Prince George’s County leads the way in many efforts to reduce air pollution while alerting employees and citizens to the potential health risks of ground-level ozone and particulate matter. The county is a member of the Clean Air Partners, a public-private partnership aimed at increasing public information about the region’s air pollution problems.
The county’s air quality procedure is standard operating procedures that outline the actions that must be taken by various county agencies whenever a code red or code yellow air quality alert is issued by Clean Air Partners. This operating procedure is updated annually to capture staff and responsibility changes within the county’s agencies.
Regional Ambient Pollutants
The Environmental Protection Agency (EPA) has set National Ambient Air Quality Standards (NAAQS) for 6 principal pollutants, which include ozone, particulate matter, carbon monoxide, sulfur oxides, nitrogen oxides and lead. These pollutants, known as criteria pollutants, are derived from numerous sources that are considered harmful to public health and the environment.
Air Quality Index Levels
The Air Quality Index (AQI) is an index used for reporting forecasted and daily air quality. The AQI uses both a color-coded and numerical scale to report how clean or polluted the air is and what associated health effects might be of concern. The AQI focuses on health effects people may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for 5 major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health. Ground-level ozone and airborne particles are the 2 pollutants that pose the greatest threat to human health in this country.
- Good - Air quality is considered good, and air pollution poses little or no risk.
- Moderate - Air quality may pose a moderate health risk, especially for those who are unusually sensitive to air pollution.
- Unhealthy for Sensitive Groups - Members of sensitive groups, children and adults with respiratory and heart ailments, may experience health effects and should limit time outside.
- Unhealthy - Everyone may experience health effects and should limit their outdoor activity. Members of sensitive groups may experience more serious health effects.
- Very Unhealthy - Everyone may experience more serious health effects and should avoid outdoor activities.
|Air Quality Index Levels of Health Concern||Numerical Value||Meaning|
||0-50||Air quality is considered good, and air pollution poses little or no risk.
|Moderate||51-100||Air quality may pose a moderate health risk, especially for those who are unusually sensitive to air pollution.
|Unhealthy for Sensitive Groups
||101-150||Members of sensitive groups, children and adults with respiratory and heart ailments, may experience health effects and should limit time spent outside. The general public is not likely to be affected.
||151-200||Everyone may experience health effects and should limit their outdoor activity. Members of sensitive groups may experience more serious health effects.
||201-300||Everyone may experience more serious health effects and should avoid outdoor activities, especially individuals with heart and breathing ailments, children, and older adults.
|Air Quality Rating||Steps to Protect Your Health & Our Environment|
Enjoy the great outdoors:
Some pollution. Even moderate levels pose risks to highly sensitive groups:
|Unhealthy for Sensitive Groups (101-150)
Pollution levels are harmful to children, older adults, and anyone with a respiratory or heart condition. Limit physical outdoor activity:
Everyone should limit strenuous outdoor activity when the air is unhealthy to breathe:
|Very Unhealthy (201-300)
Pollution levels are very unhealthy for everyone:
Do Your Share for Cleaner Air
Visit Clean Air Partners to get your daily AirAlerts and discover simple steps you can take each day to improve our region's air quality, protect your health, and reduce the risks of climate change. Read about their Air Quality Resources here.
Air Quality & Your Health
In Prince George’s County and the Washington, D.C. metropolitan area, the 2 most important pollutants that threaten human health are ground-level ozone and particle pollution. If you are a typical adult, you'll breathe in close to 3,500 gallons of air in a single day. If your atmosphere is polluted with ozone and particle pollution, you may see your lung function reduced by as much as 20%.
Ozone is an extremely reactive gas comprised of 3 atoms of oxygen. Ozone exists naturally in the earth's upper atmosphere, the stratosphere, where it shields the earth from the sun's harmful ultraviolet rays. The ozone layer in the upper atmosphere exists naturally and is essential to life because it filters harmful ultraviolet radiation from the sun, reducing the amount reaching the earth's surface. High concentrations of ozone near ground level, however, can be harmful to people, animals, crops, and other materials.
Ground Level Ozone
Ground level ozone is the main ingredient in urban and regional smog and is found in the air we breathe. It is formed through a complex chemical reaction between volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of sunlight. Sources of man-made VOCs and NOx include:
- Automobiles, trucks and buses
- Consumer products such as paints and cleaners
- Gasoline storage and transfer
- Industrial use of solvents and degreasing agents
- Large combustion and industry sources such as utilities
- Off-road engines such as aircraft, locomotives, boats, construction equipment and lawn and garden equipment
Health Effects of Ozone
High concentrations of ozone can cause shortness of breath, coughing, wheezing, fatigue, headaches, nausea, chest pain, and eye and throat irritation. The most common symptom that people have when exposed to ozone while exercising is pain when taking a deep breath.
The EPA estimates that 5 - 20% of the total U.S. population is especially susceptible to the harmful effects of ozone pollution. The following groups are most vulnerable:
- Athletes and individuals who exercise outdoors
- Children, because their respiratory systems are still developing (They're more active and spend more time outdoors, inhaling more air pollution per pound of body weight than do adults)
- Older adults, because their respiratory and immune systems lose some of their resilience (Damage caused by ground level ozone pollution can aggravate existing conditions or irritate tissues that make them susceptible to infection)
- People with pre-existing respiratory problems
You may not be able to see them but "Particulate matter" is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. These particles come in a wide range of sizes. These particles - the ones under 2.5 micrometers in diameter are called fine particles and they are too small for our respiratory systems to filter out, and end up getting trapped in our lungs where they may adversely affect our health. The very smallest pass through the lungs into the blood stream and can damage the heart. They come from a variety of sources such as:
- Burning of wood
- Construction sites
- Stone crushing
- Tilled fields
- Unpaved roads
Other particles may be formed in the air from the chemical change of gases. They are indirectly formed when gases from burning fuels react with sunlight and water vapor. These can result from fuel combustion in motor vehicles, at power plants, and in other industrial processes.
Unlike ground level ozone, particles are not a seasonal pollutant; high levels can occur any time of the year. Unhealthy levels of particle pollution in the air can cause or trigger significant health problems. These range from coughing and difficult or painful breathing to the possibility of an emergency room visit or even premature death. Exposure to particles can decrease lung function, weaken the heart, and possibly bring on a heart attack. The environment also suffers from particle pollution. Particles are the major source of haze, and can harm the environment by changing the nutrient and chemical balance in soil and water.
Health Effects With Particulate Matter
- When exposed to particulate matter, people with existing heart or lung diseases-such as asthma, chronic obstructive pulmonary disease, congestive heart disease, or ischemic heart disease-are at increased risk of premature death or admission to hospitals or emergency rooms.
- The elderly also are sensitive to particulate matter exposure. They are at increased risk of admission to hospitals or emergency rooms and premature death from heart or lung diseases.
- When exposed to particulate matter, children and people with existing lung disease may not be able to breathe as deeply or vigorously as they normally would, and they may experience symptoms such as coughing and shortness of breath.
- Particulate matter can increase susceptibility to respiratory infections and can aggravate existing respiratory diseases, such as asthma and chronic bronchitis, causing more use of medication and more doctor visits.
As a participant in Clean Air Partners, the county receives daily forecasts of regional air quality, the county the helps notify citizens and employees when unhealthy air quality is expected through AirAlerts. The ozone season generally runs between May and September. Employees and citizens are encouraged to sign up for AirAlerts. Employees with smartphones can download the Clean Air Partners App (available for both iPhone and android users).