The Parish Council was asked if our Village had become more polluted by the implementation of Traffic Calming in 2015. In particular we were asked if we could measure a particular type of pollution which was known to have detrimental health effects on the public. This is an incredibly complex subject for non scientists and we have done our best to explain it and to draw some conclusions
Traffic pollution usually consists of Nitrogen Oxides and particles of different sizes some of which can be detrimental to health if inhaled in significant amounts. We were specifically asked to consider particles known as PM2.5
The World Health Organisation (WHO) in its 2021 targets has cut the level of the very small particles PM2,5 by 50% – from 10 micrograms per metre cubed to 5micrograms per metre cubed. The WHO targets are advisory and not mandatory even though the UK is a member. The current UK legislative standard for PM2.5 is 25 milligrams per metre cubed.
A Company with specialist environmental knowledge was contacted to help us understand the key issues involved and the conclusions we reached (supported by them) are below:
- The existing UK legislated limit for PM2.5 is a completely different order of magnitude to the WHO21 proposal.
- There is new legislation and targets being prepared but not expected until Q4 2022 at least
- SSDC is our responsible authority, and it has carried out a screening process according to the the current legislation and determined that nowhere in their area requires the measurement of PM2.5. Even if we, as a Parish Council, could find a compelling case for measurement we are unlikely to persuade them to carry it out and we believe it would be too expensive for us to carry out independently.
- The figures published on some Internet sites use information purported to be from Imperial College London which are developed by modelling and not actual measurements – although their data were instrumental in establishing the congestion zone policies for London. Intrinsically, modelling is based on a series of assumptions and the results are not ‘absolute’ and normally have a range of outcomes.
- Additionally, any major change to the permitted levels of PM2.5 would result in the need for a fundamental policy shift in the way transport will be used in our society in the future.