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Background Malignant pleural mesothelioma (MPM) due to environmental and familial (domestic) asbestos exposure is well recognized. However, information on cumulative asbestos dose in subjects affected by MPM is limited. Objectives To evaluate the residual lung asbestos fibre and asbestos body burden in women with MPM with past environmental and/or familial asbestos exposure. Methods We collected lung samples from autopsies regarding 15 non-occupationally asbestos-exposed MPM cases, divided in three groups: (i) familial exposure from the Fincantieri shipyards in Monfalcone (No. 7), (ii) environmental and familial asbestos exposure from the asbestos-cement plant Fibronit in Broni (No. 6), and (iii) environmental exposure from the Fibronit plant (No. 2). Asbestos body (AB) and fibres (AF) per gram of dry lung tissue were counted by optical and scanning electron microscopy, respectively, and expressed as geometric means and standard deviations (GM, GSD). Results GM/GSD of AB counts were 6123/9.6 (Group 1), 13 800/10.4 (Group 2), and 8400/1.1 (Group 3); GM/GSD of AF were 0.6/2.1 (Group 1), 7.9/2.1 (Group 2), and 6.0/2.3 (Group 3) million. Pleural plaques were observed in 12 cases. Conclusions Exclusive familial exposure to asbestos determined cumulative doses close to those observed in moderate occupational exposure circumstances. Our results also suggest that combined environmental and familial exposures may cause unexpectedly high cumulative fibre doses.

Formalin-fixed lung tissue and paraffin blocks containing peripheral lung tissue obtained from subjects with an occupational asbestos exposure are both regarded to be suitable to determine asbestos load. Because sample preparation of paraffin blocks requires a more intense treatment than formalin-fixed tissue, we tested whether asbestos analysis of formalin-fixed lung tissue and paraffin blocks obtained from the same patients deliver comparable results.We determined numbers of asbestos bodies (AB) and amphibole asbestos fibers (AF) in formalin-fixed lung tissue and corresponding paraffin blocks from 36 patients. For AB counts, samples were digested in sodium hypochlorite. For AF analysis, tissue was freeze-dried and then ashed. Results were reported as numbers of AB and AF per gram dry lung tissue.Both AB counts as well as AF counts were lower in paraffin blocks than formalin-fixed lung tissue. Compared to formalin-fixed tissue, the limit of detection was higher for paraffin blocks, rendering more results from paraffin blocks not interpretable than from formalin-fixed tissue (8 samples versus 1 for AB and 15 samples versus 4 for AF).Asbestos analysis of paraffin blocks may lead to underestimation of asbestos exposure. This should be considered when assessing occupational asbestos exposure through lung dust analysis in medico-legal evaluation.

Asbestos‐related pulmonary conditions such as benign asbestos pleural effusion (BAPE) and diffuse pleural thickening (DPT) can develop after many years of asbestos exposure. These conditions cause progressing constrictive deficit in pulmonary function which may lead to respiratory failure and death. We report the case of a 72‐year‐old man with asbestos‐related BAPE and DPT which developed approximately 40 years after occupational asbestos exposure, leading to chronic respiratory failure and death. We were able to observe his clinical course including computed tomography (CT) scan evaluation over 11 years. In addition to this observation, moderate asbestos body concentration was confirmed in autopsy‐derived lung tissue. There are few case reports that showed radiographic course of asbestos‐related pulmonary disorder initiated as BAPE, followed by unilateral DPT and later bilateral DPT that was histologically proven with asbestos body. We consider his clinical course is important in managing this disease, especially in early phase., We report the case of a 72‐year‐old man with asbestos‐related disease, firstly benign asbestos pleural effusion and subsequently diffuse pleural thickening, which progressed over 11 years and finally presented chronic respiratory failure. After his death, moderate asbestos body concentration was proven in his autopsy‐derived lung tissue.

This work presents a comparative FEG-SEM study of the morphological and chemical characteristics of both asbestos bodies and fibres found in the tissues of Sprague-Dawley rats subjected to intraperitoneal or intrapleural injection of UICC chrysotile, UICC crocidolite and erionite from Jersey, Nevada (USA), with monitoring up to 3 years after exposure. Due to unequal dosing based on number of fibres per mass for chrysotile with respect to crocidolite and erionite, excessive fibre burden and fibre aggregation during injection that especially for chrysotile would likely not represent what humans would be exposed to, caution must be taken in extrapolating our results based on instillation in experimental animals to human inhalation. Notwithstanding, the results of this study may help to better understand the mechanism of formation of asbestos bodies. For chrysotile and crocidolite, asbestos bodies are systematically formed on long asbestos fibres. The number of coated fibres is only 3.3% in chrysotile inoculated tissues. In UICC crocidolite, Mg, Si, and Fe are associated with the fibres whereas Fe, P and Ca are associated with the coating. Even for crocidolite, most of the observed fibres are uncoated as coated fibres are about 5.7%. Asbestos bodies do not form on erionite fibres. The crystal habit, crystallinity and chemistry of all fibre species do not change with contact time, with the exception of chrysotile which shows signs of leaching of Mg. A model for the formation of asbestos bodies from mineral fibres is postulated. Because the three fibre species show limited signs of dissolution in the tissue, they cannot act as source of elements (primarily Fe, P and Ca) promoting nucleation and growth of asbestos bodies. Hence, the limited number of coated fibres should be due to the lack of nutrients or organic nature.

法医解剖後にアスベストの健康被害申請を行うために医学的検査を実施した事例を経験した．事例は，アスベスト作業歴のある60歳代の男性で，受診歴や健診歴はない．同居人は「数ヶ月前から咳や呼吸苦を生じて死亡した．」と話しているが，死因不明のために法医解剖に付された．左右の壁側胸膜に広範囲にわたる胸膜プラークと左右の肺に多発腫瘤を認め，死因を「肺癌」と診断した．後日，遺族から「石綿救済法」によるアスベストの健康被害申請のための医学的検査の依頼があり，石綿小体計測を行ったところ，乾燥肺重量1gあたり石綿小体を4,860本検出したものの認定に必要な5,000本は検出できなかった．石綿小体は病変部を含まない，肺実質の末梢側に蓄積されやすいとされている．解剖時に摘出・保存した肺組織は中枢側の病変部周囲であったため，計測結果がより低値になった可能性が考えられた．我が国ではアスベスト関連肺疾患発症者や法医解剖体数が増加している．法医解剖時に原発性肺癌を認めた場合には，アスベストの健康被害申請が行われる可能性を考慮して，肺の適切な部位の採取・保存を周知する必要があると考える． We had a forensic autopsy case that required additive pathological examination for the asbestos-related lung disease compensatory application afterwards. A man in his sixties with a history of occupational asbestos inhalation who had neither visited a hospital nor received a physical examination received forensic autopsy because of his death from unknown cause. An inmate said, “He developed cough and dyspnea, and died in the progression of the symptoms.” The autopsy revealed widespread pleural plaques on both sides of the parietal pleura and multiple tumors in both sides of the lungs. The cause of death was diagnosed as lung cancer. Additional pathological examination was asked by his family to certify that he had suffered from asbestos-related lung disease in order to apply to the Asbestos-related Damage Relief Law. The Japanese criteria of the compensation law of asbestos-related lung cancer is the detection of more than 5,000 asbestos bodies per gram of dry lung tissue, while his number of asbestos bodies was 4,860. Asbestos bodies were reported to be accumulated in the distal lung parenchyma with no pathological changes. The present lung samples were collected from proximal section around the tumor, which might have made the number of asbestos bodies less than the criteria. Both the number of patients suffering from asbestosrelated lung disease and the number of forensic autopsy cases have increased in Japan. Collecting lung samples from the appropriate lung section is essential and should be noted when the lung cancer is suspected at forensic autopsy in order to apply for asbestos-related lung disease compensation.

Background The aim of this study was to elucidate whether there is a relationship between the extent of pleural plaques and pulmonary asbestos body concentration (PABC). Methods The subjects were 207 lung cancer patients with occupational asbestos exposure. We determined the plaque extent by findings on chest images using our own criteria. PABCs were measured in resected or autopsy lung specimens. Results There was a significant relationship between plaque extent and PABC. Seventy-five percent of the patients determined to have extensive plaques based on our criteria had a PABC of ≥5,000 asbestos bodies per gram of dry lung tissue, which is one of the certification criteria of lung cancer caused by asbestos for workers' compensation in Japan. Conclusions In lung cancer patients, the plaque extent had a significant positive relationship with the PABC. The plaque extent would be useful as a proxy for PABC for lung cancer compensation purposes. Am. J. Ind. Med. 58:444–455, 2015. © 2015 Wiley Periodicals, Inc.

The traceability of asbestos fibres in human lungs is a matter of discussion especially for chrysotile. This issue is of high significance for differential diagnosis, risk assessment and occupational compensation. At present no intra-individual longitudinal information is available. This study addresses the question whether the asbestos fibre burden in human lungs decreases with time after exposure cessation.The database of the German Mesothelioma Register was screened for patients with asbestos body counts of at least 500 fibres per gram of wet lung, which had been analysed twice from different tissue excisions at minimum intervals of 4 years.Twelve datasets with individual longitudinal information were discovered with a median interval of about 8 years (range 4–21 years). Both examinations were performed after exposure cessation (median: surgery, 9.5 years; autopsy, 22 years). Pulmonary asbestos fibre burden was stable between both examinations (median 1623/4269 asbestos bodies per gram wet lung). Electron microscopy demonstrated a preponderance of chrysotile (median 80%).This study is the first to present longitudinal intra-individual data about the asbestos fibre burden in living human lungs. The high biopersistence of amphiboles, but also of chrysotile, offers mechanistic explanations for fibre toxicity, especially the long latency period of asbestos-related diseases.

Resume Nous rapportons une etude portant sur une serie retrospective monocentrique de 73 cancers du poumon operes entre juillet 2004 et decembre 2009. Tous les patients ont eu une analyse mineralogique d’un prelevement de tissu pulmonaire en plus de l’interrogatoire professionnel. La combinaison des deux permet de proposer a la declaration en maladie professionnelle pres d’un tiers des cas. Nous proposons qu’un fragment biopsique de parenchyme sain soit systematiquement preleve en cas de cancer du poumon opere. L’analyse devrait etre realisee si l’enquete professionnelle ne montre pas une exposition majeure et si le patient n’est pas connu pour etre porteur d’une maladie pleuropulmonaire secondaire a une exposition a l’amiante (plaques pleurales et asbestose).

症例は71歳, 男性. 2006年2月, 検診にて胸部異常影を指摘された. しばらく放置していたが2007年1月, 精査目的に当院を受診した. 肺癌であり, 手術を行った. 職業歴および胸膜プラークを認めたことからアスベスト肺癌を疑い, 患者救済の目的で肺内アスベスト小体濃度の計測を行った. 結果, 肺乾燥重量1gあたり27,086本のアスベスト小体を認め, 「石綿による健康被害の救済に関する法律」 (以下石綿新法) での救済が認められた. 中皮腫では診断が確定すれば労災か石綿新法で救済される. 肺癌ではアスベスト以外に喫煙などの危険因子もあり, アスベストによる肺癌と診断するには肺内アスベスト小体濃度の計測が必要な場合がある. 今回われわれは肺内アスベスト小体濃度を計測し, 石綿新法で救済された肺癌の1例を経験したので報告する.

Characterization of man-made rock-wool fibers were investigated by using optical and electron microscopic techniques and discussed how to affect on human health. The rock-wool fibers were collected from spraying on the roof. Mineralogical analyses were carried out by X-ray powder diffraction. Most fibers can exist as straight or curved fine threads with sharp points μm-nm in diameter under electron microscopy observations. The rock-wool is complex agglomerates of fibers and fumes with cement of calcite. The shape and size are significantly important factors for hazardous assessment of man-made fibers. The fibers are easily adhering to protein-rich spherical materials in 1% BSA (bovine serum albumin) and in ringer’s solution for few days aging. Spherical protein-like materials are similar to “asbestos body” with dumbbells shape. Man-made fibers have been manufactured for over 20 years, but there have been few concerns raised regarding the safety of rock-wool, were considered to be non-hazardous, because of the different durability in the lung. Present study consistently suggests that man-made fibers with fine and sharp points have similar risk as carcinogen of asbestos. The results of both patch test and adhesion materials with dumbbells shape provide clues regarding the mechanisms of tolerance in the lungs of exposed animals, and may be relevant for humans.

Study Objectives: Asbestos bodies (ABs) form as asbestos fibers become coated by a cellular iron- and protein-rich matrix. ABs have been reported in lymph nodes and a few extrapulmonary sites, but no data exist as to their formation outside of the lung. It is not clear whether the AB found in these extrapulmonary areas have been transported as mature structures from the lung or formed at the extrapulmonary site. This study was designed to determine if ABs are produced in extrapulmonary sites. The guinea pig efficiently forms ferruginous bodies in the lung and so it was chosen as a model to test the coating efficiency of amosite asbestos fibers in lung, liver and spleen. Design: Sized amosite asbestos (5 mg) was administered either endotracheally into lung (n=2) or directly into liver (n=4) and spleen (n=4) of healthy 10-week-old male guinea pigs. The lung, liver and splenic tissues were removed at 40 and 180 days post inoculation and were examined histologically for the presence of AB via light microscopy. Uncoated fibers isolated from the tissues were characterized by electron microscopy. The coating efficiency was calculated as a ratio of uncoated/coated fibers per organ. Results: The coating efficiency ratios of fibers that were collected at 40 days post-injection from the individual sites were: lung—350:1, liver—4200:1, and spleen—220,000:1. At 6 months post-injection the ratios for the individual sites consisted of: lung—176:1, liver—11,000:1, and spleen—1000:1. Conclusion: This study indicates that AB can be formed in extrapulmonary sites and that the coating efficiency in the lung is much greater than that within the liver or spleen.

Asbestos bodies are the histologic hallmark of exposure to asbestos [1–4]. These structures are golden brown, beaded or segmented, dumbbell-shaped objects that have a characteristic microscopic appearance that is readily recognized by the pathologist. Their identification in histologic sections is an important component of the pathologic diagnosis of asbestosis (see Chap. 4), and their presence serves to alert the pathologist that the patient has been exposed to airborne asbestos fibers. It is the purpose of this chapter to discuss the structure and development of asbestos bodies as well as their occurrence and distribution within human tissues. In addition, techniques for the quantification of asbestos bodies are reviewed, along with the relationship of asbestos body formation to the various types of asbestos fibers. Finally, the distinction of asbestos bodies from other ferruginous bodies based on light microscopic and analytical electron microscopic observations is emphasized. The identification and significance of asbestos bodies in cytologic specimens is discussed in Chap. 9, and the relationship between asbestos body concentrations in pulmonary tissues and the various asbestos-associated diseases is reviewed in Chap. 11.

The profiles of occupational asbestos exposure were investigated in a series of 66 hospital patients in whom pleural plaques constituted the only asbestos-induced abnormality. The relationship between a radiological semiquantitative score of pleural plaques and indices of asbestos exposure was also examined. On the basis of a standardized occupational questionnaire, four classes of asbestos exposure were distinguished in our study population: no evidence of exposure, low-level exposure, sporadic exposure at higher levels, and a remaining group of individuals with substantial exposure. Asbestos body count in bronchoalveolar lavage fluid (BALF) was used as an objective indicator of cumulative lung retention of asbestos. Our results support the data indicating that pleural plaques may occur in subjects with low-level or sporadic asbestos exposure. Although it is admitted that pleural plaques are strongly associated with past asbestos exposure, our data suggest that the stage of pleural plaques was not correlated to the level, frequency, duration of exposure nor to the amount of asbestos bodies in the BALF in subjects free of any lung parenchymal abnormalities on high resolution computerized tomography.

By the radiological examination, differential diagnosis of asbestosis from chronic interstitial pneumonia such as IPF/UIP is difficult. The pathological features of asbestosis show the peribronchiolar fibrosis which suggest that asbestos fibers cause the inflammation of bronchioli. Therefore, the criteria for pathological diagnosis of asbestosis in 2010, contain the finding of peribronchiolar fibrosis again. Chest CT scanning including HRCT for total of 38 cases clinically diagnosed asbestosis were reviewed by 3 radiologists and one pulmonologist. On the other hand, the histology of lung tissues obtained by surgery or autopsy were examined by 4 pulmonological pathologists. Furthermore, the content of asbestos bodies in the lung was counted by phase-contrast microscopy. Thirteen cases were definitely diagnosed of asbestosis in the image including HRCT and 17 cases were diagnosed by the histopathological examination showing lung fibrosis with peribronchiolar fibrosis. Only 10 cases were indicated asbestosis by both the radiological and histopathological examinations. The mean value of asbestos bodies for these cases, was 2,133,255 per gram of dry lung tissue.

A simple screening method for quantitatively analyzing asbestos bodies that can be carried out even in community hospitals, is needed in order for laborers and neighborhoods in the vicinity of asbestos factories to apply for compensation for asbestos-related injury. Eighty-eight consecutive cases of surgically resected primary lung cancer were analyzed for asbestos bodies using two methods, and the correlation between them was statistically examined. The first was the conventional technique using lung tissue digestion and phase-contrast scanning, and the second was the authors' method using light microscopy to scan the sediment of formalin-injected lung specimens. The overall correlation coefficient of the concentration of asbestos bodies between the authors' method (C(AB/SED)) and the conventional method (C(AB/DLT)) was 0.4576, a weak statistically significant correlation; in patients with occupational asbestos exposure, however, the correlation coefficient was 0.7341. Despite the cost, it may be prudent to use the conventional method under the present law for patients with C(AB/SED)>or=3.5/mL. C(AB/DLT) >3000/g dry lung tissue when C(AB/SED) is >or=3.5/mL suggests the potential for the accumulation of asbestos absorption by lung tissue.

The concentration and the length distribution of asbestos bodies in exposed human lungs have been determined in autopsy material by scanning electron microscopy after two different methods for preparing the tissue samples. The results demonstrate that the number of bodies vary between the right and left lung, as well as between the different lobes of a lung. The length distribution between the different lungs was, on the average, more or less the same; however small differences occurred between the different lobes. It was further shown that drying the tissue pieces before the analyses affected both the number and the length of the bodies. Examples of different types of asbestos bodies are presented, and their possible biological activity is discussed.

The alveolar content of fibres and asbestos bodies was assessed by bronchoalveolar lavage (BAL) in 21 asbestos sprayers. Transmission and scanning electron microscopy (TEM and SEM) and two light microscopical (LM) methods, cytocentrifugation, and Millipore filtration were used. The subjects had been exposed mainly to crocidolite asbestos for an average of 2.8 (range 0.2-13) years in 1950-75. The mean (median) total fibre count (of asbestos bodies and uncoated fibres) per ml of BAL fluid was 5500 (2800) by TEM and 2900 (1000) by SEM. The mean (median) count of asbestos bodies per ml with LM was 810 (500) with cytocentrifugation and 750 (480) with Millipore filtration, 840 (320) by TEM, and 1750 (420) by SEM. The mean proportion of coated fibres was 35% by TEM and 45% by SEM. The mean length of the coated fibres was 22 (range 4-65) microns by TEM and 34 (range 4.5-170) microns by SEM. The total fibre count exceeded 1000 fibres per ml in 70% of the cases by TEM. Asbestos body counts exceeded 1 per ml in 95% of the cases by LM. The fibre counts by SEM were in good accordance with counts by TEM except in a few cases in which the TEM result was considerably higher. In these cases the proportion of coated fibres was also low. All four counting methods appeared to give consistent results in heavily exposed cases when fibre load in the lungs was high. The counting of asbestos bodies may, however, underestimate the total alveolar fibre load in some cases.

The authors discuss the influence of postmortem tissue decomposition on the lung asbestos body (AB) burden, with the aim of evaluating the reliability of data obtained from autopsies performed for medicolegal purposes several months after deaths in possible connection with asbestos-related pathology. Eight autopsy cases were selected, each one with occupational exposure considered very probable on the basis of the history or pathologic findings. In each case the AB concentrations were assessed soon after death in one lung and after periods of 1 to 18 months in the others, which had been stored in sealed containers without fixation. AB concentrations consistently decreased with time in rotten lungs. The counts in some cases became negative a few months after death, even in cases with very high AB counts at first examination. It may be reasonably inferred that, in putrefied lungs from corpses exhumed after months of internment, the counts in digested tissues and the screening of histologic sections for AB may give false-negative results.

Asbestos body (AB) concentrations in bronchoalveolar lavage samples of 15 brake lining (BL) workers exposed only to chrysotile have been determined and compared with those from 44 asbestos cement (AC) workers extensively exposed to amphiboles. The mean AB concentrations (263 +/- 802 and 842 +/- 2086 AB/ml respectively) for those groups did not differ significantly but were much higher than those found in control groups. Analytical electron microscopy of asbestos body cores showed that in the BL group 95.6% were chrysotile fibres whereas in the AC group amphiboles accounted for 93.1%. The size characteristics of the central fibres differed for chrysotile and amphibole AB, the former being shorter and thinner. Examination of repeated bronchoalveolar lavage samples showed that the mechanisms of clearance of chrysotile fibres do not affect AB concentration for at least 10 months after cessation of exposure. It thus appears that routine counting of ABs in BAL allows the assessment of current or recent occupational exposures to asbestos. Exposures to chrysotile lead to AB concentrations comparable with those encountered in exposures to amphiboles.

The role of asbestos bodies (and associated proteinacious coating) in asbestos associated diseases is not well understood. Currently employed methods of isolation of these bodies employ harsh chemicals that lead to destruction of their proteinacious coating. In this work a method was developed that enabled the purification of whole, integral, unmodified asbestos bodies (AB) by exploiting their magnetic properties. Albumin and ferritin were found to be the major proteins associated with AB isolated from lung tissue of mesothelioma patients. Magnetically isolated AB were shown to be cytotoxic and to activate free radical production from inflammatory cells at a higher extent than that induced by bodies obtained by chemical digestion. The finding that hypochlorite-treated AB induce DNA damage, while AB obtained by the method described in this article failed to do so, together with the differential behavior of these bodies toward inflammatory cells, suggests that native asbestos bodies should be used to investigate the pathogenetic role of these structures.

Two different methods of quantifying asbestos fibre burden were assessed and the counts obtained were compared with semi-quantitative asbestos body counts in corresponding tissue sections. Comparison of the two methods found significantly different asbestos fibre counts between specimens. Each technique showed wide limits of agreement for reproducibility and interobserver variability as assessed by Bland-Altman plots, such that a repeated count could not necessarily be expected to lie within the same exposure category. Asbestos body counts in tissue sections were reproducible with good correlation between observers. Asbestos body and asbestos fibre counts showed correlation in some samples but not others. Counting of asbestos bodies is a valuable screening technique as the finding of asbestos bodies is accepted as a marker of significant asbestos exposure. When no asbestos bodies are identified asbestos fibres estimations may be useful in proving asbestos exposure. Different techniques are not interchangeable and each laboratory should establish a background range from unexposed individuals.

The concept of immunological surveillance against cancer is based on the postulate of Paul Ehrlich (1909) that tumour cells arise with enormous frequency, and that they are normally eliminated by immune mechanisms. Burnet (1970) has restated it in modern terms. One of the arguments of immunologic surveillance is the infiltration of primary tumours by lymphocytes and macrophages. In human carcinomas, an impairment of unspecific cellular defence, represented chiefly by the macrophage system, seems to play an important role as shown by Kohout (1972) using the skin window test of Rebuck and Crowley (1955). In the mouse, endotoxin-mediated necrosis and regression of established tumours may be mediated by the tumour necrosis factor (TNF) probably released by activated macrophages (Mac Pherson and North 1986).

As in most western countries, the use of asbestos has decreased in Belgium since the mid 1970's. Successive regulations have lowered the permissible levels of exposure and prohibited the use of various asbestos products. In order to assess the impact of these prevention measures on the pulmonary fibre burden of asbestos-exposed patients, the bronchoalveolar lavage fluid (BALF) asbestos body (AB) analysis database of the authors' laboratory was reviewed for the period 1983-2000. A total of 4,772 cases were considered, of which 95% were males. AB concentration exceeded 1 AB x mL BALF(-1) in 36.1%. There was essentially no change in the mean concentration of AB over the period evaluated. However, the concentrations in individuals with very high levels decreased over time. This was associated with a shift in exposure categories from primary asbestos workers to those exposed during handling of asbestos-containing materials or to asbestos in place in buildings or industrial sites. This is consistent with epidemiological data indicating that the number of severe cases of asbestosis caused by very high cumulated doses decreases but that benign pleural diseases and mesothelioma remain the most frequent asbestos-related diseases. Past prevention measures are not expected to have a measurable influence on the incidence of mesothelioma in the near future.

A series of 557 malignant mesotheliomas of the pleura diagnosed in the Trieste-Monfalcone area, Italy, in the period 1968-2000 were reviewed. The series included 492 men and 65 women, aged between 32 and 93 years (median age 69 years). Necropsy findings were available in 456 cases (82%). Occupational histories were obtained from the patients themselves or from their relatives by personal or telephone interviews. Routine lung sections were examined for asbestos bodies in 442 cases. In 109 cases isolation and counting of asbestos bodies were performed. A majority of people had histories of working in the shipyards. Asbestos bodies were observed in lung sections in 67% of the cases. Lung asbestos body burdens after isolation ranged between 20 bodies and about 10 millions of bodies/g dried tissue. Latency periods (time intervals between first exposure to asbestos and death) ranged between 14 and 75 years (mean 48.8 years, median 51.0). Latency periods among insulators and dock workers were shorter than among the other categories. High asbestos consumption occurred in many countries in the 1960s and in the 1970s. The data on latency periods obtained in the present study suggest that a world mesothelioma epidemic has to be expected in the coming decades.

In Japan, crocidolite had been used for asbestos cement pipe and spraying, and amosite had been used for building board and spraying. These two types of asbestos had stopped to use in Japan in the late 1970s. An extreme increase in imported asbestos (all 3 commercial types) was observed between 1960 and 1974. In 1960, 77,000 tons of asbestos were imported, and reached the peak as 352,316 tons in 1974. This extreme rise of asbestos imports corresponds with the recent rapid increase in mortality of malignant pleural mesothelioma. Between 1995 and 1999, an estimated mean annual death from pleural mesothelioma was about 500. The annual number of compensated occupational respiratory cancers due to asbestos exposure has also been increasing. Up to the end of March 2000, 162 cases with malignant mesothelioma and 197 cases with lung cancer were compensated. As for lung cancer, epidemiological studies are scanty in Japan. Limited environmental data of the working places in asbestos textile factories suggests that heavy asbestos exposure in the past made deaths from respiratory diseases. Less asbestos exposure will enable exposed workers to survive enough to reach cancer age. Even now smoking rate among males in Japan are over 50%. So lung cancer deaths caused by the interaction between smoking and asbestos exposure will be continuing.

A 38-year-old woman with pleural mesothelioma who had a history of neighborhood asbestos exposure during her childhood was demonstrated. She had no known history of occupational asbestos exposure. This is the first case of mesothelioma with neighborhood asbestos exposure reported in Japan. Previously-reported cases of mesothelioma with neighborhood asbestos exposure in the English language literature were reviewed.

The aim of the study was to analyze the correlation between pulmonary concentrations of asbestos bodies and asbestos fibers and to characterize asbestos body counts from lung tissue of Finnish patients occupationally exposed and unexposed to asbestos.Ninety-nine surgically treated lung cancer patients were investigated. The number of asbestos bodies in iron-stained 5-micrometers histological lung tissue sections was determined by optical microscopy, and the pulmonary concentration of asbestos fibers was assessed by scanning electron microscopy. The correlation between asbestos body and asbestos fiber counts was calculated with linear regression. The asbestos body and asbestos fiber concentrations were also compared with exposure history according to a personal interview of the patients.The average number of asbestos bodies ranged from0.1 to 750 asbestos bodies per tissue section. All the cases with definite exposure showed an average of at least one asbestos body per tissue section. An average of at least one asbestos body per section was, however, detected in 34% of the patients with unlikely exposure. The regression equation log (AF) = -0.429 + 0.600.log (AB) was found to predict the concentration of asbestos fibers (AF, 10(6) fibers.g-1) corresponding to a given number of asbestos bodies (AB) in a section of lung tissue.The background level of asbestos bodies in the lungs of patients with no specific asbestos exposure seems to be higher in Finland than in other countries. In medicolegal cases, the methodological variation involved in asbestos fiber and asbestos body counting must be recognized and all available exposure data should be used to produce the best possible estimate of the exposure.

The fraction of fibers coated in a total of 3,800 asbestos fibers from 38 patients with disease related to asbestos (100 fibers per patient) was determined, according to asbestos fiber type and size parameters. Among the 3,800 fibers, 638 (16.8%) were coated and 3,162 were uncoated. All fibers were analyzed at 2,000 x magnification (lower limit of detection: 2 microns for length and 0.06 microns for diameter). The diameter of the totally coated fibers (28.4% of total bodies; 181/638) was not measured. The percentage of coated fibers varied with the asbestos type; it was 27.1% (335/1235) for amosite fibers, 16.0% (228/1423) for crocidolite, 6.6% (60/908) for tremolite or actinolite, 6.5% (14/214) for anthophyllite, and 5% (1/20) for chrysotile fibers. Most coated fibers were longer than 10 microns and had an aspect ratio (length/diameter) of more than 20. Approximately 60% of coated fibers had an aspect ratio of more than 100. The longer the fiber, the greater the percentage of coated fibers, regardless of diameter. The increase in the percentage associated with length was more marked in fibers with a smaller diameter; the percentage of coated fibers was, therefore, greater in fibers 30 microns or less in diameter. However, in fibers longer than 30 microns, the relationship to percentage of coated fibers was not as clear, and the diameter was less important. Accordingly, the fibers with high aspect ratios, particularly long fibers, tended to show asbestos body formation. The percentage of long fibers was highest in amosite, and the percentage of fibers with an aspect ratio of more than 100 was highest in amosite and crocidolite.(ABSTRACT TRUNCATED AT 250 WORDS)