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Units manufacture asbestos-cement products

Asbestos is a generic name given to certain mineral silicates. Asbestos is a fibrous mineral occurring in natural deposits. Several studies done clearly show that the safe usage of Chrysotile has minimal impact on the health of workers in the industry. Furthermore the Sri Lanka Cancer Registry has not reported a single cancer patient due to Asbestos or due to Asbestos related deceases. With regard to release of asbestos fibres into the environment a study was conducted in Austria by Newberger. They found in a village with asbestos cement roofing sheets asbestos levels of 0.

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Asbestos still pushed in India and business is booming


Objectives: In an assessment of the risk of asbestos fibres release from asbestos cement materials, an important role is played by the assessment of the surface corrosion and by the disaggregation of asbestos cement.

The aim of this work is to evaluate the differences among several methods used for the risk assessment that lead to a specific choice of abatement techniques. Results: The results obtained with the methods, proposed in this study, for the risk assessment of the decay of asbestos cement roofs show slight differences among them, only one deviates from the others in judgement on the state of conservation of the roof.

Conclusions: It is very important to train the operator conducting the study since a completely subjectivity-free method does not exist. Whatever method is used will always be affected by the subjectivity linked to the competency and the training of the operator.

Moreover, each method on its own cannot assess the risk of exposure to asbestos, but reliable assessment of asbestos-containing materials requires the use of more than one method, such as visual inspections, a pull-up test, and an assessment algorithm. The industrial manufacture of asbestos-containing materials ACM dates back to the end of the s.

Asbestos is a stable mineral, non-flammable mineral, which is acid resistant, flexible, traction resistant, elastic, easily spinnable, and sound absorbent. The characteristics of this material and its low cost brought about its widespread use mixed with other minerals, with the aim of best exploiting its characteristics.

The largest industrial use of asbestos, at worldwide level, was in combination with cement, for the construction of a wide variety of products, such as, for example, pipelines or flat and corrugated sheets. Other important uses for asbestos were the production of asphalt- or vinyl-based products for road surfacing, isolating products for pipelines and boilers, fire sprinkler products, and electrical insulators. Among ACM, asbestos cement sheets are the most common in Italy; they were widely used for roofing materials in different categories of buildings, both in agricultural and in residential areas.

It is estimated that in Italy between and , only 3 million tonnes of asbestos cement products were used, 0. During the production of flat and corrugated asbestos cement sheets used for roofing buildings, the asbestos is incorporated into a cement matrix, which, when kept in good condition, limits the spontaneous release of fibres and so these materials do not represent an important source of pollution.

It was enriched with tricalcium silicate 3CaSiO 2 to ensure a higher resistance to pressure or with dicalcium silicate 2CaOSiO 2 to obtain a greater sheet plasticity. The mechanical performance of cementitious matrix without a fibrous reinforcement is rather mediocre. On the other hand, mixing it with a certain quantity of fibres helps give a significant increase in its resistance and above all in toughness.

The capacity of asbestos fibres to reinforce cement depends on their length, on their capacity to create interfacial links with the matrix, on the volume of the fibres there is a critical volume that is the minimum content of fibre which is capable of supporting stress beyond the break point of the matrix , and on the degree of fibre alignment in the cement matrix Chiappino and Venerandi, In Italy until , both chrysotile and amphibole asbestos were used in ACM.

Subsequently, due to the high health risks associated with the use of amphiboles, the production of asbestos cement sheets used only chrysotile, introducing a fibre mix of longer chrysotile, like the Canadian mix. Asbestos cement roofing sheets are exposed to the elements once they are put in the roof, so they are subject to deterioration from installation, which leads to a disaggregation of asbestos cement, becoming the most widespread sources of airborne toxic asbestos fibres.

This takes place in variable quantities, depending on exposure to atmospheric agents and on fractures due to indirect vibrations, etc. In the long run, the action of water, sun, ice, wind, moss, and lichen, or pollutants such as sulphur dioxide, acid rain, etc.

Water, for example, causes the dissolution of soluble salts and the subsequent leaching of calcium hydroxide, causing an increase in the porosity of the material and an increase in the speed of the subsequent disintegration Carde et al. In the presence of CO 2 , calcium carbonate is formed carbonation.

This is much less soluble than the corresponding hydroxide which possesses a higher specific volume and can cause micro fissures.

In this transformation, more water is liberated and more calcium carbonate is formed, always in the presence of CO 2 Dias et al. The damaging action of rain, due to the presence of acid radicals, such as sulphuric and nitric acid, results in a rapid dissolution of the calcium and also the disintegration of aluminates present in cement.

It has been widely reported in cement-based materials Zivica and Bajza, ; Xie et al. The strong sulphuric and nitric acids react with the chemical structure of the cement, due to the displacement of the weaker silicic acid, causing the transformation of the calcium silicate, which is insoluble in water, into calcium sulphate or calcium nitrate, which are soluble.

The result is a surface corrosion with the erosive removal of subsequent layers of dissolved cement which in this way facilitates the asbestos release. The deterioration of the composite is also aided by sudden thermal changes. The transformation of water into ice in the cavities present in a cement structure causes a disintegration effect due to the relative increase in volume Haga et al.

The surface layer of the corroded manufactured matrix becomes a colonization centre for plant organisms such as moss and lichen, which, by keeping the water in contact with the cement for a long time, contribute to the further decay of the surface, although in recent papers it was reported that lichens have a weathering and covering role Favero-Longo et al.

The final outcome of all these phenomena leads to the formation of a surface layer which is rich in fibres that are easily liberated into the environment. During the assessment of the risk of asbestos fibres release from ACM, an important role is played by the assessment of the surface corrosion. Presence of cracks and other mechanical damage should be taken into consideration as important factors.

The classification of decay of the material is based on a visual survey carried out by an experienced surveyor. The survey classifies the ACM into three classes: intact materials not susceptible to damage, materials susceptible to damage, and damaged materials.

In order to verify the release of asbestos fibres, the visual survey should be accompanied by air sampling that allows the choice of action to undertake in face of ACM. Sometimes, in order to limit the subjectivity, it is preferable to use the so-called point systems, in which the risk of the release of fibres can be summarized in a mathematical algorithm.

This work compares the different methods used for the risk assessment in order to study the differences among them in the choice of abatement method that must be taken. The Ministry of Health Decree of the 6th of September regarding regulations and technical methods for risk assessment, inspections, maintenance, and abatement of materials containing asbestos in building structures Italian Ministry of Health, DM The Ministry of Health Decree of the 20th of August for the widening of regulations and technical methods for abatement operations Italian Ministry of Health, DM The Ministerial Decree of identifies the criteria for a thorough assessment of the state of the materials, risks, inspections, maintenance, and abatement, as shown in the flow chart in Fig.

These criteria were adopted and integrated into the Ministerial Decree of According to these two decrees, the decision process for the choice of action to undertake in the face of ACM is based on the classification of these materials into three classes: intact materials not susceptible to damage, materials susceptible to damage, and damaged materials.

The Ministerial Decree of indicates, to this end, a series of parameters regarding the identification of the state of the materials and the extent of possible damage. The main indicators that are useful in the assessment of decay of asbestos cement roofs, relating to the potential release of fibres, are. Our study evaluated the roofs in 40 buildings from various categories public, agricultural, and industrial.

The methods used to evaluate the conservation state of the asbestos cement roofs were the following:. Both algorithms were integrated in Regional Plan for Protection Asbestos of the originating region. The adhesive tape is applied on the corrugated and flat roof sheets.

Regulation UNI allows evaluation of the disaggregation of asbestos cement on the basis of the quantity of material stuck to the adhesive tape expressed as gram per square centimetre. The collected material undergoes a gravimetric analysis and the classification is the following one: very good, good, poor, and very poor.

The observation by stereomicroscope permitted the detection of the abundance of the exposed asbestos fibres on the surface of the sheet. Judgement of good, poor, and very poor, according to the conservation state of the examined material, was awarded.

In order to apply the pull-up test, the analysed surfaces must be dry at least 48 h should have passed since the last episode of rain and the sheets should not have been subjected to prior cleaning procedures. In the case of sheets that showed notable signs of moss, lichen, or mould, sampling took place in areas free of the latter. For each roof, at least three pieces of adhesive tape were used.

For the flat sheets, the adhesive tape was positioned parallel to one of the two sides for at least 20 cm avoiding overlapping. For the corrugated sheets, the adhesive tape was applied across the curve, for at least two complete curves Fig.

After application, the adhesive tape was pulled delicately and was finally folded again on itself to avoid the loss of the collected material. The material stuck to the tape was first weighed using Sartorius MC1 precision balance limit: g; format unit u f : 0. The airborne particulate was sampled using 25 mm diameter and 0. The concentration of the airborne asbestos fibres was measured by analysing the sampling membranes using the SEM. Tables 1 and 2 show the A and B algorithms, respectively, used for the assessment of decay of the asbestos cement roofs.

Scores between 27 and 54 are regarded as medium risk and the roofs are to be encapsulated with water-resistant products. Scores between 10 and 26 are regarded as low risk and the roofs are to be left where they are. The second case Table 2 represents a simplified additive algorithm that assesses five parameters where each parameter is scored and the value assigned is added together to give a total score between 5 and Material assessment with total scores between 21 and 27 is classified as very poor, and in this case, within 18 months, asbestos abatement procedure should be adopted preferably removal technique.

The asbestos materials near the schools are to be removed within 6 months. Materials with scores between 11 and 20 are classified as poor and the conservation state of the asbestos cement roofing is to be yearly evaluated. Asbestos abatement operations should be performed within 3 years; in the proximity of the schools, these operations are to be completed within 1 year. The type of operation is not indicated however. Finally, materials with scores between 5 and 10 are classified as fair and in this case is not necessary abatement operation.

They will be checked every 3 years. The results of the roofs examined with two algorithms, the pull-up test and the indicators described in Decree of coupled with the observation to stereomicroscope, are shown in Table 3.

In the columns of two algorithms, the total score is shown in parentheses. The results obtained with the different methods, proposed in this study, for the risk assessment of decay asbestos cement roofs show slight differences, only the B algorithm deviates from other assessment methods in final judgement on the state of conservation of the roof.

The results obtained by priority assessment A algorithm are in accordance with the judgements mediocre or very poor obtained by the pull-up test and with visual survey by indicators coupled with stereo analysis. Figures 5—10 show the SEM images with some EDS analysis of the material stuck to the adhesive tape with the pull-up test.

Figures 5 and 7 show amosite and chrysotile fibres, respectively, with their EDS spectrum Figs 6 and 8. SEM image of amosite fibres detached from an asbestos cement roof state of conservation: very poor. SEM image of chrysotile fibres detached from an asbestos cement roof almost completely cement free state of conservation: very poor.

SEM image of cement material detached from an asbestos cement roof state of conservation: good. Table 4 shows the concentrations of airborne asbestos fibres measured in the areas adjacent to the 20 buildings in which extensive asbestos cement roofing was found. Among these, 2 roofs were public buildings, 11 industrial buildings, and 7 industrial disused sites, which showed roofing in visibly advanced states of degradation.

The pull-up test applied to public and industrial buildings judged the roofs as very poor. Mean airborne asbestos fibres concentration measured in adjacent areas to buildings with asbestos cement roofs.

Despite the high deterioration of roofing, the levels of airborne asbestos are low and comparable with those proposed by the World Health Organization WHO in urban areas. In fact, the WHO gives reference data for pollution by asbestos.

In rural areas, i. A detection limit of 0. All the asbestos fibres found during SEM analysis were chrysotile fibres and no airborne amphibole fibre was detected. The A algorithm takes into consideration the same parameters, detectable by direct visual inspection, as described in Ministerial Decree of ; each one of these is given a score in order to limit the variation caused by observer subjectivity. The elements identified to indicate a potential fibre release refer to deterioration of the material breakages, corrosion, cracks and to both wind and rain damaging actions; the parameters to determine, therefore, refer to two distinct indicator types: roof condition indicators and fibre dispersion indicators.

It is very difficult to judge visually if particles of material stick to latex gloves after having rubbed them against the asbestos cement sample.

The B evaluation algorithm Table 2 involves the evaluation of descriptive elements relating to the location and context in which the asbestos products are found, the type of sheets flat or corrugated , the extension and inclination of the roof, the damage it has been subjected to, the year in which it was built, the presence of windows in the vicinity, and the presence of schools or nursing homes in the surrounding areas.

The executives mingled over tea and sugar cookies, and the chatter was upbeat. Their industry, they said at the conference in the Indian capital, saves lives and brings roofs, walls and pipes to some of the world's poorest people.

Objectives: In an assessment of the risk of asbestos fibres release from asbestos cement materials, an important role is played by the assessment of the surface corrosion and by the disaggregation of asbestos cement. The aim of this work is to evaluate the differences among several methods used for the risk assessment that lead to a specific choice of abatement techniques. Results: The results obtained with the methods, proposed in this study, for the risk assessment of the decay of asbestos cement roofs show slight differences among them, only one deviates from the others in judgement on the state of conservation of the roof. Conclusions: It is very important to train the operator conducting the study since a completely subjectivity-free method does not exist.

Asbestos Cement (Transite)

Trivedi , James M. Barker , Stanley T. This widely read global reference tool is one of the most authoritative sources for timely information on industrial minerals and rocks, the markets they serve, and their multitude of uses. Changes in the global economy have greatly impacted the mining, processing, and marketing of industrial minerals. Additionally, the development of new technologies and a globalization of the customer base have driven fast-paced innovation in processing, packaging, transporting, and end use.

Visaka Setting Up New Asbestos Cement Plant In Orissa

All are composed of long and thin fibrous crystals , each fiber being composed of many microscopic 'fibrils' that can be released into the atmosphere by abrasion and other processes. Asbestos is an excellent electrical insulator and is highly resistant to heat, so for many years it was used as a building material. Inhalation of asbestos fibres can lead to various serious lung conditions, including asbestosis and cancer. Archaeological studies have found evidence of asbestos being used as far back as the Stone Age to strengthen ceramic pots, [3] but large-scale mining began at the end of the 19th century when manufacturers and builders began using asbestos for its desirable physical properties. Asbestos was widely used during the 20th century until the s when public recognition of the health hazards of asbestos dust led to its outlawing in mainstream construction and fireproofing in most countries.

Asbestos cement , genericized as fibro or fibrolite - short for "fibrous or fibre cement sheet" - and AC sheet , is a building material in which asbestos fibres are used to reinforce thin rigid cement sheets.

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Asbestos Cement Body Denies Health Risks

Asbestos is carcinogenic to humans; the exposure to asbestos causes a wide range of diseases. Aim: Malignant mesothelioma MM is unique for asbestos exposure. Methods: Based on the physical inventory of asbestos-cement roofing, the social-economic situation of communes, the proximity of asbestos manufacturing plants, the land use data referring to the surface of the built-up area, and the historical data on the annexations, the amount of asbestos-containing products in use was estimated by computing best Random Forest models. Per capita asbestos use is an indicator to compare the state of asbestos use among countries.

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Asbestos is harmful to human health; exposure to asbestos causes a wide range of asbestos-related diseases. Aim: Malignant mesothelioma MM is unique to occupational and environmental asbestos exposure. Methods: Environmental asbestos exposure was examined in relation to asbestos use and manufacturing, the quantity of the asbestos-containing products still in use, the concentrations of asbestos fibres in the air and the number of MM cases diagnosed each year per county. Results: The correlation coefficient of the measurements of the asbestos fibre concentrations in the air and the quantity of asbestos-cement products in use is high and amounts to 0. Meanwhile, the correlation coefficient of the measurements of asbestos fibre concentrations in air and MM morbidity rate resulting from environmental exposure calculated for particular counties in provinces is low and amounts to 0. Conclusions: There are MM cases which are still attributable to occupational asbestos exposure, although MM cases resulting from environmental exposure to asbestos have an increased MM risk. Poland is among those countries with a low MM incidence rate, which seems to be an underestimation of environmental asbestos exposure. As long as asbestos-cement products are used in the environment, actions should be undertaken to protect public health.

(A major fibre cement manufacturer in Europe) formulations and make products on a Hatschek pilot machine for asbestos replacement programmes Dr. D. Crawford, Electron Microscope Unit, University of Cape Town, (UCT) South Africa.

Akers Consulting GmbH -

Tara Strand Senior Content Writer. Jennifer Lucarelli Legal Advisor and Contributor. Asbestos cement products were largely popular throughout the mids, particularly with piping, but also with an array of roofing materials and other building materials. Transite was respected for being easy to handle, strong, resistant to corrosion and having low friction. AC pipes were used for water, sewage systems, drainage pipes and storm drainage systems, withstanding corrosion from sulfides and soil. These products could also drop operating costs, as water flowed seamlessly through the smooth, low-friction material.

CCI probes cartelisation in asbestos cement sheets market

What is Chrysotile Fibre? FCPMA has thirteen esteemed industry players who have more than 50 manufacturing units located across the country and are engaged in the production of Fibre Cement roofing sheets and Fibre Cement pipes. Fibre Cement roofing sheets provide low cost roofing solutions to the rural masses and Fibre Cement pipes are majorly used in supply of drinking water and also in drainage of sewage. FACT: Chrysotile cement is completely safe. It is not corrosive, reactive, ignitable or toxic. FACT: Thousands of asbestos fibres, invisible, are inhaled by us every day from natural resources, and cleared off by natural clearance mechanisms without harm.

Asbestos roof india

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website. Manufacture of asbestos-cement products: this article describes the processes used to manufacture asbestos cement sheet, siding, roofing, pipe, and molded products.

Understanding Asbestos

Asbestos roof india. I had planned to paint the inside of the roof with some kind of sealant, is this a good idea?

Asbestos cement

Chrysotile fibre is a naturally occurring mineral found in underground rock formations. It is also known as white asbestos.

Environmental and Occupational Exposure to Asbestos as a Result of Consumption and Use in Poland

Account Options Sign in. Minerals Yearbook , Volume 1. Bureau of Mines , - Mineral industries.

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