Overview: Students will study air quality. They will examine the ways that wildfire smoke affects the air. They will recognise why people are evacuated when air becomes smoke filled. Curriculum Goals: Grade 11- Environmental Science 20 ES20-AS1 Atmospheric Systems. Materials: Handout of the Smoke Forecasting System (SFS) provided Stop watch or watch with second hand for each pair or group of students normal size straw, (not the large Slurpee size ones), one for each student. Explore: Ask the students if anyone can explain the term air quality. (The term air quality means the state of the air around us. Poor air quality is a result of a number of factors, including emissions from various sources, both natural and human-caused.) Ask the students to list some things that they understand can affect air quality. (The specific composition of air pollution in a particular location depends primarily on the source, or sources, of the pollution. Automobile exhaust, coal-fired power plants, industrial factories and other pollution sources all spew different types of pollutants and toxins into the air. Then there are natural types of air pollution like forest fires, dust storms.) This class we are going to focus on the effects of wildfires. Listen carefully to the news clip from a past fire season in Saskatchewan. Saskatchewan wildfires cause evacuations (3:08 min) https://www.youtube.com/watch?v=pokhkdlsjm4 control click on the address or cut and paste the URL into your browser. Wildfire smoke is comprised of a mixture of gases and particles that can cause eye and respiratory tract irritation. Ask students to help list what chemicals they think are found in smoke? Forest fire smoke is a mixture of: water vapor - carbon monoxide - nitrogen oxides - hydrocarbons - other chemicals containing carbon - particles of different sizes (particulate matter) - traces of minerals. Whether or not an area will be affected by the smoke from a wild fire will depend on several factors. What way the wind is blowing, what topography the land is and how big the fires are and where they are located.
Think about it in this way - Let s consider an analogy using water to help explain how air and air emissions behave. Imagine pouring red dye into the ocean. You ll see a red pool of water for a few seconds, but it quickly disappears as the waves mix the dye into the huge mass of water. It is a combination of the amount of water, and the vigorous mixing that makes the dye disappear. Now imagine pouring that same amount of red dye into a bathtub. The bath water will turn very red because there is far less water than in the ocean, and there is no mixing with a source of clean water to dilute the dye. Just as red dye disappears in the ocean, air pollutants mix and disperse quickly in a large air shed because the air flow is not limited by topography but can travel and mix over great distances. This results in good air quality in the air shed. Sometimes, however, topography and weather combine to prevent pollutants from mixing and dispersing. In this case the pollutants become trapped within the area, like the red dye in the bathtub that continually builds up with nowhere to go. This results in poor air quality in the air shed. Once pollutants are emitted into the air, the weather largely determines how well they disperse. Turbulence mixes pollutants into the surrounding air. For example, during a hot summer day, the air near the surface can be much warmer than the air above. Sometimes large volumes of this warm air will rise to great heights. This results in vigorous mixing. Wind speed also contributes to how quickly pollutants are carried away from their original source. However, strong winds don't always disperse the pollutants. They can transport pollutants to a larger area, such as the smoke from open burning or forest fires. Sometimes the condition of the atmosphere is very still (stable) and there is very little mixing. This occurs when the air near the surface of the earth is cooler than the air above (a temperature inversion). This cooler air is heavier and will not want to move up to mix with the warmer air above. Any pollutants released near the surface will get trapped and build up in the cooler layer of air near the surface. Once pollutants are emitted into the air, the weather largely determines how well they disperse. Smoke levels from forest fires may vary considerably due to fire conditions and wind directions. People who are at higher risk such as young children, the elderly and people with heart or lung conditions should consider taking precautions when smoke conditions are light to moderate. This is usually indicated by a smoke odour and haziness or visibility that is less than eight km.people who are considered healthy should consider taking precautions when smoke conditions are heavy. Heavy smoke conditions exist when visibility is less than about four kilometers, and is especially of concern when these conditions last for a day or more. Give the students the handout SFS and go over with them how the forecasting system operates.
Activity: To get an idea what it would be like to experience breathing problems we are going to do an activity that lets you experience difficulty breathing. Air quality activity the student s activity is taken partly from this much longer document ref:http://yyy.rsmas.miami.edu/groups/ambient/teacher/air/module%20segments/u%20strawbreathinge xercise.pdf Students breathe though a straw at rest and after exercise to experience what it feels like to have asthma or other breathing problems. In obstructive diseases such as asthma and emphysema, the amount of air you can get out of your lungs quickly (or the peak flow) is markedly decreased. Go through how you want the students to carry out the activity. Straw Asthma Activity 1.Have the active student plugs their noes throughout this activity so the participant can only breathe through their mouths. 2. Working in pairs or teams, each person will first measure their respiratory rate (number of breaths per minute), the amount of time it takes to breathe in (inspiration) and the amount of time it takes to breathe out (expiration). Their partner or the rest of the team should make all measurements. This activity should be performed while the person is at rest. 3. These respiratory parameters should be recorded as No Straw; At Rest by the partner. 4. Each person will then repeat this same activity breathing through a straw while at rest. 5. These first respiratory parameters should be recorded as With Straw; At Rest by the partner. 6. Each person should then perform 20 jumping jacks (or use a jump rope or run a set distance) and then immediately take their respiratory rate, and measure their inspiration and expiration times. 7. These respiratory parameters should be recorded as No Straw; Exercise by the partner. 8. Each person should then perform 20 jumping jacks (or use a jump rope or run the same distance) again, and then using the straw to breath through, immediately take their respiratory rate, and measure their inspiration and expiration times. 9. These respiratory parameters should be recorded as With Straw; Exercise by the partner. Create a chart to record data: No Straw (At Rest) # inspiratory, # expiratory; No Straw (Active) #inspiratory, # expiratory With Straw (At Rest) # inspiratory, # expiratory With Straw (Active) # inspiratory, # expiratory Example: Name No Straw- At rest No Straw-Active With Straw-At rest With Straw-Active Once the data has been collected comparisons can be made. Students will be asked to discuss what they felt like when performing the experiment and if the results they came up with were what they expected. Conclusion: During this class we looked at what is meant by poor air quality. We discussed what wildfire smoke does to the air and when it can become a problem for residents. By participating in the straw activity we gained knowledge of what it feels like to experience. difficulties in breathing. When we hear on the news that members of communities are being evacuated because of wildfires we will appreciate what they are going through.
Handout on Wildfire Smoke Forecasting System (SFS) Page 1 There is a need for an operational wildfire smoke forecasting system (SFS) in Canada. What has been developed presently is the BlueSky Western Canada Wildfire Smoke Forecasting System. This forecast system operates out of the University of British Columbia and combines satellite imagery, information on the amount of forest fuel burning, and weather patterns, and displays the results as an animated map. British Columbia air science specialist Steve Sakiyama, one of the tool's developers, says the haze predictions try to estimate the hourly air impacts due to forest fire smoke, looking up to 48 hours into the future. "It produces a forecast of the smoke into every hour into the future, both the location and the concentration," he told CBC News. "These patterns will animate so it will give you an hour and then the next hour, and the next hour up to about two days into the future. So you'll see this interesting pattern that gives you some idea where the smoke will go." Sakiyama says, as with all forecasting systems, the program is still being developed for better accuracy.
What is PM 2.5 and why is it dangerous? Page 2 Particulate matter, or PM, is any tiny solids or suspended solids in the air. In layman s terms, you can call it dust. Or you can call it ash. Depending on the size of it, then we have a different name for it. Anything bigger than 100 microns in diameter a micron is 10 to the negative six we call them TSP, total suspended particulates. Two-point-five microns are so small it s about 30 times smaller than a human hair. So forget about even seeing that; our body does not even know that we took it in. Our lungs don t know it. Our throat doesn t feel it. You do feel the after-effect of it; you ll get throat irritation. But in the beginning you will not notice that you are breathing it in. So, if you re walking around and you re breathing in PM 2.5, there s no way you can tell. What are the risks of exposure? The smallest particles (with sizes less than 2.5 microns, PM2.5) can be inhaled deep into the lungs and are of principal concern for the relatively short exposures associated with wildfire smoke events. Exposure to PM2.5 is linked to an increased risk of mortality and aggravation of pre-existing respiratory and cardiovascular disease. Will facemasks or dust masks protect us from the smoke? In order for a mask to provide protection during a smoke event, it must be able to filter very small particles (around 0.3 to 0.1 microns), and it must fit, providing an airtight seal around the wearer s face. Dust masks are not enough. The ones commonly found at hardware stores are designed to trap large particles, such as sawdust. These masks will not protect your lungs from smoke. All persons in areas affected by the wildfire smoke are advised to limit all outdoor activity and stay indoors whenever possible to minimize exposure to the smoke. Healthy individuals are at very minimal risk for any long-term effects from breathing wildfire smoke. Once exposure to the smoke goes away, so should any symptoms. This is why when the smoke from the fires in Saskatchewan became heavy they first start to evacuate the elderly and young that may experience greater problems from inhaling smoke. The larger healthier population were evacuated when fires started to get too close to their communities. Note to teacher: Copy this handout by printing it 2 sided and after you hand it out go over it with your students before the activity.