Vermiculite


Image by/from WikiMedia Commons

Vermiculite, a hydrous phyllosilicate mineral, undergoes significant expansion when heated. Exfoliation occurs when the mineral is heated sufficiently, and commercial furnaces can routinely produce this effect. Vermiculite forms by the weathering or hydrothermal alteration of biotite or phlogopite.
Large commercial vermiculite mines currently exist in Russia, South Africa, China, and Brazil.

Vermiculite was first described in 1824 for an occurrence in Millbury, Massachusetts. Its name is from Latin vermiculare, to breed worms, for the manner in which it exfoliates when heated.

It typically occurs as an alteration product at the contact between felsic and mafic or ultramafic rocks such as pyroxenites and dunites. It also occurs in carbonatites and metamorphosed magnesium-rich limestone. Associated mineral phases include: corundum, apatite, serpentine, and talc. It occurs interlayered with chlorite, biotite and phlogopite.

Vermiculite is a 2:1 clay, meaning it has two tetrahedral sheets for every one octahedral sheet. It is a limited-expansion clay with a medium shrink-swell capacity. Vermiculite has a high cation-exchange capacity (CEC) at 100-150 meq/100 g. Vermiculite clays are weathered micas in which the potassium ions between the molecular sheets are replaced by magnesium and iron ions.

In 2014, South Africa, Brazil, the US, and China were the top producers of mined, concentrated and unexfoliated vermiculite, with about 90% world share. South Africa’s production is decreasing, while Brazil’s is significantly increasing.

While some end processors and exfoliators of vermiculite specialize, with proprietary products sold in a wide variety of industries, some have more varied end products, with less stringent technical requirements. Some vermiculite exfoliators blend with lower-cost perlite also. Vermiculite exfoliators have an international trade association called The Vermiculite Association to represent the industry’s interests and to exchange information.

Today spray-applied fireproofing materials use vermiculite, other industrial minerals, and expanded polystyrene, depending upon the exact commercial product. The ingredients for these products all have to meet stringent regulatory requirements, particularly in the US and Europe. In the past, vermiculite from the W. R. Grace mines in Montana, have been associated with asbestos. Therefore, old spray-applied fireproofing, pre-1991, may contain small quantities of asbestos. In August 2014, the NYSDoH qualified two, more exact, test methods, better designed to identify materials with this potential problem, and assist in safely dealing with any issues associated with its removal. Modern spray applied fireproofing today is made with vermiculite that does not contain asbestos and is carefully monitored at all stages of mining and production to ensure this is the case.

Although not all vermiculite contains asbestos, some products were made with vermiculite that contained asbestos until the early 1990s. Vermiculite mines throughout the world are now regularly tested for it and are supposed to sell products that contain no asbestos. The former vermiculite mine in Libby, Montana, did have tremolite asbestos as well as winchite and richterite (both fibrous amphiboles)—in fact, it was formed underground through essentially the same geologic processes as the contaminants.

Pure vermiculite does not contain asbestos and is non-toxic. Impure vermiculite may contain, apart from asbestos, also minor diopside or remnants of the precursor minerals biotite or phlogopite.

The largest and oldest vermiculite mine in the United States was started in the 1920s, at Libby, Montana, and the vermiculite was sold under the commercial name Zonolite. The Zonolite brand and the mine were acquired by the W. R. Grace and Company in 1963. Mining operations at the Libby site stopped in 1990 in response to asbestos contamination. While in operation, the Libby mine may have produced 80% of the world’s supply of vermiculite.

The United States government estimates that vermiculite was used in more than 35 million homes, but does not recommend its removal. Nevertheless, homes or structures containing vermiculite or vermiculite insulation dating from before the mid-1990s—and especially those known to contain the “Zonolite” brand—may contain asbestos, and therefore may be a health concern.

An article published in The Salt Lake Tribune on December 3, 2006, reported that vermiculite and Zonolite had been found to contain asbestos, which had led to cancers such as those found in asbestos-related cases. The article stated that there had been a cover-up by W. R. Grace and Company and others regarding the health risks associated with vermiculite and that several sites in the Salt Lake Valley had been remediated by the EPA when they were shown to be contaminated with asbestos. W. R. Grace and Company has vigorously denied these charges.

The vermiculite deposit at the mine in Libby, Montana, was (and is) heavily contaminated with asbestos. Numerous people were knowingly exposed to the harmful dust of vermiculite that contained asbestos. Unfortunately, the mine had been operating since the 1920s, and environmental and industrial controls were virtually non-existent until the mine was purchased by the W. R. Grace and Company in 1963. Yet, knowing the human health risks, the mining company still continued to operate there until 1990. Consequently, many of the former miners and residents of Libby have been affected and continue to suffer health problems. Over 400 people in the town have died from asbestos-related disease due to contamination from vermiculite mining from nearby Zonolite Mountain, where soil samples were found to be loaded with fibrous tremolite (known to be a very hazardous form of asbestos), and countless others there who insulated their homes with Zonolite have succumbed to asbestos-related diseases, most of whom never were employed in environments where asbestos was an issue.

After a 1999 Seattle Post-Intelligencer story claimed that asbestos-related disease was common in the town, the EPA, in response to political pressure, made cleanup of the site a priority and called Libby the worst case of community-wide exposure to a toxic substance in U.S. history. The EPA has spent $120 million in Superfund money on cleanup. In October 2006, W. R. Grace and Company tried to appeal the fines ($54.5 million) levied on them from the EPA, but the Supreme Court rejected the appeal. The United States government is also pursuing criminal charges against several former executives and managers of the mine for allegedly disregarding and covering up health risks to employees. They are also accused of obstructing the government’s cleanup efforts and wire fraud. To date, according to the indictment, approximately 1,200 residents of the Libby area have been identified as suffering from some kind of asbestos-related abnormality. Jury selection was to have been completed in February 2009. The case ended in acquittals on May 8, 2009. On June 17, 2009, the EPA issued a public health emergency in and near Libby, thereby allowing federal agencies to provide funding for health care, and for removal of contaminated insulation from affected homes.

Curated with thanks from Wikipedia.

Wiwilibrucke


Image by/from Peter Kappus

Wiwilibrucke (engl. Wiwili Bridge) is a bridge of the German city Freiburg im Breisgau which is also called Blaue Brucke (engl. Blue Bridge) because of its paint and it had formerly been called Stuhlingerbucke before the new Stuhlingerbucke was built for the tramway. The bridge connects the city’s district Stuhlinger to the old town as it links the church square of Herz-Jesu-Kirche to Konrad-Adenauer-Platz in spanning the railway tracks of Freiburg Hauptbahnhof. Today, Wiwilibrucke is a listed building and is used by up to 10,000 cyclists per day.

The bridge was built in 1885-86 in place of an inaccessible crossing of the same height by the Grand Duchy of Baden State Railway. It was designed by Max Meckel who had designed the Herz-Jesu church shortly before, located in the axis of the bridge. The construction was carried out by the Eisenwerk in Kaiserslautern, an industrial company that was active in iron and steel construction. The bridge was inaugurated as “Kaiser-Wilhelm-Brucke”, however, the name didn’t stick among the residents, who called it “Stuhlingerbrucke”. It crosses the station tracks and access roads on five -due to the railway tracks- uneven—. The cost of the Eisenwerk was of 151,412 German gold mark; the cost of the entire construction around 428,000 gold marks.

From 1909 to the end of 1961, the line 5 (Herdern (Freiburg) – Haslach (Freiburg)) led the Trams in Freiburg im Breisgau across the bridge. With the Railway Crossing Act, the bridge became the property of the city of Freiburg in 1978, after the track had already been removed in 1972 as part of a first refurbishment and a new concrete carriageway had been applied, to secure the usage for the next 15 years.

As part of the redesign of the station area and a related construction of the abutment on the east side in 1996, the bridge was then closed to motor traffic and was made accessible only for bicycles and pedestrians. Next to the abutment on the Stuhlinger side, the “mobile” bike-and-mobility station was built with a bicycle parking garage in 1999, called bicycle station since 2014. In 2013, the bridge was named after Freiburgs sister city Wiwili de Jinotega.

In March 2008, fundamental renovation work was started for which the bridge was successively raised by 1.50 m (4.9 ft) in five sections in order to enable work above the railway tracks. In addition to replacing many static steel parts and the road pavement, drainage channels to protect Wiwilibrucke from corrosion were installed at the edges of the roadway and in the edge area of the sidewalks. Shortly after work had started, a massive asbestos pollution was discovered which had to be removed.

The bridge piers were raised by about 50 cm to increase the safety profile for the railway. As a result, the inclination of the bridge’s entry and exit ramps was increased by half a percent. The work was originally scheduled to take nine months and to cost around 2.5 million euros. However, due to the doubling of steel consumption and additional asbestos problems, the work lasted until September 2009 and cost 6.3 million euros. A spiral staircase leading from the northern sidewalk to the bus station was not restored after renovation.

The Freiburg Marathon crosses the bridge again after the renovation. On warm days, the arches of Wiwilibrucke are partly used to sit and the bridge serves as a location for tango dances from time to time.

Since its restoration the bridge is only allowed to be gritted without the use of road salt to prevent corrosion.

The total length of the bridge from one abutment to the other was 161.8 m (530.8 ft) when it was first opened while the width of the road was 5.2 m (17.1 ft). The sidewalks were 1.7 m (5.5 ft) wide each. The access roads on either side had to be built with a slope of 4% because of the location of the connected streets. The maximum height of the individual arches varies between 2.79 m (9.15 ft) and 4.13 m (13.52 ft). The total mass of the ironwork was 540.4 metric tons (595.6 imperial tons) but it increased to about 1720 metric tons (~1900 imperial tons), including supporting structure and concrete panels.

There are two memorials located on the bridge. One is a coat with a bronzen Star of David that seemingly was forgotten in a great hurry. It reminds of the deportation of Jews in 1940 as part of the Wagner-Burckel campaign. The coat was created by Birgit Stauch, an artist from Baden-Baden. It was placed on the bridge by Johannes Ruhl, second in charge of the culture department of Freiburg in 2003.

Apart from this there are also plaques that remind of Bernd Koberstein, a communist and trade unionist from Freiburg as well as Albrecht “Tonio” Pflaum, a doctor from Freiburg. Both of them were murdered during a humanitarian aid action in Wiwili by the Nicaraguan Contras.

Curated with thanks from Wikipedia.

Wittenoom, Western Australia


Image by/from Five Years

Wittenoom is a declared contaminated site and former townsite 1,420 kilometres (687 mi) north-north-east of Perth in the Hamersley Range in the Pilbara region of Western Australia.

The area around Wittenoom was mainly pastoral until the 1930s when mining for blue asbestos began in the area. By 1939, major mining began in Yampire Gorge, which was subsequently closed in 1943 when mining began in Wittenoom Gorge. In 1947 a company town was built, and by the 1950s it was Pilbara’s largest town. During the 1950s and early 1960s Wittenoom was Australia’s only supplier of blue asbestos. The mine was shut down in 1966 due to unprofitability and growing health concerns from asbestos mining in the area.

Today, three residents still live in the town, which receives no government services. In December 2006, the Government of Western Australia announced that the town’s official status would be removed, and in June 2007, Jon Ford, the Minister for Regional Development, announced that the townsite had officially been degazetted. The town’s name was removed from official maps and road signs and the Shire of Ashburton is able to close roads that lead to contaminated areas.

The Wittenoom steering committee met in April 2013 to finalise closure of the town, limit access to the area and raise awareness of the risks. Details of how that would be achieved were to be determined but it would likely necessitate removing the town’s remaining residents, converting freehold land to crown land, demolishing houses and closing or rerouting roads. By 2015 six residents remained; in 2017 the number dropped to four and to three in 2018.

Wittenoom was named by Lang Hancock after Frank Wittenoom, his partner in the nearby Mulga Downs Station. The land around Wittenoom was originally settled by Wittenoom’s brother, politician Sir Edward Horne Wittenoom. By the late 1940s there were calls for a government townsite near the mine, and the Mines Department recommended it be named Wittenoom, advising that adoption of this name was strongly urged by the local people. The name was approved in 1948, but it was not until 2 May 1950 that the townsite was officially gazetted. In 1951 the name was changed to Wittenoom Gorge at the request of the mining company, and in 1974 it was changed back to Wittenoom. The mine closed in 1966, and the townsite was officially abolished by gazettal in March 2007.

In 1968 Wittenoom was one of only two Catholic parishes in the Pilbara.

In 1917 the Mines Department first recorded the presence of blue asbestos in the Hamersley Ranges. Langley Hancock discovered Wittenoom Gorge on the Mulga Downs property in the early 1930s. In 1937 Langley (Lang) Hancock showed samples of blue asbestos crocidolite that he had picked-up in the Gorge to Islwyn (Izzy) Walters and Walter (Len) Leonard who were at that time mining and treating white asbestos at Nunyerrie and at Lionel near Nullagine. When Hancock learned the fibre would fetch £70 per ton he immediately pegged the best claims in Wittenoom Gorge. Leo Snell, a Kangaroo shooter on Mulga Downs pegged a claim on Yampire Gorge, where there was a lot more blue asbestos. Walters and Leonard purchased Yampire Gorge from Snell and moved their treatment plant there and began mining and treating the fibre. When Leonard cabled London that there was two miles of asbestos in sight at Yampire Gorge, they cabled him back saying he should take a holiday. Leonard had to send a photograph before it was believed Yampire Gorge contained this much asbestos. Walters and Leonard cleared the way into Yampire gorge by blasting the biggest rocks and pulling them out the way with a camel team. Even after that it took them seven hours to drive their lorry the fifteen miles from the workings to their treatment plant. By 1940, twenty-two men were employed at the Yampire Gorge workings and about 375 tons were mined and transported to the coast (Point Samson) by mule team wagons. During the war communications with England became difficult and de Berrales acquired an interest in the mines. Finally in 1943 the Colonial Sugar Company through its subsidiary, Australian Blue Asbestos Ltd. took over both the Wittenoom and Yampire Mines. Lang Hancock who watched his station property transform to a town stated (1958), “Izzy Walters was the man who stuck it and produced the market that made Wittenoom of today possible. Walter’s partner Len Leonard, put it this way (1958), “But for his (Islwyn Walters) sheer grit and hard work there would be no such thing as Wittenoom. We have him to thank for that.”

Until the Second World War asbestos was mostly imported from South Africa and Canada. The Australian market for asbestos before the Second World War was worth $1 million a year, and there was export potential. Hancock had promising talks with the British, who were desperate to use asbestos as filters in gas masks, and his partners Islwyn (Izzy) Walters and Walter (Len) Leonard had negotiations with Johns Manville in the United States. When the Second World War came asbestos was in high demand for use in tanks, planes, battleships, helmets and gasmasks. In 1943 the mine was sold to CSR Limited subsidiary, Australian Blue Asbestos Pty Ltd (ABA), where Hancock remained as manager until 1948.

In 1946, the Yampire Gorge mine was closed and subsequently Wittenoom Gorge mine was opened in the same year. Production to 1956 is estimated at 590,000 tons of ore from which about 20,000 tons of asbestos were recovered. In 1947 the town of Wittenoom was built to service the nearby asbestos mine. It was built ten kilometres from the mine and mill as there was not a suitable area available to expand the original residential settlement. By 1951 the town had 150 houses and a population of over 500.

In 1948 CSR took over the asbestos project at Wittenoom as the parent company of ABA. From 1950 until the early 1960s Wittenoom was Australia’s only supplier of asbestos with 161,000 tonnes being mined from 1943 to 1966. In an internal report recommending the mine’s closure in 1966, one of CSR’s own executives admitted that “…no thorough investigation of the deposit at Wittenoom was made”. For most of the years CSR mined asbestos, the operation lost money. It struggled into profit for the five years from 1956, and then only by making its workforce work two and even three shifts a day. When the mine closed it had an accumulated debt of around $2.5 million.

In 1944, Mines Inspector Adams reported on the dust menace at Wittenoom and discussed the need to reduce dust levels, and the WA Assistant State Mining Engineer reported on the dangers of the dust being generated at Wittenoom. The first case of asbestosis at Wittenoom occurred in 1946, although it was not conclusively diagnosed until much later. In 1948, Dr Eric Saint, a Government Medical Officer, wrote to the head of the Health Department of Western Australia. He warned of the dust levels in the mine and mill, the lack of extractors and the dangers of asbestos and risk of asbestosis, and advised that the mine would produce the greatest crop of asbestosis the world has seen. He also advised the Wittenoom Mine Management that asbestos is dangerous and that men exposed would contract chest disease inside six months.

Dr Jim McNulty, who was working for the Health Department of WA, provided a first hand account of the work conditions he observed when he visited Wittenoom to do a clinical examination in 1959 (Australian Safety News, May 1995). He reported: “It was generally dirty and dusty, there were clumps of asbestos all over the floor and one’s clothing was rapidly soiled by contact with any surface….. every operation in the mine was associated with dust.” Dr McNulty repeatedly warned the company’s manager of the dangers to the miners and the people living in the town. Dr McNulty and the Health Department did not have the power to order CSR to close down the mine.

Between 1977 and 1992, eight studies involving air monitoring were carried out by the Health Department of WA and other authorities. There were a number of shortcomings with these studies, which meant the debate over risk to residents was not conclusively settled. Reports by the Environmental Protection Authority provide detail on the extent of the contamination. Inspection reports indicated that asbestos fibres were present in some quantity in almost every area of the town.

In 1978, the State Government adopted a policy of phasing down activity in the town of Wittenoom. This policy was seen as the most appropriate course of action to take in response to the widespread contamination of crocidolite in and around the town. The policy encouraged residents to relocate out of Wittenoom voluntarily, through the purchase of their homes, business and property and included a contribution to their relocation costs. The Shire of Ashburton and many local residents were opposed to closing the town; they lobbied hard to have the town cleaned up and developed as a tourist attraction.

In 1981, the Government re-affirmed its policy for phasing out Wittenoom and initiated planning for a new tourist resort. In 1984, the policy was modified by the Government to ensure that the existing State Government facilities and the Fortescue Hotel would be maintained until alternatives were available. Up until the end of 1991, over $1.4 million was spent under the phasing down policy, with the result that the population of Wittenoom fell from over 90 in May 1984 to about 45 in March 1992. Between 1986 and 1992, around 50 houses and other buildings were demolished by the Government. When the population decreased, the school, nursing post and police station were closed, with alternative services being provided primarily from Tom Price. In 1993 the airport was officially closed and the Government advised the Wittenoom residents that they would not be forced to leave, but new residents would not be encouraged to the town. A number of estimates on the cost and possible methods of rehabilitating Wittenoom and nearby mine sites were produced by organisations such as the Shire of Ashburton, the Department of Minerals and Energy and the Environmental Protection Authority.

In 1993, the Government commissioned CMPS&F Environmental to undertake a feasibility study for cleaning up the town site. The study found there was still extensive contamination, after approximately fifteen years during which attempts were made to clean up the town. The final report proposed a clean up involving removal of 100 mm (3.9 in) of contaminated top soil and replacement by gravel capping under strict guidelines. The cost was estimated at $2.43 million, and the report suggested the town could be developed further after clean up.
A systematic clean up of the town was not undertaken. Members of the Interdepartmental Committee on Wittenoom believed it was unlikely the town could be satisfactorily cleaned up and the benefits of attempting to clean up the town were not in proportion to the costs, or the risks involved. The legal implications of encouraging people to live in a town contaminated with crocidolite (even after clean up) were enormous. If residents or visitors contracted an asbestos related disease at some point in the future, it was very likely they might initiate legal action against the Government or organisations involved in such a project.

As of 2016 Wittennoom had only three permanent residents who defy the Government of Western Australia’s removal of services and stated intention to demolish the town. On 30 June 2006, the Government turned off the power grid to Wittenoom.

A report by consultants GHD Group and Parsons Brinckerhoff in November 2006 evaluated the continuing risks associated with asbestos contamination in the town and surrounding areas and classed the risk to visitors as medium and to residents as extreme.
In December 2006, Minister for the Pilbara and Regional Development Jon Ford announced that Wittenoom’s status as a town would be removed, and in June 2007, he announced that the townsite status was officially removed.

Both the Department of Health and an accredited contaminated sites auditor reviewed the report, with the latter finding that the detected presence of free asbestos fibres in surface soils from sampled locations presented an unacceptable public health risk. The auditor recommended that the former townsite and other impacted areas defined in the report be classified as “Contaminated – Remediation Required”. The Department of Environment and Conservation subsequently classified Wittenoom as a contaminated site under the Contaminated Sites Act 2003 on 28 January 2008.

However, opinion is not unanimous on the danger posed. Mark Nevill, a geologist and former Labor MLC for the Mining and Pastoral district, said in an interview in 2004 that the asbestos levels in the town were below the detection level of most equipment, and the real danger is located in the gorge itself which contains the mine tailings. Residents once operated a camping ground, guesthouse and gem shop for passing tourists. The roof of the gem shop is now caved in and the wood of the guest house is rotten, while the camping ground is nowhere to be found.

It was reported in 2018 that thousands of travellers still visited the ghost town every year as a form of extreme tourism.

The Australian Mesothelioma Registry (AMR) is another way that the Australian government is taking part in the fight against asbestos-related cancer. This national database keeps track of information about people who were diagnosed with mesothelioma after July 2010. It records all new cases in order to help the government develop policies on how to deal with asbestos that still remains in the country and reduce mesothelioma going forward.

The climate in Wittenoom is hot and humid in summer, which made working conditions in the poorly ventilated, dusty mine and mill uncomfortable. Many workers often stayed in the town for short periods only. Although around 200 people were employed at a time, approximately 7,000 workers drifted through the mine in the 23 years of its operation. Nearly half stayed for less than three months. CSR had problems attracting workers to the mine and mill, and in 1951 wrote to the Department of Immigration asking for help. CSR sent representatives to European countries, such as Italy, to recruit workers. Many European immigrants unable to find work in their own country signed a two-year contract with CSR to work at the Wittenoom mine and mill. They were unable to leave Wittenoom before the end of their contract unless they paid back CSR their fare, which for most was impossible.

Working conditions during the operation of the mines and mill at Wittenoom were extremely poor, especially in comparison to those of the 1990s. The biggest problem was the asbestos dust comprising small airborne asbestos fibres. Employees worked continuously amongst the asbestos dust in the poorly ventilated mine and mill, usually without effective personal protective breathing equipment. Safe working practices and systems of work were not evident.

The Australian Blue Asbestos Company employed 6,500 men and 500 women in the mining and milling of crocidolite at Wittenoom between 1943 and 1966. This cohort has been traced periodically for vital status and cause of death since 1975. By 1986 there were 85 deaths from pleural and peritoneal mesothelioma. None occurred within ten years of first exposure to crocidolite. A survey of dustiness in the industry conducted in 1966 has provided a basis for estimates of cumulative crocidolite exposure of the members of the cohort. Exposure-response relationships have been examined. Mesothelioma incidence rates increase exponentially with time since first exposure and also increase with intensity of exposure to crocidolite. Mathematical modelling of the relationship between mesothelioma incidence and intensity of exposure, duration of exposure and time since first exposure results in an estimate of up to 700 cases of mesothelioma in this cohort by the year 2020.

The 1990 Midnight Oil song, “Blue Sky Mine” and its album Blue Sky Mining, was inspired by the town and its mining industry, as were He Fades Away and Blue Murder by Alistair Hulett. The town and its history are also featured in the novel Dirt Music by Tim Winton.

Digital poet Jason Nelson created the work Wittenoom: speculative shell and the cancerous breeze, an interactive exploration of the town’s death. It won the Newcastle Poetry Prize in 2009.

Curated with thanks from Wikipedia

Transite


Image by/from Mewtu

Transite originated as a brand that Johns Manville, an American company, created in 1929 for a line of asbestos-cement products, including boards and pipes. In time it became a generic term for other companies’ similar asbestos-cement products, and later an even more generic term for a hard, fireproof composite material, fibre cement boards, typically used in wall construction. It can also be found in insulation, siding, roof gutters, and cement wallboard. The more prevalent transite found in wall construction and roofing tiles for example, will last anywhere from 50 years to over 100 years.

The use of asbestos, a proven carcinogen, to manufacture transite was phased out in the 1980s. It was replaced by crystalline silica, which the International Agency for Research on Cancer has classified as being carcinogenic to humans (Class 1). Crystalline silica is also known to cause silicosis, a non-cancerous lung disease.

Originally, transite had between 12-50% of asbestos fiber added to a cement base to provide tensile strength (similar to the rebar in reinforced concrete), and other materials. It was frequently used for such purposes as furnace flues, roof shingles, siding, soffit and fascia panels, and wallboard for areas where fire retardancy is particularly important. It was also used in walk-in coolers made in large supermarkets in the 1960s, 1970s and even the 1980s. Other uses included roof drain piping, water piping, sanitary sewer drain piping, laboratory fume hood panels, ceiling tiles, landscape edging, and HVAC ducts. Because cutting, breaking, and machining asbestos-containing transite releases carcinogenic asbestos fibers into the air, its use has fallen out of favor. Despite asbestos-containing transite being phased out, it is still not banned in the United States; some 230,000 deaths have been attributed to it. Demolition of older buildings containing transite materials, particularly siding made from transite, requires special precautions and disposal techniques to protect workers and the public.

The transite that is produced today is made without asbestos. Transite HT and Transite 1000 are currently available fiber cement boards that contain crystalline silica, which the International Agency for Research on Cancer has classified as being carcinogenic to humans (Class 1). Crystalline silica is also known to cause silicosis, a non-cancerous lung disease.

Curated with thanks from Wikipedia

Zetex (fabric)

Zetex fabrics were invented by Bal Dixit in 1978. This highly texturized fiberglass fabric exhibits many of the same properties as asbestos, such as resistance to heat, corrosion and rot resistance, outstanding electrical properties, ability to withstand molten metal, and thermal insulation. However, it does not carry the same health risks.

Zetex has been tested against asbestos to prove it is a good replacement. Two Zetex filaments were created, one with a 9 um diameter (G) and a 6 um diameter (DE).

Chrysotile, the most commonly encountered form of asbestos, has a density of 40 oz/yd2, while Zetex G has a density of 35 oz/yd2, and Zetex DE has a density of 32 oz/yd2.

A glove was fabricated from this material to allow for further testing to be done. A thermocouple was used to test the inside temperature of the glove while holding a 600°F(316°C) pipe. A measure was taken to see how long it took the inside to reach 140°F. Both gloves included the same wool liner. Another test was done with a 1200°F(649°C) pipe.

Zetex can be used for a variety of fire protection applications.

Zetex has replaced asbestos as the material for the large fire curtains that lower and close off the stage opening in case of a fire in a proscenium type theatre or auditorium.

During welding, workers can wear Zetex-made fire suits for protection. Also, Zetex material can be used for fabric expansion joints, creating fire barriers in buildings.

Zetex material can encapsulate gas tanks or exhaust pipes, protecting from fire caused by gas leaks.

Zetex suits can be used in welding applications, protecting the worker from sparks and other molten objects. It can also be used to create a fire barrier.

Fire departments can use Zetex made suits to battle fires due to Zetex’s heat resistant properties. Full engulfment capabilities of the suit make for a good emergency combatant.

When boxing a newly finished piece of glass for annealing a Glassblower may utilize Zetex gloves to hold the finished piece in transition from the knock off table to the annealer.

Tremolite


Image by/from Didier Descouens

Tremolite is a member of the amphibole group of silicate minerals with composition: Ca2(Mg5.0-4.5Fe2+0.0-0.5)Si8O22(OH)2. Tremolite forms by metamorphism of sediments rich in dolomite and quartz. Tremolite forms a series with actinolite and ferro-actinolite. Pure magnesium tremolite is creamy white, but the color grades to dark green with increasing iron content. It has a hardness on Mohs scale of 5 to 6. Nephrite, one of the two minerals of the gemstone jade, is a green variety of tremolite.

The fibrous form of tremolite is one of the six recognised types of asbestos. This material is toxic, and inhaling the fibers can lead to asbestosis, lung cancer and both pleural and peritoneal mesothelioma. Fibrous tremolite is sometimes found as a contaminant in vermiculite, chrysotile (itself a type of asbestos) and talc.

Tremolite is an indicator of metamorphic grade since at high temperatures it converts to diopside.

Tremolite occurs as a result of contact metamorphism of calcium and magnesium rich siliceous sedimentary rocks and in greenschist facies metamorphic rocks derived from ultramafic or magnesium carbonate bearing rocks. Associated minerals include calcite, dolomite, grossular, wollastonite, talc, diopside, forsterite, cummingtonite, riebeckite and winchite.

Tremolite was first described in 1789 for an occurrence in Campolungo, Piumogna Valley, Leventina, Ticino (Tessin), Switzerland.

One of the six recognized types of asbestos. Approximately 40,200 tons of tremolite asbestos is mined annually in India. It is otherwise found as a contaminant.

Curated with thanks from Wikipedia

Why the Deadly Asbestos Industry is Still Alive and Well

Deadly Asbestos

This video covers Russia and the USA and shows that the dangers of asbestos are not being taken seriously, or if they are, still very little is being done about them at a top level.

Why might this be? Well, one of the major sayings when it is difficult to find an answer to something happening that seems nonsensical is to “Follow The Money”. That means that you should look at the situation to see whether someone could  be making money from things staying as they are. (It follows on from the French saying, “Cherchez la femme”, which means to look for the woman behind what a man is doing!) You may also know the saying as “Money Talks”, that is, if money is available for doing or not doing something, it is likely that it will or will not be done, no matter how serious or nonsensical the situation.

Where might the money be in relation to asbestos?

  1. There is nothing as good and cheap as asbestos when it comes to fireproofing and insulating. Manufacturers still want to use it. If they cannot use it in developed countries, they will use in less developed countries.
  2. The countries or companies that own the deposits of asbestos want to make money from them.
  3. There are large deposits of asbestos available and the mines that extract it provide jobs and incomes in some remote areas, where no other jobs are available.

The Real Story of Asbestos

How Did We Find Out About Asbestos

How long have we known it’s dangerous to health?

This short video provides the answers.

Why Are Popcorn Ceilings So Terrible

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Popcorn Ceilings May Contain Asbestos

Many older houses have what are known as popcorn ceilings. If you are thinking of buying one of these older houses, then find out about these types of spray on ceiling covers before making an offer, so you know whether you are willing to live with it or able to afford the cost of removing it.

What Is A Popcorn Ceiling

A popcorn ceiling is the name given to ceilings that have been treated with a spray-on textured paint. They are also known as acoustic ceilings, because they have sound-proofing qualities. Many people do not like them, firstly because they are old fashioned and not what they consider to be in tune with modern decor and secondly because they may contain asbestos.

Does It Contain Asbestos?

Volunteers Exposed To Asbestos Dust

 

 

 

 

 

 

 

 

 

 

This case dates back to the year 2009 in Michigan, USA when a group of volunteers and untrained employees were tasked by Detroit International Bridge Co, with cleaning up an old building at Michigan Central Station. The company was subsequently fined by the OSHA for exposing these people to asbestos dust and other toxic materials.