THE Government has conceded that it does not know how many lives will be saved as a result of its tighter standards for fuel and vehicle emissions. Despite respiratory diseases regularly featuring in the vanguard of anti-traffic arguments, Baroness Jay of Paddington said the impact of cutting local pollution was not yet known.

'The recent report by the Committee on the Medical Effects of Air Pollutants estimated that the deaths of between 12,000 and 24,000 vulnerable people may be brought forward, and between 14,000 and 24,000 hospital admissions and readmissions may be associated with short-term air pollution each year,' she said.

'While a reduction in air pollution would be expected to lead to a reduction in deaths and hospital admissions for cardiovascular and respiratory illness, unfortunately, at present, we are unable to estimate the extent of the health gains projected from reductions in air pollution from particular sources, as the science is not yet developed sufficiently to quantify this effect.'