Data & Statistics

Hong Kong Air Pollutant Emission Inventory

The Environmental Protection Department (EPD) compiles the Hong Kong Air Pollutant Emission Inventory annually to analyze the quantity of local air pollutant emissions and their major emission sources for supporting the formulation of effective air quality management strategies in Hong Kong. It also provides necessary data for carrying out air quality impact assessments. The emission inventory for Hong Kong was first published on EPD's website in March 2000.

The emission inventory comprises estimates of emissions from seven source categories for six major air pollutants, namely: sulphur dioxide (SO2), nitrogen oxides (NOx), respirable suspended particulates (RSP or PM10), fine suspended particulates (FSP or PM2.5), volatile organic compounds (VOC) and carbon monoxide (CO). The emission sources include public electricity generation, road transport, navigation, civil aviation, other combustion sources, non-combustion sources, and hill fires.

Other combustion sources are defined as sources involving combustion, other than public electricity generation, road transport, navigation and civil aviation.  Major contributing sources in this sector include non-road mobile machineries operating in construction sites and container terminals.

Non-combustion sources are defined as those remaining sources that do not involve combustion, from which only VOC, RSP and FSP emissions are significant.  In this category, the major emission sources for VOC include paints and associated solvents, consumer products and printing, whereas those for RSP and FSP include paved road dust, cooking fumes, construction dust and quarry production.

In Hong Kong, hill fires are one of the sources of particulates. As most of the hill fires in Hong Kong are caused by human negligence or accidents and are sporadic in nature, their emissions cannot be reduced through emission control measures like other pollution sources.  In order to enable more meaningful comparison on the emission trends of controllable pollution sources and the effectiveness of local emission control measures, hill fires are reported separately in Sectoral Analysis.


 Overview of 2019 Emission Inventory

Hong Kong's total emissions in 2019 were 8 430 tonnes of SO2, 77 620 tonnes of NOx, 3 480 tonnes of RSP, 2 630 tonnes of FSP,  21 130 tonnes of VOC and 60 440 tonnes of CO. Due to the ongoing control measures on power plants, motor vehicles and especially the enactment of Air Pollution Control (Fuel for Vessels) Regulation from 1 January 2019 that requires all vessels, irrespective of whether they are sailing or berthing in Hong Kong waters, to use compliant fuel (including low sulphur fuel or liquefied natural gas), the emissions of SO2, NOx, RSP and FSP in 2019 were reduced by 5% to 49% as compared to the 2018 levels though the electricity consumption, vehicle-kilometer-travelled and GDP are on rising trend.


2019 Emission Inventory

The diagram below shows the emission inventory for 2019 under different emission source categories including public electricity generation, road transport, navigation, civil aviation, other combustion sources and non-combustion sources.


2019 Emission Inventory


Emission Inventory Report

2019 Hong Kong Air Pollutant Emission Inventory Report

Useful References

Intergovernmental Panel on Climate Change (IPCC)
U.S. Environmental Protection Agency (U.S. EPA - AP42)
European Environment Agency (EEA - EMEP/EEA Emission Inventory Guidebook)
Census and Statistics Department (C&SD - Hong Kong Statistics)
Electrical and Mechanical Services Department (EMSD - Hong Kong Energy End-use Data)