OPINION: NEA confusing the public with PSI explanation

Singapore Notes, 26 Jun 2013
The National Environment Agency (NEA) website was supposed to clear the air about concerns regarding the assessment of the haze danger. It turns out to be another exercise in semantics to cover up their attempts at obfuscation.
To debunk charges that the Pollutant Standards Index (PSI) do not take PM2.5 readings into account, NEA claims "PM10 would also capture what is captured in the PM2.5 readings."
Particulate matter, or PM, is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. Some particles are large enough to be seen, such as soot or smoke, others are so small they can only be detected with an electron microscope. Particles less than 10 micrometers in diameter (PM10) pose a health concern because they can be inhaled into and accumulate in the respiratory system. Particles less than 2.5 micrometers in diameter (PM2.5) pose the greater health risk, as their small size (approximately 1/30th the average width of a human hair) enable the fine particles to lodge deeply into the lungs.
There has to be good reason for the separate PM2.5 standard, if a PM10 measurement suffices. When NEA says the PM10 count also includes PM2.5 particulates, it is like saying a 6.9 million population is sustainable for Singapore, and miss out on the crucial number of foreigners included in their master plan. Apples are not oranges. Full story

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Haze: Mass media give distorted picture of PSI - TR Emeritus