be subject to this law and the Industrial Safety and Health Law shall not be applied to these measures (Article 115, para. 1). Thus, the Mining Safety Law can be regarded as a special law under the Industrial Safety and Health Law that is aimed to secure the safety and health of workers in workplaces. The Mining Safety Law requires the mining right owner to take necessary measures to prevent harm or mine pollution, which arise from the treatment of dust, etc. (Article 4, sub-para. 2), and provides that specific safety measures to be taken by the mining right owner under Article 4 shall be prescribed by ministerial ordinances (Article 30). The Mining Safety Law provides for such comprehensive delegation to ministerial ordinances by the provision of Article 30 because what should be regulated as safety measures to be taken by the mining right owner may include a wide range of specialized technical matters, and it seems appropriate to delegate this task to the competent minister in order to amend the contents of such measures as quickly as possible so that they would be in line with technological advances and the latest medical knowledge.
In light of the purpose of the Mining Safety Law and the purport of these provisions, the authority of the Minister of International Trade and Industry, the competent minister under the said law, to enforce safety regulations under the said law, and in particular, the authority to enact ministerial ordinances under Article 30 of the said law, should have been exercised at the right time and in an appropriate manner in order to amend safety regulations and ministerial ordinances as quickly as possible so that they would be in line with technological advances and the latest medical knowledge with the primary aim of improving the working environment of mine workers, preventing harm to their lives and bodies, and guaranteeing their health.

2. Given the facts mentioned above, the following is obvious: (1) The large-scale medical examination on silicosis conducted by the Ministry of Labour from September 1955 to March 1957 revealed the serious condition of coal workers suffering pneumoconiosis as it became obvious, by 1959, that more than 10,000 coal workers were diagnosed as having silicosis (about 30% of all workers so diagnosed); (2) In September 1959, the medical working group established under the Silicosis Council announced the opinion that affirmed, in light of the medical knowledge on pneumoconiosis at that time, the possibility and risk of suffering pneumoconiosis due to inhalation of any kinds of dust including coal dust, and pointed out the seriousness of health hazards in the case where pneumoconiosis became worse. The opinion also pointed out the necessity of preventing not only damage due to dust that contained free silicic acid, the cause of silicosis, but also damage due to all kinds of dust, and supervising those workers' health; (3) As the serious condition of coal workers suffering pneumoconiosis became obvious and the medical working group announced the above opinion, the need to fundamentally review the conventional measures concerning pneumoconiosis, which were only applicable to silicosis, was recognized. According to the report compiled by the Silicosis Council based on the above opinion of the medical working group, the government submitted a pneumoconiosis bill to the Diet in December 1959. This bill broadly defined pneumoconiosis, including not only silicosis due to inhalation of dust that contains free silicic acid but also other kinds of pneumoconiosis due to inhalation of mineral dust such as coal dust, so that the law would also be applicable to such a broad scope of pneumoconiosis; (4) Preventing the generation of dust is regarded as a key measure to take to prevent pneumoconiosis. By 1955, it became obvious engineering knowledge that it would be possible to prevent the generation of dust, the cause of pneumoconiosis, very successfully by using wet-type rock drills. Also by that time, light handheld wet-type rock drills had been put into practical use, and by 1960 at the latest, there were no special obstacles to requiring the use of wet-type rock drills in all coal mines. In fact, in metal mines, after the amendment of the Safety Regulations on Metal Mines, Etc. in September 1952, rapid progress was made in the laying of water distribution pipes and the use of wet-type rock drills, the rate of use of wet-type rock drills coming to 99.7% by 1954; (5) On the other hand, regarding coal mines, although the government had vigorously promoted increasing coal production as one of the postwar national policies, the designation of silicic acid areas was maintained even after the amendment of the Safety Regulations on Metal Mines, Etc. Subsequently, even after the Pneumoconiosis Law was established based on the report by the Silicosis Council in March 1960, the designation of silicic acid areas continued to exist without any substantial review being made to safety regulations including the designation criteria. The regulations requiring spraying of water before drilling and the use of wet-type rock percussive rock drills were not adopted as general safety regulations until November 1986. Due to these reasons, in coal mines, the rate of use of wet-type rock drills and the rate of implementation of water spraying were extremely low in non-designated pits, which constituted the greater part of coal mines, and the implementation of measures to prevent pneumoconiosis including general dust prevention measures was far from sufficient.
In light of these facts, the Minister of International Trade and Industry should have reviewed, by the time of enactment of the Pneumoconiosis Law on March 31, 1960, at the latest, the contents of the Safety Regulations on Coal Mines in line with the medical knowledge on pneumoconiosis mentioned above and the purport of the Pneumoconiosis Law enacted based on this knowledge, and also should have enforced new safety regulations for generally requiring effective measures to prevent the generation of dust such as the use of wet-type percussive rock drills and the implementation of spraying of water before drilling. Thus, the Minister should have exercised its supervisory authority under the Mining Safety Law as appropriate with the aim of quickly diffusing and promoting such measures to prevent the generation of dust. If such authority to enforce safety regulations (including the authority to amend ministerial ordinances) had been exercised as appropriate by that time, it would have been possible to prevent, to a significant extent, subsequent health hazards due to pneumoconiosis from spreading among coal workers.
Comprehensively taking these facts into account, the failure of the jokoku appellant to immediately exercise the authority to enforce safety regulations under the Mining Safety Law in April 1960 and afterwards should be deemed to be extremely unreasonable in light of the purport and purpose of the law and therefore illegal for the purpose of the application of Article 1, para.1 of the Law Concerning State Liability for Compensation.
Consequently, the judgment of the second instance that held the jokoku appellant liable for damages under the said paragraph can be accepted as justifiable, and the jokoku appellant's argument cannot be accepted.

III. Concerning Ground 4 for the petition for accepting the jokoku appeal argued by the attorney for jokoku appeal TSUZUKI Hiroshi and 27 other attorneys
The period of extinctive prescription set forth in the second part of Article 724 of the Civil Code shall start from the time "when the unlawful act was committed." In the case of an unlawful act from which damage arose when the act was committed, the period of extinctive prescription shall start from the time when the act was committed. However, in the case of an unlawful act from which damage, due to its nature, would arise after a considerable period of time has passed since the termination of the act of causing the damage, such as damage due to substances that are harmful to human health if they are accumulated in the body and damage that would come to appear after a certain incubation period, the period of extinctive prescription should be deemed to start from the time when all or part of damage has arisen from the act. This is because it would be significantly cruel to any affected party to allow the period of extinctive prescription to start before damage arises from an unlawful act whereas the affecting party should expect, in light of the nature of damage that could be caused by its own act, that any affected party would appear and claim damages after a considerable period of time has passed.
Pneumoconiosis is caused by dust that is inhaled into lung cells and develops fibrotic changes over a long period of time, and may cause pneumoconiosis nodules, etc. These symptoms often appear after a considerable period of time has passed since the end of the exposure to dust. For this reason, in this jokoku appeal case, the period of extinctive prescription for the right to demand compensation for pneumoconiosis damage should start from the time when such damage arose. The judgment of the second instance that goes along with this can be accepted as justifiable, and the jokoku appellant's argument cannot be accepted.

Therefore, the judgment was rendered in the form of the main text by the unanimous consent of the Justices.
Justice FUJITA Tokiyasu
Justice KANATANI Toshihiro
Justice HAMADA Kunio
Justice UEDA Toyozo
(This translation is provisional and subject to revision.)