Meet the most unlikely agents in the fight against air pollution -- pigeons. This week, a small flock of racing pigeons were strapped with pollution-sensing backpacks and sent out into the skies of London for three days to monitor the city's air pollution levels.

The backpacks are designed to monitor levels of nitrogen dioxide and ozone gases produced by diesel cars, trucks, and buses that spew out exhaust all over the city. Then this information is tweeted out to through the Twitter account @PigeonAir to raise awareness about the negative impact of air pollution on a city like London.

hi-news.ru