The EPA's Air Quality Standards are set with a significant safety margin to protect human health.
Delaware's two most significant air pollutants are "ground-level ozone" and "fine particles." Even though New Castle County, DE, has recorded the highest level of these two pollutants, it still complies with the EPA's Air Quality Standards set for ozone (by a margin of 7%) and fine particles (by 37%).
Ozone air pollutants have been found to have a higher component of natural causes. For instance, the Caesar Rodney Institute's study of air quality data from March 2020 and April 2020 (during the height of the COVID-19 lockdowns) indicates manmade pollution decreased by a shocking 50%, but ozone levels only fell by 2.5%.
Why did Delaware receive a "D" grade for ozone air pollutants from the American Lung Association?
The short answer is that the ALA used the EPA's out-of-date data and applied their own unsanctioned definitions of air quality. The EPA releases air quality data to the public on its user-friendly website within days after collection. Yet, for their 2023 air quality report, the ALA used data from 2020 to 2021 instead of data for 2022. If they had used the more recent 2022 data, New Castle County, DE's ozone grade would be a "C," not a "D."
But, there's more to this...
The EPA omits the three highest days for the ozone standard, averaging the fourth highest days over three years. The average must be 70 parts per billion or less. Those three excluded days allow for unusual events, such as the recent Canadian wildfire smoke that raises pollution. The ALA, however, omits zero days but counts every day even though most high ozone days are just a few parts per billion over the standard and well within the safety margin for health.
Ozone air pollution is produced in the presence of sunlight, so levels are usually very low. According to the EPA's 2020 to 2022 data, New Castle County, DE, met the ozone standard 99.9% of the hours from 2020 to 2022 (that's an "A" in our book).
The bottom line is that great air quality is important for human health, and Delaware has great air quality.
However, it seems most Delaware Legislators are not familiar with the most up-to-date air quality data to make informed decisions on behalf of their constituents and the citizens of Delaware. Two concerning examples are allowing DNREC to force people to buy vehicles with a $14,000 average premium price tag and choosing to subsidize offshore wind, that may add $440 a year to residential electric bills.