Should you haven’t paid consideration to the air high quality index till now, you’re most likely studying so much about it somewhat rapidly. Philadelphia and Washington, D.C. are beneath an air high quality degree that persons are calling “code purple” after its shade on the AQI scale. Right here’s what that each one means.
What’s the AQI?
The AQI, or air high quality index, is a quantity that measures a number of points of air high quality:
- Particle air pollution, each coarse particles (10 microns or much less) and high quality particles (2.5 microns or much less). Each are dangerous to breathe in, however the PM2.5 particles can get deeper into our lungs and are particularly regarding.
- Floor-level ozone, produced when pollution from vehicles, factories, and different sources chemically react within the presence of daylight. Ozone within the ozone layer of the sky protects us from ultraviolet radiation, however ozone down right here, the place we are able to breathe it in, has critical well being results.
- Carbon monoxide (CO), produced when issues are burned, together with fossil fuels in automobiles.
- Sulfur dioxide (SO2), primarily produced from energy vegetation and industrial services.
- Nitrogen dioxide (NO2), one other pollutant from automobiles and sources like energy vegetation.
These aren’t the one sorts of air air pollution, however they’re the commonest of the pollution which are regulated by the Clear Air Act.
Air high quality relies upon partly on how a lot air pollution is being produced—for instance, if there are raging wildfires in Canada or California. However your air high quality additionally depends upon what the climate is doing. For instance, excessive and low stress techniques have an effect on the place the wind blows, and warmth and daylight can set off chemical reactions that create ozone. There’s additionally a timing impact: Air high quality tends to be at its worst within the afternoon and night every day.
How do I discover out what the AQI is close to me proper now?
AQI is like temperature, precipitation, UV index, or different climate metrics: It modifications from day after day and all through the day, and the info for it’s measured at completely different stations all through the nation.
Climate apps will usually embody the AQI within the report, and you’ll see a map of AQI somewhere else. The EPA has an AirNow app that features present readings, maps, forecasts, and a breakdown of the degrees of the completely different air high quality elements.
In case your favourite app doesn’t present air high quality, a fast option to get the air high quality close to you is airnow.gov. Click on “screens close to me” beneath your air high quality outcome to see a map of native air high quality readings. There’s additionally a fireplace and smoke map that may be particularly useful throughout wildfires.
What do the colours imply?
A “good” air high quality is a rating of fifty or beneath, however the numbers proceed into the a whole lot, with an AQI over 300 thought of “hazardous.” There are completely different color-coded ranges, based on the EPA:
- Good (inexperienced, 0-50) means the air high quality is taken into account to hold little or no danger.
- Average (yellow, 51-100) signifies that air high quality is “acceptable” for most individuals, however people who find themselves very delicate to air air pollution could need to cut back their publicity.
- Unhealthy for delicate teams (orange, 101-150) signifies that it’s best to take precautions if you’re at better danger of well being results from air air pollution. This group contains youngsters (beneath 18), older individuals (over 65), and anybody who’s pregnant or has bronchial asthma, coronary heart circumstances, or different lung circumstances. If in case you have bronchial asthma, maintain your inhaler helpful.
- Unhealthy (crimson, 151-200) signifies that some individuals who aren’t in these “delicate teams” could discover well being results equivalent to coughing or irritation of the eyes, nostril, and throat. Outside actions ought to be diminished or prevented if they’re “lengthy and intense” (equivalent to train or work that will get you respiratory closely).
- Very unhealthy (purple, 201-300) means there’s an elevated well being danger for everybody. Individuals in “delicate teams” ought to positively keep away from exercising outdoors, and everybody ought to attempt to restrict their publicity to outdoors air. Should you can keep inside with air-con, that’s finest.
- Hazardous (maroon, 300 or extra) signifies that everybody ought to keep away from out of doors train, and if you happen to’re in a delicate group, keep inside and do your finest to maintain your indoor air clear.
So a “code crimson” day can be one through which the air high quality hits “unhealthy” ranges, and “code purple” signifies that air high quality is within the “very unhealthy” zone. At these larger ranges, cities generally problem warnings advising the usage of masks or different precautions.