Investigation of carbon monoxide at heavy traffic intersections of Karachi [Pakistan] using gis to evaluate potential risk areas for respiratory and heart diseases

Measurement of carbon monoxide in the ambient air at 36 locations on the busy roads of Karachi showed peak values of CO at 18 sites to be within the permissible limit of 10 ppm whereas up to 70 ppm at the other 18 sites. The evaluated carboxy haemoglobin [COHb] level was in the range of 1.1 to 15.8%