When you venture outside and take a deep breath, you expect to be inhaling a heap of fresh air, particularly if you’re in the countryside. But in truth, you’re just as likely to be filling your lungs with pollutants from dirt, dust, pollen spores, gases, and even lead. There’s just no getting away from the fact that a good percentage of air can be deemed unhealthy, so being able to monitor it on the go with a flick of a switch could be welcome news.

Arnov Sharma has created a handheld air quality meter which can use a Raspberry Pi Pico 2 connected to a gas sensor to display the current levels of a host of hazards. “My Air Quality Meter was created with the intention of measuring the degree of air pollution in my city,” he explains. “Since we’d just had an air quality issue in New Delhi, where I live, I thought it would be a good idea to try to develop a project to measure the pollution level.”

Delhi has suffered record pollution levels of late, with the Air Quality Index (AQI) measuring as high as 1500 in November 2024. Toxic air of this magnitude, which led to smog descending over the area, is 15 times the level considered satisfactory for breathing by the World Health Organisation. It was so bad that schools were temporarily closed, construction was halted, and flights were disrupted.

What’s more, it hasn’t become infinitely better since, with an AQI reading in January 2025 showing the air has remained poor, albeit at a level of 262.

...read more at raspberrypi.com