Asbestos is a naturally occurring material which has been used all over the world in a huge range of applications since its first discovery. Its chief physical properties are its durability and resistance to heat and combustion. It. is an extremely fibrous mineral and mining, milling, processing and use of asbestos and its products create many small fibres which can be either inhaled or ingested and can cause very serious health problems.

Asbestos has been used in industry since the 1880's. The link between asbestos exposure and asbestosis, or lung scarring, was firmly established by 1930, and repeatedly confirmed in many studies after that. As early as 1918, American and Canadian insurance companies were no longer insuring asbestos workers because of the assumed health hazards of the asbestos industry. In 1935, researchers in both the - United States and England reported a suspected association between asbestos exposure and lung cancer. By 1955 this association had been confirmed, and the link to several other types of cancer had been made as well.

However, the asbestos industry spent - and continues to spend - huge sums of money trying to play down the hazards of exposure to asbestos fibres and to fight off stricter legislation.

Typical industry defences of asbestos include statements that "only certain types of asbestos are bad" (blue asbestos is usually the one most often singled out); "only certain processes are dangerous" (such as spraying of asbestos); or that there are levels of exposure which are "safe".

Attempts to distinguish between -"more" and "less" hazardous types of asbestos are based on discredited science, and even single exposures to very low doses of fibres can result in harm.

"Asbestos fibres kill people very slowly. They may kill anybody who has, at any time, been exposed to asbestos dust and that, in today's environment, is almost everybody. Asbestos has killed a three-year-old who breathed dust from her father's work clothes; it has killed a weekend do-it-yourself builder who sawed asbestos sheet; it has killed a performing fire-eater who used asbestos wicks for his act. How many others with small or minimal exposures it has killed is anyone's guess, for when people die of cancer the cause of death is registered as 'cancer' and not what caused the cancer.

All workers need to be aware of the basic facts about asbestos if they are to be able to combat the industry propaganda and develop their own understanding of the hazards and how to fight them.

ASBESTOSIS: This is a disabling and often fatal scarring of the lungs; the main symptom is a shortness of breath, which gets progressively worse as more of the lung becomes scarred and useless. Asbestosis has a long "latency period"; typically the disease occurs from 10-20 years after initial exposure

LUNG CANCER: Painful and often fatal; workers who are exposed to asbestos and who also smoke face a very much, higher risk of lung cancer than other exposed workers. This is the major hazard in terms of numbers affected. Of all asbestos diseases, this is the greatest killer, even of people who have low levels of exposure to asbestos.

MESOTHELIOMA: A rapidly fatal and painful cancer of the lining of the lung (pleural mesothelioma) or abdomen (peritoneal mesothelioma) nearly always due to asbestos exposure. This disease is killing more relatively young workers. There is also a pericardial mesothelioma (in the area surrounding the heart), though there is less information about this type. Mesothelioma is not related to cigarette smoking.

OTHER CANCERS: Asbestos has been linked to many other cancer types, particularly cancer of the larynx and gastrointestinal tract (stomach, rectum, colon).

There is no cure for either mesothelioma or asbestosis. The victims usually feel no ill effects until they suddenly find themselves short of breath. The worst affected waste away and eventually die in an agonising choking spasm.

It is impossible to give a precise figure, but there can be no doubt that, globally, workers face a massive asbestos problem. Recent independent research commissioned by the UK Health and Safety Executive indicates that at least 150,000 people in the UK alone will die from asbestos-related diseases in the next 30 years. The UK is a country that has had strict controls on the use and removal of asbestos for years.

In the United States, there are some 10,000 deaths from asbestos-related diseases every year.

Asbestos occurs in a number of distinct types. The 5 major ones and their historical uses are:

1. Chrysotile (white asbestos) - more than 95% of the asbestos used in the world is chrysotile. Typical uses of chrysotile asbestos include asbestos-cement building products; asbestos-cement pressure, sewage and drainage pipes; fire-resistant insulation boards; insulation products more generally; jointings and packings; friction materials (such as car brake linings); textile products; floor tiles and sheets; moulded plastics and battery boxes; paper filter pads for wines and beers; as well as hundreds of other uses. Canada is one of the main producing countries.
2. Crocidolite (blue asbestos) - approximately 3% of the asbestos used in the world is crocidolite. Frequently used in shipbuilding because of its resistance to acids and sea water, and also mixed with chrysotile to accelerate the production of asbestos pressure pipes and sheeting.
3. Amosite (brown asbestos) - bonds well with plastics and used for floor tiles, fireproof boards in ships and for spraying insulation.
4. Anthophyllite - a talc-like form, used as an industrial talc and in paper processing, plastic products, asbestos cement pipes and friction materials.
5. Actinolite-Tremolite - found primarily as natural contaminates in other materials such as talc.

No. Every kind of asbestos can cause cancer, and every kind of asbestos can cause asbestosis - no matter whether it is white, blue, or brown asbestos. Attempts to distinguish between "more" or "less" hazardous types are based on discredited science.

The hazards of asbestos were known in the highly industrialised countries for decades before any meaningful action was taken to protect works. It was only as a direct results of trade union and public interest group campaigning and co-ordination that action was eventually taken.

Those working with asbestos have three times the chance of dying of cancer compared with those not working with asbestos - and the chances of getting lung cancer are eight times higher. Among asbestos insulation workers, 45% - almost half - die from some form of cancer.

The death rates are different for each particular kind of cancer. For lung cancer, death rates are eight times higher and the average survival time after diagnosis is only six to nine months; four out of five people with lung cancer will die within a year after they find out. Cancer of the stomach, colon and rectum is three times as common a cause of death for asbestos workers as for other people. Mesothelioma is normally an extremely rare kind of cancer and cases of this kind can almost always be traced back to some sort of asbestos exposure. In some studies of asbestos workers, more than 10% of the deaths have been attributed to mesothelioma.

Asbestos can cause cancers in workers whether or not they smoke. But the chance of getting lung cancer from asbestos exposure is increased more than ten times if the worker also smokes.

Yes. If fibres are brought into the home on working clothes, in hair, in a lunchbox - this poses a risk for a worker's family. In one study, a third of asbestos workers' family members had abnormal chest x-rays from scarring and thickening of the chest lining thirty years after their exposure at home. Cases of mesothelioma are known to have occurred after as little as one month's contact with a family member carrying asbestos fibres home with them.

The mining and processing of asbestos and its use in manufactured products constitute a billion-dollar industry. Canada is a major producer. Historically, defenders of asbestos have cited its heat, friction and acid resistant properties. In reality, most asbestos is used as a cheap reinforcement agent. 70% of asbestos is used for reinforcing asbestos cement in construction projects. The short answer is that asbestos is used in those countries and in those circumstances where there has been least resistance to its use.

Work on the principle that there is no "safe" level when it comes to exposure to asbestos. Asbestos substitutes should, therefore, always be used where possible.

• Ensure that you and your colleagues are fully aware of the dangers of asbestos, informed about its presence - at work and elsewhere.

• Avoid working with asbestos wherever possible and demand the right to stop work in unsafe conditions. In the event that working with asbestos is unavoidable, ensure that the fullest possible precautions are taken.

• Assess the nature and degree of exposure to asbestos dust. Asbestos which is sealed and not in a position where it can be broken, worked or abraded may sometimes be better left where it is - though it should be regularly monitored and, of course, it will eventually have to be removed as and when the building in which it is contained is renovated or demolished, or the product containing it is disturbed or destroyed.

• Ensure that workers in areas adjacent to those containing asbestos - or where asbestos is used or handled - are not affected by any work on the asbestos. This requires proper engineering, enclosure and decontamination procedures to ensure that fibres do not get out of the immediate area containing the asbestos

• Ensure that those most likely to be exposed to asbestos - such as asbestos removal workers or those involved in cleaning operations where exposure to asbestos fibres is a hazard - are properly protected. Airborne asbestos fibre levels can exceed 100 fibres/ml when dry methods of asbestos removal are used (as a general principle, asbestos should be removed using the 'wet' process in order to keep dust to a minimum). Only with the use of specialised respiratory protective equipment can asbestos removal workers working in contaminated environments be protected. Such protective equipment is designed to keep workers' exposure levels well below 1 fibre/ml.

• Ensure that work processes are so designed as to avoid the release of asbestos dust into the air and, where this is not possible, that the dust is eliminated as near as possible to the point where it is released.

• Ensure that asbestos waste is collected and removed from the place of work as soon as possible in suitable sealed packing, labelled as containing asbestos.