Fresh Air Curtain / Air pollution, PM2.5

There are approximately 5.7 million polices worldwide, who are servicing people in most critical situation, for example the traffic polices, they control traffic flow by standing in polluted environment at the center of intersection. Where surrounding the air pollution + chemical toxin emission by pass through cars. Even worst, in order to execute their duty, they are whistling and talk to walkie-talkie all the time. This makes them impossibility to wear mask for healthy consideration. It's serious issue for huge amount of traffic polices globally. Therefore, I am seeking a concept aims to provide fresh air but not stopping their behavior.