Including Ground Level Ozone in the Science Curricula

Waldemar Pacholik

Earth Science Teacher Central Islip, NY

Introduction

Tropospheric ozone is a serious health hazard that is usually not included in the earth science or living environment curricula in schools on Long Island. One reason for this is that most people do not know that Suffolk County often has the highest tropospheric ozone levels in New York State. While stratospheric ozone, the good ozone, is considered when discussing the effects of the destruction of the ozone layer, tropospheric ozone, the bad ozone, that is associated with smog does not receive the attention that it should. In part, this is because tropospheric ozone is usually not included in the New York State Regents Exam whereas stratospheric ozone is. The nature of tropospheric ozone should be presented repeatedly during the school year in as many settings as possible in order to emphasize the seriousness of this environmental problem.

Ground level ozone can be mention or presented as a full lesson when considering topics such as:

  • Graphing graphing of direct relationship between summer temperatures above 80o F and ozone concentration using data from ozone monitoring stations; constructing cyclic graphs of ozone variation through the day.
  • Mapping making maps by using national distribution of ground level ozone concentration data 
  • Global air mass movement and predictions where plume of ozone producing air will go.
  • Global warming burning of fossil fuels which produce nitrogen oxides and interaction with volatile organic compounds, which produce ozone during hot, sunny days.
  • Differences between stratospheric ozone and ground level ozone (good verses bad ozone).
  • Photochemical smog and components of photochemical smog that produce ozone (nitrogen oxides from urban motor vehicles interacting with natural volatile organic compounds from trees), which cause ozone related health hazard at a distance from the smog producing area. For example, New York City verses eastern Long Island. 

Bad and Good Ozone

Objectives: Students will:

  • understand development of ozone pollution in the troposphere
  • understand significant of the stratospheric ozone to the life of earth
  • how to avoid air which presents high health hazard

Background:

  • Good Ozone. Ozone occurs naturally in the Earth's upper atmosphere - 6 to 30 miles above the Earth's surface - where it forms a protective layer that shields us from the sun's harmful ultraviolet rays. Manmade chemicals are known to destroy this beneficial ozone. An area where the protective "ozone layer" has been significantly depleted-for example, over the North or South pole-is sometimes called "the ozone hole. The United States, along with over 180 other countries, recognized the threats posed by ozone depletion and in 1987 adopted a treaty called the Montreal Protocol to phase out the production and use of ozone-depleting substances. EPA has established regulations to phase out ozone-depleting chemicals in the United States.
  • Bad Ozone. In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone at ground level is a harmful air pollutant.
  • Are you at risk from ground-level ozone? Several groups of people are particularly sensitive to ozone-especially when they are active outdoors-because physical activity causes people to breathe faster and more deeply.
  • Active children are the group at highest risk from ozone exposure because they often spend a large part of the summer playing outdoors. Children are also more likely to have asthma, which may be aggravated by ozone exposure.
  • Active adults of all ages who exercise or work vigorously outdoors have a higher level of exposure to ozone than people who are less active.
  • People with asthma or other respiratory diseases that make the lungs more vulnerable to the effects of ozone will generally experience health effects earlier and at lower ozone levels than less sensitive individuals.

Photochemical Smog What Makes It Toxic

Objectives:

  • How smog develops?
  • Why ozone is a Health hazard

Photochemical smog is the chemical reaction of sunlight, nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere, which leaves airborne particles (called particulate matter) and ground-level ozone.

Nitrogen oxides are released by nitrogen and oxygen in the air reacting together under high temperature such as in the exhaust of fossil fuel-burning engines in cars, trucks, coal power plants, and industrial manufacturing factories. VOCs are released from man-made sources such as gasoline (petrol), paints, solvents, pesticides, and biogenic sources, such as pine and citrus tree emissions.

This noxious mixture of air pollutants can include the following:

Ground-level ozone also damages vegetation and ecosystems. In the United States alone, ozone is responsible for an estimated $500 million in reduced crop production each year.

 

Ozone Pollution Carried by Air Mass Circulation

Objectives: Students will be able to:

  • understand how ozone is formed at ground level
  • understand air masses
  • understand how air masses travel around the globe
  • predict movement of an ozone producing plume

Background:

Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth's upper atmosphere (stratosphere) and at ground level (troposphere). Ozone can be good or bad, depending on where it is:

  • Good Ozone. Ozone occurs naturally in the Earth's upper atmosphere - 6 to 30 miles above the Earth's surface - where it forms a protective layer that shields us from the sun's harmful ultraviolet rays. Manmade chemicals are known to destroy this beneficial ozone.
  • Bad Ozone. In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone at ground level is a harmful air pollutant.

Ground-level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC.

Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue.

Ground-level ozone also damages vegetation and ecosystems. In the United States alone, ozone is responsible for an estimated $500 million in reduced crop production each year.

  • Air masses develop characteristic of the area they stagnate over for a significant period of time. As a result they are characterized by uniform temperature, moisture content and pressure.
  • Prevalent winds move them and their pollution content around the globe changing weather and air quality on their path.
  • The air quality for the next following days can be predicted by applying principles of air mass movement.

Movement of the ozone plume with the air masses

  • Students will use maps on the airnow.org we site to predict which polluted air will move.
  • Students will watch movies which explain formation of bad ozone and why monitoring movement of ozone plume is an important information for growing number of people. www.airnow.gov/index.cfm?action=movie.main