WEBVTT NOTE Machine transcript of the film's sound; not yet checked. 1 00:00:17.480 --> 00:00:23.080 What a wonder is this, our world, still fresh and new-looking after more than four 2 00:00:23.080 --> 00:00:24.780 and a half billion years in space. 3 00:00:27.480 --> 00:00:32.520 But we know, if we travel back far enough in time, that the seemingly ageless 4 00:00:32.520 --> 00:00:34.680 planet Earth has seen many changes. 5 00:00:37.120 --> 00:00:42.040 It had a violent beginning, so violent, in fact, that any solid minerals existing 6 00:00:42.040 --> 00:00:45.120 in the first billion years have long since vanished. 7 00:00:47.180 --> 00:00:51.480 Probably they were melted down in the heat, lost in the mists of early creation. 8 00:00:58.060 --> 00:01:02.420 Throughout the Earth's lifetime, the cooler surface has often yielded to the 9 00:01:02.420 --> 00:01:03.620 seething forces below. 10 00:01:04.560 --> 00:01:08.860 Over hundreds of millions of years, during which the surface formed a relatively 11 00:01:08.860 --> 00:01:09.860 thin crust, 12 00:01:09.940 --> 00:01:15.600 the continents and sea beds shifted thousands of miles in response to the upheavals 13 00:01:15.600 --> 00:01:17.180 of the underlying mantle and core. 14 00:01:18.080 --> 00:01:22.540 In one dramatic example of volcanic activity, molten minerals violently forced 15 00:01:22.540 --> 00:01:23.540 their way to the surface, 16 00:01:24.640 --> 00:01:30.160 then cooled and hardened into rock so far a well-known 17 00:01:30.160 --> 00:01:35.160 geological story but then during 18 00:01:35.160 --> 00:01:40.880 further disturbances the hardened rock became fissured later scientists 19 00:01:40.880 --> 00:01:42.460 believe hot mineral 20 00:01:42.460 --> 00:01:47.760 bearing water flowed through the fissures dissolving some of the surrounding rock this 21 00:01:47.760 --> 00:01:51.700 solution crystallized into a network of fibrous veins from 22 00:01:54.260 --> 00:01:56.960 this unusual geological event came a 23 00:01:56.960 --> 00:02:02.080 most unusual mineral. Even before the dawn of the Iron Age, it was already 24 00:02:02.080 --> 00:02:03.080 proving highly 25 00:02:02.840 --> 00:02:09.380 useful to man. The ancient Greeks, with their well-known curiosity, investigated it and 26 00:02:09.380 --> 00:02:13.340 found its fine fibers could be spun into yarn, and it resisted fire. 27 00:02:15.530 --> 00:02:17.110 The Greek word for this 28 00:02:17.110 --> 00:02:23.090 unique mineral was asbestos. Mineral asbestos is noncombustible, even at 29 00:02:23.090 --> 00:02:24.090 extremely high 30 00:02:23.830 --> 00:02:28.690 temperatures. It inhibits certain types of chemical reaction and is extremely 31 00:02:28.690 --> 00:02:34.090 flexible and durable. All of these qualities combine to make asbestos 32 00:02:34.090 --> 00:02:36.790 especially suitable for a wide variety of demanding uses. 33 00:02:42.100 --> 00:02:43.100 Asbestos is the 34 00:02:43.040 --> 00:02:46.600 generic name given to a group of hydrated silicate materials that can be 35 00:02:46.600 --> 00:02:50.900 separated into relatively soft silky fibers which have greater tensile 36 00:02:50.900 --> 00:02:55.380 strength than many types of steel. Aside from small amounts produced in 37 00:02:55.380 --> 00:02:59.640 laboratories, man has never been able to duplicate its unique combination of 38 00:02:59.640 --> 00:03:00.680 physical, chemical, 39 00:03:00.820 --> 00:03:06.580 and textile properties in one mineral. In its natural 40 00:03:06.580 --> 00:03:08.740 state, most asbestos used in the 41 00:03:08.740 --> 00:03:14.060 United States is found in irregular crystalline veins. The name crude is applied to 42 00:03:14.060 --> 00:03:15.060 this cross-vein 43 00:03:14.780 --> 00:03:20.180 material before the fibers have been separated. The natural 44 00:03:20.180 --> 00:03:23.160 asbestos ore, or crude, is mined 45 00:03:23.160 --> 00:03:27.140 from open pit mines or underground mines, most of which are found in Canada. 46 00:03:27.580 --> 00:03:28.960 When asbestos-bearing 47 00:03:28.960 --> 00:03:33.360 rock has been exposed, it is broken up by drilling and blasting with modern liquid 48 00:03:41.370 --> 00:03:45.030 explosives. Giant power shovels remove the ore-bearing rock. 49 00:03:48.410 --> 00:03:49.550 A fleet of giant 50 00:03:49.550 --> 00:03:51.590 trucks transport the ore from the mine. 51 00:03:56.860 --> 00:03:58.860 The separation of the asbestos fiber 52 00:03:58.860 --> 00:04:03.860 from the non-useful rock around it is done in the mill. First, the ore falls 53 00:04:03.860 --> 00:04:06.320 down the chute into the jaws of a primary crusher. 54 00:04:14.740 --> 00:04:16.740 Next, it moves to screens 55 00:04:16.740 --> 00:04:22.700 and secondary crushers. Asbestos-bearing rock is 56 00:04:22.700 --> 00:04:24.380 moved on conveyors to a distribution 57 00:04:24.380 --> 00:04:30.360 point at the top of a mill. After crushing, the crushed ore 58 00:04:30.360 --> 00:04:31.820 goes through a screening process 59 00:04:31.820 --> 00:04:34.000 to separate the fibers from the ore. 60 00:04:39.440 --> 00:04:42.660 Once the fiber has been obtained, asbestos combines 61 00:04:42.660 --> 00:04:48.320 easily with many other materials. Indeed, it is estimated that as many as 3,000 different 62 00:04:48.320 --> 00:04:52.740 products which contain some asbestos are in daily use throughout the world. 63 00:04:53.820 --> 00:04:54.840 While in certain 64 00:04:54.840 --> 00:04:59.620 products the percentage of asbestos may be small. The unique properties of asbestos 65 00:04:59.620 --> 00:05:02.480 usually are responsible for the functioning of the product in a 66 00:05:02.480 --> 00:05:06.750 demanding application. Look around you. 67 00:05:06.890 --> 00:05:08.890 In the home and in the work environment 68 00:05:08.890 --> 00:05:10.390 asbestos is there. 69 00:05:15.680 --> 00:05:18.480 The heat resistant properties and fiber structure of 70 00:05:18.480 --> 00:05:22.440 asbestos make it extremely desirable as a fireproofing and insulating material 71 00:05:22.440 --> 00:05:26.280 in applications which already have prevented billions of dollars in 72 00:05:26.280 --> 00:05:32.100 property damage. Typically asbestos is used 73 00:05:32.100 --> 00:05:33.680 wherever fire and excessive heat 74 00:05:33.680 --> 00:05:38.720 are a threat to safety. As the needs of modern industry and modern living 75 00:05:38.720 --> 00:05:43.340 have expanded, asbestos has appeared in a wide range of applications suitable to 76 00:05:43.340 --> 00:05:48.580 its unique combination of properties. Long fibers are spun into yarn to lend 77 00:05:48.580 --> 00:05:50.800 strength and fire resistance to textiles. 78 00:05:57.840 --> 00:05:59.940 Asbestos combines easily with many other 79 00:05:59.940 --> 00:06:04.860 materials. For example, with cement it is formed and cured to make strong 80 00:06:04.860 --> 00:06:10.760 corrosion-free pipe. Large diameter conduits 81 00:06:10.760 --> 00:06:12.840 tap water resources and convey 82 00:06:12.840 --> 00:06:18.880 waste water. The smaller diameters are installed for such uses as underground 83 00:06:18.880 --> 00:06:20.560 irrigation and sprinkler systems. 84 00:06:24.540 --> 00:06:26.600 Asbestos cement is also highly suitable 85 00:06:26.600 --> 00:06:29.840 as a building material, particularly for architectural siding. 86 00:06:37.480 --> 00:06:38.480 Asbestos cement 87 00:06:38.340 --> 00:06:43.440 shingles are dimensionally stable. They provide fire and termite resistance, as 88 00:06:43.440 --> 00:06:46.840 well as strength and beauty for the roofs and siding of quality homes. 89 00:06:49.560 --> 00:06:53.620 Adding asbestos to asphalt paving in airport runways, highways and bridge decks 90 00:06:53.620 --> 00:06:54.740 gives numerous 91 00:06:54.740 --> 00:06:59.960 benefits in durability and safety when a thin overlay of asbestos reinforced resurfacing 92 00:06:59.960 --> 00:07:00.960 asphalt is used. 93 00:07:05.660 --> 00:07:10.480 Asbestos is almost irreplaceable in friction materials such as brake linings on our cars. 94 00:07:11.000 --> 00:07:16.460 More than 80 million cars in the U.S. stop on asbestos brake liners which depend on the 95 00:07:16.460 --> 00:07:18.560 strength and heat resistance of asbestos. 96 00:07:19.900 --> 00:07:25.890 asbestos reinforcement also improves gasket materials asbestos is 97 00:07:25.890 --> 00:07:26.930 used to make many grades 98 00:07:26.930 --> 00:07:32.050 of paper including fine papers for electrical insulation protecting large 99 00:07:32.050 --> 00:07:33.970 generators high 100 00:07:33.970 --> 00:07:39.130 voltage transformers and everyday home appliances such as coffee pots 101 00:07:40.660 --> 00:07:42.720 asbestos is a principal 102 00:07:42.720 --> 00:07:46.780 ingredient in a wide variety of thermal insulating products such as the pipe 103 00:07:46.780 --> 00:07:47.780 insulation of this 104 00:07:47.580 --> 00:07:53.580 Arctic tanker. Because it is best known for 105 00:07:53.580 --> 00:07:55.260 its high resistance to extreme heat 106 00:07:55.260 --> 00:07:58.360 and fire, industry found many key uses. 107 00:08:00.520 --> 00:08:02.760 Pipe insulations have also been used for 108 00:08:02.760 --> 00:08:06.580 insulation and safety in the petroleum and chemical industries, and power 109 00:08:06.580 --> 00:08:10.040 generating plants, bringing essential energy to jobs and families. 110 00:08:12.410 --> 00:08:13.710 New uses are 111 00:08:13.710 --> 00:08:19.210 constantly being developed. Here, an insulation containing asbestos is being 112 00:08:19.210 --> 00:08:22.070 applied to a high-gain antenna for use in outer space. 113 00:08:25.130 --> 00:08:26.350 The heat and fire 114 00:08:26.350 --> 00:08:30.210 resistant properties of asbestos are the most important reasons for its use in a 115 00:08:30.210 --> 00:08:35.990 wide range of products. The more asbestos finds its way into 116 00:08:35.990 --> 00:08:37.330 public buildings, the 117 00:08:37.330 --> 00:08:42.050 more people are able to find their way out when fire strikes. Asbestos is strong 118 00:08:42.050 --> 00:08:47.550 and non-combustible. On land it keeps the escape routes of buildings open when 119 00:08:47.550 --> 00:08:51.390 used to protect steel beams and provide a firewall between building sections. 120 00:08:54.440 --> 00:08:57.720 At sea, it protects ships' passengers and crew accommodations, 121 00:08:58.120 --> 00:09:01.240 since fireproof bulkheads reinforced with asbestos fiber 122 00:09:01.240 --> 00:09:03.660 have become the standard in ship construction. 123 00:09:04.300 --> 00:09:08.780 In fact, since the disastrous fire of the Morro Castle off New Jersey in 1934, 124 00:09:09.640 --> 00:09:12.000 asbestos has been used on U.S. passenger ships, 125 00:09:12.180 --> 00:09:15.400 and not one has been lost in a fire at sea since then. 126 00:09:18.690 --> 00:09:22.490 Without asbestos, steel structures would collapse more readily in fires. 127 00:09:23.730 --> 00:09:26.070 Brake linings would burn out in no time. 128 00:09:28.230 --> 00:09:31.650 Firefighters would be beaten back by flames instead of being able to walk 129 00:09:31.650 --> 00:09:32.650 right through them. 130 00:09:32.830 --> 00:09:35.550 And millions of BTUs of energy would be lost 131 00:09:35.550 --> 00:09:39.150 every day without asbestos in many forms of insulation. 132 00:09:44.530 --> 00:09:48.290 On the surface of the earth or voyaging toward a distant planet 133 00:09:48.970 --> 00:09:52.070 asbestos plays a unique role no other material can equal.