Pollution index Smog in São Paulo, Brazil The severity of smog is often measured using automated optical instruments such as Nephelometers , as haze is associated with visibility and traffic control in ports. Haze, however, can also be an indication of poor air quality  though this is often better reflected using accurate purpose-built air indexes such as the American Air Quality Index, the Malaysian API (Air Pollution Index), and the Singaporean Pollutant Standards Index. The Malaysian API does not have a capped value ; hence its most hazardous readings can go above 500. Above 500, a state of emergency is declared in the affected area. Usually, this means that non-essential government services are suspended, and all ports in the affected area are closed. There may also be prohibitions on private sector commercial and industrial activities in the affected area excluding the food sector. So far, the state of emergency rulings due to hazardous API levels was applied to the Malaysian towns of Port Klang, Kuala Selangor, and the state of Sarawak during the 2005 Malaysian haze and the 1997 Southeast Asian  haze.
Pollution index Smog in São Paulo, Brazil The severity of smog is often measured using automated optical instruments such as nephelometers , as haze is associated with visibility and traffic control in ports. Haze, however, can also be an indication of poor air quality , though this is often better reflected using accurate purpose-built air indexes such as the American Air Quality Index, the Malaysian API (Air Pollution Index), and the Singaporean Pollutant Standards Index. The Malaysian API does not have a capped value . Hence, its most hazardous readings can go above 500. When the reading goes above 500, a state of emergency is declared in the affected area. Usually, this means that non-essential government services are suspended, and all ports in the affected area are closed. There may also be prohibitions on private sector commercial and industrial activities in the affected area excluding the food sector. So far, the state of emergency rulings due to hazardous API levels was applied to the Malaysian towns of Port Klang, Kuala Selangor, and the state of Sarawak during 1997 Southeast Asian haze and the 2005 Malaysian haze.
R
Nephelometers
nephelometers
A
,
R
; hence
. Hence,
R
Above
When the reading goes above
D
the 2005 Malaysian haze and the
A
haze and the 2005 Malaysian