Real-time Monitoring of Air Quality
The ambient air quality in Singapore is continuously monitored through a network of air monitoring sensors across Singapore. These sensors measure the level of the six criteria air pollutants; namely, sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO) and particulate matter (both PM10 and PM2.5, with diameters of less than 10 and 2.5 micrometres, respectively).
The concentrations of these criteria air pollutants are used to compute the Pollutant Standards Index (PSI) over a rolling 24-hour period. These PSI readings are reported on an hourly basis on the NEA website, haze microsite and myENV app. The readings are broken down by the north, east, south, west and central of Singapore as measured at NEA’s five national reporting stations located in these regions.
Read more on PSI and the 6 criteria pollutants
Real-time Monitoring of Ambient Volatile Organic Compounds (VOCs)
Volatile Organic Compounds (VOCs) are organic chemical vapours which can come from both man-made and natural sources. These compounds can cause smells by themselves or when they react with other VOCs. They are often involved in complex atmospheric photochemical reactions that contribute to ground-level ozone formation. Ozone is one of the 6 key air pollutants monitored by NEA.
NEA continuously measures a variety of VOCs in the air at our monitoring stations, including at four stations located in the north-eastern region of Singapore. The VOCs monitored include Benzene, Toluene, Xylene (BTX), which are industrial emissions that are also monitored by other environmental agencies such as the United States Environmental Protection Agency.
In addition, NEA officers are equipped with portable instruments and detectors to carry out on-site measurements, and collect air samples at selected locations for laboratory analysis for a further spectrum of chemical compounds.
Read more on VOCs
Real-time Monitoring of Coastal Water Quality
NEA has a network of eight buoy-based water quality monitoring stations along the Straits of Johor and the Straits of Singapore to measure the key physical, chemical and microbiological water quality parameters.
Real-time data from these stations are continuously transmitted to an operational management system that manages and processes the data to assess if the water quality has been affected by oil spills, eutrophication of seawater, and algae blooms that may affect our fish farms located at our coastal waters.
In addition, as may be required by the situation, NEA also takes grab samples to analyse additional water quality parameters, such as heavy metals and VOCs. This has been done since 9 Mar 2019 at Pulau Ubin and its vicinity, in response to the recent incident of toxic waste dumping in Pasir Gudang.