Miasma

Miasma is a lightweight app that displays pollution data in your menu bar. The tool shows publicly available air quality data for your locality.

In addition, it gives one hour weather forecast, including air quality data and pollen prediction. The utility lists potential pollution source data, such as electrical generation, aircraft overhead, and road traffic. Furthermore, it notifies if the AQI quality worsens beyond a threshold you set and respectively, if it improves below a threshold you set. The app updates its metrics every 20 minutes.