If you see a green flag flapping beneath the Stars and Stripes in front of Cabrini High, tell your lungs to breathe a sigh of relief.
In the color-coded alert system created by the Environmental Protection Agency, green signals that the day’s air quality will be “good” – the highest rating on the federal scale that quantifies the presence of five common pollutants.
Students in Cabrini’s environmental science class have been managing the flag alerts since August 2012 through the EPA’s School Flag Program. Each morning, one of six brightly colored flags is placed beneath the American flag to signal the day’s anticipated air quality:
• “Green” means the quantity of airborne pollutants is so minimal there will be no impact on public health.
• “Yellow” communicates that the day’s air quality is “acceptable” – or that only unusually sensitive people should consider limiting prolonged, outdoor exertion.
• “Orange” signals that the air is unhealthy for sensitive groups, including children, older adults and people suffering from lung diseases such as asthma.
• “Red” warns of “unhealthy” air conditions and recommends that everyone limit their outdoor time.
• “Purple” means “very unhealthy” for all groups.
• “Maroon” warns of hazardous conditions of emergency proportions.
“So far we’ve only had to raise the green or yellow flag. For the most part the air quality is pretty good around here,” said Ann Smart, Cabrini’s environmental science teacher. “If we had been doing this project last (school) year we probably would have had a few days in the red and the purple,” she said, referring to the marsh fires which could be smelled even during rainfall and which deposited a black layer of soot on area porches.
Cleansing wind, rain
While fluctuations in local air quality have been negligible in the six months Cabrini has been documenting conditions, Smart said she and her students have noticed that they dotend to change with the weather. On calm days, for example, air quality is more likely to dip into the yellow zone, while breezy or rainy days are typically “green,” with the elements ridding the air of dust, pollen and smoke particles.
“I’m not an expert on air quality, but you’re just more aware (of it) than you were before,” said senior Ashlyn Murray of the school-based EPA campaign that hopes to educate Americans on the health risks and corrective actions needed to protect youth and at-risk individuals during periods of poor air quality.
For example, many parents do not realize their children are at greater risk from air pollution not only because their lungs are still developing, but because they breathe more air per pound of body weight than adults.
Color of the day on Web
New Orleans’ air-quality forecast – and the accompanying color-coded daily rating – are obtained every weekday morning from the site AirNow.gov. Overall air health is based on presence of five pollutants: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide and nitrogen dioxide.
While this air quality information is provided by an outside source, the Cabrini students collect their own daily weather data from their school’s atmospheric station.
“They have to test the atmosphere within an hour of the solar noon – when the sun is actually above us,” Smart explained. “Each student has a different day to do it, and it’s usually during lunch period, so they don’t miss any of their classes.”
The mailbox-like station, located in the field between the cafeteria and Cabrini’s Esplanade Avenue school building, offers ongoing digital measurements of air and soil temperature, precipitation, pH level and relative humidity. Smart’s environmental science students input the daily readings into an iPad, and also study the sky to determine the afternoon’s percentage of cloud coverage and cloud type.
“We should also be able to calculate ozone, but (that instrument) was damaged in Hurricane Isaac,” said Smart, noting that her students soon will have enough information to determine if the weather directly impacts the quality of water in adjacent Bayou St. John, which students also monitor.
“I knew the weather down here changed a lot, but I didn’t realize how many elements contribute to whyit changes,” Murray said of her work at the atmospheric station. “I like collecting data on your own because you’re doing hands-on science,” Ashlyn added, “You’re not just getting your information from a textbook.”
Beth Donze can be reached at email@example.com