Singapore cracks world’s top 10 most-polluted cities as haze continues

Indonesian fires choking this part of the region have shot Singapore into the top 10 rankings of the world’s most polluted cities, according to live data from global air quality monitoring firm AirVisual this morning.

Our haze situation remains firmly at “unhealthy” levels today, with the National Environment Agency’s (NEA) pollutant standard index (PSI) sitting at 120 as of 9am — good for #7 on the AirVisual ranking — while the air quality in Malaysia and Indonesia continues to worsen, especially in areas near Sumatra and Borneo, where most of the fires are taking place.

In Kalimantan on Borneo and Jambi on Sumatra, the haze is at hazardous levels, with staggering AQIs of 445 and 458, respectively, according to air quality monitoring site aqicn.org.

More than a thousand schools in Malaysia were reportedly forced to close due to the haze, which even led to the death of a 4-month-old baby in Indonesia.

Unsurprisingly, Indonesia and Malaysia’s capital cities, Jakarta and Kuala Lumpur, join Singapore in the top 10 of the IQAir AirVisual live ranking of polluted cities.

As of about 10 am, Singapore was ranked number 7 with a US Air Quality Index (AQI) of 142, just below Kuala Lumpur at number 6, with a US AQI of 144. Jakarta is ranked fourth with an AQI of 163 while Kuching topped the list with an AQI of 273.

Check out the rest of the top 10 rankings below:

Now, you might have noticed some disparity between the US AQI and the PSI readings Singaporeans get updated with each day. For the record, the PSI as of 9am today is at 120.

One reason behind this is that the US AQI is measured differently, as it follows an air quality index reporting system set out by the US Environmental Protection Agency, calculating four of US’ major air pollutants that are regulated under its laws. They are: ground-level ozone, particle pollution, carbon monoxide, and sulfur dioxide.

Singapore’s PSI, however, calculates six pollutants: particulate matter (PM10), fine particulate matter (PM2.5), sulfur dioxide, ozone, carbon monoxide, and nitrogen dioxide.

“The only country that adopts the USEPA AQI is the US. It is therefore incorrect to compare the PSI with other air quality indices which are calculated using different methodologies,” NEA had said on its website.

There are also no international guidelines on how air quality indices should be computed and that each country adopts a different measuring system based on their “local needs and circumstances,” the website added.

So if you’re in doubt about the indices, you might want to refer to more than one index readings for a better gauge of the air quality around you.