Public Health as Policy Driver to address
severe air pollution in Hong Kong West

Clean Air Network (CAN) reviewed the air monitoring data of Jan-June 2016 from Environmental Protection Department (EPD) and found that the roadside pollution level remains way higher than World Health Organisation (WHO) standard, which could pose substantial threat to public health. According to Hedley Index, 821 premature deaths were estimated over the first half of 2016.

To investigate the source of pollution, we need to analyze various factors from transportation, commuting patterns, city planning to routes of ocean going vessels. CAN urges the government to adopt public health as major policy drivers and to refer to public health impact as a benchmark for policy implementation.



CAN looks into the air quality data for the first half of 2016 and compare it with those from 2012-2015 for analysis. Observations and policy suggestions are summarized as below:

1) Targeted site of air pollution

The analysis is based on the average of 12 general stations from first half of 2012-2016. CAN lists out the top 3 stations with higher pollutant concentration than the 5-year average.

For sulphur dioxide, the pollutant concentration was the highest in Kwai Chung, Tsuen Wan and Shum Shui Po. This indicates the effect from ship emission.

For PM2.5, the pollutant concentration was the highest in Tuen Mun, Central and Western District and Kwai Chung.  While for PM 10, the pollutant concentration was the highest in Tuen Mun, Central and Western District and Kwun Tong. This indicates the impact from power plant emission.

For NO2, the pollutant concentration was the highest in Shum Shui Po, Kwai Chung and Tsuen Wan. This indicates the impact from roadside emission.

2) Severe road side emission

For the first half of the past 5 years, the concentration of nitrogen dioxide for all regions in HK was higher than the annual standard of WHO of 40µg/m3. The five-year averages of nitrogen dioxide concentration in roadside stations such as Causeway Bay, Central and Mong Kok were all higher than 100µg/m3, which is 2.5 times higher than the WHO standard.

The problem is mainly caused by traffic congestion with the uncontrollable growth of private cars for the past 10 years. Private cars make up over 70% of the total registered vehicles in 2014 and the number has increased with a rate of 4.6% per year for the past 10 years. According to Census and Statistics Department, Wan Chai, Central, and Western District have the highest percentages of people who commute to work by cars or by taxis. Meanwhile, the proportion of cars and taxis consists of 80% of the total vehicles entering Central District. This explains the high level of nitrogen dioxide in Central and Causeway Bay from severe road side emission.

3) Air pollution trend in western parts of Hong Kong

CAN compares and analyzes the average concentration of nitrogen dioxide and sulphur dioxide in the first half of 2016. It is found that the levels of Hong Kong Island, Kowloon West and New Territories(NT) West were higher than those of Kowloon East and NT East:


Route of OGVs explains why western parts of HK generally has a higher SOemission than the eastern parts. Major routes of OGVs are mainly located in the western part of Hong Kong, where emissions affect districts like Kwai Chung, Shum Shui Po, Tung Chung, Central and Western District, Tuen Mun, Yuen Long and Tsuen Wan.There are three factors influencing the air pollution trend found in the western part of Hong Kong: Route of Ocean Going Vehicles(OGVs), distribution of local and regional power plants, and commuting behavior and pattern of commuting to work.

Distribution of local and regional power plants also affects the air quality in the western part of Hong Kong. The season north-eastern wind brings pollutants from power plants from mainland to Hong Kong in winter. This is one of the reasons why the PM2.5 and PM10 concentrations in the western part of Hong Kong are higher than those of the eastern part – affected areas including Central and Western District, Shum Shui Po, Tuen Mun, Tung Chung and Yuen Long.

Commuting creates traffic demands. New Territories West has the second highest proportion of people who work over districts with a percentage of more than 80% for Kwai Tsing, Tuen Wan and Yuen Long. Besides, many railway, road and container development projects are launched in the western part of Hong Kong, which partly results in the air pollution trend found in HK West.

4) Public health as key policy drivers

CAN urges the government to adopt public health as key policy drivers. A holistic approach should be made to change the current transport and city planning paradigm.

First, the Air Quality Objectives (AQOs) should be tightened towards WHO standards. This is aimed as a policy benchmark for protecting public health.

As a means to cut roadside emission, individual behaviour should be changed in order to lower the traffic demand from private cars. CAN proposes the following measures to reduce traffic congestion in Central District:

Adopt electronic road pricing which embodies the polluters-pay principle;

Use traffic demand management policies to curb unlimited growth of private cars;

Replace the existing ‘low emission street’ with low emission zones;

Transform Des Voeux Road Central into a pedestrian-and tram-only precinct.

In addition, city planning and design influence citizens’ behavior. Considering that New Territories West has the largest proportion of children and elderly people who are vulnerable to air pollution and yet suffering from heavy roadside air pollution and insufficient medial resources, Clean Air Network urges the government to:

Limit car speed to 30km/hour in districts with a big elderly population so as to promote age-friendly neighborhoods;

Take into account public health impacts by air pollution when allocating medial resources across the cluster;

Implement a people-oriented and smart city planning by connecting the bicycle network to the public transportation system.

Last but not least, Hong Kong is gravely afflicted with regional pollution, especially the western part confronted with heavy ship emission. On this matter, Clean Air Network urges the government to:

Implement onshore power supply to reduce emission from cruise ships and OGVs;

Set up emission control area in Hong Kong and Pearl River Delta Region (PRD region) to reduce sulphur content;

Tighten fuel switch upper limit from 0.5% sulphur content to 0.1% by 2017;

Set up emission control area in Hong Kong before 2018;Set up emission control area in PRD region before 2019.

Story posted on
13th Jul, 2016


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