Pollution's impact on health

This article is included courtesy of Mums for Lungs.

Evidence is mounting of associations between air pollution and a number of conditions including heart and lung disease, respiratory conditions, dementia, miscarriage, stunted lung growth in children, teenage psychotic episodes and reduced cognitive ability.

The two pollutants of most concern are Nitrogen Dioxide (NO2) and Particulate Matter (PM2.5 or 10). Other dangerous pollutants include ozone and sulphur dioxide.

Nitrogen Dioxide (NO2)

Road transport is estimated to be responsible for about 50% of nitrogen oxide emissions in London. Diesel engines, once promoted as more environmentally-friendly alternatives to petrol, have contributed to the high levels of nitrogen dioxide (NO2) in London.

King’s College amongst others has strong evidence that nitrogen dioxide is harmful to health, with the most common outcomes being a shortness of breath and a cough. It inflames the lining of the lungs and reduces immunity to lung infections. This is worse for people with asthma.

In London, NO2 levels regularly exceed legal limits set by the European Union. EU standards require that NO2 annual mean value may not exceed 40 micrograms per cubic metre (µg/m3). In Brixton in 2017 that figure was 95 µg/m3). In 2018/19 monitoring in Brixton has been interrupted because of problems with the main monitoring station on Brixton Road.

Particulate Matter (PM)

Particulate Matter is tiny particles of liquids or solids such as metals or rubber suspended in the air. They mostly originate from engines (carbon emissions), and from engine wear and braking, but can include wind-blown dust. The WHO estimates that 30% of PM emissions in European cities comes from road transport. King’s College estimates that between 25% and 31% of London’s particulate emissions come from domestic wood burning for secondary heating.

According to the World Health Organisation (WHO), air pollution-related deaths are most closely linked to PM emissions. The majority of particles that can penetrate the airway are too small to see but are present in air that seems clean. Particles smaller than about 10 micrometers, (PM10, about 1/10 of a hair wide), enter the body via the lungs and are too small to be filtered out. They can then settle anywhere in the body, including the brain.

Electric Vehicles (EV)

Although EVs offer improvements on CO2 and NO2 emissions, they continue to emit damaging PM due to tyre wear.