Marlebone Road, Westminster, London: one of the worst places in the UK for particulate pollution

Diesel pollution can be broken into two primary sections: gases and particulates. The gases that are damaging directly or indirectly include nitrogen oxides, carbon monoxide and carbon dioxide.

The risks posed by the gases are worth noting. Nitrogen dioxide (NO2) reacts with oxygen (O2) in sunlight producing ozone (O3) and nitrogen oxide (NO). Ozone is toxic as when inhaled it reacts in the body releasing highly reactive free radical oxygen which is damaging as an oxidizing agent in the body.

Ozone is also highly reactive and causes airborne hydrocarbons (constituents of the particulate) to oxidize and produce smog which inhibits the respiratory system, agitates asthma, skin complaints as well as impacting the appearance of the city both by the mucky cloud hanging over it and the damage caused to buildings..

Recent work has revealed a link between NOx levels and global warming. The ozone from decomposed NOx inhibits the natural ability of plants to absorb CO2 in the usual gas exchange.

Both D3 and G1 reduce nitrogen oxide emissions. For more details of this see 'How It Works'