Village Green Project: What’s in our Air?

By Ronald Williams

What’s in our air? It’s made up of 78 percent nitrogen, 21 percent oxygen, and one percent other gases such as carbon dioxide.  An even smaller contribution comes from gaseous air pollutants such as ozone or carbon monoxide.  In addition to the gases, air contains tiny particles from both natural and man-made processes.

In the Village Green Project, my EPA colleagues and I are developing a community-based system that repeatedly measures select gases and particles so residents can monitor local air quality and know what’s in their air.

Here are three important components:

Ozone
Knowing daily changes in ozone concentrations is very important, especially to those with respiratory illnesses such as asthma.  Ozone is generally highest on sunny summer days, when sunlight fuels atmospheric chemistry and generates ozone from a mixture of emissions.   The Village Green monitor will report ozone many times during the course of the day, showing how ozone levels go up and down based upon air pollution emissions and sunlight.

Particulate Matter

Particulate matter. For a larger version, go to: http://1.usa.gov/14hbTWp

All of us are exposed to particulate matter from a wide variety of local and distant sources.  After being produced, particles can transport hundreds of miles.  We encounter it in our homes, in our cars, in our work places, and out in our yards.  Understanding how it changes in the environment on a day-by-day and even hour-by-hour basis will help local citizens be better informed about this pollutant, which has been associated with a wide variety of human health effects.

Black Carbon
There’s an old saying that ‘everyone complains about the weather, but no one ever does anything about it.’ Now here’s our chance to learn about a pollutant that may affect our climate and is also important for health. Scientists now know that combustion products, such as black carbon, have the potential to influence climate change.  Black carbon is also a good indicator of emissions from fuel-burning, including from vehicles, forest fires, and smoking.  By monitoring black carbon levels in local air, the Village Green Project will help increase our understanding of links between local pollution sources and their impact on black carbon.

Even before the monitor is up and running, we’ve received regular inquiries about the Village Green Project from community groups, environmental scientists and those involved in air quality research.  Cleary, we’ve struck a nerve with citizens, and the desire of local communities to know what’s in their air and gain information about local air quality is ever-growing!

We expect the Village Green monitor will be operating this summer.  Stay tuned to this blog for more (and for our future web site) as we move forward.

About the Author: Ron Williams is an exposure science researcher who is studying how people are exposed to air pollutants and methods to measure personal exposure.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

The Palm-Sized Wonder that Brings Life to Village Green

By Vasu Kilaru and Gayle Hagler, Ph.D.

The petite 'electronics sandwich' at the heart of the Village Green system - an Arduino board on the bottom with layers of other accessory electronic boards stacked on top.

Welcome back to the Village Green Project, an ongoing EPA research, development and demonstration project to build a solar-powered station to measure air pollutants.

This innovative new measurement system must: collect and send data; use minimal power; monitor instrument performance; and have remote on-and-off capabilities for several components to match changing conditions (off for dark and cloudy days, and then on again when the sun starts to shine).

The team searched far and wide for an on-board computer that would serve as the “brains” of the Village Green System. The computer needed to run on very little power, be flexible enough to handle all of our requirements, and ideally work using a free, publically available (“open source”) computer program.

We discovered Arduino—a microcontroller that is essentially a simple computer with an accompanying free programming tool. A wide group of people, including artists, designers and hobbyists, are already using it to build electronics like homemade clocks or robots. It works perfectly for our needs because it uses very low power and can fit in your hand.

A number of accessory electronic items allow the small circuit board to meet the requirements of the system. For example, one accessory adds a timestamp to the data being collected so anyone viewing it can see the amount of air pollutants measured at a particular time and day. Another accessory links the Arduino board with a cellular modem (similar to the “data” port of a cellphone), which then sends recorded air pollution data to our on-line database. These accessories are electronic boards that stack on top of the main Arduino board, making what looks like an electronics sandwich.

With a free programming tool available to the Arduino-user community, we are developing a custom computer program for the Village Green System—nearly 800 lines of code and counting.

So far, so good! Recently, North Carolina experienced several days of cloudy, overcast weather. The trusty Arduino board successfully handled the decrease in power—turning off several instruments during that time and then efficiently restarting them once the sun came back out.

About the Authors: Gayle Hagler is an environmental engineer who studies air pollutant emissions and measurement technologies. Vasu Kilaru works in EPA’s Office of Research and Development. He is currently working on the apps and sensors for air pollution initiative (ASAP) helping the Agency develop its strategic role and response to new sensor technology developments.

Note: Mention of trade names or commercial products do not constitute endorsement, certification or recommendation for use.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Village Green Project and Use of Sustainable Energy

By Ron Williams and Bill Mitchell

Watts up, everyone? Welcome back to the Village Green Project and learn about science as it happens at EPA! For those just joining us, EPA researchers in North Carolina are designing and building a low-cost air quality monitoring system from the ground up that can be provide local air quality data to a community.

One of our project goals is to design an air quality monitoring system that is fully self-powered and can operate for a long period of time using very little energy.

Our solution: solar power. We have identified a design that will include sustainable energy (solar power) and features that will allow the monitoring system to operate for long periods of time during the night and when it is cloudy.

One of the first things we had to do was determine how much power is needed to run a large number of environmental monitors and to transmit data from the system to our web site where we hope to make data available. Our first design shows that we will need 15 Watts to fully power all of the electrical parts (sensors, fans, control circuits, communication link).

We identified two highly efficient solar panels that we can use that are 26 inches by 41 inches in size. They are small enough for the monitor and can generate up to 60 Watts of power. The extra power that is generated can be stored in a battery for the solar cells to use when conditions are not favorable, like cloudy days. The rechargeable 12-volt battery is about the size of a car battery. This was good news as we wanted to avoid having a field of solar panels that would drive up the operating cost.

We think we worked it out on paper—now the challenge will be to see what happens when we piece it all together.  Stay tuned for more updates on our discovery process.

About the Authors: Ron Williams is an exposure science researcher who is studying how people are exposed to air pollutants and methods to measure personal exposure. Bill Mitchell is an electronics expert who provides support to a variety of air pollution research projects.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Welcome to the Village Green Project!

Welcome to the Village Green Project, an EPA exploration into new ways of measuring air pollution.

We are Gayle Hagler and Ronald Williams, researchers on the Village Green Project team. We and others on the team will blog periodically to share the goals and challenges of the project and invite you to learn more about the work.

Check out the video clips with this blog and meet us. We are excited to be sharing our discovery process for this research project with you.

The goal of the pilot project is to design and build a low-cost, solar-powered air monitoring system that will take continuous readings of several air pollutants and weather conditions and provide data to the public every five minutes.  The project is breaking ground on many fronts and is a challenging and fun puzzle, requiring a mix of tinkering skills, strategic shopping know-how, and an eye for design.

The Village Green Project got its name from history when village greens were the heart of a town where citizens came together. We borrowed the concept because our research provides the science and technology to assess air quality and support sustainable communities.

There are some important conditions that the Village Green prototype must meet: the design has to be low maintenance, energy efficient, low cost and provide real-time data. And, of course, we need to prove the system works and provides reliable data.

We are also exploring several designs that will fit into a community setting, such as a park bench with solar panels providing shade over the bench, or a play structure.  After development, we plan to install and test the first prototype in the Research Triangle area this year.

There are many technical challenges to the project. Some of the goals and questions the team has been grappling with include:

  • Low cost to install and run – Can we run the entire system on solar or wind power? Can we make measurements without needing extra laboratory work or frequent visits to maintain instruments?
  • Real-time data – How can we provide air quality measurements in minutes or hours rather than days? This will enable researchers and community members to study changes in air pollution over time.
  • Public engagement – Can we design the structure to be suitable for a public park, playground or other outdoor environment? How can we engage someone visiting the station to learn about air-quality science?
  • Sharing the data – How can we send the measurements and process the data? How can we engage citizens in this project and make it interesting for them to learn about the science behind air quality monitoring?

Members of our research team will continue to post updates here on It All Starts with Science as we work through these challenges!  Stay tuned to learn more about the technology we are exploring, the science behind the measurements and how the prototype development process goes!

About the Authors: Ronald Williams is an exposure science researcher who is studying how people are exposed to air pollutants and methods to measure personal exposure.  Gayle Hagler is an environmental engineer who studies air pollutant emissions and measurement technologies.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.