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Table of Contents I. Introduction II. Air Quality Index 101 III. Introducing the BAQI IV. The Numbers Behind the Index Where do we get our data? How does the BAQI help us avoid pollution? 4 5 7 9 10 11 V. What s next? 14
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Introduction 4 Air pollution has become one of the central public health emergencies of our time. London, for example, breached its 2017 pollution limits just 5 days into the year. Oslo temporarily banned diesel cars from its city center in order to combat pollution. Beijing is spending over $2.7 billion to improve its air. And this is all just from the first month of 2017. Air quality has long been measured using national Air Quality Indexes (AQIs), which indicate how clean the air is in a specific area and what the dominant pollutant is. But, as air quality increasingly becomes a global priority, one limitation of those AQIs becomes very clear: each country has a different way of calculating air quality levels, which means that there s no single unified, global AQI. The result? People don t have clear, consistent, and reliable information about the air they breathe, no matter where they are. The environmental engineers at BreezoMeter started asking themselves: why not? We re excited to announce that BreezoMeter has made a major step towards a global, unified formula: introducing the BreezoMeter Air Quality Index, BAQI for short. In this ebook, we ll share the thinking behind this decision, the importance of having a global AQI, and provide a detailed explanation of how the BAQI works.
II. Air Quality Index 101 5 Let s start with the basics: what is an AQI? Example AQI An AQI, typically calculated by government environmental agencies, takes different concentrations of air pollutants and wraps them all into a single number that can be shared with the public. It s meant to be a simple way to measure how healthy the air we breathe really is. AQIs, however, are very different depending on what country you re in. Here are some of the elements that can vary: 1. Scale: AQIs are typically measured on a scale, but there s no standardized scale that s accepted across the world. The official AQI for Israel, ranges from -400 to 100, while Ireland s ranges from 1 to 10, and the US AQI ranges from 0 to 500. 2. Pollutants: Most countries monitor CO, NO 2, O 3, PM 2.5, PM 10 and SO 2, but this can vary depending on the country. 3. Standards Calculations: The Chinese and American AQIs use a similar 0-500 indexing system, but Chinese standards are significantly more lenient than America, meaning the same concentration of, say, fine particulate matter, will lead to a worse AQI in the American AQI than in the Chinese AQI. A similar gap exists in almost every AQI calculation in different countries across the world. 4. Sources: Different AQIs prioritize different sources. Some are based on the effects that pollution has on human health, while others might give more weight to emission standards, or even political considerations. Source: Broward County
6 All of these inconsistencies make it hard for people and businesses, who are increasingly globally-aware, to rely on the AQI and get the most value out of it. Differences in scale, for example, make the data less intuitive and easy to read. Differences in what pollutants are measured make it nearly impossible to compare pollution from one country to another. The AQIs that are not based on what s best for human health can t be relied on or trusted. Moreover, AQI is currently calculated by averaging pollutant concentrations in the same place over few hours, based on each pollutant. In reality, people are moving around all day, so averaging pollutants concentrations at the same location over time isn t relevant. At BreezoMeter, we decided to take action, reboot the air quality index, and create one that works in real-time and is the same for people across the world.
III. Introducing the BAQI 7 To overcome all of these inconsistencies in how the AQI is measured across the world, BreezoMeter s environmental engineers and data scientists have developed the BreezoMeter Air Quality Index: the BAQI. Its global scale has a simple range: 0 (poor air quality) to 100 (excellent). The index currently takes into account the six major pollutants across the world, and additional pollutants will be added as time goes on. The BAQI Scale: The BAQI is divided into five different, color-coded levels of health concerns. They re directly related to science-based health recommendations, aimed at both the general population and at-risk groups like small children, cardiovascular patients, those with allergies, and more. Health recommendations are concise, actionable, and tailored in real-time to the pollution that s in the air. Now, people can rely on an air quality index that can be used anywhere, anytime. The BAQI is a single, independent rating that can serve as the most reliable standard for air quality across the world. Here s what a typical BAQI reading looks like:
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IV. The Numbers Behind the Index 9 On the surface, the BAQI is incredibly simple: it s a single number that will tell you the quality of the air on your street. But, the bigger story is how we got here. BreezoMeter collects so much real-time data from thousands of sources around the world. The hard part is turning all of that data into simple, actionable air quality information. That s what we set out to do. First, we studied different AQIs from countries across the world, as well as publications by the U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO). Of these standards and best practices, only those that were directly focused on pollution s effects on human health were taken into account. We made sure that any political considerations or external influences were minimized if not removed completely from our formula. Then, to take things a step further, we used academic research to develop algorithms that relied on big data and the latest advances in machine learning. The result? An accurate, reliable, and actionable BAQI.
Where do we get our data? 10 The BAQI was built as an aggregate of the AQIs of these countries, preferring the stricter approach in case of wide discrepancies between AQIs: Austria, Finland, France, Germany, Ireland, Israel, Netherlands, Norway, Poland, Singapore, South Korea, Switzerland, Taiwan, United Kingdom, United States. Let s look at an example. NO 2, which is commonly emitted by engines inside motor vehicles, is one of the most common pollutants across the world. Different countries, though, have different μg/m3 breakpoints for what they consider to be a moderate amount of NO 2, which is defined as a level of air pollution that may cause adverse effects in sensitive groups. As you can see in the table to the right, these breakpoints vary widely, ranging from just 30μg/m3 in the Netherlands to 201μg/ m3 in the UK and Ireland. We used all of these values along with scientific research to decide what the breakpoint would be for the BAQI, and settled on 100μg/m3. This means that if the dominant pollutant is NO 2 and there s 100 μg/m3 concentration of NO 2 in the air, the BAQI will show a rating of 50 out of 100, which is considered moderate.
How does the BAQI help us avoid pollution? 11 A key consideration in the BAQI is that it takes every precaution to keep people safe from pollution. This is where time comes into play. Many AQIs across the world are based on three different time frames of concentration averages: 1 hour, 8 hours, and 24 hours, depending on the pollutant. There is a logic behind it, as epidemiological studies are based on exposure over time. But here s the problem: imagine there is a high pollution level where you are, right now. It s safe to say you d like to know about that, and perhaps avoid going for a run or taking your kids to play outside. If you spread this peak over 8 hours, though, the AQI in your area is averaged out, and the peak disappears. Or, the other way around, imagine there was 6 hours of high pollution but than it clears out. An 8 hour average the AQI will show high pollution, although it is already clean. In other words, the current AQIs are not real-time, they are not relevant in a world when people are moving from place to place and want to know the air quality in real time. The BAQI fixes that, and here s how: we only average the past hour of data, and then make it correspond with the health impact it would have had if the pollution level would stay that way for the next few hours (8 or 24 depending on pollutants). Here s an example: let s say the reading from the past hour is 110 μg/m3 of PM 2.5 at your location. According to the BAQI table (below), the BAQI should be between 19 and 39. But, we take the worst-case scenario, which means calculating the BAQI based on the assumption that the concentration will stay the same for the next 24 hours. The BAQI will show exactly 19. Similar calculations are performed for all pollutants with multiple hour exposure guidelines.
12 Ultimately, this is a simple way to ensure that people know just how much they might be exposed to pollution at any time of day. As pollution changes, though, so does the BAQI, and it updates in real-time to give you a clear sense of what s in the air you breathe. Also, to be transparent and to provide choice to our users, we always provide local AQIs as well, so people can compare the BAQI with their local source. BAQI Conversion Table:
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V. What s next? 14 Air pollution continues to plague people across the world, and it s never been more vital to address it with new, innovative approaches. We believe that the first, and most important step in doing so is to make our air visible in real-time, all over the world so it can then be acted on. The BAQI is an ongoing effort to do so, but we re excited that it now helps millions of people across the world know more about the air they breathe.
15 There s a change in the air... Embrace it! BreezoMeter is the go-to partner for integrating real-time, hyperlocal air quality data into products. Get in touch: sales@breezometer.com To learn more about how our technology works, check out our new 2 minute explainer video. Thanks for reading breathe easy!