More info on Day 1, Locality 8
Information about Asbestos, source: http://en.wikipedia.org/wiki/Asbestos
SEM of Anthophyllite asbestos
Asbestos is a set of six naturally occurring silicate minerals which all have in common their eponymous asbestiform habit: long (roughly 1:20 aspect ratio), thin fibrous crystals, with each visible fibre composed of millions of microscopic "fibrils" that can be released by abrasion and other processes. They are commonly known by their colours, as "blue asbestos", "brown asbestos", "white asbestos", and so on.
Asbestos mining began more than 4,000 years ago, but did not start large-scale until the end of the 19th century when manufacturers and builders used asbestos because of its desirable physical properties: sound absorption, average tensile strength, its resistance to fire, heat, electrical and chemical damage, and affordability. It was used in such applications as electrical insulation for hotplate wiring and in building insulation. When asbestos is used for its resistance to fire or heat, the fibres are often mixed with cement or woven into fabric or mats. These desirable properties made asbestos a very widely used material, and its use continued to grow throughout most of the 20th century until the carcinogenic effects of asbestos dust caused its effective demise as a mainstream construction and fireproofing material in most countries. However around 2 million tons of Asbestos were still mined per year as of 2009, half in Russia.
Individual asbestos fibres are invisible to the unaided human eye because their size is about 320 µm wide and can be as slim as 0.01 µm. Human hair ranges in size from 17 to 181 µm in breadth. Fibres ultimately form because when these minerals originally cooled and crystallized, they formed by the polymeric molecules lining up parallel with each other and forming oriented crystal lattices. These crystals thus have three cleavage planes, and in this case, there are two cleavage planes which are much weaker than the third. When sufficient force is applied, they tend to break along their weakest directions, resulting in a linear fragmentation pattern and hence a fibrous form. This fracture process can keep occurring and one larger asbestos fibre can ultimately become the source of hundreds of much thinner and smaller fibres.
When fibres or asbestos structures from asbestos containing materials (ACM) become airborne, the process is called primary release. Primary release mechanisms include abrasion, impaction, fallout, air erosion, vibration, and fire damage. Secondary release occurs when settled asbestos fibres and structures are resuspended as a result of human activities. In unoccupied buildings or during unoccupied periods, fibre release typically occurs by fallout or is induced by vibration or air erosion.
Friability of a product containing asbestos means that it is so soft and weak in structure that it can be broken with simple finger crushing pressure. Friable materials are of the most initial concern because of their ease of damage. The forces or conditions of usage that come into intimate contact with most non-friable materials containing asbestos are substantially higher than finger pressure.
It is now known that prolonged inhalation of asbestos fibres can cause serious and fatal illnesses including malignant lung cancer, mesothelioma, and asbestosis (a type of pneumoconiosis). Health issues related to asbestos exposure can be found in records dating back to Roman times. By the beginning of the 20th century concerns were beginning to be raised, which escalated in severity during the 1920s and 1930s. By the 1980s and 1990s asbestos trade and use started to become banned outright, phased out, or heavily restricted in an increasing number of countries.
The severity of asbestos-related diseases, the material's extremely widespread use in many areas of life, its continuing long term use after harmful health effects were known or suspected, and fact that asbestos-related diseases can emerge decades after exposure ceases, have resulted in asbestos litigation becoming the longest, most expensive mass tort in U.S. history and a significant legal issue in many other countries. Asbestos-related liability also remains an ongoing concern for many manufacturers, insurers and reinsurers.
From CGE, pp 227-230: Mining history and waste stabilization at the Amiantos asbestos mine.
The mine is located south of the B9 near Pano Amiantos, high up in the Troodos, and it is impossible to miss the huge scar on the landscape. There are many viewpoints, but the best is on the outside of a bend along the B9 to the northwest of Pano Amiantos, at an obvious layby that has a very comprehensive information board (36492055E, 3865564N). Before considering the mined area, it is informative to examine the cuttings and slopes along the B9 in order to appreciate the highly altered, smashed and unstable nature of the serpentinite in this area. With patience, veins of chrysotile asbestos and picrolite should be found, although better examples exist at stop 2.4.
The use of asbestos in human culture dates back at least 4,500 years, when evidence shows that inhabitants of the Lake Juojärvi region in East Finland strengthened earthenware pots and cooking utensils with the asbestos mineral anthophyllite (see Asbestos-ceramic). The word asbestos comes from the ancient Greek σβεστος, meaning "unquenchable" or "inextinguishable". One of the first descriptions of a material that may have been asbestos is in Theophrastus, On Stones, from around 300 BC, although this identification has been questioned. In both modern and ancient Greek, the usual name for the material known in English as "asbestos" is amiantos ("undefiled", "pure") whence the term for it in, e.g., French amiante and Portuguese amianto. In modern Greek, the word σβεστος or ασβέστης stands consistently and solely for lime.
Mining at Amiantos may date back to ancient times, because the place probably takes its name from "amanthius" and was the name given to asbestos by the ancients. Modern mining of chrysotile asbestos took place between 1904 and 1988, ending mainly because of the slump in the market caused by health concerns. Ore was extracted on a series of open benches on the mountainside, but few, if any, of these remain visible today. The average chrysotile grade was about 0.8 - 1 per cent, and ore was processed by crushing, hammering, milling, screening, fibring, aspiration and grading into long or short fibres. About half of the ore mined at Amiantos was processed on site, as was apparent from the plume of fine dust that would drift down the valley. Annual production peaked at around 40,000 tonnes of fibre in the late 1940s and early 1950s. As 99 per cent of the ore was unmineralized, this peak production would have generated about 4 million tonnes of spoil each year. In total, a million tonnes of chrysotile asbestos was recovered during the entire operation of the mine, which required the excavation and processing of some 130 million tonnes of rock. The legacy of these activities is the scarred landscape and the huge quantity of spoil and tailings, although this does not represent the total volume of waste produced.
During the first few decades of operation, waste was dumped down slope to be washed away during the winter months. In 1934 this practice caused a huge flood in Kato Amiantos, which killed ten people and prompted a move to constructing stable waste piles on site. Such was the volume of waste generated that it was necessary to infill the Loumata Valley on the southern side of the mine site. In order to permit safe drainage through the waste pile, a 1.3km - long culvert was constructed along the base of the valley. When the culvert was buried to a depth of 100m, it structurally failed in places. When this was recognized in 1978, it raised great concern over the stability of the waste pile, and dumping ceased. Today, water that accumulates in the reservoir at the western end of the waste pile seeps slowly through the pile and issues at the base as springs, much to the benefit of farmers down stream who use the water to prolong irrigation during the summer months.
The waste pile remains hazardous today and threatens the safety of Kato Amiantos below. From Pano Amiantos there are very good views of the steep, barren and permeable lower slopes of the waste pile, which show evidence of movement by creep and slumping (a major slump scar is clearly visible on the southern side of the pile), and erosion by gullying. Liquefaction is another problem that may result from shaking during an earthquake, but the waste piles are not predicted to fail even with an earthquake of Richter magnitude 7.5 beneath the site. The movement of fine sediment that includes chrysotile fibres threatens water quality, and fibres have been reported in fluvial sediments as far down stream as the Trimiklini and Kouris reservoirs.
In 1994 the mine was closed down permanently in order to permit reclamation and redevelopment of the area, which commenced in 1995 and is expected to be complete by 2010. Restoration focuses both on stabilization of spoil, tailings and slopes by reprofiling and revegetating, and on improvement of drainage to transport water to the edges of the waste pile and to reduce erosion and transport of sediment, especially that bearing asbestos fibres. Following terracing of the slopes and attainment of a slope gradient of 2 m horizontal for every 1 m vertical, a ditch is cut into the terrace and is filled with manure and locally derived gabbroic soil, a million cubic metres of which will be needed in total. The soil is then planted or seeded in order to create mixed forest and plant communities similar to those that exist in the surrounding area. An important part of the revegetation and stabilization of the slopes will involve hydro-seeding, whereby a mixture of pulped or mulched organic material, binding substance and seeds will be sprayed onto the slopes to provide a basis for seed germination and growth to form a protective layer against slope erosion. The fully reclaimed site will be used for recreation, tourism and environmental education.
