when the winds are from the north we do get some of the PRD pollution but conversely they get ours when the SW winds cross HKG. After much pushing the Govt finally with brown trousers clamped down on the power company emissions. CLP - Exxon Mobil is actually cleaner than HK Electric which does not have enough gas turbine capability to burn the 50% gas target set by the Govt. Local Power station emissions have actually decreased significantly whilst roadside pollution has increased , mainly from the old diesel buses nose to tail in Central, Causeway Bay and Mongkok. The Govt f-d up by mandating particulate traps without specifying SCR devices in the exhaust systems that caused an increase in NO2 emissions. A Uni report on this embarrassed them and they are now funding SCR for the buses.
China actually had flue gas desulphurization installed before Hong Kong in their power stations. The problem is the lack of supply in PRD causes black and brownouts so the factories burn low quality diesel in their standby gennies. Since HKG is not a 'country' it is not recognised by Marpol and cannot impose its own ship emissions laws for HK port and sea lanes and this is where we get pollution from year round. Whilst ULSD in our trucks is restricted to parts per million the bunker fuel is 3% sulphur. There is also an interesting story in SCMP today regarding Peak Oil.