EPD

Cheung Chi-fai – SCMP
Jan 10, 2008

Government officials monitoring air pollution in the Pearl River Delta have had to move the goalposts for pollution reduction after estimating that emissions levels in 1997 were twice as high as had been thought.

The Pearl River Delta Air Quality Management Plan review said particulates emission in the delta region in 1997 was 520,000 tonnes, more than double the 245,000 tonnes previously estimated.

A 40 per cent underestimation in sulfur dioxide and nitrogen oxides emissions were also found in the review. As a result, emissions data from 1997 that serve as a baseline for measuring progress towards reducing pollution have been raised, according to the review paper.

As the 1997 data had been underestimated by as much as 112 per cent in the case of particulates, changes to the baselines would have a big influence on determining how far the region was from achieving emission reduction targets.

In 2002, Hong Kong and Guangdong province agreed to pursue pollution target cuts of between 20 and 55 per cent in four major pollutants by 2010 from 1997 levels.

By underestimating the baseline emissions, the extent of emission reductions required by 2010 would be smaller, making it easier to achieve the targets. Overestimates, however, meant more efforts were needed.

Changes to the baseline data, however, would also lead to different maximum allowable emission limits. The review report said the underestimation on the 1997 data was due to factories failing to declare emission levels accurately, mismatches between reported emissions and amount of fuel used, and industrial processes not taken into account.

The paper said an emission calculation methodology in keeping with standards in the United States and European was completed for Hong Kong and Guangdong in 2005. It was then used to review the 1997 and 2003 emission figures – the most up to date data available for Guangdong.

Alexis Lau Kai-hon, an atmospheric scientist at the University of Science and Technology, said updating the baseline data would have an impact on how targets could be met.

“Lifting the baseline not just means more efforts to cut emissions are needed, it also means higher levels of emissions will be tolerated, too,” he said.

Data released by the Environmental Protection Department showed that not only were the 1997 baselines adjusted, the yearly emission data of Hong Kong have also been revised based on the new formula. As a result, Hong Kong was moving faster towards meeting the 2010 targets.

For example, the city had reported nitrogen oxide emissions in 2005 were 15 per cent below the old 1997 baseline but the difference widened to 17.8 per cent against the revised baseline. Figures from 1996 show the city had already met its 2010 target in nitrogen oxide emissions.

Lina Lim – SCMP
1:00pm, Jan 08, 2008

Pollution levels in Hong Kong on Tuesday reached dangerous levels – according to the territory’s Environmental Protection Department (EPD).

Pollution at general stations in the city recorded unhealthy levels of nitrogen dioxide and respirable suspended particulates between the 61 (high) to 105 (very high) point range.

Meanwhile, roadside stations in Causeway Bay, Central and Mongkok recorded more alarming levels at 91, 111 and 100, respectively.

People with heart or respiratory ailments were advised to avoid going outdoors for prolonged periods of time.

Respirable suspended particles are suspended particulates smaller than 10 micrometres which have the ability to penetrate deeply into the lungs.

Depending on their source and existing meteorological conditions, the particles can be made up of a number of different constituents such as silicon, aluminium, calcium, manganese and iron from construction sites and carbon, lead, bromine and hydrocarbons from vehicular emissions.

Nitrogen dioxide, however, enters the air as a result of combustion processes which involve high temperatures, such as those produced by power plants and vehicular engines.

It is a corrosive light brown gas which can cause urban haze or photo-chemical smog.

Hong Kong has a serous problem with air pollution and the growing government is under pressure to deal with the problem – particularly because of the effect it is having on people’s health.

It has been estimated that over 2,000 people annually die in Hong Kong because of air pollution; while others suffer serious health effects.

A government study several years ago argued that 80 per cent of the city’s pollution came from factories and power plants in southern China.

But a report by the Hong Kong University of Science and Technology and Civic Exchange, a think-tank, argued that in 2006 Hong Kong’s air pollution was largely the result of local factors. This included the city’s road traffic, coal-fired power stations and ships.

A report on the results from the Air Quality Monitoring Network (AQMN) (2006)

Air Science Group
Environmental Protection Department
The Government of the Hong Kong Special Administrative Region

This report summarises the 2006 air quality monitoring data collected by the Environmental Protection Department’s monitoring network.

As a result of the enhanced vehicle emission control programme implemented by the Government since 2000, concentrations of respirable suspended particulates, nitrogen oxides and sulphur dioxide at roadside have been dropping gradually over the past few years.

Over the past years, concentrations of ozone have been on a slow rising trend, reflecting a deterioration in regional air quality. On this front, the Hong Kong Special Administrative Region Government and the Guangdong Provisional Government are implementing a Regional Air Quality Management Plan to improve air quality in the Pearl River Delta Region.

As in previous years, concentrations of sulphur dioxide, carbon monoxide and lead remained at levels well below their respective Air Quality Objectives limits in 2006.

See the full report on the results from the Air Quality Monitoring Network