ALBAWABA - Hanoi, the capital of Vietnam, found itself engulfed in a dense cloud of pollution on Tuesday, impacting its nearly nine million residents and casting a veil over the city's towering buildings. The city took the unenviable top spot on the air quality monitor IQAir's global list of the most polluted cities on that particular day. The levels of PM2.5 pollutants in the atmosphere were alarmingly high, classified as ...