Meteorological and regional factors do not form the complete picture.
Hong Kong needs to tackle local pollution.

Earlier this week, the Environmental Protection Department (EPD) claimed that meteorological and regional factors were the key reasons that lead to the severe air pollution in Hong Kong. However, Clean Air Network (CAN) evaluated different data and found local pollution as a significant source influencing Hong Kong’s air quality.

Similar levels of Ozone emission in Hong Kong and Guangdong
According to the data from Guangdong-Hong Kong-Macao Regional Air Quality Monitoring Information System, from 2006 to 2014, the average Ozone level in Guangdong was 57 µg/m3 ; while Hong Kong side (three stations: Tap Mun, Tsuen Wan and Tung Chung) recorded 56 µg/m3 over the same period. However, when looking at the increase rate from 2006 to 2014, we found that the average level of Ozone in all general monitoring stations in Hong Kong had increased by 27.2%, compared to the Guangdong side’s ratio of 19.5% over the same period.

In other words, Hong Kong has a much higher increase rate of Ozone level. And if we look at the data from 2010 to 2014, the increase rate for Hong Kong was 17.1% and Guangdong, 6.1%. This means regional ozone could not account for all ozone increase in Hong Kong. Clean Air Network therefore urges the government to tackle the issue both locally and regionally. Hong Kong government can make use of the current platforms to strengthen cross-border cooperation and set up emission reduction targets for Ozone.

Meteorological factors not enough to explain air pollution situation
On Tuesday’s press conference, EPD said that in 2015, there were days of high regional air pollution, yet the prevailing wind from the north was more easterly. Eastern parts of Hong Kong were therefore more affected by the air pollutants. However, if we look at Tap Mun and Kwun Tong, both situated in the East, we found that pollution hours actually decreased. Take Kwun Tong as example, in 2015, pollution hours dropped by 12% compared to last year. According to the wind rose of Hong Kong Observatory, the main direction of the wind for Kwun Tong was northeasterly from 1992-2014. As such, wind direction could not completely explain the change in air quality in different districts. Local pollution remains a more significant factor.

Correlation between traffic flow and air quality at roadside
Clean Air Network analysed the traffic flow of three cross harbour tunnels and found that traffic flow increased from 228,000 daily trips in 2005 to 251,000 in 2014. At the same time, NO2, a key indicator of roadside emission, increased at a similar rate as monitored in four stations (Causeway Bay, Central, Central and Western and Eastern). In other words, the worsening traffic contributed to the rising of nitrogen dioxide concentration.

According to the Hedley Environmental Index, in 2015, 2196 people died prematurely due to air pollution. Clean Air Network calculated the percentage of bad pollution days among fifteen districts with monitoring stations and extrapolated the death and money loss figures onto each district.  It was found that citizens living in rural area were exposed to slightly less health threat compared with those living inside urban areas.

Preview for 2016 policy address: Tackle local pollution with comprehensive transport management
In conclusion, neither meteorological nor regional factors were the most influential variables in shaping Hong Kong’s air quality. In terms of reducing local Ozone level, Hong Kong government should place more focus on reducing NOx such as tightening the control of vehicle emissions. As LPG minibuses and taxis accounted for about 40% of the local nitrogen oxides, mandatory replacement of catalytic converters should be implemented and more stringent monitoring and testing should be carried out.

Fundamentally, demand-side transport management should be employed. More people-oriented planning such as setting up pedestrian zones (for example Des Voeux Road Central Tram & Pedestrian Precinct) , extensive low emission zones and pollution-pegged Electronic Road Pricing are needed in Hong Kong in order to alleviate traffic congestion and air pollution. Hong Kong cannot sustain with the outdated mode of car-oriented planning. CAN urges the government to cope with these issues in the forthcoming policy address and place emphasis on cross-department cooperation between EPD and Transport Department.

In terms of marine emission, CAN recommends further tightening of fuel standard for fuel switching at berth to 0.1% Sulphur content fuel; applying onshore power in all terminals and setting up of Emission Control Area in PRD regions ultimately.

CAN also hopes to see the review of Hong Kong’s air quality objectives included in the policy address. The authorities had already delayed presenting their plan on the review process for a couple months. As Hong Kong’s current standard still fall short of WHO recommendations, standards need to be raised in order to protect public health.

Story posted on
10th Jan, 2016


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