A recent study has confirmed the link between pollution and heart attacks. Researchers at St George's Hospital Medical School, London, say one in 50 heart attacks reported at hospitals in London may be caused by outdoor pollution. Nearly 6,000 heart attacks can be avoided every year in the UK if emissions are controlled, say the researchers who examined admissions for circula-tory diseases in London hospitals between 1987 and 1994. High levels of nitrogen dioxide, sulphur dio-xide, carbon monoxide and soot in the patients' lungs and blood were strongly associated with heart attacks. Emission of carbon monoxide is a major cause of concern because it binds with haemoglobin and reduces the ability of the blood to transport oxygen ( British Medical Journal , August 5, 1997).