Last night the BBC broadcast a programme on air pollution entitled Fighting for Air (BBC2 on 19/8/2018). It was presented by Dr. Xand van Tulleken in a populist and dramatic style.
He first did a simple test by “cleansing” his system by donning a chemical weapons suit followed by 3 hours of deliberately breathing in traffic fumes. He did blood pressure tests, analysed blood composition and checked for brain function before and after. This unscientific and uncontrolled test apparently showed a slight increase in blood pressure and blood clotting and possibly a very small change in cognitive function. No actual data was given. Bearing in mind that such tests as blood pressure can vary significantly from hour to hour, and the other tests likewise, this proves nothing at all. Note that there have been a number of scientific studies of a possible link between blood coagulation and air pollution but no clear conclusions about which pollutants are relevant and no specific link to heart disease or stroke risk identified. That did not stop Dr van Tulleken alleging such a link.
He then moved to Kings Heath High Street near Birmingham. This road exceeds national legal limits for NOX apparently by a small amount at some times. It is used by a large number of diesel buses (no hybrids or electrics), and by significant numbers of HGVs. Traffic is stop/start with high congestion because of traffic lights that are not linked and road side parking as people move in and out of the parking spaces.
Dr van Tulleken persuaded the local council to suspend the parking bays for a day (filled with bay trees instead) and to synchronise the traffic flights to provide a “green wave” and he also persuaded the bus company to offer free tickets. The result was the volume of traffic remained the same, but NO2 fell by 10%. It is not clear to what extent any adjustment was made for other factors such as weather changes although mention was made that the changes were measured against wider area changes.
Local shopkeepers were not happy particularly a butcher who had traded in the road for 50 years.
Comment: In summary all this programme showed is that smoothing traffic flows may significantly reduce some emissions from vehicles. We already knew that, for example from studies of speed hump schemes. Replacing road side parking by off-street parking is clearly something that councils should look at. I only wish that removing such parking be done in my local High Street (Chislehurst in the London Borough of Bromley) which has been proposed in the past but never progressed (there is already plenty of off-street parking). It would both reduce the air pollution and reduce congestion by improving the flow of traffic.
What the programme did not demonstrate was that air pollution is a major health hazard or a public health emergency as the Doctor disclaimed. Indeed the High Street Butcher demonstrated how much cleaner his shop is than it used to be suggesting particulate emissions were lower than a few years ago.
In conclusion, another disappointing and hysterical programme on air pollution rather than a truly balanced study of the issues.
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