Columbia subject headings:
Automobiles--Motors--Exhaust gas--Toxicology.
Environmental policy--Great Britain.
Environmental policy--United States.
Lead--Toxicology--Great Britain.
Pediatric toxicology--Great Britain.
Harvard subject headings:
Princeton subject headings:
Automobiles--Motors--Exhaust gas--Political aspects.
Gasoline--Anti-knock and anti-knock mixtures--Physiological effect.
Lead--Physiological effect.
Lead--Toxicology--Great Britain--Political aspects.