Danger In The Air!
Teacher Background
Activity #4: Finding and Analyzing Air Quality Data

Purpose: The students will collect air quality data and explore correlations between weather and concentration of pollutants. They will use the World Wide Web (WWW) or other resources like the newspaper or government agencies.

The activity opens with questions about air pollutants and their sources. These questions may be used as a pretest.

Further Discussion:
Ask the students what they are breathing when they inhale and exhale. Most may say oxygen. Have them look at the page on composition of the atmosphere. Ask the students how we know that our air is polluted. They may answer that they can see car exhaust and smoke coming from chimneys. Ask the students what types of gases they think these pollutants are. Have them look at the definitions of pollution page and begin the particulate activities.

Air Quality Data

Several states in the US give air quality values for their major cities on a daily basis. Below is listed a resource on the WWW that will enable you to explore your home state for air quality information. Also listed are links to states that do give daily air quality values. You may want to use these states as a comparison to your own state and city or town.

Utah: Utah Department of Environmental Quality/ Division of Air Quality/Air Monitoring Center/Air Pollution Report for Wasatch Front Areas:

Texas: Texas Natural Resource Conservation Commission/ Office of Air Quality/ Monitoring Operations/Peak Ozone Levels - Up to date ozone level values for selected cities in Texas.

California: California Air Quality Control Districts/ South Coast Counties/Current Readings at Air Monitoring Subregions - Up to date readings by the smog control agency of Los Angeles, Orange and Riverside Counties.

Michigan: Daily ozone readings for selected cities and towns in Michigan.

Other Air Quality Data Resources: Many newspapers now list air quality levels along with weather information. Check your local newspaper. Check your local government air quality agency, they may be able to give you air quality data.

Puget Sound Area Residents: The students will need to be provided with air quality data. The Seattle Times gives air quality data for carbon monoxide, particulates, and ozone on their weather page. The data is listed Monday through Friday. A copy of the newspaper will need to be provided daily. Air quality values may also be obtained by calling the Puget Sound Air Quality Control Agency at 1-800-552-3565. The students record the air pollution data on the table provided in the activity or on a table they create.

Weather Data

  • The University of Washington
  • The Weather Channel
  • The Weather Processor
  • The Weather Underground
  • At the end of the activity students will graph their data.

    Pollution Standards Index

    The Air quality data is listed as the pollutant standards index (PSI) developed by the Environmental Protection Agency.

    The Pollutant Standard Index (PSI) was developed by the Environmental Protection Agency to provide accurate, timely, and easily understandable information about daily levels of air pollution. The PSI is calculated daily for all major metropolitan areas of the United States with populations exceeding 200,000. Index figures enable the public to determine whether air pollution levels in a particular location are good, moderate, unhealthful, or worse. In addition, EPA and local officials use the PSI as a public information tool to advise the public about general health effects associated with different air pollutant levels.

    The PSI converts the measured pollutant concentration in a community's air to a number on a scale of 0 to 500. The most important number on the scale is 100, since that number corresponds to the air quality standard established under the Clean Air Act. A PSI level in excess of 100 means that a pollutant is in the unhealthful range on a given day; a PSI level at or below 100 means that a pollutant reading is in the satisfactory range.

    The intervals and the terms describing the PSI air quality levels are as follows:

    From 0 to 50 good
    From 50 to 100 moderate
    From 100 to 200 unhealthful
    From 200 to 300 very unhealthful
    Above 300 hazardous

    Question: Which days had the highest levels of air pollutants? Which pollutant was the highest?
    Answer: Will vary depending on data collected. The weather should usually be sunny, high pressure and little to no wind.

    Question: What was the weather like on each of those days?
    Answers: The weather will usually be sunny, with high pressure and little to no wind. Weather conditions are often stable.

    Questions: On days when pollution levels are the highest are there similar weather readings? What are the similarities?
    Answers: Sunny days.

    Questions: On days when low levels of pollution are present, what is the weather like?
    Answers: Cloudy to partly cloudy, windy.

    Questions: Describe how you think the weather affects the levels of air pollutants?
    Answers: Students should look for patterns in weather and pollution levels. When the pollution values rise it will be usually accompanied by clear, sunny weather conditions and a temperature inversion (weather and air pollutants module link) occurs. A Temperature inversion may occur. A Temperature inversion is a weather condition which causes a warm air mass to overlie cold air and inhibit mixing of air in the lower atmosphere, there by trapping any pollutants in place. When pollution values lower the weather conditions are cloudy and winds and precipitation help to disperse pollutants.

    Questions: Why do we have days we are not able to use our fire places or wood stoves?
    Answers: The weather conditions are clear, sunny, high pressure system and little or no wind.

    Questions: Why on hot, sunny summer days pollution values rise to unhealthy levels?
    Answers: The weather conditions are clear, sunny, high pressure system and little or no wind.

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