5.1 Constituents of tobacco smoke 5.2 Quantity of tobacco per cigarette 5.3 Tar, nicotine and carbon monoxide levels 5.4 Package labelling of tar, nicotine and carbon monoxide levels 5.5 Smokers' awareness and understanding of package labelling requirements, and knowledge of tar level and other toxic substances in cigarettes 5.6 Package labelling of health warnings 5.7 Smokers' awareness of health warnings 5.8 Agricultural chemicals, flavourings and other additives