Air Toxics Under the Big Sky A University of Montana Center for Environmental Health Sciences Education Outreach Project Lesson Two

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1 Lesson Title: Air Quality and Respiratory Health Subjects Addressed: Science, Health Air Toxics Under the Big Sky A University of Montana Center for Environmental Health Sciences Education Outreach Project Lesson Two Grade Level: High School Class Time: 1-2 class periods Lesson Developed By: Andrij Holian, Ph.D., CEHS Director/Respiratory Toxicologist Inquiry-Based Lesson (Inquiry category that best describes the level of this lesson is highlighted) Guided Inquiry Challenge Inquiry Free Inquiry Teacher provides some Teacher provides question, Students choose questions questions and/or instructions students design and implement and design and implement for investigation. experiments. experiments. Identify the Lesson s Core Understanding (Describe importance of lesson - helps maintain focus): In order to get a complete understanding of environmental issues, it is imperative to experience exposure to as many facets of the subject as possible; in this case, human health. Lesson Summary (A quick recap): Students learn the history and the importance of studying air pollution via a PowerPoint presentation and discussion. Objectives (By the end of this lesson, students should be able to ): Describe how two important catastrophic air quality events led to the study of air quality as it relates to human health. Explain how pollution exacerbates respiratory ailments. Inclusion of American Indian Content (The ways in which this lesson addresses any of the Seven Essential Understandings): American Indian and Alaska Native adults have the highest asthma rate among single-race groups, according to data released in Based on a 2002 survey, 11.6 percent of Native Americans said they suffered from asthma. This was significantly higher than the national average of 7.5 percent, and much higher than every other single racial or ethnic group. IEFA standard 3 - Students demonstrate knowledge of characteristics, structures and function of living things, the process and diversity of life, and how living organisms interact with each other and their environment. Aligning with Standards (Cite Montana Content and Performance Standards): Health Standard 5 Students demonstrate the ability to use critical thinking and decision making to enhance health. Science Standard 2 Students demonstrate knowledge of properties, forms, changes and interactions of physical and chemical systems, and demonstrate thinking skills associated with this knowledge.

2 Preparing for the Lesson Materials/Incorporation of Technology: PowerPoint Presentation: Air Quality and Respiratory Health Student Note Taking Sheet: Air Quality and Respiratory Health Thin Coffee-Stirrer Straws (one per student) Article: Donora, Pennsylvania Air Pollution Disaster of 1948 (extension activity) Article: The London Smog Disaster of 1952 (extension activity) Student Handout: What is Asthma Video: The Donora Smog WQED (extension activity) Video: Donora Smog Weather Channel (extension activity) Vocabulary: Catastrophic - a momentous tragic event Epidemiology - the study of populations to determine the frequency and distribution of disease and measure risk Hazardous - involving or exposing one to risk (as of loss or harm) Temperature inversion - an atmospheric condition that is upside down from the normal situation. Instead of warm air being near the ground with cooler air above it, cold air is trapped near the ground capped by a blanket of warm air. Adaptations for Exceptionalities (Instructional strategies and activities aligned with various learning styles and diversity of student population): The included PowerPoint presentation can be made available for student review. Resources: Implementing the Lesson Anticipatory Set (The hook that sets the stage and is directly related to the learning at hand): 1. Give each student a coffee-stirrer straw. Ask them to place the straws in their mouths and breathe only through the straw for 20 seconds. Instruct students not to breathe through their nose. (This may be difficult for some students, so encourage them to stop if necessary.) 2. Discuss what this activity illustrates. (It simulates what breathing can feel like for someone with chronic lung disease.) 3. Our previous lesson focused on particulate matter, particularly respirable particles that come from manmade and natural sources, both indoors and out. PM can come from wildland fires, wood stove and fireplace emissions, volcanoes, road dust, burning candles, cigarette smoke, or from microwaving popcorn. Today we re going to focus on the history of why we even became concerned with PM in the first place and the impact it has on human health and physiology.

3 Introduction (Performance standards are clearly communicated: students should be able to articulate the academic expectations and what is required to be proficient): In today s lesson, you will be expected to garner information pertaining to the history of air quality research and how that research has helped us understand health effects. Body of Lesson (The use of effective and varied instructional strategies to convey the lesson s core understanding): USE THE INCLUDED POWERPOINT PRESENTATION TO PROVIDE AN OVERVIEW OF AIR QUALITY AND RESPIRATORY HEALTH. (THE CLASSROOM TEACHER CAN OPT TO HAVE STUDENTS TAKE NOTES USING THE PROVIDED STUDENT NOTE TAKING SHEET.) Although poor air quality has been noted since Roman times, it took two major catastrophic air quality events to bring to attention the correlation between air quality and human health to provide the impetus for studying particulate matter Consequently, the link between various illnesses and air pollution has become much clearer as a result of ensuing epidemiological studies. DONORA a small industrial town located in the Monongahela River Valley of Pennsylvania experienced the worst air pollution disaster in U.S. history (Oct 26-31, 1948) pollution came from a combination of sources: the zinc smelting plant, steel mills' open hearth furnaces, a sulfuric acid plant, a slag dump, and coal burning steam locomotives and river boats sulfur, carbon monoxide and heavy metal dusts were trapped by a temperature inversion 20 people were asphyxiated and died, while over 7,000 were hospitalized or became ill LONDON the worst air pollution disaster on record (Dec 5-10, 1952) the weather had been considerably colder than usual for weeks. As a result the people of London were burning large amounts of coal and smoke which bellowed from their chimneys pollution came from thousands of tons of black soot (sticky particles of tar and gaseous sulfur dioxide) that combined with the fog to form acid aerosol all of which was trapped by a temperature inversion 4,000 12,000 deaths were attributed to this fog event nobody realized what was happening until it was noticed that the undertakers were running out of coffins and the florists were running out of flowers To move students along the inquiry continuum, pause at slide 7 of the PowerPoint presentation. Use the instructions in the notes section (also located on the student note taking sheets) to conduct a short data analysis activity. Have students use the data from the graph to calculate a) the average number of deaths per day b) the average smoke concentration (in micrograms/cubic meter) and c) the average sulfur dioxide concentration (in micrograms/cubic meter) for the dates December 1-4. Epidemiological investigations began helping us learn that exposure to environmental or occupational pollutants occur through three mechanisms: inhalation, dermal, and ingestion. Air pollution can affect our health in many ways with both short-term and long-term effects. Examples of short-term effects include irritation to the eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia. Other symptoms can include headaches, nausea, and allergic reactions. Short-term air pollution can aggravate the medical conditions of individuals with asthma and emphysema. Long-term health effects can include chronic respiratory disease, lung cancer, heart disease, and even damage to the brain, nerves, liver, or kidneys.

4 Body of Lesson (Continued): Different groups of individuals are affected by air pollution in different ways. Some individuals are much more sensitive to pollutants than are others. Young children and elderly people often suffer more from the effects of air pollution. People with health problems such as asthma, heart and lung disease may also suffer more when the air is polluted. The Air Toxics Under the program focuses on particulate matter, one of the Environmental Protection Agency s (EPA s) six criteria pollutants (nitrate, ozone, carbon monoxide, sulfate, lead). Particulate matter consists of dust, soot and smaller particles in the air. It is emitted by a number of sources, including automobiles and fuel burning, but can also be formed in the air as different chemicals react. Some types of PM can be seen with the naked eye (such as soot or smoke). Other forms of PM are so small that a microscope is needed to see them. As the size of the particles decreases, so does our bodies defense mechanisms. This is the reasons we are concerned with particles 2.5 microns and smaller. These particles result from combustion and are respirable. As the airways progress through the lungs, they become smaller, like branches of a tree, so PM (<2.5 microns) can reach the small airways. Once there, PM 2.5 results in inflammation causing the smooth muscles on the outside of the airways to contract and squeeze down and mucus cells in the airways to fill them up. Both actions cause air to be trapped in the lungs, decreasing air movement. When asthma is under control the airways are clear, and air flows easily in and out. When asthma is not under control, the sides of the airways in the lungs become inflamed and swollen. During an attack, muscles around the airways constrict, and less air passes in and out of the lungs. Excess mucus forms in the airways, clogging them even further. The attack, also called an episode or exacerbation, can include coughing, chest tightness, wheezing, and difficulty breathing. Asthma can be difficult to diagnose in infants, young children, the elderly, smokers, workers exposed to chemical inhalants, people with seasonal allergies, and people with recurrent acute respiratory infections. Regular physical exams that include measurements of lung function and evaluations of a patient s allergic status can help ensure a proper diagnosis. Asthma is a disease of the small airways. It is a chronic inflammatory disease that starts in early life and can produce irreversible loss of lung function. It may cause wheezing, breathlessness, chest tightness, and/or nighttime or early morning coughing. Risk factors are characteristics of people that increase the probability that they will experience a specific disease or a condition associated with a disease. Risk factors for asthma include genetic predisposition and environmental exposures. However, just because a person is at risk for a disease does not mean that he or she will develop that disease. Being aware of the risk factors may help people take precautions to avoid acquiring those diseases or conditions. Genetic predisposition Environmental exposures Other contributing factors American Indian and Alaska Native adults have the highest lifetime prevalence of asthma among singlerace groups So does air pollution only affect people living in cities? We generally think of PM being a result of fossil fuel combustion (coal, oil, diesel) and therefore more of a big city concern. However, PM 2.5 can also emanate from other sources, such as biomass combustion, dust, and trash burning. And we ve learned that the chemical composition of such particles is different than that associated with fossil fuel combustion.

5 Body of Lesson (Continued): So it s important is to learn about local sources of air pollution and then use that information to design interventions that will improve air quality. The Institute of Medicine has identified agents in the home that can have an effect on asthma. These three biological agents are considered causes of asthma exacerbations: cat, cockroach, and house dust mite allergens. These four biological exposures are associated with aggravating the disease: dog allergen, fungi or molds, and rhinoviruses. These chemical agents can exacerbate asthma: environmental tobacco smoke, biomass, smoke, high levels of nitrous oxides, formaldehyde, and fragrances. Indoor Air Exposures and Asthma Exacerbation Biological Agents Chemical Agents cat * environmental tobacco smoke cockroach * biomass smoke house dust mite * NO 2, NO x (high levels) dog * formaldehyde fungi/mold * fragrances rhinovirus Clinical Features environmental exposure - cough/wheezing - bronchodilator controller agent improvement Closure (The bow that ties things up and directly refers back to the anticipatory set): As we close today, let s go back to our opening activity when we used coffee stirrers to help us experience what the breathing process feels like for a person with a lung disease. With that in mind, what explanation would you give for why researchers examine respirable particles? Extensions (Ways this lesson can be tied to additional learning opportunities): Students can extend/enforce their understanding of the two catastrophic air events mentioned by reading the included articles, visiting the listed websites, or watching the documentary listed in resources. Students can read the attached asthma information. Assessing the Lesson Tools (Multiple ways to provide meaningful feedback on student learning): Class participation Student Note taking Sheet: Air Quality and Respiratory Health Instructor Quiz on the Reflections optional reading(s) (Notes to self: what worked, what didn t, etc.): Instructor Reflections (Notes to self: what worked, what didn t, etc.): 'Environmental Health Science Education for Rural Youth' Grant Number 1R25 RR020432, is funded by a Science Education Partnership Award (SEPA) grant from the National Center for Research Resources, a component of the National Institutes of Health.

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7 Air Toxics Under the Big Sky Notes: Air Quality and Respiratory Health ANSWER KEY 1. Although it has been known since Roman times that cities create bad air quality, it took these two major catastrophic air quality events to bring to attention the correlation between air quality and human health and to provide the impetus for studying particulate matter: Donora, Pennsylvania Worst air pollution disaster in U.S. history (1948) The London Smog The worst air pollution disaster on record (1952) 2. Epidemiological investigations soon began, focusing on particulate matter (PM) in urban areas. What is PM and what are some of its sources? Particulate matter consists of the dust, soot and smaller particles in the air. Some sources of PM include automobiles, fuel burning, and unpaved roads. 3. Epidemiological investigations also determined that rural areas have also experienced an increase in PM levels. What are some events that can contribute to that increase? Biomass combustion, dust, trash burning 4. Elevated levels of air pollutants have been linked with adverse respiratory effects such as asthma. What is asthma? Asthma is a chronic inflammatory disease that starts in early life; it can produce irreversible loss of lung function. 5. Biological agents in the indoor environment can trigger asthma symptoms and attacks. Biological agents include: Cats, dogs, cockroaches, house dust mites, fungi/mold, and rhinovirus 6. Chemical agents in the indoor environment can trigger asthma symptoms and attacks. Chemical agents include: Environmental tobacco smoke, biomass smoke, NO 2, NO x (high levels), formaldehyde, and fragrances 'Environmental Health Science Education for Rural Youth' Grant Number 1R25 RR020432, is funded by a Science Education Partnership Award (SEPA) grant from the National Center for Research Resources, a component of the National Institutes of Health.

8 The London Smog Disaster ANSWER KEY Problem: How did the London Fog of December 1952 affect the health of the citizens of London England? Procedure: Use the graph to answer the following questions. 1. Use the data from the graph to calculate a) the average number of deaths per day b) the average smoke concentration (in micrograms/cubic meter) and c) the average sulfur dioxide concentration (in micrograms/cubic meter) for the dates December 1-4. Record your results in the table below. 2. Repeat your three calculations for the following: December 5-9 and December Record your results in the table below. Parameter December 1-4 December 5-9 December a) Average number of deaths per day ~302 ~701 ~506 b) Average smoke concentration (micrograms per cubic meter) ~94 ~370 ~89 b) Average Sulfur dioxide concentration (ppb) ~125 ~574 ~121 Analysis: 3. Based on your calculations, which time period had the highest average deaths per day? Highest average smoke concentration? Highest average sulfur dioxide concentration? Deaths- December 5-9; Smoke- December 5-9; Sulfur Dioxide- December Compare the December 1-4 time period to the December time period. How do the average values for each parameter compare? Are there any averages within a parameter that are considerably different? Deaths: Day 1-4 (302); Day (506) Smoke: Day 1-4 (94); Day (89) Sulfur Dioxide: Day 1-4 (125); Day (121) The numbers of death is the only considerable difference. Conclusion: 5. Referring to the graph, what generalization can be made about the relationship between the smoke concentration or sulfur dioxide concentration and the daily death rate during the period December 1-15, As smoke and sulfur dioxide concentrations increased, the number of deaths also increased. The number of deaths also fell when smoke and sulfur dioxide rates decreased. The number of deaths correlates to the concentrations of smoke and sulfur dioxide. 6. Looking at your data table, why do you think the averages for the December 1-4 time period and the December time period are very similar for the smoke concentration and the sulfur dioxide concentration, yet the death rate averages for the same two time periods are very different? What does this suggest about the long-term health effects of smoke and sulfur dioxide as air pollutants? Increased concentrations of smoke and sulfur dioxide can impact health long beyond when the exposure occurs, which in this case resulted in deaths. This suggests exposure to these pollutants can have a long-term impact on human health possibly causing death or chronic illness.

9 Air Toxics Under the Notes: Air Quality and Respiratory Health NAME: DATE: 1. Although it has been known since Roman times that cities create bad air quality, it took these two major catastrophic air quality events to bring to attention the correlation between air quality and human health and to provide the impetus for studying particulate matter: 2. Epidemiological investigations soon began, focusing on particulate matter (PM) in urban areas. What is PM and what are some of its sources? 3. Epidemiological investigations also determined that rural areas have also experienced an increase in PM levels. What are some events that can contribute to that increase? 4. Elevated levels of air pollutants have been linked with adverse respiratory effects such as asthma. What is asthma? 5. Biological agents in the indoor environment can trigger asthma symptoms and attacks. Biological agents include: 6. Chemical agents in the indoor environment can trigger asthma symptoms and attacks. Chemical agents include: 'Environmental Health Science Education for Rural Youth' Grant Number 1R25 RR020432, is funded by a Science Education Partnership Award (SEPA) grant from the National Center for Research Resources, a component of the National Institutes of Health.

10 The London Fog Problem: How did the London Fog of December 1952 affect the health of the citizens of London England? Procedure: Use the graph to answer the following questions. 1. Use the data from the graph to calculate a) the average number of deaths per day b) the average smoke concentration (in micrograms/cubic meter) and c) the average sulfur dioxide concentration (in micrograms/cubic meter) for the dates December 1-4. Record your results in the table below. 2. Repeat your three calculations for the following: December 5-9 and December Record your results in the table below. Parameter December 1-4 December 5-9 December a) Average number of deaths per day b) Average smoke concentration (micrograms per cubic meter) b) Average Sulfur dioxide concentration (ppb) Analysis: 3. Based on your calculations, which time period had the highest average deaths per day? Highest average smoke concentration? Highest average sulfur dioxide concentration? 4. Compare the December 1-4 time period to the December time period. How do the average values for each parameter compare? Are there any averages with in a parameter that are significantly different? Conclusion: 5. Referring to the graph, what generalization can be made about the relationship between the smoke concentration or sulfur dioxide concentration and the daily death rate during the period December 1-15, Looking at your data table, why do you think the averages for the December 1-4 time period and the December time period are very similar for the smoke concentration and the sulfur dioxide concentration, yet the death rate averages for the same two time periods are very different? What does this suggest about the longterm health effects of smoke and sulfur dioxide as air pollutants?

11 Donora, Pennsylvania Air Pollution Disaster of 1948 Donora, Pennsylvania, a small industrial town located on the Monongahela River Valley, experienced the worst air pollution disaster in U.S. history in Pollution from the U.S. Steel Corporation's Donora Zinc Works smelting operation and other sources containing sulfur, carbon monoxide and heavy metal dusts, was trapped by a weather phenomenon called an inversion, in which a warm air mass traps cold air near the ground. According to the Pennsylvania Bureau of Industrial Hygiene, the pollution came from a combination of the zinc smelting plant, steel mills' open hearth furnaces, a sulfuric acid plant, slag dump, and coal burning steam locomotives and river boats. The heavy industry of Western Pennsylvania had created pollution problems for nearly a century. By the mid- 1900s, other industrial contributors to the pollution that blanketed the air in Donora include the open hearth furnaces of the steel mills, a sulfuric acid plant, slag dumps, coal burning steam locomotives, and river boats. The valley of Donora, surrounded by hills, caused the dense polluted fog to remain close to the ground where people easily inhale the dangerous chemicals. Between October 26 and 31, 1948, 20 people were asphyxiated and over 7,000 were hospitalized or became ill as the result of severe air pollution. Of the fatalities, two had active pulmonary tuberculosis. The other seventeen were known to have had chronic heart disease or asthma. All were between 52 and 85 years of age. As a result of this tragedy in Donora, the U.S. took notice of the industrial pollutants emitted into the air and how they affected human health. Before this smog disaster occurred, the mayor of Pittsburgh anticipated air pollution related health problems. Eventually, the Donora episode helped him to prohibit the use of coal as a residential heating source, replacing it with clean natural gas. By 1952, diesel engines in locomotives and riverboats replaced coal power engines. By 1955, almost 97 percent of Pittsburgh s emissions were reduced and the smog had cleared. In addition, the Pennsylvania state government established the Division of Air Pollution Control in 1949 to study air quality and its effect on human health. Statewide clean air regulations were enacted in 1966, and in 1970, the Pennsylvania legislature passed an "Environmental Bill of Rights," stating that, among other things, people had a right to clean air. Material retrieved from:

12 The London Smog Disaster of 1952 Days of Toxic Darkness Early on 5th of December 1952 the London sky was clear, the weather was considerably colder than usual, as it had been for some weeks. As a result the people of London were burning large amounts of coal and smoke bellowed from the chimneys. The winds were light and the air near the ground was moist, conditions ideal for formation of radiation fog. During the day of 5th December the fog was not particularly dense, it possessed a dry smoky character, however when nightfall came the fog thickened and visibility dropped to a few meters. Road, rail and air transport were brought to a standstill. Theatres had to be suspended when fog in the auditorium made conditions intolerable. But, most importantly the smoke-laden fog that shrouded the capital brought the premature death of an estimated 12,000 people and illness to many others. This "pea soup" smog stayed stewing away for five days from the 5 to the 10 December as more and more pollution entered it before winds from the west blew it down the Thames Estuary and out into the North sea. The science The fog was triggered by the formation of a static layer of cooler air close to the ground as the nighttime temperature dropped. This is known as temperature inversion. Normally, air closer to the ground is warmer than the air above it, and therefore rises. Inversions are frequent on winter nights after the ground has cooled down so much that it begins to chill the air closest to it often causing mist to form as water vapor precipitates on dust particles. Normally the morning sun swiftly breaks through the mist and heats the ground, which warms the air above it, breaking the inversion. But in December 1952 the accumulation of smoke close to the ground was so great that the sun never broke through, and the air stayed cool and static. The term smog simply describes fog that has soot in it. Winter smog in which smoke, sulfur dioxide from the city s chimneys, accumulated in the foggy air had been a feature of London life since at least the 17th century. However the industrial revolution of the 19th century in Britain s major cities gave a dramatic increase in air pollution. On 5th December 1952 hanging in the air were thousands of tons of black soot, sticky particles of tar and gaseous sulfur dioxide, which had mostly come from coal burnt in domestic hearths. Smoke particles trapped in the fog gave it a yellow-black color. The water from the fog condensed around the soot and tar particles. The sulfur dioxide reacted inside these foggy, sooty droplets to form a solute sulfuric acid creating in effect a very intense form of acid rain. During the four days between the 4 and 8 December 1952 smoke measurements taken at the National Gallery in London suggest that the PM 10 concentration was 56 times the level normally experienced at the time and the levels of sulfur dioxide in the air increased by 7 fold peaking at around 700ppb. The health effects of the London smog On the week beginning the 5th December 1952 thousands of Londoners died in the worst air pollution disaster on record. Nobody realized what was happening until it was noticed that the undertakers were running out of coffins and the florists out of flowers. Only later it was realized that the number of deaths during the days of the smog was three or four times normal. People with bronchitis and other respiratory conditions such as asthma wheezed to their deaths in their beds. Most deaths were a result of respiratory and cardiac distress. Many victims died in their beds from asphyxiation because of the smog.

13 Since that time the adverse health effects of smog have been identified, including: An increased number of deaths Increased hospital admissions and sick days Respiratory effects Short term decrease in breathing ability and increase in chest pains Inflammation of the lungs and damage to respiratory cells Permanent lung damage and reduced quality of life due to ozone. Increased number of asthma attacks due to nitrogen dioxide. Cardiovascular effects A lack of oxygen in the bloodstream in those with heart disease due to carbon monoxide. An increased risk of cancer Increased susceptibility to infection among children Death rates During the smog the death rate rose dramatically. The previous week the death rate had been 2062, which was close to normal for that time of year. In the following week 4703 people died. The death rate peaked on the 8th and 9th, at 900 per day. In parts of the East End, death rates during the period of the London smog were nine times the normal. The death rate remained above normal through the winter and was still 2 per cent up the following summer. There were almost a thousand more deaths per week than expected according to the normal winter rates until the spring of that year. The deaths which resulted from the smog can be attributed primarily to pneumonia, bronchitis, tuberculosis, and heart failure. How many people actually died? The accepted figure is that the London smog killed around 4000 people. The official reports published at the time used these figures. However they count only the deaths during and for two weeks after the smog. The reason this was done was that death rate returned to normal at this time for a short while. However, there was a second peak in deaths and people have since realized that the rates returning to normal was due to registrations being delayed because of Christmas holidays. Deaths remained higher than normal for a long time after this point. These delayed deaths add an extra 8000, bringing the total number of people the smog killed up to 12,000. Many people nowadays accept this as the real figure for deaths due to the London Smog, although the exact number can never be known. The majority of the people who died were old and many already suffered from chronic respiratory and cardiovascular complaints. Two thirds of the 4000 victims were over 65. The death rate actually rose most in the 45 to 64 year olds. In fact it rose to three times the normal value. Mortality from bronchitis and pneumonia increased more than sevenfold. Twice the normal number of babies died in the week of the smog. Why did these effects occur? Pollutants such as smoke and sulfur dioxide were partly to blame. However, research has shown that the adverse effects of the smog were not as much due to the original pollutants- the soot and sulfur dioxide- as to the acidity of the air. Breathing in acid aerosol irritated the bronchial tubes, which produced large amounts of mucus and became inflamed. While nobody measured the acidity at the time, the ph was probably at least as low as 2. Cleaning up the act! The Great London Smog galvanized the government to clean up the nation s air and as a consequence the first clean air acts were introduced. The 1956 Clean Air Act was directed at domestic sources of smoke pollution authorizing local councils to set up smokeless zones and make grants to householders to convert their homes from traditional coal fires to heaters fuelled by gas, oil, smokeless coal or electricity. The 1968 Clean Air Act: Tall Chimneys brought in the basic principal for the use of tall chimneys for industries burning coal, liquid or gaseous fuels. Thanks partly to pollution legalization but also to slum clearance, urban renewal, and the widespread use of central heating in the houses and offices of Britain pea-soupers have become a thing of the past. Material retrieved from:

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15 What is Asthma? Asthma is a chronic disease that affects the airways, the tubes that carry air in and out of your lungs. In asthma, the inside walls of the airways are inflamed, or swollen. The inflammation makes them very sensitive, and they tend to react strongly to things that you are allergic to or find irritating. When they react, they get narrower and less air flows through to your lungs. This causes symptoms like wheezing, coughing, chest tightness, and trouble breathing, especially at night and in the early morning. Asthma cannot be cured, but most people with asthma can control it so that they have few and infrequent symptoms and can live normal, active lives. When asthma symptoms become worse than usual, it is called an asthma episode or attack. In a severe asthma attack, the airways can close so much that not enough oxygen can get to your vital organs. People can die from severe asthma attacks. Common asthma symptoms include coughing, wheezing, chest tightness, shortness of breath, and faster or noisy breathing. Researchers still do not know what causes asthma, although they do know that if other people in your family have asthma, you are more likely to develop it. Being exposed early in your life to things like tobacco smoke, infections, and some allergens may also increase your chances of developing asthma. Retrieved from:

16 What Causes Asthma Symptoms and Attacks? There are things in the environment that bring on your asthma symptoms and lead to asthma attacks. Some of the more common things include exercise, allergens, irritants, and viral infections. Some people have asthma only when they exercise or have a viral infection. The list below gives some examples of things that can bring on asthma symptoms. Allergens Animal dander (from the skin, hair, or feathers of animals) Dust mites (contained in house dust) Cockroaches Pollen from trees and grass Mold (indoor and outdoor) Irritants Cigarette smoke Air pollution Cold air or changes in weather Strong odors from painting or cooking Scented products Strong emotional expression (including crying or laughing hard) and stress Others Medicines such as aspirin and beta-blockers Sulfites in food (dried fruit) or beverages (wine) A condition called gastroesophageal (GAS-tro-e-sof-o-JEE-al) reflux disease that causes heartburn and can worsen asthma symptoms, especially at night Irritants or allergens that you may be exposed to at your work, such as special chemicals or dusts Infections How Is Asthma Diagnosed and Treated? Doctors find out whether you have asthma by looking at your family history of asthma and allergies, exploring the things that seem to cause your symptoms or make them worse, and giving you a test, called spirometry, that measures how much air you can blow out of your lungs after taking a deep breath and how quickly you can do it. They may also perform tests to find out if you have allergies, to see how your airways react to exercise, to find out whether you have gastroesophageal reflux disease or sinus disease, and to rule out heart disease and other lung diseases. Asthma is treated with two kinds of medicines: quick-relief medicines to stop asthma symptoms and long-term control medicines to prevent symptoms. Short-acting inhaled beta-agonists are the preferred quick-relief medicine. The most effective, long-term control medicine is an inhaled corticosteroid, which reduces inflammation in your lungs. Most long-term control medicines must be taken daily, even when you do not have symptoms. Other long-term control medicines include inhaled long-acting beta-agonists, leukotriene modifiers, cromolyn, and theophylline.

17 Most asthma medicines are inhaled. As a result, they go straight to your lungs where they are needed. It is important to learn how to use your inhalers correctly. Many people with asthma need to monitor their condition with a peak flow meter. This is a handheld device that measures how well your lungs are working. A peak flow meter can help you detect early changes in your condition, especially if you change your medicines, and warn you of a possible attack even before you feel symptoms. Parents of children with asthma need to help them manage their asthma, including making sure the child uses his or her medicines properly and watching for any signs of an attack. Older people with asthma may need to adjust their treatment because of other diseases or conditions that they have. Some medicines that many older people take can interfere with asthma medicines or even cause asthma attacks. It is especially important for pregnant women with asthma to control their asthma. Uncontrolled asthma can limit the supply of oxygen to the fetus. Doctors recommend that it is safer to take asthma medicines during pregnancy than to take the chance that you will have an attack. Regular physical activity is just as important for people with asthma as for the rest of the population. If exercise brings on your asthma symptoms, talk to your doctor about the best ways to control your asthma when you are active. Material retrieved from: Graphic retrieved from:

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