The Guardian, 1 March 2016:
Your editorial underlines the indifference of the mayor of London to air pollution which, according to the Royal College of Physicians and the Royal College of Paediatrics and Child Health, causes 40,000 premature deaths annually in the UK. But there are equally serious effects at the other end of life.
Small particulates (PM2.5) can cross the placental barrier and are associated with a number of negative outcomes including low birth weight. The WHO limit for small particulate is 25 micrograms per cubic metre of air, a level that is regularly exceeded in most UK cities. However, foetal effects are without threshold and are seen at levels below 25 micrograms.
It is not just the overall weight that is affected. Brain development is also compromised, and several studies link exposure to particulates, and oxides of nitrogen (NOx) to delayed neurocognitive development and lower IQ (See pages 34-41 of the RCP report).
Toxic metals like lead and small particulates like PM2.5 can cross the placental barrier, designed to protect the unborn foetus from harm. Our negligence has resulted in the replacement of one potent neurotoxin, lead, with another, PM2.5, derived almost exclusively in places like London from diesel-powered vehicles. It is equally dangerous, equally insidious and equally deserving of a total ban.
Dr Robin Russell-Jones
(Former chair, Campaign for Lead-Free Air)
Stoke Poges, Buckinghamshire