Who impacts the impactors??

Hi, welcome back to Standing Room only.

Ok, so I realise that this blog is geared towards human impacts upon the environment but I thought it was about time that we had a little segway into how we are impacting ourselves. With that today’s blog post is going to be on a major problem that Hong Kong and in fact Asia in general are facing -  Air Pollution!

Having visited Hong Kong myself I can attest that there is definite evidence of air pollution which can display itself as a haze that appears across the harbour, making visibility very poor on some days.

This blog post is going to primarily focus on the causes and effects of air pollution with a strong focus on Hong Kong.

So, what causes air pollution?

There are a number of contributing factors to air pollution but generally we can lump them into three catagories:

• Agriculture
• Burning of fossil fuels (e.g. transportation)
• Emissions from factories and other industrial activities

These factors are clearly anthropogenic in origin and increase proportionally. An increased population on the scale and density of HK magnifies the effects of air pollution to the extent that it has become a serious environmental issue. Levels of air pollution are demonstrated by an Air Quality Index (AQI) (formerly the Air Pollution Index).

Visibility in Hong Kong on a bad (left) and good (right) day. Image courtesy of blogs.wsj.com/chinarealtime

There has been a lot of research undertaken on air pollution that, unsurprisingly, predominantly focuses on the impact of air pollution on human health. Meteorological influences over air pollution levels are also well studies.

Tai et al (2010) look into how meteorological conditions have an effect on air pollution (Particulate Matter PM2.5). They conclude that there is a link between meteorological conditions and air pollution and suggest that the findings point to the possibility of climate change affecting future air pollution. Although this study focuses on the air pollution in the United States, the indications are clearly applicable to Hong Kong.

A more recent study undertaken by Fung and Wu (2014) looks into the relationship between intraseasonal variations of air pollution and meteorological variables in Hong Kong as this is important in regions that experience monsoon like conditions, which includes Hong Kong.  The meteorological conditions that the study predominantly focuses on are precipitation, wind direction and wind speed. Fung and Wu conclude that the intraseasonal relationship is complex and that whilst precipitation generally favours improved air quality, more robust data is required. They also conclude that the impact of wind speed on the API  intraseasonal variations is dependent on the season and differs year to year. Finally the study has found high API values are usually encountered under northerly winds in Hong Kong, however, there are cases when winds from other directions may lead to air quality problems.

Every year an estimated half million urban deaths in Asia are thought to be caused by air pollution (Brajer et al, 2005), however, compared to other cities in Asia, Hong Kong actually has relatively clean air due to pollution control measures put in place over the last two decades . They discuss how high levels of particulate matter (PM10) and nitrogen dioxide (NO2) have been linked to several health problems. These include:

• Decreased lung function;
• Bronchitis;
• Emphysema; and
• Heart disease;

Some of these health issues can even lead to premature death. Brajer et al (2005) assess the health benefits of reducing air pollution in Hong Kong by estimating the resulting health improvements from additional cleanup of the air pollution using data provided by several sources including Hong Kong’s Environmental Protection Department and the Department of Health . The study concludes that whilst there has been some success when it comes to the mitigation efforts that has been put in for air pollution, there is still a long-term air pollution problem in Hong Kong. It estimates a projected gain of several billion dollars (U.S dollar) should Hong Kong achieve further reduction in air pollution levels which is a significant amount. So the benefits of cleaning up air pollution will not only improve human health, it will also save a substantial amount of money.

So, what can be done to help clean up the air pollution? In March 2013, the Hong Kong Government issued a document called 'A Clean Air Plan for hong Kong' the main driving force for this plan was to improve the health of the public. The plan focuses on ways to reduce roadside air pollution which includes changing vehicular technology. Examples of this is changing the fleet of taxis and Public Light Buses (PLB) from diesel to Liquefied Petroleum Gas (LPG) and increasing the use of hybrid or Electric Vehicles (EV). The plan also identifies the need for reducing marine emissions by changing the fuel used for operating vessels and also reducing power plant emissions (although this has been greatly reduced already) by changing the fuel mix used and improving energy efficiency in buildings across Hong Kong.

It’s a long road to improving air quality in Hong Kong, however it is clearly being recognised as a necessity and by undertaking the few changes mentioned above, there will hopefully be significant improvements to come!

If you’re curious you can visit the website http://aqicn.org/city/hongkong/, to see the real time AQI for Hong Kong, at the time of writing this blog (HK time monday 5am) Hong Kong had an AQI of 162 which is classed as being unhealthy!

Courtesy of http://aqicn.org/city/hongkong