This channel (https://thingspeak.com/channels/322661) reports the CO2 or pollutant level returned by an MQ-135 sensor. You can compare this with the average atmospheric CO2 level available at https://www.co2.earth.

using a libelum board to measure the air quality in the city of torino-Italy

The air quality sensor monitor the concentration of PM2.5 in indoor locations. It is developed and made in Hong Kong. Contributor: Leo Siu, Leo Chan, Eddie Yung Citizen Science Project coordinator: Maria Li

Live display of Fort Collins Ozone levels, Temperature, Humidity, Wind speed, and UV Index. Data obtained from the Colorado Department of Public Health & Environment and AccuWeather 3416 W. LaPorte Ave.

Live display of Denver Ozone levels, Temperature, Humidity, Wind speed, and UV Index.

Measuring PM2.5

DiyBio and ICN2 develop of dust sensor test

POWIETRZE na Zeromskiego / WROCLAW

A channel to check air quality in Pekan area.

Temperature, humidity and air quality sensor

PM measurement In Sofia, Bulgaria with PPD42ns sensor

PM particles counter

hackAIR sensor in Haarlem

The Air Quality Index Acquiring Ability system (AQILITY) Mark II is an independently developed air quality monitoring system in SG stationed at SST with hobbyist-grade electronics for monitoring multiple parameters of air quality. NOTE: ALL VALUES ARE RAW

The Air Quality Index Acquiring Ability system (the AQILITY) is an independently developed air quality monitoring system in Singapore with hobbyist-level electronics such as the Shinyei PPD42NS dust sensor and the MQ lineup of gas sensors.