Gestão de pequenos volumes de materiais de cimento-amianto no Brasil: do uso aos resíduos / Management of small volumes of asbestos-cement materials in Brazil: from use to waste

A gestão dos resíduos da construção civil (RCC) é desafio aos administradores públicos, o estudo do sistema de gestão do município de São Paulo realizado nessa Tese, após cinco anos da efetivação do sistema de rastreamento Coletas Online no município, apontou melhorias, como o aprimoramento da fiscalização dos RCC no transporte e destino, e a ampliação do número de Ecopontos, porém apesar do aumento do fluxo para os pequenos volumes, os RCC perigosos continuam à margem desta infraestrutura, dependendo de logística reversa que nem sempre atende a diversidade de RCC gerados, como para os pequenos volumes de materiais de cimento-amianto (MCA). Para o cálculo estimativo da quantidade de MCA foram pesquisadas a evolução de mercado e banimento do amianto, levantados dados de consumo interno de crisotila, de 1998 (período de permissão de uso) até 2017 (ano do banimento), a geração de resíduos de cimento-amianto (RCA) (2012 a 2017), assim como o percentual de fibras por compósito e fator durabilidade. Constatou-se significativa diferença entre a média anual de produção de MCA (1,38 milhões t) e a geração de RCA (17 mil t), evidenciando grande quantidade em uso e que a capacidade instalada dos aterros classe I no país está aquém da demanda projetada de RCA. O Sistema de gestão internacional do Reino Unido (RU) escolhido fornece instruções técnicas aos autoconstrutores, para a remoção segura de pequenos volumes de cimento-amianto e proporciona o fluxo desses resíduos pelo transporte e destinação adequados, por meio de contratação de empresa regulamentada, intermediada pelo Poder Público. O fluxograma elaborado nesta tese possibilita de forma simples aos gestores, verificar o risco do uso das telhas de cimento-amianto (TCA) em moradias de baixa renda, pela identificação das TCA, verificação de seu estado de conservação, caracterização construtiva das moradias, e após a associação dos dados, a tomada de decisão sobre a necessidade de coleta de amostras atmosféricas. Os resultados das quantidades de fibras /cm³ definem as medidas, monitoramento para (≤ 0,1 f /cm³) ou para (> 0,1 f/cm³), gestão de risco à Saúde Pública e Ambiental na localidade. Instruções técnicas de segurança foram adaptadas do R U para a realidade nacional, com a finalidade de capacitar gestores públicos para ações de desamiantização de pequenas áreas de TCA (20m²) de regiões onde há risco de inalação de fibras de amianto pela população local. Foram elaboradas orientações que abrangem a remoção, manejo, uso de EPIs, EPRs, sinalizações, limpeza, embalagem, coleta, transporte e destinação com segurança ocupacional e ambiental para a grande demanda projetada de pequenos volumes de resíduos de cimento-amianto, geradas de forma difusa, nas moradias de baixa renda do país. Portanto, é premente inserir a gestão sustentável dos MCA em uso e dos RCA de forma segura, na agenda de políticas públicas ambientais e de saúde no país. A desamiantização das moradias será cada vez mais urgente devido a aceleração da degradação das TCA ao longo do tempo pelas alterações climáticas. Os diagnósticos das condições ambientais das moradias ajudam a prevenir problemas de saúde causados pela inalação das fibras de amianto. A capacitação de gestores por meio das instruções técnicas proporciona parceria para a desamiantização das moradias de baixa renda e reduzem o descarte irregular dos RCA, enquanto novas rotas tecnológicas devem ser estabelecidas para seu retorno ao mercado consumidor, mitigando a destinação em aterros classe I. Medidas alinhadas aos objetivos de desenvolvimento sustentável, ODS 12 para consumo e produção responsáveis.

The management of waste construction (CDW) is a challenge to public administrators, the study of the management system of the municipality of São Paulo conducted in this Thesis, after five years of effectiveness of the online collection tracking system in the city, pointed out improvements, such as the improvement of the supervision of the CDW in transport and at destination, and the increase in the number of Ecopontos, however, despite the increase in the flow for small volumes, hazardous CDW remain on the margin of this infrastructure, depending on reverse logistics that does not always meet the diversity of CDW generated, such as small volumes of asbestos-cement materials (ACM). For the estimation of the amount of ACM, the evolution of the market and the banning of asbestos were researched, collecting data on the internal consumption of chrysotile, from 1998 (period of use permission) to 2017 (year of ban), the generation of cement waste -asbestos (CWA) (2012 to 2017), as well as the percentage of fibers per composite and durability factor. There was a significant difference between the average annual production of ACM (1.38 million t) and the generation of CWA (17 thousand t), evidencing a large amount in use and that the installed capacity of class I landfills in the country is below the projected CWA demand. The UK international management system chosen provides clear technical instructions to the self-builders, for the safe removal of small volumes of asbestos cement and provides the flow of these wastes by the appropriate transport and disposal, through the hiring of a regulated company, intermediated by the Government. The elaborate flowchart makes it possible for managers verify in a simplified way the risk of using asbestos-cement tiles (ACT) in low-income homes, by identifying ACT, checking their state of conservation, constructive characterization of the homes, and after associating the data, decision making on the need to collect atmospheric samples. The results of the amounts of fibers /cm³ define the measures, monitoring for (≤ 0.1 f/cm³) or for (> 0.1 f/cm³), risk management to Public and Environmental Health in the location. Technical safety instructions were adapted from the R U to the national reality, with the purpose of training public managers for asbestos removal actions in small areas of ACT (20m²) in regions where there is a risk of inhalation of asbestos fibers by the local population. Guidelines were developed covering the removal, handling, use of PPE, EPRs, signaling, cleaning, packaging, collection, transportation and disposal with occupational and environmental safety for the large projected demand of small volumes of asbestos-cement waste, generated in a diffuse, in the country's low-income housing. Therefore, it is urgent to insert the sustainable management of the ACMs in use and the ACWs in a safe manner, on the agenda of environmental and health public policies in the country. The asbestos removal of housing will be increasingly urgent due to the acceleration degradation of ACTs over time by climate change. Diagnosing the environmental conditions of the housing will help prevent health problems caused by the inhalation asbestos fibers. The training of managers through technical instructions provides a partnership for the asbestos removal of low-income housing and reduces the irregular disposal of ACW, while new technological routes must be established for their return to the consumer market, mitigating the disposal in class I landfills. Measures aligned with sustainable development goals, SDG 12 for responsible consumption and production.

Asbestosis: un problema del siglo XX que persiste en el siglo XXI / Asbestosis: A Problem of the XX Century that Persists in the XXI Century

El Asbesto ha sido conocido y utilizado desde la antigüedad por ser un excelente material aislante, ignífugo y por poseer resistencia a los ácidos. Los griegos lo utilizaban en las lámparas votivas para sus deidades y Alejandro el Grande, agasajaba a sus invitados con comidas servidas sobre un mantel confeccionado con dicho material. El toque de hechizo lo efectuaba al culminar el banquete, cuando lo arrojaba al fuego para que se consumiese lo orgánico, rescatando el mantel sin sufrir alteraciones, al ser incombustible. El Asbesto se clasifica en dos grandes grupos: las SERPENTINAS (entre las que más del 90% de la explotación industrial lo compone el crisotilo) y las ANFÍBOLAS (crocidolita o "amianto azul" y la amosita o "amianto marrón)

Unveiling neotropical serpentine flora: a list of Brazilian tree species in an iron saturated environment in Bom Sucesso, Minas Gerais

Serpentine soils are those holding at least of 70% iron-magnesium compounds, which make life intolerable for many species. Although plant's adaptation to environmental toughness is widely studied in tropics, virtually nothing is known about Brazilian serpentine flora. Our aim was to bring up and characterize the serpentine flora in Bom Sucesso, Minas Gerais state, Brazil. We performed expeditions utilizing rapid survey sampling method to identify the arboreal compound in the area. Plants within circumference at breast high (CBH) up to 15,7 cm were included in our study. A specialist identified all the individuals to species level. We found 246 species located in 59 botanical families. Fabaceae, Myrtaceae and Melastomataceae were the most representative families in the area. Serpentine areas usually present a few species capable to survive to adverse conditions, contrasting the high number found in our study. To our knowledge, this is the first floristic survey in serpentine areas in the neotropics, reinforcing the need for more studies about plant diversity in those areas. It seems that serpentinites is not the key factor influencing plant diversity in the neotropics. The high diversity found in our study strengthens serpentine areas as a place for conservation concern.

Mortalidade por câncer associada à exposição cumulativa de amianto crisotila em indivíduos adultos e idosos: revisão sistemática / Cancer mortality associated with cumulative exposure to chrysotile asbestos in adults and the elderly: a systematic review

Resumo: Introdução: Os asbestos são minerais compostos por fibras naturais que foram muito utilizados na indústria devido suas propriedades físico-químicas que lhe garantem a exposição às altas temperaturas sem sofrer alteração. Existem dois tipos de fibras sendo que somente as serpentinas (crisotila) ainda são extraídas e comercializadas em alguns países. Contudo, se por um lado, as serpentinas trouxeram facilidades para a civilização, por outro, geraram dilemas conflituosos acerca de sua toxicidade no ambiente e na saúde das pessoas. Objetivo: Buscar evidências na literatura científica sobre a mortalidade por câncer entre a população adulta e idosa que foram submetidas à exposição cumulativa aos asbestos crisotila no ambiente ocupacional, paraocupacional ou ambiental. Metodologia: Trata-se de uma revisão sistemática de literatura. Para tanto, utilizaram-se os critérios de revisão sistemática estabelecidos pelo Instituto Joanna Briggs para identificar o nível de evidência - prognóstico; assim, os estudos do tipo coorte sem limite de data, nos idiomas português, inglês, alemão, espanhol e italiano, foram exclusivamente analisados. As bases de dados para a averiguação dos estudos foram a Medline/Pubmed, Cinahl, ScienceDirect, Scielo, Web of Science, The Cochrane Library, Lilacs e Scopus. Resultados: O protocolo desta revisão sitemática foi submetido ao PROSPERO sob número de registro CRD 42018095749. Recuperados 1643 artigos que após a análise inicial, resultou em 139 artigos. Destes, quatro foram selecionados para identificar a relação entre a mortalidade por câncer e a exposição ao crisotila puro. Devido à heterogeneidade das informações, não foi possível estabelecer a metanálise, portanto, procedeu-se à síntese narrativa dos dados. Discussão: Os estudos de coorte apresentaram fragilidades metodológicas que impossibilitaram estabelecer o nível de evidência de que a mortalidade por câncer está aumentada na população exposta ao crisotila. Porém, ainda que a evidência científica não tenha sido definida com esta revisão sistemática, destaca-se que há indícios de que tal hipótese possa ser verdadeira. Considerações: Ressaltamos sobre a importância dos estudos de coorte seguirem rigorosamente as diretrizes de qualidade para descrever as informações necessárias que viabilizem ao leitor avaliar o estudo e utilizar os dados de forma confiável. Recomendamos maiores investimentos em pesquisas na área, com descrição metodológica rigorosa e detalhada do estado vital dos participantes, concentração e natureza das fibras inaladas, tempo de exposição com especificação em horas por dia, local da exposição, diagnóstico confirmado e notificado compulsoriamente em sistemas competentes nos países de origem, e medidas de prevenção de fatores de confusão para que se estabeleça o crisotila puro como nexo causal do aumento de mortalidade por câncer. Todavia, enquanto não se estabelecer a evidência, é imprescindível que haja esforços no sentido de administrar recursos para a prevenção e o tratamento das doenças relacionadas aos asbestos.

Abstract: Introduction: Asbestos are minerals composed of natural fibers that have been widely used in the industry due to their physicochemical properties that guarantee exposure to high temperatures without alteration. There are two types of fibers and only the serpentines (chrysotile) are still extracted and marketed in some countries. However, while on the one hand serpentines have brought facilities for civilization, on the other, they have generated conflicting dilemmas about their toxicity to the environment and people's health. Objective: To find evidence in the scientific literature on cancer mortality among the adult and elderly population that were submitted to cumulative exposure to asbestos chrysotile in the occupational, para-occupational or environmental environment. Methodology: This is a systematic literature review. To do so, the systematic review criteria established by the Joanna Briggs Institute were used to identify the level of evidence - prognosis; therefore, the cohort studies with no date limit in the Portuguese, English, German, Spanish and Italian languages were exclusively analyzed. The databases for the investigation of the studies were Medline / Pubmed, Cinahl, ScienceDirect, Scielo, Web of Science, The Cochrane Library, Lilacs and Scopus. Results: The protocol of this sitematic review was submitted to PROSPERO under registration number CRD 42018095749. Recovered 1643 articles that after the initial analysis, resulted in 139 articles. Of these, four were selected to identify the relationship between cancer mortality and exposure to pure chrysotile. Due to the heterogeneity of the information, it was not possible to establish the meta-analysis, therefore, the narrative synthesis of the data was done. Discussion: Cohort studies showed methodological weaknesses that made it impossible to establish the level of evidence that cancer mortality is increased in the population exposed to chrysotile. However, although the scientific evidence has not been defined with this systematic review, it is emphasized that there is evidence that such a hypothesis may be true. Considerations: We emphasize the importance of cohort studies to strictly follow the quality guidelines to describe the necessary information that will enable the reader to evaluate the study and use the data reliably. We recommend greater investments in research in the area, with a detailed and detailed methodological description of participants' vital status, concentration and nature of inhaled fibers, time of exposure with specification in hours per day, location of exposure, diagnosis confirmed and reported compulsorily in competent systems in countries of origin, and measures to prevent confounding to establish pure chrysotile as a causal link to the increase in cancer mortality. However, as long as the evidence is not established, efforts must be made to administer resources for the prevention and treatment of asbestos-related diseases.

Adverse health effects of asbestos: solving mysteries regarding asbestos carcinogenicity based on follow-up survey of a Chinese factory

The present review summarizes the results of several follow-up studies assessing an asbestos product manufacturing plant in Chongqing, China, and discusses three controversial issues related to the carcinogenicity of asbestos. The first issue is the amphibole hypothesis, which asserts that the carcinogenicity of asbestos is limited to amphiboles, such as crocidolite, but not serpentines, such as chrysotile. However, considering the possible multiple component of asbestos carcinogenicity in the presence of tobacco smoke or other carcinogens, chrysotile cannot be regarded as non-carcinogenic. Additionally, in a practical sense, it is not possible to assume "pure" chrysotile due to its ubiquitous contamination with tremolite, which is a type of amphibole. Thus, as the International Agency for Research on Cancer (IARC) assessed, all forms of asbestos including chrysotile should be regarded carcinogenic to humans (Group 1). The second issue is the chrysotile/tremolite paradox, which is a phenomenon involving predominant levels of tremolite in the lung tissues of individuals who worked in locations with negligible levels of tremolite due to the exclusive use of chrysotile. Four possible mechanisms to explain this paradox have been proposed but this phenomenon does not support the claim that amphibole is inert. The final issue discussed is the textile mystery, i.e., the higher incidence of cancer in asbestos textile plants compared to asbestos mines where the same asbestos was produced and the exposure levels were comparable. This phenomenon was first reported in North America followed by UK and then in the present observations from China. Previously, levels of fiber exposure were calculated using a universal converting coefficient to estimate the mass concentration versus fiber concentration. However, parallel measurements of fiber and mass concentrations in the workplace and exposed air indicated that there are wide variations in the fiber/mass ratio, which unjustifies the universal conversion. It is possible that contamination by airborne non-fibrous particles in mines with mass fiber conversion led to the overestimation of fiber concentrations and resulted in the textile mystery. Although the use and manufacturing of asbestos has been banned in Japan, more than 10 million tons of asbestos had been imported and the majority remains in existing buildings. Thus, efforts to control asbestos exposure should be continued.

Metástasis cutánea de mesotelioma pleural / Cutaneous metastasis of pleural mesothelioma

Las metástasis cutáneas de mesotelioma pleural son muy raras y con una supervivencia muy corta. Se presenta un paciente de 80 años, con una placa eritematoviolácea duro elástica ubicada en flanco abdominal derecho, de 8 meses de evolución y rápido crecimiento. Se realiza diagnóstico de metástasis cutánea de mesotelioma pleural, se indica tratamiento quimioterápico paliativo pero fallece por falla multiorgánica, sin llegar a recibirlo...

Monitoring and analysis of asbestos concentration in working environment of different asbestos-producing technologies in a certain area / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze asbestos exposure level between 1984 and 2010 in a district of malignant mesothelioma with clustering incidence in Zhejiang Province, in order to improve the recognizing and early diagnosis of malignant mesothelioma, protect the health of workers.</p><p><b>METHODS</b>Monitoring data of total asbestos dust concentration in the air of workplace from 1984 to 2010 in asbestos textile enterprises, family hand spinning operation, brake production, and asbestos board production in Zhejiang Province were collected in the local CDC. A total of 766 TWA copies of mass concentration were collected, and 1233 copies of MAC data. Asbestos mass concentration and fibre counting concentration of 29 points of family hand spinning operation were parallel determinated in the same time and the same sampling point. Raw asesbtos materials and dust composition of local asbestos processing corporations were collected and analyzed using X-ray diffraction method.</p><p><b>RESULTS</b>Raw materials of asbestos used between 1984 and 2010 in this area were chrysotile from Sichuan, Qinghai, Xinjiang, Russia, Zimbabwe, and some were mixed with SiO2, CaCO3 and other impurities. Raw materials used in asbestos board production were blue asbestos. Dust concentration between 1960s and 1980s in asbestos processing plants far exceeded the national standard. After then the dust concentration decreased significantly, but still higher than the national standard. 95.2% of air dust concentrations in the workplaces of asbestos factories exceeded the standard, and dust concentrations of workplaces of raw material, spinning, weaving, carding and labor insurance were above 90% in which carding work had the highest median concentration. 37.9% of dust mass concentrations in hand spinning work exceeded the standard where textile machinery side had the highest value. Beating job in asbestos board manufacturing and grinding job in brake production had higher concentrations.</p><p><b>CONCLUSIONS</b>Most of production technologies in asbestos processing industry exceed the standard level, indicating that the workers were at risk for malignant mesothelioma and other asbestos related diseases, which should draw high attention.</p>

CT Characteristics of Pleural Plaques Related to Occupational or Environmental Asbestos Exposure from South Korean Asbestos Mines

OBJECTIVE: This study evaluated the CT characteristics of pleural plaques in asbestos-exposed individuals and compared occupational versus environmental exposure groups. MATERIALS AND METHODS: This study enrolled 181 subjects with occupational exposure and 98 with environmental exposure from chrysotile asbestos mines, who had pleural plaques confirmed by a chest CT. The CT scans were analyzed for morphological characteristics, the number and distribution of pleural plaques and combined pulmonary fibrosis. Furthermore, the CT findings were compared between the occupational and environmental exposure groups. RESULTS: Concerning the 279 subjects, the pleural plaques were single in 2.2% and unilateral in 3.6%, and showed variable widths (range, 1-20 mm; mean, 5.4 +/- 2.7 mm) and lengths (5-310 mm; 72.6 +/- 54.8 mm). The chest wall was the most commonly involved (98.6%), with an upper predominance on the ventral side (upper, 77.8% vs. lower, 55.9%, p < 0.001) and a lower predominance on the dorsal side (upper, 74.9% vs. lower, 91.8%, p = 0.02). Diaphragmatic involvement (78.1%) showed a right-side predominance (right, 73.8% vs. left, 55.6%, p < 0.001), whereas mediastinal plaques (42.7%) were more frequent on the left (right, 17.6% vs. left, 39.4%, p < 0.001). The extent and maximum length of plaques, and presence and severity of combined asbestosis, were significantly higher in the occupational exposure group (p < 0.05). CONCLUSION: Pleural plaques in asbestos-exposed individuals are variable in number and size; and show a predominant distribution in the upper ventral and lower dorsal chest walls, right diaphragm, and left mediastinum. Asbestos mine workers have a higher extent of plaques and pulmonary fibrosis versus environmentally exposed individuals.

Policy alternatives to reduce the health and economic effects of continued asbestos use in the Philippines

OBJECTIVES: Asbestos is a carcinogenic mineral substance formerly used widely in the construction industry, all forms of which, except for chrysotile asbestos, have been banned in the Philippines. This article aims to propose policy alternatives to reduce the health and economic effects of continued asbestos use in the country.METHODS: Records of asbestos-related diseases, and asbestos industry-related data in the country were consolidated. The impact of continued asbestos use on the national economy were estimated incorporating natural mortality, regulations of the Department of Labor and Employment (DOLE), and concepts of multiplier effect and net present value. Round table discussions validated data and generated policy recommendations.RESULTS: Filipinos directly and indirectly exposed to asbestos-containing materials (ACMs) are 5,289 and 30,000, respectively. The contributions of these groups to the national economy were estimated at PhP 1.08 Billion annually for workers directly exposed to ACMs and PhP 6.83 Billion annually for workers indirectly exposed. Two policy options--adjustment of threshold limit values, and a total ban--are presented.CONCLUSION: A total ban on all forms of asbestos is shown to be the more cost-effective policy option for the country. It is recommended that government agencies, stakeholders in the asbestos industry, and the general public be involved in strategies for improving surveillance on asbestos exposure, increasing public awareness, and promoting the use of asbestos alternatives.

[Determination of toxicological indexes of carbon nanotubes and Chrysotile according to invitro cytotoxicity on Human Lung epithelium cells]

In this study the cytotoxicity to human epithelial lung cells of single-walled carbon nanotubes, multi-walled carbon nanotubes and chrysotile was compared based on the following cytotoxicity indices: no observable adverse effect concentration [NOAEC], inhibitory concentration 50 [IC50], and Total Lethal Concentration [TLC]. Human epithelial lung cells were exposed to different concentrations [1 to 1500 micro g/ml] of carbon nanotubes and chrysotile for 6 and 24 hours. Cytotoxicity was assessed using the MTT assay. NOAEC, IC50, and TLC idices were determined by probit analysis. The results showed statistically significant correlations [p<0.001] between cytoxicity and exposure concentration in the case of all the three compounds. The NOAEC and IC50 indices were lowest for the multi-walled carbon nanotubes, while the single-walled carbon nanotubes showed the lowest TLC index. Cytotoxicity of multi-walled carbon nanotubes at low concentrations was higher than that of single-walled carbon nanotubes and chrysotile. This would mean that exposure to this compound occurs at low concentrations. Thus, cytotoxicity of multi-walled carbon nanotubes is a cause for concern. It can be concluded, then, that, like chrysotile fibers, crabon nanotubes are also considerably toxic to human epithelial lung cells

The dose-response relationship of chrysotile asbestos exposure and lung cancer in cohort study / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To clarify the dose-response relationship between asbestos dust exposure and lung cancer incidence in chrysotile asbestos miners by fixed cohort study and to investigate the incidence rates of lung cancer in exposure to different concentrations of asbestos dust.</p><p><b>METHODS</b>A retrospective cohort study was conducted in 1932 asbestos miners who registered from January 1, 1981 to December 31, 1988, had worked for at least 1 year, and had no obvious cardiopulmonary diseases; the cohort study began in July 2009 and covered a time span of 29 years (1981 - 2009). The personal information, occupational history, disease history, and health data of these miners were recorded, and the monitoring data on dust concentrations in the mine over the years were collected. The dose-response relationship between asbestos dust concentration and lung cancer incidence was established by the method of life table; a regression equation was fitted to predict the excess incidence rates of lung cancer under the conditions of different working years and dust concentrations.</p><p><b>RESULTS</b>A significant dose-response relationship was observed between cumulative exposure (Ce) and cumulative probability (Px) of lung cancer incidence, and the smokers hada higher Px than nonsmokers. When Ce was less than 2000 mg/m(3)·each year, Px reached 6.58/10000; when Ce was not less than 2000 mg/m(3)·and less than 3000 mg/m(3)·each year, Px reached 91.72/10000; when Ce was more than 5000 mg/m(3)·each year, Px was as high as 141.02/10000. The three models were fitted to obtain the optimal regression equation: Px = -0.0004Ce(2) + 0.0052Ce - 0.0011 (r(2) = 0.9387). In the workshop of asbestos mine in this study, the average dust concentration was 85 times higher than the limit in 2009, so the excess incidence rate of lung cancer was 112.598/10000 if the miners worked under this condition for 40 years, according to the equation.</p><p><b>CONCLUSION</b>There is a significant dose-response relationship between cumulative asbestos exposure and lung cancer incidence in chrysotile asbestos miners. The risk for lung cancer rises as asbestos exposure increases.</p>

Comparative study of the cytotoxicity induced by chrysotile asbestos, rock wool and substitute fibers in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the cytotoxicity induced by chrysotile asbestos (CA), rock wool (RW) and wollastonite (WS).</p><p><b>METHODS</b>V79 cells were divided into 4 groups. i.e. CA group, WS group, RW group and control group (200 microl PBS). The exposure concentration of dusts was 100 mg/L, The cell viability was detected by MTT and lactate dehydrogenase (LDH) activity assays. The technique of scanning electron microscopy was used to examine the change of V79 cells.</p><p><b>RESULTS</b>SiO2 was main constituent for 3 kinds of dusts. In MTT assay, the cell viability of RW and WS groups was 64.8% and 65.7%, respectively, which were significantly higher than that (54.5%) of CA group (P < 0.01). In LDH assay, the LDH activity of RW and WS groups [(15.7 +/- 50.9), (12.3 +/- 3.7) U/L, respectively] was significantly lower than that [(20.2 +/- 0.9) U/L] of CA group (P < 0.05). In scanning electron microscopy examination, it was found that the two ends of V79 cells in CA group contained a great deal of fibers remaining bodies, but the V79 cell appearance in RW and WS groups was normal.</p><p><b>CONCLUSION</b>The cytotoxicity induced by RW and WS is significantly lower than that induced by CA for V79 cell.</p>

Mesotelioma maligno: experiencia clínico-patológica de 247 casos / Malignant mesothelioma: clinical and pathological features from 247 cases

Objective: This study describes the frequency, occupational, clinical, and pathological features in a large cohort of cases of Malignant Mesothelioma (MM) from the National Institute of Respiratory Diseases (INER), in México. Methods: A retrospective and transversal study was carried out in medical records of patients diagnosed with MM between the years 1991 to 2007. Results: Of the 247 patients, 184 were male and 63 were female with an average age of 51-60 years. Dyspnea and chest pain were the presenting symptoms in most of the patients. Exposure to asbestos was referred only in 34 percent of cases but direct exposition only was documented in five of them. Clinical features of MM patients were similar in asbestos related and non-asbestos related malignant mesothelioma. Conclusion: Although a growing tendency is observed in, the number of cases with MM, in many of them was not possible to establish the source of asbestos exposure.

Objetivo: Este estudio describe la frecuencia, características patológicas, ocupación y exposición a asbesto en una cohorte grande de casos de mesotelioma maligno (MM) admitidos en el Instituto Nacional de Enfermedades Respiratorias (INER), en México. Método: Se llevó a cabo un estudio retrospectivo y transversal en los registros médicos de pacientes diagnosticados con MM entre los años 1991-2007. Resultados: De los 247pacientes, 184 fueron hombres y 63 fueron mujeres con un promedio de edad de 51 y 60 años. Disnea y dolor torácico fueron los principales síntomas observados. Exposición a fibras de asbesto fue referida sólo en 34 por ciento) de los casos, aunque una exposición directa sólo puedo ser documentada en cinco de ellos. Las características clínicas de los pacientes con MM fueron similares en aquellos con y sin exposición a asbesto reconocida. Conclusión: Aunque se observa una tendencia creciente en el número de casos con MM, en muchos de ellos no fue posible establecer una fuente de exposición a asbesto como la causa de contaminación para el desarrollo de la enfermedad.

Chrysotile fibers induced apoptosis of human bronchial epithelial cells and effect of oxidation / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the apoptosis rate and the reactive oxygen species (ROS) level induced by chrysotile fibers in BEAS-2B cells and the blockage effect of free radical scavengers on the induction of chrysotile fibers.</p><p><b>METHODS</b>The cell survival rate, the morphological variation of BEAS-2B cells, the apoptosis rate, the expression levels of gene caspase-3 and the ROS generation level were measured by using trypan blue phagocytosis, hematoxylin and eosin staining, oligonucleosomal DNA fragmentation assay, FCM, RT-PCR and fluorescent probe DCFH-DA in the suspension (0, 5, 10, 20, 100 and 200 microg/cm(2)) and the filtrate (0, 100, 200, 400, 800 and 1600 microg/ml) of chrysotile fibers. Addition of free radical scavengers such as catalase, dimethyl sulfoxide and mannitol prevented the radical generation and gene expression.</p><p><b>RESULTS</b>Survival rates of BEAS2B cells treated by the suspension (0, 5 and 10 microg/cm(2)) and the filtrate (0, 100 and 200 microg/ml) of chrysotile fibers for 24 hours were above 90%. The apoptotic rates of BEAS-2B were increased with the concentration of suspension and filtrate from chrysotile fibers (P < 0.05). Otherwise, caspase-3 mRNA and ROS were stimulated by chrysotile fibers. Free radical scavengers such as CAT, DMSO and mannitol could reduce these stimulations. The ROS blocking rate of suspension of chrysotile fibers was 23.7%, 21.6% and 11.2% respectively, and that of filtrate was 37.9%, 40.3% and 10.6% respectively.</p><p><b>CONCLUSION</b>Apoptosis is induced in BEAS-2B cells exposed to chrysotile fibers suspension and filtrate. Generation of ROS plays an important role in chrysotile fibers-induced BEAS-2B cell apoptosis.</p>

A Case Study of a Foundry Worker with Localized Asbestosis: an Uncommon Occurrence in Korea / 대한산업의학회지

BACKGROUND: Foundry workers are known to be exposed to silica and have an increased risk of silicosis. There are also reports that state these foundry workers were associated with asbestos-related change in the X-ray results of the lungs. This report discusses a case of localized asbestosis developed in a foundry worker who worked in 12 Korean foundries. CASE REPORT: A 49-year-old man who worked at molding and melting for 30 years, presented with sore throat, cough and yellow sputum for 1 month. From physical and clinical examination, pulmonary tuberculosis was highly suspicious; therefore, he was medicated for 6 months. After tuberculosis medication, the radiological finding was reactivation of tuberculosis, and an asbestos body was detected at a transbronchial lung biopsy. During an operation, operators found multiple palpable masses and bullae localized in the right upper lobe (RUL) and performed right upper lobectomy and right middle lobe wedge resection. Using hematoxylin-eosin stain and iron stain, we could detect asbestos bodies by light microscopy. We analyzed the asbestos fiber burden in dry lung tissue by transmission electron microscopy with energy dispersive X-ray spectrometer (TEM-EDX). The fiber type was chrysotile and the fiber burden was 23.26x106 fiber/g dry lung. DISCUSSION: This case study of a foundry worker with localized asbestosis is uncommon in Korea. We found an occupational relationship between the foundry worker and localized asbestosis through various investigative techniques such as measurements taken at his working environment, clinical, radiological and pathological examination of the foundry worker and mineralogical examination of the asbestos fiber.

A Case Study of a Foundry Worker with Localized Asbestosis: an Uncommon Occurrence in Korea / 대한산업의학회지

BACKGROUND: Foundry workers are known to be exposed to silica and have an increased risk of silicosis. There are also reports that state these foundry workers were associated with asbestos-related change in the X-ray results of the lungs. This report discusses a case of localized asbestosis developed in a foundry worker who worked in 12 Korean foundries. CASE REPORT: A 49-year-old man who worked at molding and melting for 30 years, presented with sore throat, cough and yellow sputum for 1 month. From physical and clinical examination, pulmonary tuberculosis was highly suspicious; therefore, he was medicated for 6 months. After tuberculosis medication, the radiological finding was reactivation of tuberculosis, and an asbestos body was detected at a transbronchial lung biopsy. During an operation, operators found multiple palpable masses and bullae localized in the right upper lobe (RUL) and performed right upper lobectomy and right middle lobe wedge resection. Using hematoxylin-eosin stain and iron stain, we could detect asbestos bodies by light microscopy. We analyzed the asbestos fiber burden in dry lung tissue by transmission electron microscopy with energy dispersive X-ray spectrometer (TEM-EDX). The fiber type was chrysotile and the fiber burden was 23.26x106 fiber/g dry lung. DISCUSSION: This case study of a foundry worker with localized asbestosis is uncommon in Korea. We found an occupational relationship between the foundry worker and localized asbestosis through various investigative techniques such as measurements taken at his working environment, clinical, radiological and pathological examination of the foundry worker and mineralogical examination of the asbestos fiber.

Compensation and Diagnosis of Asbestos Related Disease / 가정의학회지

Asbestos is a fibrous silicate that was widely used because of its heat resistance properties. Asbestos exposure affects workers involved in mining or processing asbestos or those involved in the use of asbestos in the shipbuilding, construction, and textile- and insulation-manufacturing industries. There are three commonly available types of asbestos; chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). All three have been associated with cancerous and non-cancerous lung disease. Asbestos-related diseases includes benign pleural effusion, pleural plaques, diffuse pleural thickening (a non-malignant disease affecting the lung lining), rounded atelectasis, asbestosis (a scarring of the lung tissue caused by asbestos), mesothelioma and lung cancer. Mesothelioma is a malignant pleural or peritoneal tumor that rarely occurs in patients who have not been exposed to asbestos. The latency period of most asbestos-related disease is 10 years or longer, asbestos-related disease remains an important public health issue. The clinical diagnosis of asbestos related diseases should be based on a detailed interview of the patient and occupational data on asbestos exposure, signs and symptoms, radiological and lung physiological findings and selected cytological, histological and other laboratory studies. Radiological imaging plays a pivotal role in the diagnosis and management of asbestos-related disease.

Inhibitory mechanisms of three compounds for chrysotile-induced biological activities / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of aluminum citrate (AC), rare earth compounds (REC) and sodium selenite (SS) on the surface elements of chrysotile fibers and the inhibitory mechanisms of three compounds for chrysotile-induced biological activities.</p><p><b>METHODS</b>After being soaked in 250, 500 and 1000 microg/ml aluminum citrate solutions, 125, 250, 500 and 1000 microg/ml mixed rare earths solutions or 125, 250, 500 and 1000 microg/ml sodium selenite solutions for 10 min or 1 hour, the fabrication and the levels of surface elements of chrysotile fibers were determined.</p><p><b>RESULTS</b>Aluminum citrate, mixed rare earths or sodium selenite all could be adsorbed by chrysotile fibers. After pretreatment of chrysotile fibers with aluminum citrate, mixed rare earths or sodium selenite solutions for 10 min or 1 hour, the corresponding elements or ion on the surface of chrysotile fibers increased with the increase of concentration of the solutions.</p><p><b>CONCLUSION</b>Pretreatment of chrysotile with aluminum citrate, mixed rare earths or sodium selenite solutions can change the fabrication and the levels of surface elements of chrysotile fibers, and inhibit the biological activities of chrysotile by "sealing" some "active sites" on the surface of chrysotile fibers.</p>

Cancer mortality and asbestosis among workers in an asbestos plant in Chongqing, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate whether asbestosis is a risk factor for mortality of lung cancer.</p><p><b>METHODS</b>A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors.</p><p><b>RESULTS</b>During the 30-year follow-up, 584 male workers constituting a total of 14,664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR = 3.72) and nonmalignant respiratory diseases (OR = 2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR = 3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis.</p><p><b>CONCLUSION</b>High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.</p>

Nested case-control study of chrysotile and lung cancer / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between simple exposure to chrysotile and lung cancer.</p><p><b>METHODS</b>The nested case-control study method was used. All of lung cancer cases collected from a male fixed prospective cohort with follow-up of 30 years served as cases and a 1:4 matched proportion was used to select non-cancer case as controls. Controls matched for sex age (+/-5 years old), work time (+/-5 years) and smoking were collected in the same cohort.</p><p><b>RESULTS</b>Forty cases died of lung cancer in the study cohort, and the incidence was higher than the average incidence (SMR =1.77). The top four work types of death density were raw material (741.5), combing and spinning (424.3), weaving (365.0), and repairing (285.5), which was consistent with exposed level. According to the exposed level of chrysotile, the research objects were divided into the high level group and the low level group. The result demonstrated that lung cancer incidence of the high exposed level group of chrysotile was higher (OR = 3.7 95% CI 2.30 approximately 8.16), compared with the low exposed level group.</p><p><b>CONCLUSION</b>Simple exposure to chrysotile can increase the risk of lung cancer for workers who are exposed to chrysotile.</p>