Restriction On Exhausts Urged

Press, Volume CVIII, Issue 31627, 13 March 1968, Page 6

Restriction On Exhausts Urged

Immediate steps should be taken to make provision in the Transport Act for exhaust discharge to be vertical to the rear of the cab on heavy vehicles and towards the middle of the road on other vehicles, said the Health Department’s chemical inspector (Mr D. R. Pullen) this week.

He was commenting on a statement from the Christchurch branch of the Clean Air Society which drew attention to the increases in the number of vehicles with exhaust pipes mounted on the left side of the chassis. “The fumes are directed straight at the pavements and close to pedestrians,” the society said. “Would the Health Department’s chemical inspector comment on this new source of direct air pollution?”

Diesel and petrol-engined motor vehicles emitted two distinct types of air pollution, said Mr Pullen. One was visible in the form of smoke, and the other was Invisible consisting of gaseous combustion products such as carbon monoxide, aldehydes and oxides of nitrogen. “Visible pollution is highly undesirable,, but can be controlled and legislation has been formed to prohibit the emmission of smoke,” Mr Pullen said. “Invisible pollution cannot be eliminated, only controlled; first by devices fitted to the vehicle, and second by adequate dispersal. “Motor vehicles cause substantial local pollution particularly in congested or in narrow roads. This, however, falls away rapidly with distance, and the critical positions would be pavements and fronts of shops. “Research in England has shown that the effect on pedestrians depends largely on the geometry of the tail pipe and when this was projected towards the middle of the road, or discharged vertically, effects were reduced to a minimum.

“In view of this research how can we justify the situation where large numbers of heavy vehicles and motorcars discharge exhaust gases directly towards the pavement at a range of from

as little as one to two feet in some areas.

“Immediate steps should be taken and provision made in the Transport Act that approved positions of exhaust discharge be vertical to the rear of the cab on heavy vehicles and towards the centre of the road on all other vehicles; motor cycles and scooters to discharge at the rear. This legislation should apply to all new vehicles imemdiately and to existing vehicles within 12 months, the position of the tail pipe to be in correct alignment for the issue of a warrant of fitness,” said Mr Pullen.