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PubMedDate not supplied

[Presence of asbestos in naval vessels: study of airborne fiber concentrations on Italian railways ferry boats].

Asbestos has been widely used on ships as an insulating material due to its fire-resistant and sound-absorbent properties. It was therefore deemed appropriate to measure the concentrations of airborne asbestos fibres on two ferries in regular service on the Civitavecchia-Golfo Aranci route. Decontamination work had been carried out on these vessels in order to remove, as far as possible, or to confine asbestos. Between 1994 and 1998, the Ultrastructures Laboratory of the Istituto Superiore di Sanità analysed 123 samples via scanning electron microscopy (SEM) with elementary dispersion X spectroscopy (EDXS). The results showed that in 98.4% of the samples concentrations in the air were below 2 fibres/litre, which is the value set by Ministerial Decree of 6/9/94 for buildings to qualify for effective decontamination status. Concentrations above this value, between 2 and 10 fibres/litre, were found in one ferry engine room, where workers were not continuously present since a remote control box was installed there. The results show that there is no environmental dispersion of asbestos fibres in usual navigation conditions; the situation is comparable to that in buildings where asbestos-containing safety materials have been used and that are subject to period checks in accordance with the guidelines included in Ministerial Decree of 6/9/94. Legislation is deemed necessary to make law 257/92 applicable to naval vessels in order to define univocal criteria for risk evaluation, checking, maintenance and custody procedures of asbestos-insulated vessels, and procedures for each job on board involving handling or removal of asbestos-containing material.

Air Pollutants↗

PubMed2000

Increased mesothelioma incidence in New Zealand: the asbestos-cancer epidemic has started.

AIMS: To examine the incidence and mortality patterns for malignant mesothelioma and pleural cancer in New Zealand between 1962-1996, and relate these to past use of asbestos. METHODS: Data concerning cases of mesothelioma 1962-1996, deaths from pleural and lung cancers 1974-1996, and data on imports of raw asbestos and asbestos products were obtained from government registers and publications. Time trends were analysed using different models. RESULTS: Mesothelioma incidence rates have increased progressively in New Zealand since the 1960s, and reached 25 per million for men in 1995. The increase follows an exponential model departing from a crude 'background rate' of 1-2 per million in 1984, and is particularly steep in males 50 to 60 years of age. The incidence is expected to double by 2010. CONCLUSION: New Zealand has entered an unrivalled period of occupational cancer deaths resulting from past workplace exposure to airborne asbestos fibres. The steep rise in mesothelioma incidence is likely to be accompanied by increases in other asbestos related diseases such as lung cancer. The unique causal association between mesothelioma and asbestos may be used to monitor changes in the public health impact of these exposures. The notification by medical practitioners of all potential asbestos related conditions/exposures to the Occupational Safety and Health (OSH) service is of great importance.

Adult↗

PubMed2000

[Evaluation of the mineral fibers content of pulmonary tissue in people engaged in extraction and concentration of chrysotile asbestos and in those living near enterprises].

The authors determined concentration of asbestos fibers in lung tissue samples obtained in hospital of Asbestos town in Sverdlovsk region. The samples were taken from 47 individuals who died with various causes. of Workers engaged into extraction and beneficiation of chrysotile asbestos at Bazhenovsky field, into production of chrysotile asbestos goods and those who reside in close proximity to the enterprises demonstrated no differences in general content of fibrous particles and of chrysotile asbestos fibers in lung tissue, if compared to workers of the same enterprises and industrial regions dwellers of Canada (being second, after Russia, for total chrysotile asbestos production). The study proved concentrations of amphibole asbestos fibers to be one order lower than those in Canada.

Adult↗

PubMed2001

The interaction of asbestos and smoking in lung cancer.

Both cigarette smoke and inhaled asbestos fibres can cause lung cancer, but the assessment of how these agents act in combination is a matter of great difficulty. In non-smokers, the condition is so rare that, in any cohort of asbestos workers, the standardised mortality ratio (SMR, that is the ratio of the numbers of deaths observed and expected) is quite imprecise. The SMR for smokers, with which it has to be compared, is also subject to sampling error, making the interaction even more unstable. This accounts for much of the variation that has bedevilled evaluation. The debate has been concentrated on two hypotheses: additive (asbestos and cigarette smoke act independently) and multiplicative (asbestos produces an effect proportional to the effect of smoking). The very few data available until 1977 failed to fit the former and fitted the latter only poorly. They would have fitted better a hypothesis of greater synergism, but the only one proposed was too convoluted. So the multiplicative model appeared the only alternative, and was deemed 'accepted'. The ratio of lung cancer SMRs for non-smokers and smokers was generalised into the relative asbestos effect, RAE, with all the advantages of a parametric statistic (Berry et al., 1985, British Journal of Industrial Medicine 42, 12). On the multiplicative hypothesis, RAE=1, while RAE>1 indicates less synergism. The RAEs for the three most recent of the six results then available were >1; for one, P<0.005. From the six results combined, it was concluded that 'overall non-smokers have a relative risk of lung cancer due to asbestos that is 1.8 times that of smokers'. Some admitted uncertainty about the figure 1.8 was seized upon and even the thrust of the conclusion has been very largely disregarded. So too has the RAE and all its benefits. As a result, all later reviewers have been led into error, much of it serious: in particular, they have failed to appreciate how much of the variation arises from the inevitable imprecision of all RAEs. This failure led reviewers in 1994 to discard, quite without justification, those interactions which were less than multiplicative and came from cohort studies. Although case-referent studies seemed to support the multiplicative hypothesis, the information from them is essentially unreliable. Thus it cannot weaken the conclusions from the cohort studies, that the multiplicative hypothesis is untenable and that the relative risk of lung cancer from asbestos exposure is about twice as high in non-smokers as in smokers; the best estimate of RAE is 2.04, with 95% confidence interval 1.28-3.25. This finding is not only of high statistical significance but of great social and scientific importance.

Asbestos↗

PubMed2001

Lack of interaction between asbestos exposure and glutathione S-transferase M1 and T1 genotypes in lung carcinogenesis.

An interaction between occupational carcinogens and genetic susceptibility factors in determining individual lung cancer risk is biologically plausible, but the interpretation of available studies are limited by the small number of exposed subjects. We selected from the international database on Genetic Susceptibility and Environmental Carcinogens the studies of lung cancer that included information on metabolic polymorphisms and occupational exposures. Adequate data were available for asbestos exposure and GSTM1 (five studies) and GSTT1 (three studies) polymorphisms. For GSTM1, the pooled analysis included 651 cases and 983 controls. The odds ratio (OR) of lung cancer was 2.0 [95% confidence interval (CI) 1.4-2.7] for asbestos exposure and 1.1 (95% CI 0.9-1.4) for GSTM1-null genotype. The OR of interaction between asbestos and GSTM1 polymorphism was 1.1 (95% CI 0.6-2.1) based on 54 cases and 53 controls who were asbestos exposed and GSTM1 null. The case-only approach, which was based on 869 lung cancer cases and had an 80% power to detect an OR of interaction of 1.56, also provided lack of evidence of interaction. The analysis of possible interaction between GSTT1 polymorphism and asbestos exposure in relation to lung cancer was based on 619 cases. The prevalence OR of GSTT1-null genotype and asbestos exposure was 1.1 (95% CI 0.6-2.0). Our results do not support the hypothesis that the risk of lung cancer after asbestos exposure differs according to GSTM1 genotype. The low statistical power of the pooled analysis for GSTT1 genotypes hampered any firm conclusion. No adequate data were available to assess other interactions between occupational exposures and metabolic polymorphisms.

Adult↗

PubMed1992

On the relationship between theoretical presumptions asbestos genotoxicity and the practical monitoring of exposed workers.

From the genotoxic viewpoint, there exists a sufficient evidence for asbestos carcinogenicity to human population and animals. Asbestos is a solid cancer promoter (cocarcinogen) of non-mutagenic character having epigenetic effects (15, 16). No data have been published on its mutagenic activity in "in vivo" conditions in man. The only results are those of our pilot study carried out in the period of 1981-1983, which cast doubts on the official view of non-mutagenic character of asbestos--at least under occupational conditions of its processing (34, 36, 37). The study presented here represents ten years' efforts made in the biological (cytogenetic) monitoring of persons occupationally exposed to asbestos in a factory for its processing (occupational risk). Simultaneously, a preliminary answer is given to the question whether the Osinek factory (situated in a housing area) is or is not dangerous for inhabitants of the town of Kostelec nad Orlicí, namely for their genetic apparatus (environmental risk). Using the method of chromosome aberrations analysis in peripheral blood lymphocytes, a total of 431 subjects (245 males and 186 females) were examined in the period of 1981 to 1988. Of these, 111 persons were from control workplaces (from Osinek or--starting from 1984--from other plants in Kostelec nad Orlicí; in addition to that 14 pensioners without any occupational exposure were examined). The average age of workers exposed to asbestos risk was 42.7 years, in the controls it was 43.9 years, in pensioners exposed to asbestos earlier 63.5 years and in those never exposed to asbestos 66.5 years. The average number of years spent at Osinek factory amounted to 21.5 years. About one third of employees were found to suffer from allergies (first of all those of air passages) and one sixth from chronic ailments of the upper air passages (Staphylococcus aureus, Haemophilus influenzae and Streptococcus beta-haemolyticus were diagnosed most frequently). A third part of workers from high-risk workshops are smokers, only a fourth of the controls. About 40% of workers regularly consume alcoholic drinks. The average morbidity rate at Osinek in 1981 to 1988 was 6.3% (in workers as high as 9%), which is about 2% higher as compared with mean values obtained in the district of Rychnov nad Knĕznou and East-Bohemian region. Within the nine-year period (1981-1989), 21 occupational diseases were diagnosed, while in the previous 24 years there were 24 cases of an occupational disease. Earlier they were mainly asbestoses (87%), in the last period mainly cancer diseases coinciding with asbestosis (81%).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMedDate not supplied

Mesothelioma mortality among former asbestos-cement workers in Israel, 1953-90.

Asbestos workers have long been recognized as a high risk group for the development of mesothelioma and other cancers. In this study we collated from a variety of sources 26 mesothelioma deaths that occurred between 1978 and 1990 among a cohort of some 4,441 former workers from an asbestos-cement plant in northern Israel. Since the expected number of deaths for this number of Israeli males in this age-group over this period is 0.12 cases, the risk of this disease was more than 223 times the national rate, age and sex adjusted [standardized mortality ratio (SMR) = 22,351, P < 0.001]. The mean years of exposure of persons who died from mesothelioma was 16.2 (SE 2.5). The mean latency period for mesothelioma cases from onset of exposure to death was 25.6 years (SE 1.3). Additional follow-up systems are needed to ensure complete reporting of asbestos-related diseases, including epidemiologic follow-up of asbestos-exposed workers after cessation of their work, with regular analysis of death and cancer registry data for high risk groups. Asbestos-related cancer is an important element in cancer epidemiology that requires further development in Israel. Studies of former workers, their families and of persons who worked or attended school adjacent to the asbestos-cement factory, as well as follow-up of other former worker groups exposed to asbestos are recommended.

Adolescent↗

PubMed2002

[The relationship between glutathione S-transferase M1 genotypes and lipid peroxidation in asbestos workers].

OBJECTIVE: To study the relationship between glutathione S-transferase M1 (GSTM1) genotypes and lipid peroxidation of asbestos workers. METHODS: 94 asbestos workers and 51 controls were selected as subjects. The general information, occupational history and individual habits were collected by questionnaires in all participants. The venous blood was sampled and the plasma was separated for the detection of malondialdehyde (MDA) level and lymphocytes for DNA isolation and GSTM1 genotyping. RESULTS: MDA level was significantly higher in asbestos workers [(0.283 +/- 0.054) nmol/L] than that in controls [(0.163 +/- 0.053) nmol/L, P < 0.01], however, neither duration of exposure nor accumulated asbestos exposure dose was related to MDA levels; MDA levels in control workers with GSTM1 +/- genotype [(0.190 +/- 0.034) nmol/L] were significantly higher than that in control workers with GSTM1 +/+ genotype [(0.138 +/- 0.055) nmol/L, P < 0.01]. Among asbestos workers, the same trend could be found, but the differences was not significant(P > 0.05). When the workers were stratified by duration of exposure or accumulated asbestos exposure dose, MDA levels in individuals with GSTM1 -/- genotype were also higher than those with GSTM1 +/+ genotype, but the differences were also not significant(P > 0.05). CONCLUSION: Both exposure to asbestos and deficiency of GSTM1 genotype were related to lipid peroxidation in workers, but the role of the former may be more important than that of the latter.

Asbestos↗

PubMed2003

[Identification of asbestos in bulk materials by polarised light microscopy and phase contrast--method and results].

The implementation of the 1997 law on the banned use of asbestos, entailing a successive elimination of asbestos products, is planned for 30 years. Asbestos identification in samples of bulk materials is essential before starting dismantling works. The presented method of asbestos identification by polarized light microscopy and phase contrast involves the study of the following optical parameters of asbestos fibers: color, morphology, refractive index, anisotropy, pleochroism, optic nature and extinguish angle. The major advantages of this method are: small material samples, short time of analysis, high asbestos sample detectability (0.1%) and high reliability of results. This paper presents the results of asbestos identification in over a dozen of samples of bulk materials derived from various buildings and installations.

Asbestos↗

PubMed1992

Asbestos exposure in buildings.

Asbestos-related diseases are dose-related. Among these, asbestosis has occurred only with the heavy exposures of the past, is a disappearing disease, and is of no concern with the very small exposures from building occupancy. A possibly increased incidence of lung cancer has been included in risk analysis, but probably is also related to high exposure in that both epidemiologic and experimental data suggest a link between the process of alveolar inflammation and fibrogenesis and carcinogenesis. The major concern has been mesothelioma in that it has occurred with much lower household and neighborhood exposure. Additionally, anxiety concerning buildings with ACM has been heightened by finding of friable asbestos in about 20% of public buildings, discovery of environmental asbestos fibers and asbestos bodies in autopsies, and demonstration of a linear relationship between exposure and lung cancer risk in occupational groups, inviting extrapolation to a much lower dose. Legislative and regulatory mandates, promotional activities of abatement companies, adverse court decisions placing the onus of repairs on asbestos manufacturers, and a "pandemic of mediagenic disease" all have contributed to panic among building owners, school boards, insurers, and others. In that there is neither clinical nor epidemiologic support for asbestos-related disease from building occupancy, risk estimates have been based on extrapolation from past experience with generally high-dose occupational exposure. However, only a few epidemiologic studies have contained quantitative estimates of exposure, and these have been measured in terms of all particles, with conversion to asbestos fibers uncertain and the fiber type and dimension largely unknown. To these uncertainties must be added the unproved assumption of a linear dose-response down to very low levels of exposure with no threshold. At the other end of the scale extrapolation has required measurements of present building exposure, and these have been revised downward as methods for collection and analysis have improved. Risk estimates in this country and abroad have assumed exposure to 0.001 f/mL, with indicated lifetime risks for cancer ranging from about 2 to 20 per 1 million students. However, these estimates have assumed mixed fiber exposure whereas most building exposure comes from chrysotile, which is much less toxic than the amphiboles.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollution, Indoor↗

PubMedDate not supplied

[Asbestos risk in the textile industry: braking systems on machinery used until the 1990's].

BACKGROUND: We recently described asbestos risk in the non-asbestos textile industry as the result of fibre dispersion from ceilings, pipe insulation and machines. OBJECTIVES: The widespread use of brakes with asbestos linings on the machines as well as other functional details were considered for a proper evaluation of their role in producing atmospheric pollution METHODS: All the information was collected on the basis of the personal technical experience of two of the Authors and by direct observation of the machines. RESULTS: All the textile machines (ring spinning, twisting, warping, winding, looms) used until the 1990's were without exception equipped with asbestos-lined mechanical brakes. The heavy action required produced relatively rapid wear of the linings and the dust produced was spread into the atmosphere by the continuous action of the "travelling blowing cleaners" and by the daily cleaning of the machines using compressed air at the end of the shift: violent air blowing undoubtedly caused redispersion of the fine dust from the brakes and also acted as a mechanical grinder on the bundles that sedimented on the machines from the ceilings and pipes, producing more ultrathin respirable fibres. CONCLUSIONS: the contribution of textile machinery to atmospheric pollution by asbestos fibres was significant and due both to the widespread use of brakes with asbestos-containing materials and to the continuous action on the machines of compressed air blowers. Asbestos pollution was certainly high in all the factories so that in the near future still further mesothelioma cases among ex-workers are to be expected.

Air Pollutants, Occupational↗

PubMedDate not supplied

[Air-dispersed asbestos fiber pollution in urban areas: current and previous levels].

Over the last twelve years (since the Lombard Regional Law n 41 on asbestos came out in 1986) I have had the opportunity to actively take part into monitoring campaigns both in working environments and in several urban areas. At the beginning analysis were performed almost exclusevely using phase contrast optical microscope (MOCF). This technique, even with its well known limits, has lead to measurments of asbestos pollution never exceeding 4-5 fibers L(-1) in urban areas. The reported value had lowered to 1-2 fibers L(-1) by the beginning of the nineties and, in the following years it has become even lower. The introduction of scanning electronic microscope (SEM) has not only confirmed these data but also shown lowered values of asbestos fibers in air (< 0.05 fibers L(-1)). This is to be related with the use of artificial fibers (glass and synthetical fibers) in cars braking systems instead of natural mineralfibers (asbestos). Nowadays the concrete-asbestos roof coverages can be a potential environmental pollution source if their surfaces are not protected. The reported indoor levels of pollution are similar to the outdoor ones and to levels reported in areas nearby rock-caves. The levels of asbestos pollution reported in the previous years using MOCF have been nowadays confirmed using SEM, expecially as far as buildings reclaimed from asbestos are concerned.

Air Pollutants↗

PubMed2005

Mortality from malignant neoplasms among workers of an asbestos processing plant in Poland: results of prolonged observation.

OBJECTIVES: The study on mortality from cancer among workers of an asbestos plant manufacturing asbestos yarn, cloth, cords, packings, stuffing, brake linings and asbestos-rubber sheets was launched in the 1980s. The present paper discusses the results of further tracing of asbestos workers of the same plant. MATERIALS AND METHODS: The study cohort covered 4497 workers employed at the asbestos plant in 1945-1980. The follow-up of the cohort continued until 31 December 1999. Deaths by causes were analyzed using standardized mortality ratio (SMR) calculated by the person-years method. The mortality pattern of the general population of Poland was used as reference. RESULTS: The availability of the cohort was 93.1% (2805 men and 1382 women were traced). Mortality from malignant neoplasms in total (281 deaths among men, SMR = 118, 95%CI: 105-133 and 135 deaths among women, SMR = 159, 95%CI: 133-188) as well as that from lung cancer (102 deaths among men, SMR = 126, 95%CI: 103-153 and 18 deaths among women, SMR = 259, 95%CI: 153-409) were significantly higher than in the general population. Unlike earlier stages of analysis, the present study revealed an increased risk of pleural mesothelioma (2 deaths among men, SMR = 510, 95%CI: 62-1842 and 3 deaths among women, SMR = 2033, 95%CI: 419-5941). Mortality analysis among workers with asbestosis and in those without diagnosed asbestosis, did not reveal direct association between the risk of asbestos-induced lung cancer and previously diagnosed asbestosis. CONCLUSIONS: The prolonged cohort tracing showed an increased risk of asbestos-related cancers. It concerned mainly workers hired by the plant between 1945-1955, when the working condition were most strenuous.

Adult↗

PubMedDate not supplied

[Health surveillance of subjects formerly exposed to asbestos in Puglia].

The massive use of asbestos affected several industrial areas of Apulian region in the last decade. It has been estimated that in our country there are thousands of asbestos exposed workers and about 10.000 of them received CONTARP-INAIL document attesting their asbestos exposure for over ten years ex D.L. 257/92. Owing to the lack of any regional rules and guidelines on the medical surveillance of asbestos ex-exposed people, since 1994 our operative hospital unit has activated a sanitary protocol in order to satisfy growing requests of assistance and emergent controls for this part of people. During a 12 year activity 629 asbestos ex-exposed workers have been examined. 21% of these workers had two checks, thanks to these the recognition of 22 new tumoral and non-tumoral asbestos-correlated pathologies has been possible. This experience makes it clear that the activation of new procedures for early diagnoses of some asbestos-correlated pathologies is necessary, in fact more proposals for a redevelopment of sanitary assistance in the regional field are suggested.

Adult↗

PubMed1991

Tissue reaction following a second exposure to amosite asbestos.

An inherently long latency period exists between the time of asbestos exposure and the development of asbestos related clinical signs in man. By this stage the events reflect the cumulative responses and offer little with regard to characterizing the acute inflammatory reactions. Similarly, studies of asbestos-induced diseases employing animal models have often emphasized the investigation of chronic events, particularly the development of fibrosis and/or cancer. However, short-lived neutrophils, which exhibit a substantial potential to produce tissue damage through the generation of superoxide radicals and elastase, have been shown to constitute a component of the acute response to asbestos in this animal model. Repetitious exposures to asbestos could logically simulate extensions of this acute response and thus be an important contributor to the development of fibrosis. In order to assess this concept, animals received two exposures to asbestos. The parenchyma exhibited both 'established' lesions consisting primarily of foci of closely-packed, fibre-laden macrophages within alveoli, and 'new' lesions consisting of a mixed cell inflammatory response (including neutrophils and macrophages) as well as considerable alveolar exudate. Repeated infiltration of neutrophils to the site of renewed lung injury following a second exposure to asbestos may correspond to events occurring in human lungs exposed similarly to repeated exposures of the dust.

Animals↗

PubMedDate not supplied

[Asbestos in indoor areas].

In 1994 the FRG will probably be the first country with a complete ban on asbestos. But it will take until the next century before all the buildings are free from asbestos contamination. The Public Health Services is urged to keep a close watch on asbestos removal operations. The costs will amount to several thousand million DM in Germany. Planning and implementation of all renovation should be carried out on the basis of the asbestos guidelines. A previous measurement program to identify and count the fibres is usually not necessary. The guidelines, discussed in this article, allow to assess the urgency of the renovation operations. Special attention is paid to the six million night-storage heaters in the Federal Republic of Germany. Drinking water contaminated with asbestos is less important for the asbestos concentration of the aerosol in buildings. After a comprehensive synopsis on the so far mostly unpublished fibre concentrations in buildings, comments on the risk assessment concerning the residence in asbestos-contaminated buildings are made.

Air Pollution, Indoor↗

PubMed1991

Autopsy indicators of exposure to asbestos and lung cancer.

In many instances, only post-mortem examination can provide probative data about (i) the presence of lung cancer and (ii) its relationship to exposure to asbestos. Moreover, the results of an autopsy may suggest that a thorough investigation of occupational history should be carried out, since such information is rarely recorded in clinical records. We considered pathological indicators for selecting subjects who had a high likelihood of previous occupational exposure to asbestos. The positive predictive value of pleural plaques ranged from 20 to 75%, depending on their size and on the concentrations of asbestos bodies and uncoated mineral fibres in the lung. The probability of no exposure was greater than 90% if neither asbestos bodies nor uncoated mineral fibres were found. Another purpose of our work on lung cancer and exposure to asbestos was to investigate the relationships between exposure and the occurrence of specific cell types of lung cancer in an autopsied population. Both work history and asbestos body count were considered. The matched analysis showed some tendency towards an association between the occurrence of adenocarcinoma and the presence of indicators of exposure to asbestos.

Adenocarcinoma↗

PubMed1990

[A study for non-asbestos casting liners. An experimental study of the adaptability of MOD casting to die].

Asbestos liners for investment metal casting has frequently been used in dental laboratory work. In recent years, the dangerous properties of asbestos to the human body were reported in Europe and the United States, and casting liners without asbestos were developed and marketed by many manufacturers. These are so-called non-asbestos liners. This study evaluated the adaptability of MOD inlay castings to dies using 8 kinds of commercial non-asbestos liners of ADA standard No. 2 specifications. The results were as follows; Single and double layers of Casting ribbon, New Asbestos Ribon, Shofu experimental, and KAOLIN showed good adaptation. Shofu experimental with a single layer showed the best marginal adaptation (10 microns). OVAL LINERS and CASTING LINERS with single layer showed good adaptation, but with double layers the adaptation was poor. In FLASK LINER, the double layer showed better adaptation than that with a single layer. Most non-asbestos liners used in this study are adequate in useful to MOD inlay castings.

Asbestos↗