Saigon: Air Quality and Trends

Smack dab in the middle of downtown Saigon sits the U.S. Consulate. In the beginning of February 2016, right before the nation’s largest holiday of Tết (the Lunar New Year), the U.S. Consulate started broadcasting air quality index (AQI) numbers on an hourly basis. The numbers and history can be found here

The AQI numbers are a measure of small particulate matter in the air that we breathe. Specifically, the AQI numbers are related to PM2.5 (or 2.5 micrometers) particulates are so small that when humans inhale them, they are able to pass from the lungs into the bloodstream. If air pollution is getting directly into your lungs, it’s not good. High levels of PM2.5 have been linked to a whole host of nasty stuff, including asthma, cardiovascular diseases and even birth defects.

So in this city packed full of motorbikes, cars, buses, trucks, not to mention all of the dust from construction and smoke from burning wood and charcoal, it was nice to see the numbers and at least be aware of the air quality. Hell, my friend and I even set up a Twitter bot to broadcast the AQI numbers a couple of times a day

Unfortunately, it’s not looking good. I took all of the data from February 5th, 2016, through December 31st, 2016, and sifted through it, looking for peaks, valleys and trends. The slightly good news is that the AQI only hit unhealthy levels 6% of the days in 2016. The more sobering news is that on only 0.9% of the days, the AQI stayed at healthy levels.

What is even more disturbing is the trend that I saw in the data. Although the AQI numbers fluctuated over the course of the year, probably due to wind, rain and other weather patterns, the fact is that the average high AQI in February was 105 (51-100 is considered moderate), but by the end of December, the average high AQI was 126 (101-150 is unhealthy for sensitive groups).

Over the course of the whole of 2016, the average AQI measurement in Saigon was 85. This is squarely in the “moderate” category, but it is edging toward the “unhealthy for sensitive groups” range. Standards according to the U.S. Environmental Protection Agency (EPA) say that an AQI of below 100 is generally acceptable.

However, there were a number of times that the AQI in Saigon went above 101 and remained there for 24 hours or longer. This is scary. These longer periods of time are when the health of everyone begins to be affected, and this occurred 27 times over the course of the year. Specifically, these periods were:

  1. From 10 p.m. February 7th through 7 p.m. February 10th (72 hours).
  2. From 12 a.m. February 18th through 3 a.m. February 20th (52 hours).
  3. From 8 p.m. February 20th through 8 p.m. February 21st (25 hours).
  4. From 9 p.m. February 23rd through 9 p.m. February 24th (25 hours).
  5. From 9 p.m. February 28th through 11 p.m. March 3rd (99 hours).
  6. From 1 a.m. March 26th through 4 a.m. March 27th (28 hours).
  7. From 9 a.m. March 27th through 6 a.m. March 30th (70 hours).
  8. From 4 p.m. April 14th through 11 a.m. April 16th (45 hours).
  9. From 9 a.m. May 16th through 1 p.m. May 20th (101 hours).
  10. From 10 p.m. May 20th through 5 a.m. May 22nd (32 hours).
  11. From 4 p.m. June 8th through 3 p.m. June 9th (24 hours).
  12. From 9 p.m. June 23rd through 12 p.m. June 25th (41 hours).
  13. From 9 p.m. July 22nd through 8 p.m. July 24th (48 hours).
  14. From 3 p.m. October 3rd through 5 p.m. October 5th (27 hours).
  15. From 6 p.m. October 8th through 8 p.m. October 9th (27 hours).
  16. From 8 p.m. October 10th through 5 a.m. October 16th (130 hours).
  17. From 12 a.m. October 22nd through 8 a.m. October 23rd (33 hours).
  18. From 8 a.m. October 24th through 7 p.m. October 25th (26 hours).
  19. From 7 a.m. October 31st through 8 p.m. November 1st (38 hours).
  20. From 4 a.m. November 10th through 11 p.m. November 11th (44 hours).
  21. From 7 p.m. November 14th through 3 a.m. November 18th (81 hours).
  22. From 9 p.m. November 24th through 3 a.m. November 27th (53 hours).
  23. From 3 p.m. November 27th through 3 p.m. November 29th (49 hours).
  24. From 6 p.m. December 6th through 9 p.m. December 11th (126 hours).
  25. From 1 p.m. December 16th through 6 p.m. December 17th (30 hours).
  26. From 9 p.m. December 17th through 8 p.m. December 22nd (118 hours).
  27. From 1 a.m. December 23rd through 4 a.m. December 29th (148 hours).

Keep in mind, these are only the periods of 24 hours or more when the AQI exceeded 100 for 24 hours or more. Out of a total of 7884 hours of data, 1890 of them have an AQI of 100 or more, or 24% of the time.

Here are some visualizations from the data.

AQI Ave

AQI Monthly Ave

Levels of AQI lead to health problems and even death, yet nothing has been done to address these problems. Deaths from air pollution in Vietnam have increased recently, but no one is speaking out.

Meanwhile, in a dramatic about-face for the worse, Vietnam decided not to pursue clean nuclear energy, instead opting for more and more coal-fired plants, which in turn will lead to more deaths from air pollution. An interesting note is that Vietnam cannot even produce enough of its own coal now, so it will have to import coal to burn at these coal-fired plants.

According to Vietnamese media, there are currently 19 coal-fired power plants in the nation as of 2016. The plan is to increase this number to 31 by 2020, and 51 by 2030. And with a number of these coal-fired power plants planned for the Mekong Delta and other regions adjacent to Saigon, the AQI in town is only going to get worse.

Another huge aspect of pollution here that leaders refuse to acknowledge is that vehicle use is choking the city, literally. Even public buses, meant to reduce congestion and pollution, do not help as they occupy motorbike lanes and belch out black and putrid smoke due to poor maintenance.

I use an air filter when I sleep and a pollution mask when riding a motorbike. If Saigon continues hellbent on its current path of self destruction, I will have to use both all hours of the day.

Note: It is important to remember that all of the AQI data is from one collection point: The U.S. Consulate on Le Duan in downtown Saigon. This area is arguably much lower in pollutants than other areas due to smaller roads, fewer huge construction projects, etc. The AQI along highways and construction sites is surely much higher.

It is also worth noting that there are some brief periods of time over the year when the AQI monitor was down and there is no data available. This is most likely due to technical problems at the monitoring station itself.