Ground-level ozone is the main ingredient in urban smog. Ozone is not emitted directly into the air, but is formed when gases called nitrogen oxides (NOx) and volatile organic compounds (VOC) react in the presence of sunlight. NOx is usually a by-product of high-tem- perature combustion. Common sources are cars and power plants. VOCs include organic chemicals that vaporize easily, like gasoline.

Ground-level ozone forms readily in the atmosphere during hot and sunny times. Because people are exposed to this ground-level ozone and its harmful health effects, it is often referred to as “bad ozone.” Ozone can also form naturally in the stratosphere. Here it provides a protective layer above the earth that shields us from the sun’s harmful ultraviolet rays. Because people are not directly exposed to this ozone, and because it provides a useful purpose, it is often referred to as “good ozone.”

High concentrations of ozone can cause shortness of breath, cough- ing, wheezing, headaches, nausea, and throat and lung irritation. People who suffer from lung diseases like bronchitis, pneumonia, emphysema, asthma, and colds have even more trouble breathing when the air is pol- luted. These effects can be worse for anyone who spends significant peri- ods of time exercising or working outdoors. When we exercise heavily, we may increase our intake of air by as much as 10 times our level at rest.

Children are also at an increased risk of respiratory problems caused by ozone. Their lungs are still developing, and they breathe more rap- idly and inhale more air pollution per pound of body weight than adults.

In general, when ozone levels are high, your chances of being af- fected by ozone increase with the amount of time you spend being active outdoors and taking part in strenuous activities. For example, walking to a nearby store is not considered a strenuous or prolonged outdoor activity, but playing soccer is. Indoor, air-conditioned areas typically have half the ozone levels that are present outdoors. So, you can avoid unhealthy expo- sure to ozone by staying indoors in these cooler areas during the day.

Another way to avoid unhealthy exposure to ozone is by limiting the time you are active outdoors or by reducing your outdoor activity level. For example, instead of running or jogging for an hour, run for just 30 minutes or take a walk. You can also plan outdoor activities for times when ozone levels are lower, usually in the early morning or evening.

Use this Air Quality Index (AQI) to plan your activities. The Envi- ronmental Protection Agency (EPA) created the index as a way to re- port daily quantities of five major pollutants. In Texas, the AQI is gen- erally a convenient measure of ground-level ozone because it is the most common air pollutant.

• Texas Natural Resource Conservation Commission, tnrcc.state.tx.us
• Clean Texas Air, www.cleantex.org
• S. Environmental Protection Agency (EPA), www.epa.gov
• American Lung Association, lungusa.org
• City, county, municipal air quality

Good (0 to 50)—Level Green

• No warning is issued at this level. No health effects are expected.

Moderate (51 to 100)—Level Yellow

• No warning is issued at this level. Concentrations of ozone at this level may cause some respiratory effects from prolonged exposure during outdoor activity in people who are unusually sensitive to ozone.

Unhealthy for Sensitive Groups (101 to 150)—Level Orange

• If you are a member of a sensitive group—children who are active outdoors, adults involved in strenuous outdoor activities, people with a respiratory disease such as asthma, and people who are unusually susceptible to ozone—exposure to concentrations of ozone at this level may causesome respiratory symptoms, such as coughing or pain when taking a deep breath. These people should limit prolonged outdoor activity.

Unhealthy (151 to 200)—Level Red

• If you are a member of a sensitive group (see description in Level Orange), exposure to concentrations of ozone at this level will increase your chances of experiencing respiratory symptoms, such as coughing or pain when taking a deep breath. These people should avoid prolonged outdoor activity. Everyone else should limit prolonged outdoor activity.

Very Unhealthy (201 to 300)—Level Purple

• If you are a member of a sensitive group (see description in Level Orange), exposure to concentrations of ozone at this level will cause severe respiratory symptoms and impaired breathing. Stay in an air-conditioned room and avoid outdoor exertion. Everyone else should limit outdoor exertion.

Hazardous (301 to 500)—Level Maroon

• If you are a member of a sensitive group (see description in Level Orange), exposure to concentrations of ozone at this level will cause severe respiratory symptoms and impaired breathing. Stay in an air-conditioned room and avoid all outdoor exertion. Level Maroon emergency conditions are extremely rare, but they are more likely to affect the entire population. Everyone should avoid all outdoor exertion.

Introduction

Recess and unstructured play outdoors is vital to our goals of increasing physical activity for children. Most children can participate in vigorous play in an outdoor environment if  properly clothed. Weather precautions are necessary while students wait outside for school to begin and wait for transportation home from school. Hypothermia can result from prolonged exposure to the cold.  Due to our rapidly changing weather, students are frequently unprepared in wearing enough clothing to provide adequate protection. Because of this unreliability, our district must take extra caution to provide a safe environment for all students during inclement weather.

Temperature and Wind-chill Factor Recommendations

Temperature plus wind velocity or wind chill is a prominent factor in determining cold weather safety. As the speed of the wind increases, it carries heat away from the body more quickly. The effective temperature is the air temperature multiplied by the wind velocity; commonly know as the wind chill factor (see the following chart).  Conditions in the shaded zone make it dangerous for time spent outside.  Wet weather and wet clothing create more rapid heat loss from the body, therefore increasing the risk for hypothermia even in cool temperatures (above 40 degrees).  Also, 50% to 60% of the body’s heat loss takes place from the head and hands. Children cool more rapidly than adults due to their relatively greater surface area to body mass ratio.

The decision for students to be outside is determined by the campus administrator. If the weather is questionable for an outside activity such as recess, these websites report the temperature and wind chill factor:  www.weather.com website or the www.srh.noaa.gov

It is the recommendation of the Grand Prairie ISD School Health Advisory Council that during a temperature or wind chill factor of 40°students will wait indoors with supervision for school to begin. Students with clothing appropriate for cold weather shall be sent outside to wait for transportation home for 10 minutes. After 10 minutes they shall be allowed back into the building. Students without appropriate clothing for cold weather shall remain inside the building. During inclement weather of rain, snow, lightening, or an approaching storm, students will remain inside.

In an interest to protect student health, faculty and staff should follow the protocols below on ozone action and   heat advisory days.  Students will be allowed outside for Physical Education, recess, or extracurricular activities using the following guidelines:

Sensitive groups are defined as children who are active in outdoor activities, people involved in high-energy activities, and people with respiratory disease. Students with respiratory disease should follow the advice of a doctor or guardian.

In order to help keep the campus informed, designate a person on your campus to be responsible for notifying you of ozone action days. This person should follow ozone colors posted on the following website:  www.airnow.gov for the hourly air quality index.

In addition, you can use one or all from the following methods for notifying your campus:

1. E-mail alerts to the teaching staff
2. Use color coded flags in easily visible areas.
3. Include ozone levels in the morning announcements
4. Include a definition of the ozone level for the day, temperature (high expected) and precautions.

During times of excessive heat, the following precautions will be taken for all outdoor physical activity including, but not limited to: recess, physical education classes and /or outdoor field trips.

• Start slowly getting students acclimated to hot-weather exercise.
• Use a 1-to 2 ratio of exercise to rest schedule. Example: 5 minutes of vigorous exercise to 10 minutes of rest and fluid replacement.
• Students should be hydrated prior to outdoor activities and drinking water shall be easily accessible.
• During extended periods of outdoor activity (> 30-35 minutes) periodic drinking should be enforced.
• Students should not have recess or Physical Education classes outside during extreme heat > 95 degrees.
• Teachers are advised to use precaution on days when the temperature or heat index is high. Limit outside activity to no more than 15 minutes and ensure that students have access to adequate water prior to and/or after outside play. Be aware that hot playground equipment may cause burns.

See Coaches and Trainers regarding outdoor activity during Athletics.

In order to help keep the campus informed, designate a person on your campus to be responsible for notifying you of heat action days. This person should follow the listed heat index posted on the following website:  www.weather.com for the hourly temperature and heat index readings.