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.

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.