NOVEMBER 25-DECEMBER 26: The realtime Air Quality Index (AQI) for the period Nov 25-Dec 2 ranged from a low of 27.98 micrograms per cubic meter (µg/m3) to a high of 53.68 µg/m3. The average for all eight sensors combined was 45.90 µg/m3, which falls in the good green zone of 0-50 (“Satisfactory”).
The low of 27.98 µg/m3 was recorded at a location in the Yorkshire neighborhood surrounded by woods with a light tree canopy overhead. The high of 53.68 µg/m3 was recorded at the Riverdale Drive sensor in south Jamestown.
As we reported back in November, the AQI at Riverdale reached 471 µg/m3 at 10:19 pm on the evening of November 25th, and remained high well into the next morning. High AQI numbers (30-minute averages) were recorded by all of the sensors during that time, especially at Main Street (160 µg/m3), Forestdale (142 µg/m3), and Mackay Rd #2 (120 µg/m3). The wind was blowing from the SSW at an average 7.5 mph during this overnight period, according to readings taken at PTI airport.
For comparison and informational purposes, in February 2024 the EPA set the federal annual average standard for PM2.5 at 9.0 µg/m3, and the 24-hour average standard at 35 µg/m3. The World Health Organization (WHO) guideline states the annual average PM2.5 level should not exceed 5 µg/m3, and 24-hour average exposures should not exceed 15 µg/m3 more than four days in a year.
For the period Nov. 25 through Dec. 26, the raw PM2.5 level averaged 7.89 µg/m3 for the eight sites combined, comfortably below the EPA standard (9.0) but higher than the WHO guideline (5.0).
So, except for the high levels recorded on November 25th and 26th and occasional spikes here and there, Jamestown’s air quality numbers averaged out quite nicely for this reporting period.
NOVEMBER 23, 2024 – WEEK 1: Here’s how our EPA (loaner) Air Sensors performed during the period Nov. 16-22, the first full week of operation for all eight sensors. The data shown below is for particulate matter AQI (Air Quality Index). Go HERE for more info on PM2.5 and the new regulatory health standards.
Notice how the levels generally rise and fall in sync, with some locations spiking higher throughout the time period. Those spikes in the orange and red zones are too high – we want to see less of these, and more of the green zone:
Oddly, two 20-hour cycles last weekend were very similar – look at how the air particulates rose and fell between 4:30 pm Sunday, Nov. 18 through noon Monday, Nov. 19; and then again 4:30pm Monday, Nov. 19 through noon Tuesday, Nov. 20:
Here’s a quick video demonstrating how your can create these graphs on the Purple Air map. Give it a try – it’s super easy: