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Solidification and stabilization of asbestos waste from an automobile brake manufacturing facility using cement

Chan YM, Agamuthu P, Mahalingam R

J Hazard Mater, 2000 Oct 02;77(1-3):209-26.
PMID: 10946129

Currently, the generated brake lining waste dust, which contains asbestos as its major component, is disposed of into a secure landfill without any additional treatment. As an alternative to this, solidification/stabilization (S/S) disposal of the dust was investigated using Portland cement alone and Portland cement mixed with activated carbon (AC), as the binders. Toxicity Characteristics Leaching Procedure (TCLP) results on the solidified matrix showed that cement was able to immobilize the heavy metals, Ba, Zn, Cr, Pb, Cu and Fe, to within the limits set by the US EPA for TCLP. Addition of AC to the cement reduced the leaching of heavy metals by an additional 4-24% compared to cement alone. The pH of the TCLP leachate extracted from virgin cement, and from dust treated with cement with or without AC was found to increase to 10.9-12.5 as opposed to an initial value of 4.93 for the TCLP extract for the untreated dust. Results of ANS 16.1 (modified) leach protocol revealed that Ba in cement-treated samples showed the highest leach rate, followed by Zn, Pb, Cr, Cu and Fe. The leach rate of heavy metals decreased with progress in time. Cement mixed with AC exhibited similar leach characteristics, however, the leach rate was lower. The linear relationship between the cumulative fraction leached (CFL) and the square root of leaching time in all cement-based samples indicate that a diffusional process is the controlling transport mechanism for the leaching of the heavy metals. The obtained Leachability Indices (L(i)) of 7.6-9.1 and 8.3-9.5 for cement and cement with AC, respectively, were low but exceeded the guidance value of 6, which clearly indicates that all the heavy metals studied are retained well within solid matrices. Cement-based S/S hardening times increased from 30 to 96 h as the dust content increased from 40 to 70 wt.%. The resulting solid matrices exhibited a compressive strength ranging from 1 to 12 MPa, which was well above the specified limit of 414 kPa for such matrices. An economic analysis indicates that the disposal costs for the dust in the only available secure landfill would increase by 40.3% if one were to go for the cement S/S option. Addition of AC to the cement would escalate this by an additional 43.8%. Although the S/S of brake lining dust using cement effectively immobilized the heavy metals of concern, cost considerations may hinder the commercial adaptation of this technique for waste disposal unless new regulatory demands are implemented.

Matched MeSH terms: Asbestos/metabolism*
A cross-country comparative overview of the asbestos situation in ten Asian countries

Takahashi K, Karjalainen A

Int J Occup Environ Health, 2003 Jul-Sep;9(3):244-8.
PMID: 12967160

Information about asbestos issues at the national level was compiled for ten Asian countries (China, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Taiwan, Thailand, and Vietnam) regarding 1) bans and consumption levels; 2) occupational exposure limits (OELs) and medical follow-up schemes; and 3) statistics and compensation status of asbestosis and mesothelioma victims. Only Singapore and recently Japan have adopted a total ban an asbestos. China, a major producer of chrysotile, showed an increasing consumption trend, which was typical of the less industrialized countries. Considerable differences between countries existed in OELs (0.1 to 5.0 fibers/mL) and medical follow-up of exposed workers. National statistics for asbestosis and mesothelioma were available for only the industrialized countries, where reported cases as well as compensated cases were relatively few. There is need to improve the quality and quantity of information, but the available information attests to unfavorable conditions in the less industrialized countries. Hence the experience of industrialized countries regarding asbestos and its use should be utilized to the fullest to improve the situation worldwide.

Matched MeSH terms: Asbestos/adverse effects*; Asbestosis/etiology*; Asbestosis/epidemiology*
Fulltext Additive Synergism between Asbestos and Smoking in Lung Cancer Risk: A Systematic Review and Meta-Analysis

Ngamwong Y, Tangamornsuksan W, Lohitnavy O, Chaiyakunapruk N, Scholfield CN, Reisfeld B, et al.

PLoS One, 2015;10(8):e0135798.
PMID: 26274395 DOI: 10.1371/journal.pone.0135798

Smoking and asbestos exposure are important risks for lung cancer. Several epidemiological studies have linked asbestos exposure and smoking to lung cancer. To reconcile and unify these results, we conducted a systematic review and meta-analysis to provide a quantitative estimate of the increased risk of lung cancer associated with asbestos exposure and cigarette smoking and to classify their interaction. Five electronic databases were searched from inception to May, 2015 for observational studies on lung cancer. All case-control (N = 10) and cohort (N = 7) studies were included in the analysis. We calculated pooled odds ratios (ORs), relative risks (RRs) and 95% confidence intervals (CIs) using a random-effects model for the association of asbestos exposure and smoking with lung cancer. Lung cancer patients who were not exposed to asbestos and non-smoking (A-S-) were compared with; (i) asbestos-exposed and non-smoking (A+S-), (ii) non-exposure to asbestos and smoking (A-S+), and (iii) asbestos-exposed and smoking (A+S+). Our meta-analysis showed a significant difference in risk of developing lung cancer among asbestos exposed and/or smoking workers compared to controls (A-S-), odds ratios for the disease (95% CI) were (i) 1.70 (A+S-, 1.31-2.21), (ii) 5.65; (A-S+, 3.38-9.42), (iii) 8.70 (A+S+, 5.8-13.10). The additive interaction index of synergy was 1.44 (95% CI = 1.26-1.77) and the multiplicative index = 0.91 (95% CI = 0.63-1.30). Corresponding values for cohort studies were 1.11 (95% CI = 1.00-1.28) and 0.51 (95% CI = 0.31-0.85). Our results point to an additive synergism for lung cancer with co-exposure of asbestos and cigarette smoking. Assessments of industrial health risks should take smoking and other airborne health risks when setting occupational asbestos exposure limits.

Matched MeSH terms: Asbestos/adverse effects*
Fulltext Global economic burden of asbestos related diseases in comparison with the costs of production and consumption

Syed Mohamed Aljunid, Ahmad Munir Qureshi, David B

Malaysian Journal of Public Health Medicine, 2017;17(1):111-125.

Occupational cancers, including mesothelioma and lung cancer are linked to the use of asbestos. Annually, at least 100,000 global deaths are attributed to asbestos exposure putting a heavy burden on national budgets. Expenses incurred on treatment of asbestos related diseases (ARDs) reduce households and national resource savings, while ARDs culminate in terminal burdens. The objective of this study is to measure the economic burden of ARDs and to assess the economic impact of asbestos consumption. The health and economic burden of asbestos was estimated in macro-global consumption-production model using production function frontier-based and generalized least squared approach for asbestos products and cost tabulation. Production, in metric tons (Mt) was adopted as a dependent variable among explanatory variables, including consumption. Information on treatment cost of asbestos related diseases (mesothelioma, asbestosis and lung cancer) was obtained from costing information and published literatures. Annual total economic burden of asbestos is at USD 11.92 billion. Out of this cost, USD 4.34 billion per annum is the economic burden of managing three common ARDs. The cost of compensation for patients suffering ARDs is USD 4.28 billion. From the remaining USD 3.3 billion, USD 2.93 billion is the value of asbestos consumed in 2003 and USD372.15 million is the loss of earning due to hospital visits and admissions. For every USD 1 spent on consumption of asbestos, global economy has to absorb almost USD 4 due to health consequences of ARDs. Banning of asbestos production and usage in production of goods has far-reaching impacts on household welfare, health and economic development. The insights revealed are expected to inform decision makers the need to ban all forms of asbestos, especially in developing countries where usage is increasing.

Matched MeSH terms: Asbestos; Asbestosis
Composition of heavy metals and airborne fibers in the indoor environment of a building during renovation

Latif MT, Baharudin NH, Velayutham P, Awang N, Hamdan H, Mohamad R, et al.

Environ Monit Assess, 2011 Oct;181(1-4):479-89.
PMID: 21181256 DOI: 10.1007/s10661-010-1843-3

The renovation of a building will certainly affect the quality of air in the vicinity of where associated activities were undertaken, this includes the quality of air inside the building. Indoor air pollutants such as particulate matter, heavy metals, and fine fibers are likely to be emitted during renovation work. This study was conducted to determine the concentration of heavy metals, asbestos and suspended particulates in the Biology Building, at the Universiti Kebangsaan, Malaysia (UKM). Renovation activities were carried out widely in the laboratories which were located in this building. A low-volume sampler was used to collect suspended particulate matter of a diameter size less than 10 μm (PM₁₀) and an air sampling pump, fitted with a cellulose ester membrane filter, were used for asbestos sampling. Dust was collected using a small brush and scope. The concentration of heavy metals was determined through the use of inductively coupled plasma-mass spectroscopy and the fibers were counted through a phase contrast microscope. The concentrations of PM₁₀ recorded in the building during renovation action (ranging from 166 to 542 μg m⁻³) were higher than the value set by the Department of Safety and Health for respirable dust (150 μg m⁻³). Additionally, they were higher than the value of PM₁₀ recorded in indoor environments from other studies. The composition of heavy metals in PM₁₀ and indoor dust were found to be dominated by Zn and results also showed that the concentration of heavy metals in indoor dust and PM₁₀ in this study was higher than levels recorded in other similar studies. The asbestos concentration was 0.0038 ± 0.0011 fibers/cc. This was lower than the value set by the Malaysian Department of Occupational, Safety and Health (DOSH) regulations of 0.1 fibers/cc, but higher than the background value usually recorded in indoor environments. This study strongly suggests that renovation issues need to be considered seriously by relevant stakeholders within the university in order to ensure that the associated risks toward humans and indoor environment are eliminated, or where this is not feasible, minimized as far as possible.

Matched MeSH terms: Asbestos/analysis*
Fulltext Respiratory conditions in Malaysian asbestos cement workers

Lim HH, Rampal KG, Joginder S, Abu Bakar CM, Chan KH, Vivek TN

Med J Malaysia, 2002 Sep;57(3):340-7.
PMID: 12440274 MyJurnal

A cross-sectional study was conducted to determine the prevalence and type of respiratory conditions including asbestos-related diseases among Malaysian asbestos cement workers. The study population consisted of 1164 workers who had undergone medical surveillance from 1995 to 1997, including full history, physical examination, chest radiography and spirometry. More than half the male workers were smokers or ex-smokers, with smokers having more respiratory symptoms and signs, and reduced FEV1 compared with non smokers. The five most common respiratory conditions diagnosed were bronchial asthma, chronic bronchitis, pulmonary tuberculosis, upper respiratory tract infections and allergic rhinitis. On follow-up, there were also two cases of asbestosis and one case of bronchial carcinoma. The asbestosis cases were probably related to heavy occupational exposure to asbestos fibres in the past, before governmental regulations were gazetted in 1986. Further follow-up is essential for continued monitoring of the health status of asbestos workers.

Matched MeSH terms: Asbestos/adverse effects*
Use of asbestos building materials in Malaysia: legislative measures, the management, and recommendations for a ban on use

Safitri Zen I, Ahamad R, Gopal Rampal K, Omar W

Int J Occup Environ Health, 2013 Jul-Sep;19(3):169-78.
PMID: 23885771 DOI: 10.1179/2049396713Y.0000000028

Malaysia has partially banned the use of asbestos. The prohibition of asbestos building materials in schools, clinics, and hospitals built by government started in 1999. Since 2005, prohibition has also been applied to all government buildings. However, asbestos construction materials such as roof and ceiling tiles are still sold in the market. There are no acts or regulations prohibiting the use of asbestos in private buildings in Malaysia. Asbestos was first used for industrial purposes in Malaysia in the 1960s and the first regulations related to asbestos have been around since the 1980s. Non-governmental organizations have been pushing the government to impose a total ban since the 1980s. Asbestos is still used in the manufacturing sector under the "control use" concept. The study found difficulties in established and validated medical record data on asbestos-related diseases. This paper reviews existing asbestos-related regulations and guidelines in Malaysia and discusses the urgency for a total ban in the use of asbestos in building materials in the country. In the meanwhile, stricter enforcement of occupational safety and health regulations related to the use and exposure of asbestos among workers in the manufacturing, construction, maintenance, and demolition sectors has been in place.

Matched MeSH terms: Asbestos*
Well-differentiated Papillary Mesothelioma of the Tunica Vaginalis

Tan WK, Tan MY, Tan HM, Pathmanathan R, Tan WP

Urology, 2016 Apr;90:e7-8.
PMID: 26773348 DOI: 10.1016/j.urology.2015.12.046

A 39-year-old man presented with painless scrotal swelling for 2 months. He denied any asbestos exposure but worked with wall and ceiling plaster. Physical exam revealed a large right scrotum which transilluminated. Scrotal ultrasonography revealed a large right hydrocele and a polypoidal mass along the anterior wall of the scrotum. Magnetic resonance imaging of the abdomen and computed tomography of the chest showed no metastases. He underwent a right inguinal scrotal exploration and wide excision of tunica vaginalis and a partial epididymectomy. Pathology revealed well-differentiated papillary mesothelioma of the tunica vaginalis. The patient had an uneventful recovery.

Matched MeSH terms: Asbestos
Lung cancer knowledge among secondary school male teachers in Kudat, Sabah, Malaysia

Al-Naggar RA, Kadir SY

Asian Pac J Cancer Prev, 2013;14(1):103-9.
PMID: 23534705

BACKGROUND: The objective of this study is to determine knowledge about lung cancer among secondary school male teachers in Kudat, Sabah, Malaysia.
MATERIALS AND METHODS: A cross-sectional study was conducted among three secondary schools located in Kudat district, Sabah, Malaysia during the period from June until September 2012. The protocol of this study was approved by ethics committee of Management and Science University, Malaysia. The aims were explained and a consent form was signed by each participant. Respondents were chosen randomly from each school with the help of the headmasters. Self-administrated questionnaires, covering socio-demographic characteristics and general knowledge of lung cancer, were distributed. Once all 150 respondents completed the questionnaire, they passed it to their head master for collecting and recording. All the data were analyzed using Statistical Package for the Social Sciences (SPSS) version 13. ANOVA and t-test were applied for univariate analysis; and multiple linear regression for multivariate analysis.
RESULTS: A total of 150 male secondary school teachers participated in this study. Their mean age was 35.6 ∓ 6.5 (SD); maximum 50 and minimum 23 years old. More than half of the participants were Malay and married (52%, 79%; respectively). Regarding the knowledge about lung cancer, 57.3% of the participants mentioned that only males are affected by lung cancer. Some 70.7% mentioned that lung cancer can be transmitted from one person to another. More than half (56.7%) reported that lung cancer is not the leading cause of death in Malaysian males. As for risk factors, the majority reported that family history of lung cancer is not involved. However, 91.3% were aware that cigarettes are the main risk factor of lung cancer and more than half (52%) believed that second-hand smoking is one of the risk factor of lung cancer. More than half (51.3%) were not aware that asbestos, ionizing radiation and other cancer causing substances are risk factors for lung cancer. Quitting smoking, avoiding second-hand smoking and avoiding unnecessary x-ray image of the chest (53.3%, 96.0%, 87.3%; respectively) are the main preventive measures mentioned by the participants. For the factors that influence the participants knowledge, univariate and multivariate analysis showed that only race was significant.
CONCLUSIONS: Overall, the knowledge of school male teachers about lung cancer was low. However, few items were scored high: cigarettes are the main risk factor; avoiding second-hand smoking; and avoiding x-rays. Interventions to increase lung cancer awareness are needed to improve early detection behavior. Increase the price of pack of cigarettes to RM 20 and banning smoking in public places such as restaurants are highly recommended as primary preventive measures.

Matched MeSH terms: Asbestos/adverse effects
GPTMS-Modified Bredigite/PHBV Nanofibrous Bone Scaffolds with Enhanced Mechanical and Biological Properties

Kouhi M, Jayarama Reddy V, Ramakrishna S

Appl Biochem Biotechnol, 2019 Jun;188(2):357-368.
PMID: 30456599 DOI: 10.1007/s12010-018-2922-0

Bioceramic nanoparticles with high specific surface area often tend to agglomerate in the polymer matrix, which results in undesirable mechanical properties of the composites and poor cell spreading and attachment. In the present work, bredigite (BR) nanoparticles were modified with an organosilane coupling agent, 3-glycidoxypropyltrimethoxysilane (GPTMS), to enhance its dispersibility in the polymer matrix. The polyhydroxybutyrate-co-hydroxyvaletare (PHBV) nanofibrous scaffolds containing either bredigite or GPTMS-modified bredigite (G-BR) nanoparticles were fabricated using electrospinning technique and characterized using scanning electron microscopy, transmission electron microscopy, and tensile strength. Results demonstrated that modification of bredigite was effective in enhancing nanoparticle dispersion in the PHBV matrix. PHBV/G-BR scaffold showed improved mechanical properties compared to PHBV and PHBV/BR, especially at the higher concentration of nanoparticles. In vitro bioactivity assay performed in the simulated body fluid (SBF) indicated that composite PHBV scaffolds were able to induce the formation of apatite deposits after incubation in SBF. From the results of in vitro biological assay, it is concluded that the synergetic effect of BR and GPTMS provided an enhanced hFob cells attachment and proliferation. The developed PHBV/G-BR nanofibrous scaffolds may be considered for application in bone tissue engineering.

Matched MeSH terms: Asbestos, Amphibole/chemistry*

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