Category: AirCare

  • Air quality 2019: Things you should know about Whitefield, Bangalore

    Air quality 2019: Things you should know about Whitefield, Bangalore

    Introduction

    This article describes the assessment of air quality around Whitefield (Bangalore, India) for the period Aug 2018 to Dec 2019 based on the data from 13 citizen managed low cost realtime air quality monitors and one government manual monitor. For the assessment, we will be using the PM2.5 (particulate matter of size 2.5 microns or below measured in μg/m3) measurements done by 14 PM2.5 monitors at various locations around Whitefield.

    https://aircare.mapshalli.org
    Figure 1: Air quality monitors showing current PM2.5 values @Jan-18-2020 10:30AM

    For an in depth analysis, we will be using data from an AirCare monitor at Ferns Paradise and compare with the data from the AirCare monitor at Windmills.

    PM2.5 are particles or droplets of size 2.5 microns or less are a major part of polluted air and is associated with various negative health effects. There is no safe limit for PM25 and the WHO guideline value is 10 µg/m3 for annual average. Long term exposure to these particles cause increased rates of heart disease, stroke, lung diseases, kidney disease, and diabetes. For 10 µg/m3 increase in PM2.5 the life expectancy reduces by one year. Exposure to 10 µg/m3 of PM2.5 is equivalent to smoking half a cigarette per day. You can read about PM2.5 and its harmful effects here.

    https://aircare.mapshalli.org
    Figure 2: PM2.5, last 24 hours averages, and loss of life expectancy @ Jan-18-2020 10:30AM

    Findings & Analysis

    Why do we want to use the USA air quality standards in our analysis?

    In the analysis described in this article, we have used the US air quality standards instead of the India air quality standards.

    Figure 3: Mismatch of air quality assessment between WHO/USA vs Indian standards.
    Values displayed are for PM2.5 in µg/m3

    Indian air quality standards are very relaxed. For example, an 60 µg/m3 24 hour PM2.5 exposure is considered euphemistic Satisfactory, whereas as per USA standards it is considered Unhealthy!

    60 µg/m3 of PM2.5 is 6x the WHO guidelines, equivalent to smoking 3 cigarettes a day, and losing of 6 years of life!

    In India, the air quality is reported via air quality index that is in the range (0-500). Air quality index is more suitable to report a single index number when considering many pollutants like PM2.5, PM10, NO2, etc. All the research reports that analyze health effects are based on raw PM2.5 values averaged to 24 hours and yearly. We have used raw PM2.5 number for the analysis. The air quality assessment is based on USA air quality standards are described here.

    Yearly snapshot

    The following picture shows the daily air quality assessment for two Whitefield locations for everyday of the year.

    Figure 4: Ferns Paradise – Daily air quality assessment as per USA air quality standards – PM2.5 µg/m3
    Figure 5: Windmills – Daily air quality assessment as per USA air quality standards – PM2.5 µg/m3

    The above two figures shows that Ferns Paradise had more Good air quality days when compared to Windmills. Note the high number of Unhealthy air quality level days during the months of January and February.

    Table 1: Air quality ranking and loss of life expectancy

    The table below shows the best air quality rank, Aug 2018 to Dec 2019 period PM2.5 averages, and loss of life expectancy for Whitefield locations.

    Table 1: Ranking, PM2.5 and loss of life expectancy
    * Based on partial data

    The PM2.5 levels are 3.8x times of that of WHO guidelines and fall in the Unhealthy for Sensitive Groups USA air quality assessment category, meaning that members of sensitive groups may experience health effects and the general public is not likely to be affected. The following table shows a comparison of average life expectancy lost due to various causes.

    Source: https://aqli.epic.uchicago.edu/pollution-facts/
    Figure 6: Life expectancy lost due to various causes

    Table 2: 2018 to 2019 reduction in PM2.5 pollution

    The table below shows the yearly PM2.5 pollution level changes from 2018 (Aug-Dec) to 2019 (Aug-Dec):

    Table 2: 2018 – 2019 changes in PM2.5 and ranking of locations
    * Do not have data for the comparison

    From 2018 to 2019, the air quality has improved from Unhealthy for Sensitive Groups to Moderate category. Moderate means that the air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution. All location except Ramagondanahalli show good improvement in air quality.

    The reduction in PM2.5 levels can be attributed to the following known significant factors:

    • 24% increase in Wind Speed from 2018 to 2019.
    • 54% increase in rain from 2018 to 2019.
    • Graphite India Private Ltd factory partial shutdowns during the months of Oct-Dec 2018 and permanent closing down in Feb 2019.

    There is an unquantified increase in pollution due to increased number of vehicles, open waste burning, construction, and road dust. The following chart shows the source contributions for the year 2015 and 2030 (projected) from http://www.urbanemissions.info/india-apna/bengaluru-india/.

    Source: http://www.urbanemissions.info/india-apna/bengaluru-india/
    Figure 7: 2015 Sources of pollution

    .

    Source: http://www.urbanemissions.info/india-apna/bengaluru-india/
    Figure 8: 2030 Projected sources of pollution

    PM2.5 Monthly History

    Figure 9: PM2.5 History from 11-Aug-2018 to 11-Jan-2020

    Monthly Averages

    Figure 10: Monthly Averages

    The Unhealthy (64 µg/m3) air quality level is found during January. Top three months with Unhealthy for Sensitive Groups (47 µg/m3) air quality levels are: November, December, and February. Top three months with Moderate (16 µg/m3 ) air quality levels are : June, July, and August.

    During the months of June to September, the south west monsoon has a monthly average wind speed greater than 6 km/hr that effectively transports away the particulate matter reducing the pollution. During the same time, the monsoon rain also washes away the particulate matter but to a lesser extent. The monthly average wind speed (0.2 km/hr ) and the rain fall is at their lowest in January causing the particulate matter to linger close to the source.

    Figure 11: Relationship between PM2.5 pollution and Wind speed

    Wind speeds greater than 6 km/hr significantly reduces the PM2.5 pollution to levels below 20 µg/m3. Large number of open lands being converted buildings would reduce the wind speed and hence would increase the pollution levels.

    Day of the Month

    Figure 12: Day of the Month

    Days of the month with Unhealthy for Sensitive Groups (40 µg/m3 ) air quality levels are: 4th, 5th, and the 6th. Top three days of the month with Moderate (29 µg/m3) air quality levels are: 2nd, 14th, and the 15th.

    Day of the Week

    Figure 13: Day of the Week

    The PM2.5 pollution levels remain the same independent of the day of the week.

    Hour of the Day

    Figure 14: Hour of the Day

    Hours of the day with Unhealthy for Sensitive Groups (45 µg/m3) air quality are: 06:00AM – 08:00AM. Hours of the day with the Moderate (25 µg/m3 ) air quality levels are: 01:00PM – 03:00PM.

    The air that is closer to the earth is warmer and denser than the air above. The higher you go the air becomes colder and thinner. The air temperature decreases by ~1 degree centigrade for every 100m increase in altitude. The warmer air that closer to the ground rises transporting any particulate matter.

    During the winter months (Nov, Dec, and Jan) the skies are clear, the air is calm and stable, and the nights are longer. The winter sun, low in the sky supplies less heat to the earth’s surface; this heat is quickly radiated cooling air closer to the ground. A less dense warm air moves in to create a warm air cap/lid called the Inversion Layer, as shown in Figure 15.

    Figure 15: Temperature Inversion

    During the winter early morning hours, this inversion layer traps the pollutants along with the cooler air rich in moisture and is called the smog as shown below in Figure 16. This is the primary cause of high pollution during the winter mornings.

    Figure 16: Smog trapped over the city of Almaty, Kazakhstan during a temperature inversion.

    Once the Sun heats up the land and the air later in the day, the inversion layer is broken and the pollutants are carried away.

    Recommendations

    Summary

    Annual PM2.5 pollution levels across Whitfield (Bangalore) is estimated to be around 38 µg/m3. This is 3.8x times of the WHO guideline of 10 µg/m3. An estimated 3.9 years of life expectancy is lost due to PM2.5 pollution; this is 2x of the years lost due to smoking!

    Mother nature has helped in reducing pollution by 31% year over year through winds and extended monsoon rain. Citizens have played a role in shutting down multiple polluting industries around Whitefield.

    The number vehicles, road dust, and open waste burning continue to rise unabated every year.

    Citizens

    Citizens should become more aware of air quality standards and apply pressure to the government to follow WHO guidelines and adopt international standards. Become aware of who can influence actions to improve air quality. Residents need to actively promote walkability in the neighborhood and public transport through increasing number of BMTC Buses, METRO, Sub-urban rail.

    Citizens should eliminate their outdoor activities like walking, playing, and exercising when the air quality levels are Unhealthy for Sensitive Groups or worse: be aware of the poor air quality till 08:00AM. You can get a real time air quality for your location (or closer) at https://aircare.mapshalli.org. You can reduce the indoor air pollution level to less than 10 µg/m3 by installing and operating an indoor air purifier.

    Home Owner Associations

    Home owners associations should maintain their Diesel Generators and eliminate mosquito fogging as it causes significant pollution with no real benefits; instead use alternate and proven methods for mosquito control.

    Government

    Central Pollution Control Board (CPCB)

    From a policy front, Indian government should come up a realistic air quality standards aligned with WHO standards and adopt best practices from other countries.

    Karnataka State Pollution Control Board (KSPCB)

    Whitefield, the technical powerhouse of India just has one manual government air quality monitor! It is high time to replace the manual government monitor installed in EPIP, Whitefield with a real time continuous monitor that provides timely information to the citizens.

    BBMP, local Corporators, and the local MLA

    Include improvement of air quality in your manifesto and in the ward improvement plans.

    Ensure that the roads are cleared off dust and improve road infrastructure to prevent resuspension of road dust. Increase street cleaning using mechanized cleaners and manually remove dust from the roads and footpaths

    Proper disposal of garbage and penalizing garbage burning will also help.

    Acknowledgments

    We thank various individuals and home owner associations for hosting the 12 AirCare air quality monitors and one Purpleair monitor. They also spend their energy on a continuous basis to keep the monitors up and running. Rahul Bedi provides us with critical weather data for analysis.

    A list of individuals whom we want to thank are: Manoj (RxDx), Dr. Sunitha Maheshwari (RxDx), Clement Jayakumar (Ferns Paradise), Ajit Lakshmiratan, (Gulmohar), Zibi Jamal (Wind Mills), Ramakrishnan (Palm Meadows), Srinivas Ganji (Brigade Lakefrnont), Vivekanand (Gadjoy), Dr. Jagadish Prasad (Femiint Health), Mithun (PSN), Mukesh (Bren Unity), and Rahul Bedi (Pride Orchid).

    Epilogue

    How good are the low cost air quality monitors?

    The questions people always ask are the following: how good are the low cost sensors, have they been calibrated and recalibrated, will the data be used and accepted by government including the courts?

    The following figure shows correlation between the government monitor and one citizen air quality monitor.

    Figure 17: High correlation (R2=0.9) between government and private monitors
    Data shown is monthly PM2.5 in µg/m3

    Government including the courts will not accept data from low cost air quality monitors operated by citizens. We have shown that the data collected by large number of low cost monitors is as good as the expensive government monitors. The citizens air quality monitors provide better real time data and are able to capture the variations from location to location more effectively. We hope the data can be used in discussions to influence government to install more government real time air quality monitors.

  • Why you should not take morning or evening walks?

    Why you should not take morning or evening walks?

    Updated: Oct-01-2018

    Executive Summary

    Do you know someone who lives in the Whitefield area who goes for morning or evening walks? Why are we recommending that you should not take morning or evening walks? What is the best time to walk then?

    Based on the air quality analysis based on the data from March-01-2018 to Sep-30-2018, from Purple Air sensor located at Thubarahalli we found the following:

    • Air quality is the worst between 06:00AM – 08:00AM and between 07:00PM – 08:00PM.
    • Air quality is worse during the months of March and April; it becomes better during June and July.
    • Saturday has the worst air quality and Monday is the best day.
    • 13th of every month has the best air quality and 31st  has the worst air quality.

    Are you concerned about air quality and pollution? Want to know how to plan your day so that you are exposed to least amount of pollution? Please continue reading… The following topics are covered in detail:

    1. What is PM2.5 and how does it relate to pollution?
    2. Where to view PM2.5 data for Whitefield, Bangalore?
    3. Data analysis of air pollution from March-01-2018 to Sep-30-2018 and findings.
    4. How does pollution change month by month?
    5. What are the best and worst air quality days in a month?
    6. Which day of the week is the most polluted?
    7. Which hours of the day is the most and least polluted?

    What is PM2.5 and how does it relate to pollution?

    The term PM2.5 refers to fine particles or droplets of size 2.5 microns are less. This is 30 times smaller than an human hair. These particles are so small that they can reach your blood stream through the lungs. These particles come from vehicle exhausts, , vehicle brakes, construction, road dust, and fuel burning. Long term exposure to these particles cause increase rates of chronic bronchitis, reduced lung function, lung cancer, kidney disease, and diabetes.

    PM2.5 is measured in µg/m (micro grams in a cubic meter).

    PM2.5 Standards

    WHO PM2.5 standards

    WHO recommended guidelines is 10µg/mfor annual average and 25 µg/m3 for 24 hour average. There is no safe level of PM2.5.

    USA PM2.5 standards

    The USA standard for PM2.5 (µg/m3  24 hours), category, and health impacts are shown below.

    •  0 to 12.0 – Good
      • Air quality is considered satisfactory, and air pollution poses little or no risk.
    • 12.1 to 35.4 – Moderate
      • Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
    • 35.5  to 55.4 – Unhealthy for Sensitive People
      • Members of sensitive groups may experience health effects. The general public is not likely to be affected.
    • 55.5 to 150.4 – Unhealthy
      • Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects.
    • 150.5 to 250.4 – Very Unhealthy
      • Health alert: everyone may experience more serious health effects.
    • 250.5 to 500.4  – Hazardous
      • Health warnings of emergency conditions. The entire population is more likely to be affected.

    Where to view current values of PM2.5 in Whitefield, Bangalore?

    You can view the latest value (PM2.5 short term) and 24 hour average values at:

    https://aircare.mapshalli.org

    AirCare operates community based high density air quality network for Whitefield. Currently, there are 12 such sensors in operation.

    You can also view data from one government sensor at:

    http://aqicn.org/city/india/bangalore/bwssb/

    Data analysis of air pollution from March-01-2018 to Sep-30-2018 and key findings

    Mr. Rahul Bedi has been operating an air quality and weather station at Pride Orchid, Whitefield.  The sensor data is available at purpleair.

    We have analyzed over  222,216 sensor readings and found the following:

    • Air quality is the worst between 06:00AM – 08:00AM and between 07:00PM – 08:00PM.
    • Air quality is worse during the months of March, April, and Sep; it is better during June and July.
    • Saturday has the worst air quality and Monday is the best day.
    • 13th of every month has the best air quality and 31st of the month has the worst air quality.

    How does pollution change  month by month?

    Although the air quality is becoming better over the months, it is expected to become worse after the monsoon is over and during the Diwali season.

    What are the best and worst air quality days in a month?

    After all, 13th is not an unlucky day, it is the least polluted day  in a month. Don’t step out of the house on the 31st.

    How does pollution change by the day of the week?

    How does pollution change by the hour of a day?

    The best time to walk is during the lunch hour!  Avoid those early morning walks!

    Conclusion

    Hope the above data analysis can help to plan your days and hours better and avoid air pollution. You can contribute by becoming a host of a community air quality sensor. Read more about it here.

  • Methods to configure an IoT device for the first time

    Methods to configure an IoT device for the first time

    Introduction

    In this article, I will discuss the challenges in setting up an IoT device for the very first time and suitable methods to address these challenges.

    Many IoT devices are now being shipped to end consumers and these consumers are expected to setup the devices. For example, the product AirCare IoT is a Raspberry PI based air quality sensor that needs to be setup by a consumer for the first time.

    Although AirCare IoT has a built-in ethernet port, we expect the unit to be installed in a garage or a balcony where an ethernet cable is not expected to be available. The only other option is to use the Wi-Fi network.  Also, no display monitor with keyboard can be  connected to the IoT to allow easy configuration. Consumers expect a device such as this be easily setup using an phone app.

    Expected Procedure for Configuration

    A consumer would expect the following logical steps to configure the device:

    1. If not done already, download the app from the app store.
    2. Turn on the power for the device.
    3. Launch the app in the phone, the device should auto recognized, perform an easy setup.

    Challenges

    Factory shipped IoT can’t connect to Wi-Fi network at home

    In order for the above procedure to work, the IoT device should be connected to a Wi-Fi network is generally accessible from the app.  This is not possible, as the IoT shipped from the factory does not know your home Wi-Fi network name and the password! The first step in the setup should logically involve providing the home Wi-Fi network and the password.

    The IoT can be shipped to host an hot-spot with a known name (SSID), for example, AirCare Config, and a known password. The user can be instructed to connect  their phone to this Wi-Fi network temporarily to complete the setup. The user after a successful setup can connect the phone to their regular home Wi-Fi network.

    Once the network settings are available, the IoT can join the home Wi-Fi network.  The IoT can fall back to be an hot-spot if the credentials are invalid or has other connectivity issues.

    Can’t find the IP address of the just setup IoT

    Now we face a new challenge! Once the IoT connects to the home Wi-Fi network we need to know its IP address to connect to it from the app. This process would involve accessing the Wi-Fi router admin page and inferring the IP address. We can’t expect a consumer to perform this action!

    Conversely, the IoT can’t connect to the app because it does not know the IP address of the phone or the phone IP address could have changed. Also, the incoming network connections to apps are also discouraged in practice. The app would have learnt the MAC address of the IoT and can do use RARP (Reverse Address Resolution Protocol)  to map MAC address to the IP address. This level of deep networking stack access is not available to the apps.

    Furthermore, there is no central server like system at home that can share such information.

    Solution: Use an publicly hosted custom registry that can map MAC address to the IP Address

    In this solution, the IoT upon joining the home Wi-Fi network registers itself to a registry server using a well defined REST API as following:

    POST http://aircare-registry.mapshalli.org/register

    Parameters:

    • MAC address
    • IP address

    Now, the android app can query to get the IP address as follows:

    GET http://aircare-registry.mapshalli.org/register/<mac_address>

    Returns:

    Access credentials and other parameters have been omitted for brevity. The IP address of the IoT itself is not a publicly visible IP address but private address that is only valid in the local Wi-Fi network. The session mapping of public IP address to the private address is done automatically by the local router(s) using the NAT protocol.

    The app needs to manage its own MAC address to IP address table and use TTL values to intelligently query to get the IP address.

    Further Study

    The challenges and solutions points to the glaring gap of lack of centralized IoT management at home.

  • Why should you care about AirCare? – The Genesis

    Why should you care about AirCare? – The Genesis

    Introduction

    This is my first blog article!  I want to explain a new and exciting project called AirCare. The goal of AirCare is to provide air quality data using a network of low cost air quality sensors around Whitefield, Bangalore. These sensors are hosted by citizens themselves but share data openly to benefit all.

    Background

    Last year, at the request of my mentor, I worked with another student on a project to measure impurities in water. On that project, I worked only on the technical aspect of the solution, namely to develop an interface to capture/enter data related to the impurities in the water. Later, when I was discussing possible project options with my mentor, we naturally zeroed in on air pollution.

    Whitefield, chokes in pollution

    We live in Bangalore, India. Bangalore is the IT/tech capital of India, commonly referred to as the Silicon Valley of India. In recent years, Bangalore has seen a huge influx of people from other cities. There are the tech and back office workers hired by the multinationals of Europe and the US. Then there is the entire support economy that indirectly caters to these tech workers. A lot of this influx has been to an area called Whitefield, where I live.

    Why is Whitefield polluted?

    From a pollution perspective, the impact is twofold: Firstly, there are a lot more vehicles on the road, resulting in a huge increase in the amount of carbon fuel based particulate matters in the air.  Secondly, the availability of land/space in the Whitefield area has also meant a tremendous construction boom. Buildings in India are made of brick, mortar and concrete. The construction activity and resultant debris/dust on the roads results in a lot of dust particles in the air. The problem can be extended to other parts of India as well.

    What is AirCare and why should you care?

    Respiratory problems are rampant. Regulation is non-existent. I am embarking on this project with the help of my mentor. We want to develop a low-cost way of measuring air pollution at various locations, capturing the data and providing tools to analyze the data so that some remediation could be achieved.

    We are making our knowledge and software open source!

    We are making the the hardware and software solutions open source. This will enable anyone in the world make a similar network of air quality sensors for their community.

    In the future blogs, I will explain our journey covering technical and social aspects of the project.