People should wear masks and glasses when going out, said the environment watchdog.
According to report of the administration, the levels of heavy concentration of fine dust, specifically known as PM2.5, in the air in Hanoi exceeded the national standards from September 12 to 29.
The city’s 13 Air Quality Index in Hanoi has shown that hourly PM2.5 concentrations maintained high. For instance, an air quality monitor in the U.S. Embassy Hanoi was measured at 200 which everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects.
The comparison between this year AQI and last year’s made by the environment watchdog has shown concentration of dust PM10 and PM2.5 has gone down from 2010.
However, concentration of dust PM2.5 was likely to increase in September compared to previous month and the same period in the years before.
The environment administration said that weather condition affects air quality in Hanoi much. It is seasonal transaction, the weather is getting cold, roaring fireplaces and wood stoves and idling vehicles in the winter all add up to higher levels of particulate matter (the particles that make up smoke) and carbon monoxide (from vehicle emissions). Cold temperatures and stagnant air have a way of creating a build-up of these substances near the ground.
Moreover, the environment watchdog blamed low rainfall and farmers burning the leftover straw to make room to plant their new plantings for the pollution on these days.