Hawaii Island Takes 7 Of The Top 10 Spots For Cleanest Air In North America

The IQAir Air Quality Index that gauges the grade of air quality across many of the world’s cities in 2020 lists Hawaii Island has 7 of the top 10 cities in North America, and the least polluted city in the entire poll, based on the amount of fine particulate matter in the air! The report determined that the cleanest air in the world last year was Waimea, HI, with fine 2.5PM averaging 2.2 µg/m3. Here are the 15 least polluted cities in North America on average in 2020 based on PM2.5 measurements: (Location - µg/m^3) 1. Waimea, HI, USA - 2.2 2. Kailua Kona, HI, USA - 2.6 3. Grand Portage, MN, USA - 3.1 4. Ocean View, HI, USA - 3.2 5. Bar Harbor, ME, USA - 3.2 6. Pahala, HI, USA - 3.3 7. Naalehu, HI, USA - 3.4 8. St. Andrews, Canada - 3.5 9. Hilo, HI, USA - 3.5 10. Waikoloa Village, HI, USA - 3.5 11. Dunn Center, ND, USA - 3.5 12. Clyde, NC, USA - 3.6 13. Fort Chipewyan, Canada - 3.8 14. Honolulu, HI, USA - 3.8 15. Kingston, Canada - 3.9 Waimea’s average rating of 2.2 µg/m^3 is the lowest ranking for cities in the entire world, with Australia coming in closely behind with several cities between 2.4 and 2.6µg/m^3, and Finland (Muonio) with a 2.8µg/m^3. The findings are limited by the amount of suitable monitoring stations that poll frequently enough to fit IQAir’s criteria, but in North America alone there are 5,500 monitors covering 1,700 cities encompassed into the report. The report notes that wildfires are the primary source of fine particulate matter (PM2.5) that is basis of the findings (fires are estimated to make up 70% of PM2.5 in the air), but in Hawaii we also have volcanoes that produce PM2.5. 2020, however, was a year of low emissions from Kilauea. The most recent eruption of Kilauea that began on December 20th, 2020 did not prevent Hawaii Island from taking the ‘least polluted regional cities’ ranking in the last year, but that eruption might prevent a repeat next year as most of that eruption carried into 2021. None of the Big Island locations that ranked among the least polluted cities in 2020 made the list in 2018, which can be easily explained by the legendary LERZ eruption of Kilauea that year, and prior to that the 35 year long eruption of Puʻu ʻŌʻō blanketed much of the island in VOG. Following the end of the 2018 eruption the air quality dramatically improved across the island, but mainly in West Hawaii. Many of the Hawaii cities listed in 2020 also made the list for least polluted air in North America also made the list in 2019. How do these findings match-up with your experiences? The full 2020 World Air Quality Report from IQAir is available here: https://www.iqair.com/world-most-polluted-cities/world-air-quality-report-2020-en.pdf NOTE: The cutoff for a ‘city’ is a population of greater than 5,000 people. I had to lookup the population of Hawaiian Oceanview Estates as I had doubts about exceeding that 5,000 person threshold, but according to the Census Bureau in 2019 there are 5,011 people in that region.