ASBESTOS Dear friends,
When I was about fifteen years old, use of asbestosfor roofing started in my native in Kerala. The asbestos sheets were large in size, do not requiremore slanting as for tile roofing, required less supporting wooden frame. Most homes started to have anextension hall in the front with asbestos. Many homes removed backside room called chayippu,extended and reconstructed with asbestos roof. They could be used like rooms. Cinema theatreswhich were having thatched coconut leaf roofing were directed to remove it androof with asbestos sheet to avoid firerisk. The college Istudied in my native was having two floors, roofing was with asbestos sheet (1961-1964) except Principalroom in the front, which had RCC roofing with tower clock installed above it. Asbestos sheetswere fire resistant. In telephone exchanges cabins were directed to be replaced withasbestos in metal frames. It marred the appearance, but fire risk was moreimportant. “Number please”manual exchanges were more prone to fire risk… However asbestossheets were fragile, though having more thickness. Till tin sheets appeared, asbestos sheets were moreprominent. When I constructed my home in Chennai in 2005, overhead water tankwas covered with thick asbestos sheets were provided in aluminium frame. Aftertree branches falling from nearby compound and breaking, mica sheets are fittedin aluminium frame are provided now. I understand thatKerala has banned furtheruse of asbestos now. But Tamilnadu has not banned. Today in Yahoo opening page I found an interesting articleabout asbestos sheets. I thought of FORWARDINGit to my friends. This posting is 21 pages, please read atleisure time. Gopalakrishnan 23-11-2023. ARTICLE Asbestos was a miracle material, virtually impervious tofire. But as wefixed city fires in other ways, we came to learn about its horrific downsides. Few materials fell from grace like asbestos. Once cherished as analmost-magical material, it is now the archetypal carcinogen. We spentover a century integrating it into buildings, wiring, pipes, brake pads, andmore, and we now spendbillions of dollars a year removing it. But the standard story of asbestos as a mistake – oreven a crime – of massive proportions does not do justice to the real benefitsit brought. Asbestos wascentral to mitigating urban fires, which cost thousands of lives each year asmodern cities grew larger, denser, and more flammable. But as we learned to control urban fires without it, asbestos’s healthcosts seemed less and less worth bearing. Asbestosis in its final days and soon the material will almost disappear entirely. Miracle materials are not all manmade. Asbestos is a family of sixnaturally occurring silicates, made from the same elemental blocks as sand orglass, organized in delicate fibrous strands that tease apart likecotton candy and compare with steel in tensile strength. Chrysotile or whiteasbestos, the commercially dominant form, is a serpentine silicate, withfibrous strands that crumble to the touch; the remaining five are amphiboles(including crocidolite, blue asbestos), spiky forests of short and fragile needles.In all its forms, asbestoshas remarkable properties: it’s light, waterproof, and, most famously,fireproof. The unique structure of asbestos requires a uniqueset of circumstances to form. Thefibers of asbestos are crystals precipitated out of a solution of minerals inhot water under pressure. This is hydrothermal synthesis, a process used to grow artificial crystals inlaboratory settings (or candy from syrup). The low-silica rocks in which asbestos originates are foundnaturally across the planet, and asbestos has been found and mined on everyinhabited continent. The firstwritten record of asbestos was by Theophrastus, who categorized it correctly by including it in hismineralogical work, On Stones. He did better than most, considering that ananimal origin for asbestos was a common misconception in the ancient world:asbestos was credited to everything from phoenix feathers to the mythicalsalamander to Princess Bride–style literal volcano-dwelling fire rats. Its rarity and invulnerability to fire gave asbestos anair of mystique and an association with power. Charlemagne is said to have had a tablecloth of pureasbestos that he would throw into the fire as a party trick, and Emperor Ashoka of India sent a gift of asbestos cloth to Sri Lanka.Earnest pilgrims into the Holy Land were sold pieces of asbestos cloth asremnants of the Holy Shroud, made credible by their immunity to fire. Benjamin Franklin paid for histime in Europe by selling an asbestos purse to a collector (for which hewas paid ‘handsomely’). Yet asbestos existed only as an interesting noveltywithout a clear use. That use case cameinto being in the late nineteenth century. The fast-growing cities of the time were exceptionally flammable, withdensely clustered buildings full of wood, fabric, and open flames.Electrification was new; fire codes were yet to become ubiquitous (orstringently applied). In some cases, even roads were made of timber. Unsurprisingly, ‘Great Fires’ struck virtually everymajor city. Theaters, full of flammable set elements and a tightly packedaudience, were a frequent source of fire. The risky productions themselves did not help – 31of the 1,108 theater fires documented worldwide between 1797 and 1897 werestarted by fireworks on the stage. Theater fires started mostly on the stage and thenspread to the audience. It was critical that the two areas be separated to protect theaudience. Theater owners attempted to separate the stage and audience withheavy curtains of sheet metal, called ‘iron curtains’. Experiments on a scalemodel following a fire in Vienna’s Ringtheatre in 1881 showed theirlimitations. A fire on the stage would blow the hot metal curtain out onto theaudience it was meant to protect, not only endangering them but alsoextinguishing the gaslights meant to light the way to safety. In otherinstances, the curtain could collapse onto the stage or fail to descend at all. Engineers and regulators experimented with adiversity of materials for safety curtains, settling on asbestos. The 1903 fire at the Iroquois Theatre in Chicago ledto an exemplary institutional response. The Iroquois supposedly had an asbestoscurtain that failed to come down during the fire, but later investigation ofthe remnants of the curtain revealed that the curtain was mostly vegetablefiber. Following the fire, Chicago ordered all its theaters to be closed downimmediately, while in New York inspectors went around setting fire to theatercurtains, in search of dupes being passed off as asbestos by noncompliant ownership.The message now was clear:asbestos, or nothing. Theaters were not the only place where fires werecommon. Movie theaters, schools, hotels, hospitals, ships, and ports allexisted under the threat of fire. Asbestoswas gradually introduced in each. Ports wereparticularly keen on fire safety. A fire port-side could easily spread among ships anddestroy them, as it did famously in the 1900 Hoboken Docks fire in New Jersey. A fire that started in bales of cotton stored on a pier spread with thewind to stores of flammable turpentine and oil, which exploded in quicksuccession. Within 45minutes, the fire had destroyed three piers and three major transatlanticliners belonging to the Norddeutscher Lloyd shipping company, and claimed over200 lives. Navies and merchantnavies were eager and early adopters of asbestos. When NorddeutscherLloyd finally rebuilt the pier, asbestos felt was among the materials used. The firstmass-produced asbestos products in the United States were gas fireplaces, eventually joined by protective suits for firefightersand materials for roofing, felting, and boiler insulation. Asbestosbecame the standard material for applications as diverse as brake pad liningsand insulation for electrical wiring. In the case of brake pad linings,asbestos was the only reliable material until well into the 1940s, and remainsone of the few permitted uses in the United States today. Scientific American wrote in 1919 that ‘new uses of this material arebeing found almost daily’. Production keptpace: prices fell from $128 per ton to $30 per ton in the United States from 1890–1904following the discovery of commercially viable deposits in Canada and improvedmethods of refinement and transport. It was rapidly becoming price competitive in construction in the form ofroofing tiles and in products where it could be blended with cheaper material,as in asbestos stucco and asbestos-cement shingles. One particularly clever product was asbestos paint, which made woodenstructures flame-retardant.Patented in 1878, it was already on federal buildings, including the USCapitol, by 1879. My note- Asbestos paint is a new information to me. Asbestos becamemore important than ever in World War II. It was classified as a critical material by the USWar Production Board, and its scope expanded from its traditional roles offireproofing, friction reduction, and insulation to substituting othermaterials that were even more desperately needed elsewhere. It became the material of choice foraircraft hangars and ordnance stores, military prefabs, ductwork, and even commongutters and downspouts. Soon, conservation orders were issued limitingits use and privileging defense applications. The Navy was atthe forefront of asbestos use. Shipboard fires engulfed vessels that had limited meansof fire suppression. Newer classes of ships such as the Essex featured asbestoscurtains and fire doors, and no ships were lost to fire after 1942. In lateryears, as many as a third of all asbestos-related cancer cases in the US wouldbe linked to US Navy ships or shipyards. The postwar era combined a heightened awareness ofthe risk of fire with a massive wave of new construction. Asbestos was cheapenough to use in every building. America produced and imported asbestos at a fantasticrate. Asbestos consumption tripled between 1940 and 1950, increasing from240,000 metric tons to 400,000 metric tons from 1940–1941 alone. At one point, as many as 4,000 products contained asbestos, includingtoothpaste. Thingswould soon change. As early as 1898, factory inspectors noted theeffects of asbestos on workers who breathed in its fibers, with one going sofar as to call it ‘theevil dust’ (safety reports were a lot more colorful then). A 1918 reportto the US Bureau of Labor Statistics, ‘Mortality from Respiratory Diseases inDusty Trades’, explained that ‘in the practice of American andCanadian life insurance companies asbestos workers are generally declined onaccount of the assumed health-injurious conditions of the industry’. In 1924, Nellie Kershaw, a 33-year-old Britishasbestos spinner, died. The inquest concluded that the cause of her death wassuffocation traced to profound scarring of her lung tissue from being laceratedwith microscopic asbestos fibers. The coroner who led the inquest called it ‘asbestos poisoning’. Her employer, the largest asbestos factory inthe world and the owner of asbestos mines in Canada and South Africa, rejectedthe report. Nellie Kershaw’s death was not entirely withoutconsequence. The coroner pressed on, publishing his results in The BritishMedical Journal. Kershaw’s illness now had a name –asbestosis – and a British government survey of the asbestos industry in 1930found that a quarter of all workers were suffering from it. The next year, Britain passed Asbestos IndustryRegulations, 1931, the world’s first regulation dealing specifically withasbestos. That did not immediately put a stop to asbestos, evenin the United Kingdom. The event that finally did set off a wave of asbestosbans across advanced economies came over 30 years later, at a conferenceconvened at the New York Academy of Sciences in 1964. This conference was organized by Irving J. Selikoffof New York’s Mount Sinai Hospital. Selikoff had spent years interviewing workers involved with asbestos,among them asbestos weavers, pipe insulators, and shipyard workers. He later published results in1965 and 1968 that suggested asbestos might be a carcinogen, but at the1964 conference, he may have had his greatest impact by catalyzing theconversation in the first place. The conference itself was largely aconsolidation of already available knowledge and presented little that was newor surprising, but the momentum it generated made a definite difference, and inthe case of Selikoff, enemies. Asbestos use collapsed in the wealthy world almost asdramatically as it had risen. The bans took off, slowly, in the early seventies. Denmark was first, banning asbestos for insulation and waterproofing in1972. Sweden followed with a ban on asbestos spraying in 1973. The first total ban came in 1980, with Denmark again leading thecharge. Eachsuccessive decade saw more jurisdictions join in restricting the use ofasbestos, partially or fully, for the first time: eight more in the 1980s, 24in the 1990s, and 36 in the 2000s. The bans were augmented with requirements to remove asbestos wherefound in existingbuildings. As the threat of fire dwindled, Asbestos prohibitions spread. Asbestos is now banned in at least 66 countries,including all members of the European Union, the United Kingdom, Japan, Australia,and South Africa. The United Statesis often cited as a rare industrialized country without a total ban, but it was no laggard inpursuing restrictions, either. Thefirst American restriction came in 1973, followed in quick succession byfurther restrictions in 1975, 1977, and 1978. An effort by the EnvironmentalProtection Agency to ban asbestos completely in 1989 was the closest the UnitedStates came to a complete ban on asbestos. In 1991, a Federal appeals court overturned provisions ofthe ban that would have come into force in 1993 and 1996, effectively protecting asbestos usein brake drum linings, roofing and flooring felt, and asbestos tiles.Despite this, the popularity of asbestos in the United States continued tofall. The move against asbestos in the United States wasglobally consequential. The United States had traditionally imported nearly allof its asbestos and was the largest asbestos importer in the world. In 1970,the United States had imported close to 590,000 metric tons of asbestos; in2000, this had collapsed to below 15,000 metric tons. Global trade in asbestosfell from 2.4 million to 1 million metric tons between 1970 and 2000, and the United States was responsible for 40 percent of this decline in volume. Substitutes have been found for most applications.The majority of substitutes are natural or synthetic fibers that are notconsidered carcinogenic. Asbestoshas been replaced in fiber-reinforced cement by cellulose fibers, ininsulation by fiberglass and mineral wool, and in clothing by aramid fibers. Elsewhere, itsunique confluence of useful properties has proved harder to replicate. Asbestoscement, which was used to make cheap, durable pipes and prefabricated sheetsfor wall cladding, was by far the biggest use of asbestos, accounting for 80 percent of asbestos production in 1988.A particularly interesting niche where asbestos persists is in the productionof chlorine. Asbestosdiaphragms are used in the chlor-alkali process, the dominant technology formanufacturing chlorine, to separate the anode and cathode of anelectrolytic cell. An alternative method uses polymer membranes instead. Thesemethods have traditionally been considered ‘low concern’ from a health andsafety standpoint; some researchers now suggest that we should be moreconcerned, but switching to the alternative method is expensive. The economiccase for asbestos slowed its decline in many places. Canada’s exit wasparticularly protracted, given its former status as a leading producer. Thecosts of damages and litigation, over $70 billion in the United States alone,have resulted in widespread bankruptcies of asbestos manufacturers and closuresof asbestos mines. The last asbestos mine in Canada, which wasalso the world’s largest, discontinued operations in 2011. While Canadaceased mining, a ban on export did not come into force until the penultimateday of 2018. The town of Asbestos, Quebec, home to that final mine, abandonedits name in 2020. The costs of abatement have been just as significant.That asbestos is implicated in asbestosis (limited mostly to workers withdirect exposure, such as Nellie Kershaw) and mesothelioma (cancer of themesothelium, which forms a lining around the lungs) is universally accepted. What’s controversial is the benefitfrom removing asbestos from all structures, given the risk to buildingoccupants tends to be low. It is instead people who work directly withhigh concentrations of asbestos – such as shipyard and textile workers – whoare at high risk. The Environmental Protection Agency estimates thereare over 700,000 public and commercial buildings in the US that containasbestos, as wellas 45 percent of the nation’s 100,000 schools. The number of residentialbuildings that contain asbestos is simply not known. Rachel Maines, the authorof Asbestos and Fire, figures essentially every building constructed in thetwentieth century prior to 1980 contains it. The requirement to remove asbestosin the built environment wherever found, so-called “in-place” asbestos, hasgiven rise to an abatement industry in the United States with annual revenuesalready exceeding three billion dollars. These are expensive projects, where aconsultant must be retained, workers must wear protective gear, and theworksite must be isolated with negative pressure. The cost of such abatement at a national scale wouldlikely run into hundreds of billions of dollars, for uncertain benefits. Asbestos isdangerous only when inhaled, and it cannot be inhaled except as airborne fibersthat are released when asbestos is disturbed. Since abatement takes theform of ripping or scraping off asbestos from the places where it is found, itgenerates clouds of airborne fibers where there were none, and needs to bedisposed of very carefully by abatement workers. While the healthconsequences of removing asbestos are not yet fully understood, there are not currentlyreasons to be concerned. And natural sources of asbestos can confound data. Forexample, a large study using data across California found that the odds ofdeveloping mesothelioma declined by 6.3 percent for each ten kilometers ofdistance from the nearest source of environmental asbestos. If members of the‘control group’ in a study, who are assumed to have no exposure to asbestos,actually had natural exposure to asbestos, researchers would underestimate theharms they face and the risks of further exposure to asbestos in occupationalwork. How many lives didasbestos itself save in the final reckoning, net of the deaths it caused? It’simpossible to say.This is what we know: Fire deaths fell by over 90 percentin the United States over the twentieth century; asbestos was present inthousands of applications as a fire retardant; and without effective brake pads, the roadswould have been much more dangerous. However, at the same time that asbestosbecame ubiquitous, fire codes matured, firefighting technology improved, andthe insurance industry laid down stringent requirements for coverage. There are common-sense compromises that sit betweencomplete complacency and abatement regardless of cost. New York City Local Law76/85 required asbestos to be removed in the cases of demolitions andrenovations, but did not call for it to be removed proactively from all placeswhere it existed. Theaterremains an iconic industry in New York City, and many theaters continue to haveasbestos curtains. The same calculus features in global attitudes towardasbestos. Even as the developed world has abandoned asbestos, others haveexpanded their production. The two leading producers are Russia and Kazakhstan,which have built upon Soviet-era operations to account for over 83 percent ofall exports. The market is similarly concentrated on the importers side as well– the three largest importers of asbestos account for over 65 percent of allimports, and the top ten are all in Asia. Russia is itself a major consumer, inthird place behind China and India. India, where asbestos is called ‘the poor man’smaterial’ and asbestos roofs are an alternative to safer, but more expensive,tin or fiberglass roofs, is also beginning to move away from asbestos. The country banned thedomestic production of asbestos in 1986, but not its use, becoming the largest importer ofasbestos in the world by 2003. In 2011, the Supreme Court of Indiadenied a public interest filing to ban asbestos, favoring continued regulationby states instead. In 2018, the western state of Maharashtraforbade the inclusion of asbestos in regional development plans. The following year, the southern state of Keralaordered the removal of asbestos roofing in schools. The impact on trade figures has been slow butcertain. The global trade in asbestos fell from over $500 million to under $300million from 2012–2018, with India reducing imports by over $100 million,the most of any country. The next-largest importers, Indonesia andChina, also cut down. As these countries grow richer, they too may soon decidethat the costs of asbestos have come to outweigh its benefits. Author Mano Majumdar is a management consultant at a globalconsulting firm. He has a background in chemical engineering, and has taught ata leading Canadian business school -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/thatha_patty/56908253.4349341.1700749351437%40mail.yahoo.com.
