Study to suss out air pollutants here

Feng Zengkun The Straits Times AsiaOne 29 Jan 15;

Singapore is planning to start a comprehensive study of its key air pollutants so it can understand how to better manage them.

The National Environment Agency (NEA) has asked for proposals for a 14-month project to develop an emissions inventory of several air pollutants, including sulphur dioxide, carbon monoxide and particulate matter.

The study will look at all land-based sources including motor vehicles, power stations, refineries, waste incinerators and gas stations, aircraft emissions, transboundary sources and even natural sources such as sea spray.

The pollution in 2013 will be used as the base year, and this will be calculated using information such as the vehicle population, typical distances travelled, fuel type used and a review of historical air quality data.

NEA said in tender documents that the new inventory must be detailed and flexible enough that it can be used to model how emissions would change if factors such as air pollution control equipment, fuel type, aircraft flight paths and the motor vehicle fleet composition are changed.

The inventory will also be used to "prioritise air pollutants of concern and to develop targeted approaches to control the pollutants", the NEA added.

The study will look abroad to pollution in Malaysia and Indonesia that may affect the Republic.

These sources include industrial areas and road traffic in Johor, Malaysia, shipyards in Batam and haze from these nearby countries.

To make sure the inventory passes muster, the contractor must review the systems used in several developed places including Britain, Germany, Japan, Hong Kong and California in the United States.

The deadline for the proposals is Feb 17. Experts lauded the attention to detail in the proposals.

"It's very good that the inventory will include hourly emissions and differentiate the emissions by day of the week and month of the year," said Dr Erik Velasco, a research scientist at the Singapore- MIT Alliance for Research and Technology's Centre for Environmental Sensing and Modeling.

He said emissions inventories always lag by one or two years due to data needs, so 2013 would be a proper base year for the study.

But since Singapore had its worst haze then, "it would be a biased year... if transboundary emissions are included".

The NEA specified that the contractor must quantify based on available data the pollution arising from transboundary smoke haze for that year.

Dr Velasco, who gave a course on air quality management, including emissions inventories, to the authorities last year, added that Singapore should look to places such as Los Angeles, Paris, Toronto, Mexico City and Tokyo in developing its inventory.

"Those are cities with good and long experience developing emissions inventories.

Singapore is a city-state, so inventories at different scales, such as the country or state scale, may not fit its needs," he said.