EXPOSURE TO ASBESTOS CIGARETTE SMOKING

1. EXPOSURE TO ASBESTOS & CIGARETTE SMOKING A SYNERGIC EFFECT By: Beth Higgins

2. CASE STUDY 2 employees (Peter �Puffy� & Bob) work at an Asbestos Insulation Manufacturing Plant in Quebec. They both have been working at the facility since they were 18. Every break Puffy would go out for a smoke. Bob was a non-smoker. Controls at the plant were minimal. No respirators were worn. Puffy and Bob stopped working at the plant when it shut down in 1978. 10 Yrs after stopped working Puffy developed Asbestosis and Lung Cancer. He died 2yrs later in 1990. Bob had the same exposure to asbestos fibres, was of similar build, and age. The only difference was in lifestyle � Puffy was a smoker. 1955 started at company Did the same job at the plant (worked the same line) Synergism of these 2 contaminants played a role in Bill dying of asbestosis and Bob not. Worked for 23 yrs at plant Plant shut down where they were 41 1955 started at company Did the same job at the plant (worked the same line) Synergism of these 2 contaminants played a role in Bill dying of asbestosis and Bob not. Worked for 23 yrs at plant Plant shut down where they were 41

3. DEFINATION OF SYNERGISM The situation in which the combined effects on a biologic system of 2 chemicals acting simultaneously is greater than the algebraic sum of the individual effects of these chemicals. 2 + 3 = 20

4. ASBESTOS BACKGROUND INFO Asbestos is the name given to a group of 6 different fibrous minerals that occur naturally in the environment. Amosite Chrysotile Crocidolite Tremolite Actinolite anthophyllite -All forms of asbestos are hazardous and all can cause cancer. Asbestos minerals consist of thin, separable fibres that have a parallel arrangement. The fibers are strong and flexible enough to be spun & woven & are heat resistant. Due to characteristics � asbestos has been used for a wide range of manufactured goods, mostly in building materials. Stopped production???? Chrysotile (white asbestos) is the most common form of asbestos. Used at Bill and Bob�s plant.-All forms of asbestos are hazardous and all can cause cancer. Asbestos minerals consist of thin, separable fibres that have a parallel arrangement. The fibers are strong and flexible enough to be spun & woven & are heat resistant. Due to characteristics � asbestos has been used for a wide range of manufactured goods, mostly in building materials. Stopped production???? Chrysotile (white asbestos) is the most common form of asbestos. Used at Bill and Bob�s plant.

5. You are most likely to be exposed to asbestos by breathing in asbestos fibres that are suspended in air. You can also be exposed to asbestos by drinking asbestos fibres that are present in water. Because ingested asbestos fibres are poorly absorbed, the tissue most highly exposed to ingested asbestos is the GI tract epithelium. GENERAL INFORMATION ON ROUTES OF EXPOSURE - How a substance enters the body determines how much of it enters, and which organs are exposed to the largest concentration. For example, the amount of chemical that is orally toxic, may not be toxic when applied to the skin, or visa versa. INHALATION: This is the most common route of entry into the body. i.e./ any form of contaminant (dust/mist/fume/gas/vapour) can enter into the body through normal breathing (inhalation). INGESTION: If personal hygiene practices are not good such as washing hands before eating, then harmful substances can pass from the hands, to your food, and ultimately to your stomach through ingestion i.e. / metal dust, wood dust, oil mist ABSORBTION THROUGH THE SKIN: Many solvents can be absorbed through the skin, or eyes. i.e. / varsol, toluene PUNCTURE: needles, metal slivers, wood slivers If you breathe asbestos fibres into your lungs, some of the fibres will be deposited in the air passages & on the cells that make up your lungs. Most fibres are removed from your lungs by being carried away or coughed up in a layer of mucus to the throat, where they are swallowed into the stomach. This usually takes place within a few hours. Fibres that are deposited in the deepest parts of the lung are removed more slowly. Some fibres may move through your lungs and can remain in place for many years and never be removed from your body. If you swallow asbestos fibres (water or fibres that are moved to your throat from your lungs) nearly all of the fibres pass along your intestines within a few days and are excreted in the feces. A small # of fibres may penetrate into cells that line your stomach or intestines, and a few penetrate all the way through & get into your blood. Some these become trapped in other tissues, and some are removed in your urine. If you get asbestos fibres on your skin, very few of these fibres, if any, pass through the skin into your body. Epidemiology studies of asbestos-exposed workers & supporting animal studies indicate that inhalation of asbestos is the principal route of exposure. Some studies have also indicated that oral exposure may be linked to the development of gastrointestinal cancer. You are most likely to be exposed to asbestos by breathing in asbestos fibres that are suspended in air. You can also be exposed to asbestos by drinking asbestos fibres that are present in water. Because ingested asbestos fibres are poorly absorbed, the tissue most highly exposed to ingested asbestos is the GI tract epithelium. GENERAL INFORMATION ON ROUTES OF EXPOSURE - How a substance enters the body determines how much of it enters, and which organs are exposed to the largest concentration. For example, the amount of chemical that is orally toxic, may not be toxic when applied to the skin, or visa versa. INHALATION: This is the most common route of entry into the body. i.e./ any form of contaminant (dust/mist/fume/gas/vapour) can enter into the body through normal breathing (inhalation). INGESTION: If personal hygiene practices are not good such as washing hands before eating, then harmful substances can pass from the hands, to your food, and ultimately to your stomach through ingestion i.e. / metal dust, wood dust, oil mist ABSORBTION THROUGH THE SKIN: Many solvents can be absorbed through the skin, or eyes. i.e. / varsol, toluene PUNCTURE: needles, metal slivers, wood slivers If you breathe asbestos fibres into your lungs, some of the fibres will be deposited in the air passages & on the cells that make up your lungs. Most fibres are removed from your lungs by being carried away or coughed up in a layer of mucus to the throat, where they are swallowed into the stomach. This usually takes place within a few hours. Fibres that are deposited in the deepest parts of the lung are removed more slowly. Some fibres may move through your lungs and can remain in place for many years and never be removed from your body. If you swallow asbestos fibres (water or fibres that are moved to your throat from your lungs) nearly all of the fibres pass along your intestines within a few days and are excreted in the feces. A small # of fibres may penetrate into cells that line your stomach or intestines, and a few penetrate all the way through & get into your blood. Some these become trapped in other tissues, and some are removed in your urine. If you get asbestos fibres on your skin, very few of these fibres, if any, pass through the skin into your body. Epidemiology studies of asbestos-exposed workers & supporting animal studies indicate that inhalation of asbestos is the principal route of exposure. Some studies have also indicated that oral exposure may be linked to the development of gastrointestinal cancer.

6. The structure of the lung is simple � consisting of 2 structures: the bronchial tubes & air sacs or alveoli. The bronchi are a system of branching tubes that serve as air conduits leading to fresh air deep into the structure of the lungs & serving as pathways to eliminate air from which oxygen has been removed. The environmental air is brought into intimate contact with a very large alveolar-surface area, the potential for damage is great if the air contains toxic material. 3 main regions 1) nose to vocal cords (upper air passage); 2) vocal cords to Bronchial (mid air passage); 3) alveolarThe structure of the lung is simple � consisting of 2 structures: the bronchial tubes & air sacs or alveoli. The bronchi are a system of branching tubes that serve as air conduits leading to fresh air deep into the structure of the lungs & serving as pathways to eliminate air from which oxygen has been removed. The environmental air is brought into intimate contact with a very large alveolar-surface area, the potential for damage is great if the air contains toxic material. 3 main regions 1) nose to vocal cords (upper air passage); 2) vocal cords to Bronchial (mid air passage); 3) alveolar

7. Depending largely on size & shape, deposition of inhaled asbestos fibres may occur in lung tissue. Some fibres may be removed by mucoiliary clearance or macrophages while others may be retained in the lungs for extended periods. Inhalation exposure is regarded as cumulative & exposures have been expressed in terms of concentration of fibres over time. THE BODY�S FIRST LINE OF DEFENSE AGAINST AIRBORNE PARTICULATES- (A.K.A. -MUCOCILIARY MECHANISIM): Particles >10um in size enter into the nose and are trapped by your nose hairs. Particles <10um in size travel further into your respiratory tract. The smaller the particle size the further into the respiratory tract they will travel before deposition.). Particles <10um in size enter and land on the cilia, or mucous which lines the respiratory tract and becomes trapped. Thousands of cilia beat rhythmically some several hundred times a second towards the airway opening. The cilia is what causes the mucus to continuously flow upward. The major direction of force, or flow is always toward the airway opening (mouth, nose). There, the mucus and particulate substances are either swallowed or coughed from the body. This mucociliary mechanism is the respiratory systems first line of defense against a potentially hostile environment. Very small particles travel farther into the lungs (alveoli) and must rely on another one of the body�s defenses to clear them from the respiratory tract. THE HUMAN BODY HAS FOUR BUILT IN DEFENSES AGAINST AIRBORNE PARTICULATES: Coarse Hairs: Hair inside the nose trap large dust particles as soon as they are inhaled. Cilia: Tiny hairs called cilia, line the respiratory tract and move up and down rapidly to force mucus and trapped particles up the throat to the mouth. The particles and mucus are either swallowed or coughed from the body. Mucus: The respiratory tract is lined with a thin film of mucus which traps some of the smaller particles that pass by the nose hairs Reflexes: Coughing, clearing the throat, and sneezing rids the throat, mouth, and nose of mucous and particles The respiratory system protects the body from many airborne particles by the defenses mentioned above, but at high exposure levels to which the workers are not protected, the contaminants can overwhelm the bodies defenses. Depending largely on size & shape, deposition of inhaled asbestos fibres may occur in lung tissue. Some fibres may be removed by mucoiliary clearance or macrophages while others may be retained in the lungs for extended periods. Inhalation exposure is regarded as cumulative & exposures have been expressed in terms of concentration of fibres over time. THE BODY�S FIRST LINE OF DEFENSE AGAINST AIRBORNE PARTICULATES- (A.K.A. -MUCOCILIARY MECHANISIM): Particles >10um in size enter into the nose and are trapped by your nose hairs. Particles <10um in size travel further into your respiratory tract. The smaller the particle size the further into the respiratory tract they will travel before deposition.). Particles <10um in size enter and land on the cilia, or mucous which lines the respiratory tract and becomes trapped. Thousands of cilia beat rhythmically some several hundred times a second towards the airway opening. The cilia is what causes the mucus to continuously flow upward. The major direction of force, or flow is always toward the airway opening (mouth, nose). There, the mucus and particulate substances are either swallowed or coughed from the body. This mucociliary mechanism is the respiratory systems first line of defense against a potentially hostile environment. Very small particles travel farther into the lungs (alveoli) and must rely on another one of the body�s defenses to clear them from the respiratory tract. THE HUMAN BODY HAS FOUR BUILT IN DEFENSES AGAINST AIRBORNE PARTICULATES: Coarse Hairs: Hair inside the nose trap large dust particles as soon as they are inhaled. Cilia: Tiny hairs called cilia, line the respiratory tract and move up and down rapidly to force mucus and trapped particles up the throat to the mouth. The particles and mucus are either swallowed or coughed from the body. Mucus: The respiratory tract is lined with a thin film of mucus which traps some of the smaller particles that pass by the nose hairs Reflexes: Coughing, clearing the throat, and sneezing rids the throat, mouth, and nose of mucous and particles The respiratory system protects the body from many airborne particles by the defenses mentioned above, but at high exposure levels to which the workers are not protected, the contaminants can overwhelm the bodies defenses.

8. CIGARETTE SMOKING Interferes with Cilia function (Paralyzes) Normal mucus secretion (increases) Normal function of alveolar macrophages The mucociliary mechanism is sensitive to a # of substances & diseases, & can be rendered partially or even totally ineffective. One or more of the 2000 chemicals in cigarette smoke can paralyze the cilia over the entire tracheobronchial system & stop the flow of blanket of mucus. Studies have shown that 1 puff of cigarette smoke is sufficient to paralyze the cilia for as much as 20 to 40 min. This eliminates 1 of the lung�s major defense mechanisms & is quite probably one of the major factors leading to lower respiratory tract infections & possibly to the development of chronic bronchitis. Other substances are irritants in response the mucous glands produce & secrete more mucus in an attempt to wash away the irritant. The combination of the cessation of mucus flow & the increase production of mucus leads to an increase in intraluminal mucus, with partial or total blockage of smaller bronchi. Decrease in airway caliber & increase in resistance to air flow through bronchi. If a substance such as smoke or asbestos fibres is ingested by the macrophages & injuries & eventually destroys the macrophage, the chemicals within the macrophage are released into the environment of the alveolus & damage the delicate lining layer. The damage is repaired by formation of scar tissue. If the damage is extensive the result is a significant amount of scar tissue, lung function is severely altered.The mucociliary mechanism is sensitive to a # of substances & diseases, & can be rendered partially or even totally ineffective. One or more of the 2000 chemicals in cigarette smoke can paralyze the cilia over the entire tracheobronchial system & stop the flow of blanket of mucus. Studies have shown that 1 puff of cigarette smoke is sufficient to paralyze the cilia for as much as 20 to 40 min. This eliminates 1 of the lung�s major defense mechanisms & is quite probably one of the major factors leading to lower respiratory tract infections & possibly to the development of chronic bronchitis. Other substances are irritants in response the mucous glands produce & secrete more mucus in an attempt to wash away the irritant. The combination of the cessation of mucus flow & the increase production of mucus leads to an increase in intraluminal mucus, with partial or total blockage of smaller bronchi. Decrease in airway caliber & increase in resistance to air flow through bronchi. If a substance such as smoke or asbestos fibres is ingested by the macrophages & injuries & eventually destroys the macrophage, the chemicals within the macrophage are released into the environment of the alveolus & damage the delicate lining layer. The damage is repaired by formation of scar tissue. If the damage is extensive the result is a significant amount of scar tissue, lung function is severely altered.

9. INHALATION There are over 4000 chemical agents in cigarette smoke, including over 60 carcinogens These substances are irritants to the delicate lining of the tracheobronchial tree & respiratory passages. Inhalation of cigarette smoke may lead to: Chronic bronchitis Pulmonary emphysema Bronchogenic carcinoma (lung cancer)

10. INHALATION Studies in animals & humans indicate that inhalation of asbestos fibres may lead to: Asbestosis (fibrotic lung disease) Pleural plagues & thickening Cancer of the lung, pleura, & peritoneum May increase cancer at other sites (evidence not strong) Can lead to death or a shortened lifespan from asbestosis or cancer Another tissue that may be affected in humans exposed to asbestos in air is the pleura. The most common effect is the formation of thickened fibrous areas called plaques, thickening may also occur. An increased incidence of pleural plaques has been noted at relatively low cumulative exposures 0.12 f-yr/mL. Localized p.p are not thought to of signif. Health concern, although pleural thickening & pleural plaques are associated with impairment of respiratory function. Significant effects on other tissues have not been detected. Researches have found that the occurrence of asbestosis & lung cancer correlates with cumulative exposure.Another tissue that may be affected in humans exposed to asbestos in air is the pleura. The most common effect is the formation of thickened fibrous areas called plaques, thickening may also occur. An increased incidence of pleural plaques has been noted at relatively low cumulative exposures 0.12 f-yr/mL. Localized p.p are not thought to of signif. Health concern, although pleural thickening & pleural plaques are associated with impairment of respiratory function. Significant effects on other tissues have not been detected. Researches have found that the occurrence of asbestosis & lung cancer correlates with cumulative exposure.

11. ASBESTOSIS Workers who repeatedly breath in asbestos fibres may develop a slow buildup of scar-like tissue in the lungs and surrounding membrane. The scar-like tissue doesn�t expand & contract like normal lung tissue � breathing becomes difficult. Blood flow to the lung may decrease � causes heart to enlarge. People with the disease have a shortness of breath & a cough. Breathing high levels of asbestos fibres for a long time may result in scar-like tissue in the lungs & in the pleural membrane (lining) that surrounds the lung. Asbestos fibres > or equal to 5 um in length This is a serious disease & can eventually lead to a disability or death in people exposed to high amounts of asbestos over a long period (Like Bill) Changes in the membrane surrounding the lung � pleural plaques are common in people occupationally exposed to asbestos ASBESTOSIS- Particles and fibers of asbestos stick to and damage the sides of the tiny tubes that carry oxygen to the air sacs inside the lungs. Scar tissue develops around these particles and prevents oxygen from getting into the bloodstream. Workers handling asbestos also develop a form of cancer called mesothelioma, a cancer of the chest cavity lining. Deposition of asbestos fibres in the lungs can lead to substantial non-neoplastic fibrotic injury & may even cause death. Asbestosis results from a prolonged inflammatory response stimulated by the presence of fibres in the lungs. Alveolar macrophages, which normally phagocytize foreign bodies deposited in the lungs, engulf the asbestos fibres & remove them. Short fibres can be cleared this way, long fibres can�t be removed & this results in an ongoing focal inflammatory response. With time, some fibres move from the lung to the interstitium where additional inflammatory events take place leading to the development of interstitial pulmonary fibrosis & a progressive loss of lung compliance & respiratory function. Breathing high levels of asbestos fibres for a long time may result in scar-like tissue in the lungs & in the pleural membrane (lining) that surrounds the lung. Asbestos fibres > or equal to 5 um in length This is a serious disease & can eventually lead to a disability or death in people exposed to high amounts of asbestos over a long period (Like Bill) Changes in the membrane surrounding the lung � pleural plaques are common in people occupationally exposed to asbestos ASBESTOSIS- Particles and fibers of asbestos stick to and damage the sides of the tiny tubes that carry oxygen to the air sacs inside the lungs. Scar tissue develops around these particles and prevents oxygen from getting into the bloodstream. Workers handling asbestos also develop a form of cancer called mesothelioma, a cancer of the chest cavity lining. Deposition of asbestos fibres in the lungs can lead to substantial non-neoplastic fibrotic injury & may even cause death. Asbestosis results from a prolonged inflammatory response stimulated by the presence of fibres in the lungs. Alveolar macrophages, which normally phagocytize foreign bodies deposited in the lungs, engulf the asbestos fibres & remove them. Short fibres can be cleared this way, long fibres can�t be removed & this results in an ongoing focal inflammatory response. With time, some fibres move from the lung to the interstitium where additional inflammatory events take place leading to the development of interstitial pulmonary fibrosis & a progressive loss of lung compliance & respiratory function.

12. Studies in humans & animals indicate that inhalation exposure to asbestos fibres may lead to the development of pulmonary disease including asbestosis &/or lung cancer & mesothelioma of the pleura or peritoneum. Asbestos workers have increased chance of getting 2 types of cancer These disease don�t develop immediately following exposure to asbestos, but appear only after a # of years. CHRONIC (LONG TERM) RESPONSE: Not all contaminants bring on an acute, or immediate response and that is why so many workers may not know that they are breathing in harmful particulates. Signs of illness and disease will appear over a period of time. This slow reaction to breathing toxic particles is called a chronic response. It may take years of exposure to a particular contaminant before some people show a chronic response. Lung cancer is usually fatal while mesothelioma is almost always fatal � often within a few months of diagnosis. Asbestos-related lung diseases or signs of these diseases have been reported in groups of occupationally exposed humans with cumulative exposures ranging from about 5 to 1,200 fibres-years/mL. Such cumulative exposures would result from 40 yrs of occupational exposure to concentrations ranging from 0.125 to 30 f/mL. Asbestos exposure is also suspected of increasing the risk of cancer in the GI tract & laryngeal cancer, although the evidence is less consistent than for lung cancer or mesothelioma. Studies in humans & animals indicate that inhalation exposure to asbestos fibres may lead to the development of pulmonary disease including asbestosis &/or lung cancer & mesothelioma of the pleura or peritoneum. Asbestos workers have increased chance of getting 2 types of cancer These disease don�t develop immediately following exposure to asbestos, but appear only after a # of years. CHRONIC (LONG TERM) RESPONSE: Not all contaminants bring on an acute, or immediate response and that is why so many workers may not know that they are breathing in harmful particulates. Signs of illness and disease will appear over a period of time. This slow reaction to breathing toxic particles is called a chronic response. It may take years of exposure to a particular contaminant before some people show a chronic response. Lung cancer is usually fatal while mesothelioma is almost always fatal � often within a few months of diagnosis. Asbestos-related lung diseases or signs of these diseases have been reported in groups of occupationally exposed humans with cumulative exposures ranging from about 5 to 1,200 fibres-years/mL. Such cumulative exposures would result from 40 yrs of occupational exposure to concentrations ranging from 0.125 to 30 f/mL. Asbestos exposure is also suspected of increasing the risk of cancer in the GI tract & laryngeal cancer, although the evidence is less consistent than for lung cancer or mesothelioma.

13. POTENTIAL OF HAVING A LUNG DISEASE The levels of asbestos in air that may lead to lung disease depend on several factors: How long you were exposed How long it has been since your exposure occurred The age at which exposure occurred Whether you smoked cigarettes Fibre type and size Amphibole asbestos types may be more harmful than chrysotile Fibres greater than 5.0�m are more likely to cause injury than fibres with lengths less than 2.5�m. There is no doubt that inhalation of asbestos can lead to increased risk of lung cancer & mesothelioma. Conclusively demonstrated in #s studies of occupationally exposed workers and confirmed in a # of animal experiments. Bill and Bob were exposed for It has been yrs since exposure begun Bill smoked; Bob didn�t Cigarette smoking and asbestos exposure together significantly increase your chances of getting lung cancer. All asbestos fibre types are fibrogenic � there may be some differences in potency among fibre types. Smoking combined with asbestos exposure doesn�t appear to increase the risk of mesothelioma. Scientific debate concerning the difference in the extent of disease caused by diff. fibre types & sizes. Some of these differences may be due to the physical & chemical properties of the diff. fibre types. E.g.. There have been studies that suggest that amphibole asbestos types (tremolite, amosite, crocidolite may be more harmful than chrysotile particularly for mesothelioma. Other data indicate that fibre size dimensions (length & thickness) are impt. Factors for cancer-causing potential. Some data indicate that fibers with length > 5.0 um are more likely to cause injury than fibres with lengths < than 2.5 um. There is strong evidence from animal inhalation studies, intrathoracic & intraperitoneal dosing studies, & in vitro studies that long fibres are more carcinogenic than short fibers. This relationship may be associated with the inability of macrophages to engulf & remove fibres that are significantly larger than themselves. Results from human studies have suggested that short fibres also play a role in pulmonary fibrosis. Some researches believe that long fibres may initiate events & shorter fibres once present may have increased effects on macrophage activity & subsequent fibrosis.There is no doubt that inhalation of asbestos can lead to increased risk of lung cancer & mesothelioma. Conclusively demonstrated in #s studies of occupationally exposed workers and confirmed in a # of animal experiments. Bill and Bob were exposed for It has been yrs since exposure begun Bill smoked; Bob didn�t Cigarette smoking and asbestos exposure together significantly increase your chances of getting lung cancer. All asbestos fibre types are fibrogenic � there may be some differences in potency among fibre types. Smoking combined with asbestos exposure doesn�t appear to increase the risk of mesothelioma. Scientific debate concerning the difference in the extent of disease caused by diff. fibre types & sizes. Some of these differences may be due to the physical & chemical properties of the diff. fibre types. E.g.. There have been studies that suggest that amphibole asbestos types (tremolite, amosite, crocidolite may be more harmful than chrysotile particularly for mesothelioma. Other data indicate that fibre size dimensions (length & thickness) are impt. Factors for cancer-causing potential. Some data indicate that fibers with length > 5.0 um are more likely to cause injury than fibres with lengths < than 2.5 um. There is strong evidence from animal inhalation studies, intrathoracic & intraperitoneal dosing studies, & in vitro studies that long fibres are more carcinogenic than short fibers. This relationship may be associated with the inability of macrophages to engulf & remove fibres that are significantly larger than themselves. Results from human studies have suggested that short fibres also play a role in pulmonary fibrosis. Some researches believe that long fibres may initiate events & shorter fibres once present may have increased effects on macrophage activity & subsequent fibrosis.

14. POTENTIAL OF HAVING A LUNG DISEASE Other data indicates that short fibres can contribute to injury. Fibres thicker than 3.0�m are of lesser concern, little chance of penetrating to the lower regions of the lung. Other data indicates that short fibres can contribute to injury � appears true for mesothelioma, lung cancer, & asbestosis. The relationship between fibre size & carcinogenicity may vary betwn lung cancer & mesothelioma, but this is not yet clear. Asbestos-induced respiratory disease can take a long time (10-20yr) to develop & in some workers continue to progress long after the exposure has ceased. Asbestos is a known human carcinogen. Most studies in humans have involved exposure to chrysotile � most widely used type of asbestos.Other data indicates that short fibres can contribute to injury � appears true for mesothelioma, lung cancer, & asbestosis. The relationship between fibre size & carcinogenicity may vary betwn lung cancer & mesothelioma, but this is not yet clear. Asbestos-induced respiratory disease can take a long time (10-20yr) to develop & in some workers continue to progress long after the exposure has ceased. Asbestos is a known human carcinogen. Most studies in humans have involved exposure to chrysotile � most widely used type of asbestos.

15. POTENTIAL OF DEVELOPING LUNG CANCER A person�s change of developing lung cancer is Increased 5x when there has been asbestos exposure & does not smoke cigarettes Increased 10x if a person smokes cigarettes & not exposed to asbestos dust Increased 50-90x when there is asbestos exposure & cigarette smoking combined There is evidence that quitting smoking will reduce the risk of lung cancer among people who have been exposed to asbestos dust, by a much as half after at least 5 years w/o smoking. Smoking does not increase the risk for developing mesothelioma. Smoking weakens the lungs contributing to the negative health effects of asbestos exposure. Smoking alone can cause lung cancer. Asbestos can cause lung cancer. Taken together, asbestos & smoking multiply the risk of lung cancer significantly (a synergistic effect). Studies in the science of epidemiology confirm that the combination of smoking & asbestos exposure creates a risk of cancer much higher than just adding the risks together. Latency is about 20 to 30 years 7 out of 10 were smokers or former smokers (average exposure of 27 years) There is evidence that quitting smoking will reduce the risk of lung cancer among people who have been exposed to asbestos dust, by a much as half after at least 5 years w/o smoking. Smoking does not increase the risk for developing mesothelioma. Smoking weakens the lungs contributing to the negative health effects of asbestos exposure. Smoking alone can cause lung cancer. Asbestos can cause lung cancer. Taken together, asbestos & smoking multiply the risk of lung cancer significantly (a synergistic effect). Studies in the science of epidemiology confirm that the combination of smoking & asbestos exposure creates a risk of cancer much higher than just adding the risks together. Latency is about 20 to 30 years 7 out of 10 were smokers or former smokers (average exposure of 27 years)

16. THANK YOU!!! If you are exposed to asbestos, many factors determine if you�ll be harmed. These factors include the dose (how much), the duration (how long), the fibre type (mineral form and size distribution), and how you come in contact with it. You must also consider the other chemicals you�re exposed to and your age, sex, diet, family traits, lifestyle (including whether you smoke tobacco), and state of health. Asbestos diseases follow a dose-response relationship curve. This means the more asbestos you inhale (dose) the greater the risk of contracting an asbestos � related disease. Smoking harms nearly every major organ of the body (2). The risk of developing smoking-related diseases, such as lung and other cancers, heart disease, stroke, and respiratory illnesses, increases with total lifetime exposure to cigarette smoke (7). This includes the number of cigarettes a person smokes each day, the intensity of smoking (i.e., the size and frequency of puffs), the age at which smoking began, the number of years a person has smoked, and a smoker�s secondhand smoke exposure. If you are exposed to asbestos, many factors determine if you�ll be harmed. These factors include the dose (how much), the duration (how long), the fibre type (mineral form and size distribution), and how you come in contact with it. You must also consider the other chemicals you�re exposed to and your age, sex, diet, family traits, lifestyle (including whether you smoke tobacco), and state of health. Asbestos diseases follow a dose-response relationship curve. This means the more asbestos you inhale (dose) the greater the risk of contracting an asbestos � related disease. Smoking harms nearly every major organ of the body (2). The risk of developing smoking-related diseases, such as lung and other cancers, heart disease, stroke, and respiratory illnesses, increases with total lifetime exposure to cigarette smoke (7). This includes the number of cigarettes a person smokes each day, the intensity of smoking (i.e., the size and frequency of puffs), the age at which smoking began, the number of years a person has smoked, and a smoker�s secondhand smoke exposure.