Campaign for Lead Free Air

Tetraethyl lead was first added to gasoline in the 1920s as an “anti-knock” agent, which is a cheap method of boosting the octane rating. It is not possible to use catalytic converters with leaded fuel as the lead coats the platinum and renders the catalyst ineffective. Lead free gasoline was therefore introduced into Japan in the late sixties, and into the US in the mid seventies in order to enable the use of catalytic converters and thus mitigate photochemical pollution.

However, by 1979, in the face of growing evidence of the harmful effects of lead on children's behaviour, neuro-cognitive development and IQ, the Department of Health and Social Security (DHSS) commissioned a report under the Chairmanship of Professor Lawther. The subsequent report, Lead and Health[10] recommended that the lead content of petrol should be reduced from 0.4 to 0.15g/L, but there was no recommendation to introduce lead-free petrol. Nor was there any recommendation to lower the lead level deemed safe from 35 microgrammes per decilitre of blood.

In 1980 the Conservation Society Pollution Working Party published a response to the Lawther report “Lead or Health”[11] co-authored by Professor Derek Bryce-Smith PhD, DSc, C Chem, FRSC, Professor of Organic Chemistry at Reading University, and Dr Robert Stephens, PhD, DSc, C Chem, FRSC, Reader in Organic Chemistry at the University of Birmingham, but HMG resisted their call for unleaded petrol under pressure from both the motor manufacturers and the petroleum industry.

The first edition of CLEAR's newspaper listed the campaign's objectives:

• To urge that the fixed limit of 0.15 grams per litre for lead in petrol should be introduced earlier than the official date of 1985 and be for existing cars only.
• To demand that as soon as possible, and in any event by 1985, all new cars sold in the UK market be required to run on lead-free petrol.
• To demand that as soon as possible, and in any event by early 1985, all petrol stations be required to have lead-free petrol available for sale to the public.
• To urge that taxation on the sale of petrol should be imposed to create a price advantage to motorists purchasing lead-free petrol.
• To maintain surveillance on the use of lead generally and to encourage enforcement of measures necessary to reduce lead pollution wherever it occurs.

In 1982 the CLEAR Charitable Trust organized an international conference on the biological effects of low-level lead exposure, and the subsequent proceedings, Lead versus Health,[12] were co-edited by Russell-Jones and Michael Rutter FRS, Professor of Child Psychiatry at the Institute of Psychiatry. A key chapter (8), “The contribution of lead in petrol to human lead intake” was co-authored by Russell-Jones and Dr Bob Stephens, and concluded that lead in petrol was contributing at least 70% to the lead intake of a 2-year-old child in Western society. This contrasted with the Government's figure of 10 per cent as outlined in the Lawther Report which had ignored the contamination of above-ground crops by airborne lead.

Other key chapters were provided by Herbert Needleman from Harvard University (Chapter 12) and Clair Patterson from the California Institute of Technology (Chapter 2). In 1979, Professor Needleman had published a seminal paper in the New England Journal of Medicine that demonstrated dose-dependent relationships between elevated levels of lead in shed milk teeth and a host of negative outcomes in children, including distractibility, hyperactivity lower IQ and a tendency to get easily frustrated.[13]

Clair Patterson had built an ultra-clean laboratory in the early fifties in order to measure the minuscule quantities of lead isotopes in an iron meteorite from the birth of the solar system; by which means he was able to date the age of the Earth at 4.55 billion years, an estimate that has never been superseded.[14][15] Using his ultraclean facility, Patterson was able to demonstrate that natural levels of lead in prehistoric and pristine samples were orders of magnitude lower than official estimates, most of which were measuring lead contamination. His key contribution was his “measles diagram” demonstrating that if the lead burden of a pre-technological human was represented by one dot, and a patient with clinical lead poisoning was represented by 2000 dots, then the lead burden of a typical adult living in Western society was represented by 500 dots. For no other toxin was there such a narrow gap between what is known to be typical and what is known to be toxic.

However, the reason that the conference created headlines was because Professor Rutter, who had sat on the Lawther Committee, changed his mind about the causality of lead, and its association with lower IQ in children.[16]