Tuesday, July 03, 2007

Cardiff council 'reply' to Cardiff Cycling Campaign post on air pollution

Not just cyclists are choking from the fumes!
Cardiff Council 'replies' on City Centre Polluted Air Posted on Monday, July 02 @ 23:43:08 BST by max.wallis Cardiff Cycling Campaign
Cardiff Council respond to the issues the Cycling Campaign raised over the Chartered Inst. of Physiotherapists' assessment of particulate pollution, viz:
# Cardiff is the third worst urban centre for PM10 in statistics for the first 3 months of the year
# routing cyclists down St Marys Street will subject them to higher air pollution
The Council put out the following Press Statement (reported in the Penarth Times)
"Cardiff Council is fully committed to supporting cycling and will continue to implement more facilities for cyclists. "The council believes that taking general traffic out of St Mary Street will certainly not make matters worse. Buses are becoming cleaner and Cardiff Bus has one of the youngest, and hence cleanest, fleets of buses. "Stationary and slow moving buses, unable to get through traffic or delayed by illegal parking, stay in the city centre for longer. The reduction of traffic in St Mary Street will help make bus use more attractive, reduce the number of slow moving or stationary buses in the city centre and will also be welcomed by many cyclists too."We pressed for proper answers and were informed in summary
# dust storms in Jordan, Egypt and the Sahara, agricultural fires in Ukraine and urban pollution from Europe
# the readings on North Road (Briardene) were much lower
# St Marys Street air quality is poor
# no assessment of cyclists’ exposure on St Marys Street, because they won’t spend much time there.
The full Council statement is as follows:
There are no plans to increase the number of buses using St Mary Street.
General traffic will however be removed. If traffic volumes are reduced and there is no increase in the number of buses, there is no reason to argue that this will result in increased diesel particulates. Further more buses will spend less time queuing so will be on that street for lesstime. Again, there is no reason for this to result in increased diesel particulates. There have been some regional and national particulate episodes whichaffected monitoring sites over the whole of South Wales and much widerafield in the UK during March 2007. These have skewed Cardiff's (andeveryone else's) readings upwards during the period in question. These episodes were of long-travelled material, i.e. not from local sources.The March 2007 episodes had the following features:a) Easterly air flows affecting the UK, air coming all the way fromRussia across central Europe.b) Increased particulate matter was recorded across most sites fromMarch 24th to April 2nd.c) Dust storms from Jordan and Egypt were seen on satellite imagesmoving north over the Mediterranean on March 21st, joining into theeastern air flow towards the UK.d) Widespread agricultural fires in Ukraine and western Russia were alsospotted by satellite on March 20th and will have been transported to theUK by the easterly air.e) The easterly air would also have picked up secondary nitrate andsulphate particulates formed from emissions across the industrial andpopulated areas of Europe. The conclusion is that the Saharan dust probably contributed to thefirst day or two of the incident, and later on it was the fires andsecondary particulate matter.The monitoring doesn't apportion sources or speciate the materialmeasured; is it therefore misleading to label the particulate matter as"diesel" or assume that it is traffic-derived. It is difficult to identifythe exact cause of each PM10 - whether from taxi, bus, train etc -although the press release attributes 25% of PM10s to transport, so it isagreed most are from other sources.It is also misleading to compare monitoring over a few months to anannual average standard. During the first few months of the yearmeasured concentrations will be higher than the annual average due to bothhigher emissions locally (e.g. from space heating, etc) and because ofatmospheric conditions.We have no detailed figures for the exposure to air pollution forspecific road user-groups. Exposure is a function of pollutantconcentration and the length of time that a person is exposed to it. It isnot possible estimate exposure for cyclists, or any other road user-group,given that no two road users follow the same route on their journeys.Exposure must therefore be directly measured and research studies arebeing carried out in London in this specific area of work. The air quality standards refer to pollutant concentrations in ambient airmeasured over a specific time-period. Cyclists will not, generally, spend a long enough period of time travelling down St Mary Street on their cycles to make direct comparison with the air quality standards in this single location valid. The air quality standard in force in the UK is 40 microgrammes per cubicmetre of air as an annual average. The annual mean measured at the CardiffCentre site in 2006 was 27 microgrammes per cubic metre. At Briardene Road Safety Centre on North Road, i.e. close to high volumes of traffic andtherefore more likely to be measuring traffic-derived pollution, the annual mean was just 21 microgrammes per cubic metre. However the Council fully acknowledges that air quality is poor on St MaryStreet, having declared an Air Quality Management Area for it, and hence the measures being taken to address it. The measures being taken will reduce concentrations of both PM10 and nitrogen dioxide.The Council's reviews and assessments of air quality are available on our website.
END of Council Statement