u approach polluon U.S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 September 1974 ------- RAPS: a new approach to air pollution T"1 he largest, most comprehensive investigation of air pollution ever undertaken is now in prog- ress—and it is being conducted here in the St. Louis metropolitan area. The project is the Regional Air Pollution Study or, more simply, RAPS. It is being conducted by the U.S. Environmental Protection Agency (EPA) to develop models for testing air quality manage- ment techniques that will help curb air pollution in greater St. Louis. That alone would be enough to merit attention, but there is more. RAPS is also a major pilot study; what is learned here will be applied in other cities and other nations. Because RAPS and its results are important to you, as well as to your brothers and sisters here and around the world, this leaflet has been pre- pared so that you will know what is happening, why it is happening, and what it will mean. The problem Air pollution is recognized as a real problem that poses a very real threat to our health and our environment. The evidence is extensive: scientific studies have been made, documented evidence compiled, and brought before Federal, State and local governments. Virtually everyone has come to realize that there are dangers, real and potential, from air pollution. But at the same time, there is a feeling, par- ticularly among young people like yourself, that this public awareness has not been followed by enough action. If the problem is immediate, they maintain, the solutions should be too. They feel that little progress is being made against this threat to health and the environment. It may seem that way but it is not so. Far more is being done than you might imagine. EPA and State and local government environmental agen- cies have long been active enforcing pollution control laws passed by Congress. So why does the problem continue? One stumbling block to achieving clean air is resolving situations which involve conflicts and compromises between enforcing agencies and polluters, large and small. How do we take cor- rective action without getting harmful side effects? For instance, we could clean up the air by elimi- nating the major sources of pollution—cars, trucks, trains, planes and industry. But this is not practical. What would happen if we could not produce the food, clothing and other goods we need for life itself? We must seek to meet air quality standards, keeping pollution at a low enough level to protect the public health and welfare and at the same time maintain our quality of living. To do this, we must obtain information as complete and as accurate as possible so that we can better evaluate what is the proper action to take. Is that what RAPS will do? That's precisely what RAPS will do. It will give us a more detailed measurement of air pollu- tion than we have ever had before. RAPS will feed those measurements into computers to ob- tain answers and allow predictions to be made under various pollution conditions. And RAPS will test a variety of methods for controlling pollu- tion. It will enable us to check alternative strate- gies, and determine what really works best to bring pollution under control. How will RAPS change things? RAPS will greatly enlarge on what we currently know about how much pollution is in the air and how much we can tolerate. RAPS will tell us about the air above each part of our metropolitan region. It will reveal what pollutants exist over each area, the direction in which they are moving, and what chemical changes occur as pollutants mix and as they are exposed to sunlight and other elements. With such detailed measurements and through computer analysis, scientists hope to develop mathematical models that will guide us toward accurate and effective control procedures. In short, RAPS is designed to provide the in- formation which will be the basis for reasonable and effective air pollution controls—and while gathering the information it will test which air pollution control strategies work best. How is RAPS organized? RAPS is a $22 million, 5-year scientific proj- ect funded and conducted by EPA. The Rockwell International Corporation is the prune contractor and several subcontractors from the St. Louis area will handle specific jobs such as equipment installation or data management. Numerous local, State, and Federal agencies are cooperating in the project, and qualified local college students are participating in some of the field studies and meas- urements. When it is completed RAPS will make it easier for EPA to control air pollution. For you it will mean cleaner air to breathe. ------- 100R74O11 Why St. Louis? It's a good question. Your city doesn't have the cleanest air in the Nation, but neither does it have the dirtiest. So why was it selected? This area was chosen for several reasons. Of 33 American cities, St. Louis was found to be similar to the other 32. Your city has a climate that is most like the majority of other U.S. urban areas. It has a wide variety of emissions as deter- mined by fuels used, industrial production proc- esses and pollution mix. It is also reasonably isolated from the pollution of other major sources outside the area. It is far from the oceans and Great Lakes, hills and mountains, all of which can have an effect on air pollution. And the greater St. Louis region is also large enough to conduct this study. Finally, St. Louis has had previous air pollu- tion studies and the continuing work of existing environmental agencies provides available back- ground information, particularly in the area of meteorology, emissions and air quality. How will RAPS be carried out? In order to properly study the region, covering roughly a 25-mile radius from the Gateway Arch, a network of 25 remote air monitoring stations has been established. Stations will also be located in the greater St. Louis area in both Missouri and Illinois. (See map.) In addition, this network will be supplemented by 10 monitoring stations opsrated by local agencies. Each station contains analytical equipment to measure pollutants and meteorological conditions, plus a minicomputer to acquire the data and transmit information to a central headquarters. Information will also be gathered by mobile vans and aircraft. The highly advanced electronics equipment used in the monitoring stations also will be contained in mobile units. On the ground we will be monitoring the hourly emission rates of smokestacks and calculating emission rates through plant fuel consumption or plant process schedules. Helicopters and fixed-wing aircraft will sample the air. Photography and radar will be used to study air pollution rising up from the street and river traffic and from the railroads. We are even going to check the effects aircraft may have on the problem, including that of our sur- veillance aircraft. This is what RAPS is really all about, collecting and evaluating information needed to test our clean air strategies. So what in particular will RAPS be involved with? A great many things. The investigation will be conducted across the wide spectrum of the physi- cal sciences and will include some of the social sciences as well: meteorology, atmospheric chem- istry, aerosol physics, applied mathematics and even health and welfare studies and economic analysis. All will be employed to gather and evaluate the information about air pollution. Information gathered on a continuous basis will be available for automatic retrieval. Scientists will use it to develop mathematical models which de- scribe air pollution under virtually any circum- stances. Proposed methods for controlling pollu- tion can be tested against the models. Scientists also expect to evaluate such new remote sensors as lidar and acoustic sounders. Research for the project is being conducted nationwide by a variety of institutions. Locally, Washington University is studying how gas pollutants change into par- ticles in the air. Students and instructors at St. Louis University and the University of Missouri are looking into the relationship between pollution and vegetation, i.e., how plants act as filters to remove particles from the air. The analysis and re-analysis will be done at the central support facility located in Creve Coeur. It houses both manual and automated data proc- ------- THE SCENE AT ST. LOUIS: Below, a lab technician inspects large plastic bags that will be used for ah- samples taken with the help of equipment (lower right) in each of the 25 Regional Air Monitoring Sys- tems (RAMS) throughout the greater St. Louis area (far right). At middle right is computer, built by Rockwell International, that receives and stores data from the RAMS. Weather maps, right, are important aids in the RAPS program. ------- essing equipment and is linked to the monitoring stations that are scattered throughout the city via telephone circuits. The support facility also has offices and a laboratory for instrument mainte- nance and repair. We think RAPS is pretty important So do a lot of other people. The information gathered will not only be studied by your State and local environmental agencies, but by those of foreign governments as well. Under a protocol agreement between the United States and the Soviet Union, the two countries will study and evaluate the data collected from RAPS—St. Louis and a similar study now underway in the Soviet city of Leningrad. During the next several years representatives of Russia and other nations will be visiting your city to observe the RAPS opera- tion firsthand. What can students do to help? RAPS is truly a program for the people. Its primary goal is to give you and your parents a better life, one in which the air will be clean. The most important thing you can do is to tell your parents and your friends about RAPS. For if RAPS is to be successful, we will need the understanding and cooperation of St. Louis area citizens. There will be some minor inconveniences. The helicopter flights, for instance, will be noisy because we need helicopters to handle the meas- uring equipment. Those flights will be made during February, August and November for the next three years. If you help explain RAPS, you will help people understand the need for those nights. RAPS also will involve measurements of emis- sions from smokestacks at major industrial loca- tions in ths area. These will involve the use of laser beams, and new remote sensors to detect pollution will be tested. For these parts of the RAPS program, cooperation will be needed from business and industrial leaders. If you help make RAPS known in St. Louis, you will be helping us to obtain that cooperation. We hope you will agree that RAPS is important to us all. If you would like to get further involved in the type of work that RAPS will be concerned with, here are several experiments for you to try in your classroom. They all deal with air, and are divided into intermediate and high school level. Although these experiments are not as sophisti- cated as those that will be conducted by _ the RAPS program, they will give you a visual idea of the pollution problems in St. Louis. ------- Experiments Reproduced from "Air Pollution Experiments for Junior and Senior High School Science Classes" (Second Edition) with permission of the Air Pollution Control Association, Pittsburgh, Pa. INTERMEDIATE—AIR CONCEPT Acid gases and aerosols are prime ingredients of urban air pollution. These gases may damage plants, corrode metals, crumble stone, and in heavy concentration, they can make men and animals ill. EQUIPMENT A large funnel, an air pump or aspirator (most pet shops sell air pumps), filter papers, one for each exposure site, large enough to cover the large end of the funnel, a piece of wire screen the same size. Tape to hold filter paper on funnel, 1 ounce of 0.01M sodium bicarbonate solution, 1 ounce of glycerin, 2 or 3 ounces of a dilute solu- tion of 10 percent hydrochloric acid in a beaker, 3 eye-dropper bottles, 2 or 3 feet of rubber or glass tubing, chart and graph. (See Figure 1 and Figure la.) PROCEDURE Cut filter paper big enough to fit over the large opening of the funnel with a Vi-inch overlap. Tape it on. Add a drop of glycerin to the center of the paper. Add a drop of the indicator solution to the center of the paper. More drops may be necessary if the color is not apparent. Add a drop of sodium bicarbonate solution to the center of the paper. [NOTE: Support the filter paper with a piece of wire screen cut to fit over the opening of the funnel if the moistened paper cannot withstand the flow of air through it without rupturing. Place the screen on the funnel, then place the paper over it. Secure both with tape or a rubber band.] Attach the tubing to the small end of the funnel and to the air pump. Start the air pump and the timer. Do a preliminary test, drawing air from above the open bottle of dilute hydrochloric acid. Stop the pump when a red color is visible. Test some air: Take samples from a chemistry laboratory, outdoors, hi a kitchen, from exhaled breath. Record the results on a chart and bar graph to illustrate the presence of acid gases at the test site. (See Figure la.)>Record on the chart the site location, the time you started taking the air sample, and the time the treated filter paper began to react with the gases. Show the elapsed time figures in the form of a bar graph. Then you will have a complete picture of the acid gas con- centrations encountered in the test. Figure 1 Air Assembly Figure la Air Graph STARING STOPPING ELAPSED TIME (Show in form of bar graph) SITE TIME TIME A B C D E F G H 0 5 10 15 20 25 30 35 40 45 * (MINUTES) ------- HIGH SCHOOL—AIR CONCEPT This experiment demonstrates that the air in which we live and which we breathe is not always as clean as it appears to be. EQUIPMENT Small vacuum pump or water aspirator having an air volume capacity of approximately % cubic foot per minute. Two pieces of 28-mm (outside diameter) glass tubing 50- to 75-mm long, with 1.2-mm wall thickness (be sure glass tubing is cut square and the ends are fire polished to avoid cut fingers). Window screen disc cut 28-mm in diameter, two rubber stoppers to fit glass tubing. Each stopper to have an 8-mm hole in center. Two 75-mm pieces of 8-mm outside diameter glass tubing. Whatmann #41 filter paper 28-mm diam- eter discs, rubber band, 1-inch wide, to fit snugly around 28-mm tubing, or 1-inch masking tape, burette stand with a 3-finger clamp, plastic (Tygon or Nalgon) or rubber tubing to connect filter to vacuum pump and to act as a probe to collect outdoor air, flowmeter (rotameter) of appropriate range, or a wet or dry gas meter if available. A critical orifice of proper size may be used to control air flow at the maximum rate desired. Glass bottle (1-gal. capacity) fitted with 2-hole rubber stopper containing one long and one short piece of 8-mm glass tubing. The bottle should be nested in a corrugated board box for safely. ASSEMBLE APPARATUS Set the screen on top of one piece of 28-mm tubing (now called cylinder #1). Place a filter paper disc on the screen. Place the other piece of 28-mm tubing (cylinder #2) on top of the filter paper, press the two cyl- inders together and make an air-tight seal with the rubber band or with masking tape. Insert a small glass tube in a hole through each rubber stopper. Place one stopper in the lower end of cylinder #1 and the other stopper in the upper end of cylinder #2. Mount the assembly in the burette stand with cylinder #2 in the upper position. Using plastic or rubber tubing, connect cylinder #1 to the lower tap on the rotameter or to the inlet of other type of flow measuring device. Con- nect the outlet of the rotameter or other flowmeter to the inlet side (long glass tube) of the 1-gallon bottle. (This bottle evens out any fluctuations due to the vacuum pump. It is called a surge or buffer bottle.) Similarly connect the outlet tube from the surge bottle to the inlet tap of the vacuum pump or other source of vacuum. Connect a long piece of plastic or rubber tubing to the inlet end of cylinder #2, and pass the other end through a window. The stem of the funnel should be inserted in the tubing hanging outside. The funnel should hang upside down to prevent rain from entering the tubing. PROCEDURE Start the vacuum pump and record the time. Measure and record the rate of air flow. Allow air to pass through the filter for two hours or as long as required to darken the filter paper noticeably. Measure and record the rate of air flow. Stop the vacuum pump and record the time. Dismantle and observe the soiling of the filter paper. If a photometer to measure transmittance of light through ths soiled filter paper is available, a quantitative evaluation of the amount of soiling can be made. QUANTITATIVE EVALUATION Theory—The amount of discoloration on the filter paper is approximately proportional to the quantity of solid particles suspended in the air. This makes it possible to relate the decrease in light transmittance through the paper to the amount of particles collected on it. The light transmittance of the paper can be measured with a photometer before and after filtering the air by placing the clean filter disc and later, the exposed filter disc against the photometer window and noting the intensity of light transmitted in each test. From these measurements the optical density of the soiled filter paper can be computed in COHS. The COH is an abbreviation for Coefficient of TVU.S. GOVERNMENT PRINTING OFFICE 1974: 624-971 ------- Haze and one COH unit represents an optical density of 0.01. The optical density of the deposit or soiling is the logarithm to the base 10 of the ratio of the intensity of light transmitted through the clean filter paper to the intensity of the light transmitted through the soiled filter paper. In terms of percentage, it can also be the ratio of percent transmittance through the clean paper (considered as 100%) to the percent transmit- tance through the soiled paper. Therefore, I0 Iog10 100% It where, I0 = It = %T = %T average light intensity transmitted through clean filter paper, light intensity transmitted through the soiled paper, and percent light transmitted through the soiled paper when the light transmittance through clean paper is considered as 100% Since Iog10 of 100 = 2.0, we have O.D. = 2.0 - log %T By definition, one COH unit equals an optical density of 0.01. Thus, the number of COHS represented by the actual O.D. found equals O.D./0.01 = 100 X (2.0 — log %T). COH unit measurements are usually expressed as COHS per 1,000 linear feet of air passed through the filter paper. The concept of linear flow, upon which the expression COHS per 1,000 feet is based, considers that through each point on the surface of the filter a long stream of air passes leaving its load of dirt particles deposited. One might think of the sample as a long column of air the same diameter as the diameter of the exposed filter paper and with a volume equal to the measured volume of the air sample. Computations 1. Volume of air = R2 — RI (for dry or wet gas meter), R2 = final reading in cubic feet R! = original reading in cubic feet or, volume of air — ^ 1 "*" *' (for rotameter or critical orifice) 2 F! = initial flow rate in cubic feet per minute F2 = final flow rate in cubic feet per minute t = sampling time in minutes Corrections for Temperature and Pressure The value R2 — RI for the gas meter should be corrected for temperature and pressure according to the Charles' and Boyles' laws. Each F value for the rotameter or orifice should first be corrected to what it would be at the standard temperature and pressure at which the measuring device was calibrated: 2. Area = TT d2, where d is the inside diameter of ""4" the cylinder in feet _ cm. in. ft. Ft. = mm. X X X ^r— mm. cm. in. Volume 3. 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