My health improved considerably after I started using air-purifier to beat Delhi pollution woes. I take frequent breaks from the city and lock myself in when I

My health improved considerably after I started using air-purifier to beat Delhi pollution woes. I take frequent breaks from the city and lock myself in when I feel pollution is bad. I live in one of the particularly worse parts of Delhi (pollution wise). Is there a cheap way to measure air quality inside the house? Is it a job for a mini drone? I really care about city-based air pollution, but don't know much about it.