https://www2.purpleair.com/products/list 私にとって、彼らは製品を販売する会社のように見え、地図は二の次です。彼らは自分たちのものを地図上で宣伝することさえあります。

“PurpleAir is built on the ideal of sharing data and by doing this, empowering individuals to effect change. All public PurpleAir data is available to download under various licenses from private, not for profit use to educational and commercial use. The common element between these uses is to share attribution.” (https://community.purpleair.com/t/about-the-data-category/70) – based on that maybe 4/5 blocks would be accurate. There do not seem to be any trackers or advertisements on the site.