HK Air Pollution Varies with Weather

[DocMartin Williams]

I saw a recent item in the South China Morning Post, saying that even though June 2008 was the wettest month on record for Hong Kong, pollution levels were still high; said to have surprised experts.

Just had quick look at data on Env Protection Dept website – and can see that for the general stations, air pollution was mostly medium or low: at Tap Mun, say, air pollution was low for 564 hours. But at roadside stations, air pollution was always medium or high – not low for even one hour.
So, air pollution at roadsides not readily swept out by rain and/or winds off the sea – but seems the Pearl River Delta filth does indeed get carried/washed away with such weather. This seems right to me – as lately had scintillatingly clear days, when not raining, by contrast to typical smog.

Checking December last year, when air drier, winds more off mainland, see very different picture. Still bad at roadsides, of course, tho not a massive shift: mostly high, sometimes very high.
But at general stations, see a major shift: just 13 hours in total (12 at Tap Mun, one at Tai Po) with low air pollution, otherwise moderate or (mainly) high, with tens of hours of very high air pollution.
Here, seeing shift to pollution over Hong Kong being from Pearl River Delta. Can see this by eye, too, as air woefully murky during dry conditions with northerly breezes/light winds.

[DocMartin Williams]

Just a few days after I posted the above, a typhoon approached Taiwan, and gentle airstream from mainland brought us hideous smog.

Took these shots a couple of days ago; yesterday’s SCM Post said there was record smog – including record API of 202 at Tap Mun, well away from HK city. Note that on left, shot is before 5.30 – a few days earlier (with winds off the sea), had been intense blue sky, not feeble blue shading into grey.

Once again, our smog is making international news, including in the Guardian:

Quote:

Hong Kong choked in a thick, hot blanket of air pollution on Tuesday with the city gearing up to host Olympic equestrian events, prompting one leading riding nation to bemoan the less than ideal conditions.

Hong Kong chokes in pollution as horses arrive [the Guardian]

[DocMartin Williams]

Climate change as well as weather variations important re air pollution. New report from Union of Concerned Scientists (in US); info includes:

Quote:

Climate Change and Your Health: Rising Temperatures, Worsening Ozone Pollution, the first in a UCS series on Climate Change and Public Health, combines projections of future climate-induced temperature increases with findings on the relationship between ozone concentrations and temperature to explore the potential “climate penalty on ozone pollution.”

This "climate penalty” demonstrates how higher temperatures could increase ozone pollution above current levels, explores the resulting expected health consequences in 2020 and 2050, and examines the anticipated economic costs of these health impacts in 2020.

Climate Change and Your Health: Rising Temperatures, Worsening Ozone Pollution

[Author]

Posts