money is not the thing being measured but the instrument with which we measure it


Non Exhaust Emissions

The health effects of particulate matter have become increasingly recognised. Headlines last summer over diesel manufacturers emission fraud have led us to believe that exhaust emissions are the main problem. Yet non-exhaust emissions actually contribute just as much if not more to the problem than the much talked about vehicle emissions.  The figure below shows the estimated annual emissions of PM10 and PM2.5 from exhaust (E) and non-exhaust (NE) from a 1km radius in central Bristol.

Non-exhaust emissions are composed of dust from road abrasion, tyre, brake and engine wear. Using data from the European Environment Agencythe handbook of external costs of transport and transport data from 2010wattsthecost estimate non exhaust PM2.5 and PM10 cost the UK nearly £1bn in health effects.

A recent report questions the safety of artificial football pitches made from old car tyres. It highlights the potentially lethal hidden compounds in “rubber” tyres. Figure 2 shows the elements contained in their dust. Arsenic, Cadmium, Lead and even gold are included. This combined with brake, engine and road surface wear creates a cocktail of particles, which not only do we all inhale but also contaminates the land.

The vast Autumn crop of leaves that falls around the country has a “contaminated waste” classification from the environment agency. Instead of being sent to the nearest anaerobic digester to generate heat and electricity, the tax payer has to pay for them to be sent to landfill where they slowly turn into Methane, a Greenhouse gas 84 times more warming than CO2.

So, what can we do about this? The simple solution is to use lighter, smaller vehicles. A bicycle also has tyres and brakes made of the same materials as that on cars, but the forces involved are a fraction of that in a car and negligible compared with a HGV or Bus, so far less material is worn and re-suspended from the road.

A ban on older Vespa Mopeds in the Italian City of Genoa that don’t meet modern emissions regulations has recently made the headlines. However the Italians, whilst known for their love of the petrol engine, are far more sensible with their private transport choices, opting for smaller vehicles.

Why is it we don’t all pedal round 5 seater cars? Because the energy to shift 1000kg to work and back is phenomenally greater than to move 20kg. So why are we using fossil fuels to do the same?

Next week wattsthecosts takes a closer look at vehicle efficiency and weight.


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