If you're reading this, you are likely concerned about air pollution, both indoors and outdoors. Indoor and outdoor pollution sources differ, as does the composition of the compounds that can have a negative effect on our body.
There are over 200 types of regulated pollutants that can cause cancer or have adverse health effects, but the primary components of outdoor air pollution are as follows:
Particulate Matter (PM) - a mix of solid particles and liquid droplets in the air, which includes aerosols, smoke, fumes, dust, ash, and pollen. Fine particulate matter (PM2.5) has a diameter of 2.5 microns or less, and PM10 is less than 10 microns. PM2.5 is known to cause serious health problems, such as premature death, and can be dangerous for those with asthma, cardiovascular or lung disease.
Volatile Organic Compounds (VOCs) - organic chemicals like benzene or formaldehyde, which evaporate quickly at room temperature. Most scents or smells are comprised of VOCs, and may not be harmful in small doses, but have to compound long-term health effects.
Nitrogen Oxides/dioxides (NOx) - produced from the reaction of nitrogen and oxygen during combustion (fossil fuel engines, energy production). NOx causes inflammation of the airways and is a contributor to PM levels.
Sulfur Dioxide (SO2) - a sharp smelling gas created through industrial processes (mining, coal power plants) and fossil fuel engines. SO2 is the primary component of acid rain and irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest.
Ground-level ozone (O3) - a result of the chemical reaction between VOCs, NOx, and sunlight. O3 irritates the respiratory tract and eyes.
Carbon monoxide (CO) - CO is released when something is burned. The greatest sources of CO to outdoor air are cars, trucks and other vehicles or machinery that burn fossil fuels. Breathing air with a high concentration of CO reduces the amount of oxygen that can be transported in the bloodstream to critical organs like the heart and brain.
Carbon Dioxide (CO2) - a byproduct of combustion, as well as a result of the metabolic process in living organisms. Worldwide outdoor CO2 levels are not high enough to interfere with respiration, but indoor CO2 levels quickly rise without proper ventilation. Moderate to high levels of carbon dioxide can cause headaches and fatigue, and higher concentrations can produce nausea, dizziness, and vomiting.
While most sources of pollutants are man-made (the burning of fossil fuels, agriculture, dust and wildfires, waste management, mining operations), non-human activities (animals and vegetation) also contribute to poor outdoor air quality. Controlling the sources of outdoor air pollutants is a large and complex task, but you can do your part by avoiding the use of fossil fuel transportation and reduce the burning of solid matter (eg wood-burning stove).
Indoor pollutants are easier to recognize and control. The following household items are known to produce VOCs, PM, and other harmful compounds. Take extra care during indoor activities involving the following items, such as wearing an N95 breathing mask or by reading Improving the Air Quality in Your Home
Cigarettes or other sources of tobacco smoke
Stoves, Heaters, fireplaces, and chimneys
Unvented space heaters
Solvents
Paints and thinners
Adhesives
Hobby and craft supplies
Dry cleaning fluids
Glues
Wood preservatives
Cleaners and disinfectants
Moth repellents
Air fresheners
Building materials and furnishings
Copy machines and printers
Pesticides