MODULE II: AIR QUALITY
Overview: The overall goal for all Community Science in the ECV is to build power so that you can advocate for improved Environmental Health. This lesson gives you the background to understand that some data are “invisible” to the eye but are still measurable. It also builds power by giving youth control over the data collection and analysis processes. Building a community sourced and managed air monitoring network allows students ownership from the ground up. This lesson focuses on air quality, what the health concerns are and how to measure it. It also creates a physical and social network of monitors in the ECV. The goal is to develop and use data generated from a Community Built System to advocate for improved Air Quality.
Background: The main components of the air in our atmosphere are nitrogen (78%) and Oxygen (21%). Other components include argon, carbon dioxide, water vapor, particles, and other gases. Particles that are present in the air include dust, dirt, soot, smoke, and liquid droplets. The particles that can cause harm to humans or animals are called Particle Pollution or Particulate Matter (PM). Generally, they are a mixture of solid and liquid droplets suspended in the air. Particles can be of many sizes and shapes and also be made up of different components. There are inorganic compounds (ammonium sulfate, ammonium nitrate, sodium chloride), organic chemicals, soot, metals, soil or dust particles, biological materials (pollen and mold spores), and acids (sulfuric acid). Particles are measured by their diameter. Those with a diameter smaller than 10 micrometers (µm) can cause the greatest problems. This is because they can pass through the nose and throat and enter the lungs. Particles greater than 2.5 up to 10 micrometers are called coarse particles (PM10) and particles smaller or equal to 2.5 micrometers are called fine particles (PM2.5). Ultrafine particles measure less than 0.1 micrometer (PM0.1).
Where does particle pollution come from?
Some particles are emitted from construction sites, unpaved roads, smokestacks, or fires. These are primary particles. Secondary particles are formed in atmospheric reactions and involve chemicals like sulfur dioxides and nitrogen oxides (emitted from power plants, industries and automobiles). These are mostly fine particles. Other activities that produce particle pollution are cooking, smoking, dusting, and vacuuming.
Where are they and how long do they stay in the air?
Even an air that looks clean, particle pollutants are found. They occur all time of the year and can remain in the atmosphere for days or weeks. Particles that were produced in one area travel for thousands of miles to other regions and change the air quality. The levels of particle pollution are higher near busy roads, urban and industrial areas, areas with smoke due to wood stoves, fireplaces, campfires, or wildfires, and hot humid days.
How to measure Particulate Matter?
There are several instruments to measure different particles sizes and concentrations. Measuring particle concentration is important to standardize emission limits of air quality. The EPA has set National Ambient Air Quality Standards for six principal pollutants. The table below shows the standards for PM10 and PM2.5
Health implications of Particulate Matter: Scientific studies have linked exposure to particle pollution to health problems such as:
Premature death in people with heart or lung disease; Nonfatal heart attacks; Irregular heartbeat; Aggravated asthma; Decreased lung function; Increased respiratory symptoms (irritation of the airways, coughing, difficulty breathing) Some people are more likely to be affected by the exposure - people with heart or lung diseases, children, and older adult.