Song Hong 2016 Half Marathon

Sewers in the Sky

Bad air quality is finally getting the media coverage it deserves. So what’s the solution? 


Two to three years ago, virtually nothing was published in the local media about air quality. But now it’s becoming a recurring theme and getting considerably more ‘air time’.


So, here are some stats on Hanoi.


At the time of writing, according to the US Embassy, the air quality index (AQI) is at 160. Should this level remain for the next 24 hours, then this is deemed to be unhealthy. Another air quality monitor in the Long Bien area of Hanoi has the AQI at 90. The risk to people’s health is minimal. While the unofficial air monitor in Tay Ho puts the level at 158. Within minutes it has dropped back down to 70, unhealthy but not dangerous. Even within one city, air quality is at different levels at different times.


When you consider that for air quality to be safe, the AQI should be less then 60, this all sounds negative. Click on to look at the eight-day forecast for the region, and you really start to worry. Much of the area around China, Southern Vietnam, Cambodia and Central Thailand is light pink, pink and purple, denoting dangerously high AQIs. Compare this to Europe ( and you can see the difference; except for Moscow, no pink at all. Then look at the world map ( and it’s clear where the pollution hotspots are focused.


Yet, from May all the way through to September, it seemed that Hanoi’s AQI might be getting better.


Could Something Have Changed?


I was first shown the ‘unofficial’ air quality monitor website in Tay Ho by a friend. Using a number of apps he tracks the daily readings in Hanoi. We were talking about pollution and I was saying that Ho Chi Minh City seems to be better than Hanoi. “Not a chance,” he said, and began to show me the evidence.


There are three main air monitors in Hanoi, but the only one that gives historical data is the one in Tay Ho ( Scroll down the homepage to see the various graphs and you can see that prior to May 2015, there were periods when the AQI in Hanoi was dangerously high. So high that it’s easy to see why Vietnam’s capital has been labeled one of the most polluted cities in the world.


Yet since May 1, except for a short period in mid-September, the AQI seems to have got significantly better. So, the question is why?


Gone with the Wind


Hanoi has some serious pollution problems, with traffic being the biggest cause. According to a recent article in Vietnam News, the volume of vehicles on the road is increasing by 12 to 15 percent a year. This is exacerbated by traffic congestion in densely populated areas, leading to an even greater concentration of air pollutants.


Other causes of pollution, says the newspaper, are emissions from industrial zones, craft villages, construction sites, charcoal production and garbage from residential areas. Crop burning at the end of the harvest season helps to exacerbate this.


Yet nothing has changed in the city over the past six months. So, the recent decline in pollution levels may well be due to another factor — wind.


As Dominique Browning writes in a 2012 article in Time, “Wind connects us. It is such a huge force, moving in such enormous sweeps across our land, that it overwhelms all the boundaries we have thrown up, the ways in which we measure where we are — backyards, city limits, state lines… We share the air.”


Due to its rampant industrialisation and large-scale increase in car use, China has the highest AQI numbers in the world. If the wind blows southwards from China, then the recipient is going to be Vietnam and in particular, cities like Hanoi.


So, the only conclusion we can reach is that changes to Hanoi’s air quality must simply have been a result of the wind coming from a different direction.


Sewers in the Sky


There are many ways to reduce the pollution in Vietnam’s biggest cities; limiting charcoal burning for cooking, and encouraging the use of solar energy; move polluting industries out of the inner city and require them to install systems to deal with emissions; create and enforce legislation to reduce exhaust emissions. That the local press is talking about this and that answers are being searched for is positive.


However, as we share the air, the key reduction will only come when the world decides to work together on air quality. At present we are using the skies as our sewers. Only when we stop doing that will be able to ensure good air quality.


Last modified onSunday, 27 September 2015 16:26

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