People who smoke tobacco are at an increased risk of developing non-infectious diseases of the gas exchange system and the cardiovascular system. In 2004, a study was carried out on the most popular brands of filter cigarettes from each of the six World Health Organization (WHO) regions. In this study, the smoke passing through the filter was analysed for the tar, nicotine and carbon monoxide (CO) content for each brand of cigarette. For each WHO region, the mean content of tar, nicotine and carbon monoxide of the different brands of cigarette was calculated. The results are shown in Fig. 2.1. Key to WHO regions AFRO = African Region AMRO = Region of the Americas EMRO = Eastern Mediterranean Region EURO = European Region SEARO = South-East Asia Region WRPO = Western Pacific Region [Figure 2.1]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2019). The mark or mark type is shown in brackets.

1. [1] (a) EMRO and SEARO / Eastern Mediterranean and South-East Asia (Regions)
2. [2] (b) max 1 (tar data mark or nicotine makes platelets sticky) if tar / CO also stated any two from: (AFRO) has more nicotine ; R has more, tar / tar and nicotine / CO and nicotine (see below) nicotine makes platelets sticky / AW ; A damages endothelial lining (so turbulent blood flow) so increases clotting risk R if also state tar makes platelets sticky 0.92 and 0.77–0.79 mg (per cigarette) or 9.2 v. 7.7-7.9 mg (per cigarette) or (AFRO) 1.3-1.5 mg (per cigarette) higher ; correctly extracted numerical data for tar is alternative to gain mp 3 ecf 12.5-12.7 v. 11.3–11.5 mg / (AFRO) 1.0–1.4 mg higher
3. [4] (c) allow, Hb / hb, for haemoglobin and allow CO for carbon monoxide any four from: 1 haemoglobin, has a higher affinity for / binds more readily with, carbon monoxide (than oxygen); A carbon monoxide displaces oxygen from haemoglobin A carbon monoxide binds to Hb and decreases its affinity for oxygen 2 carboxyhaemoglobin formed ; 3 binding is, (mainly) irreversible / permanent / (more) stable (than oxygen binding) / AW ; 4 decreases saturation of haemoglobin with oxygen (in the lungs) / less haemoglobin available to bind oxygen; A less oxyhaemoglobin formed / less oxygen binds to haemoglobin cigarette smoke: 5 low concentration of oxygen in inhaled cigarette smoke ; 6 ref. to (in airways), narrowed lumen / inflammation / increased mucus / accumulated, mucus ; A bronchial constriction 7 (so) lower concentration of / less, oxygen, reaching alveolus / in alveolar air or (so) less oxygen, diffuses / AW, (from alveolus) into bloodstream / reaches red blood cells / reaches haemoglobin (in red blood cells) ; R ref. to consequence of emphysema must be in context of mp 5 or 6 8 AVP; e.g. nicotine causes vasoconstriction and reduces blood supply (to extremities)