الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Exposure to CO is thought to be the most common cause of poisoning both ln industry and at homes. A sizable portion of the workforce in any country has a significant occupational exposure to CO. A large deal of attention has been paid to the effect of exposure to concentrations much lower than those causing definit poisoning. Also, there has been much concern with the effect of the gas on smokers, who inhale considerable quantities of CO with tobacco smoke. Many occupational ~roups of workers are subjected to high CO exposure. These include traffic policemen, automobile drivers, garage personne 1 , metallurgical workers, petroleum workers, chemical industries workers and firefighter The health significance of CO is largely due to the fact that it forms a strong coordination bond with the iron atom of the protohaem complex in haemoglobin forming COHb and thus impairs the oxygen-carrying capa city of the blood. The dissociation of Hb02 is also al tered by the blood COHb. In addition, CO binds to myoglobin in muscle and to intracellular cytochrome oxidase, thereby blocking cel- lular oxidase and causing anoxia. The main areas of concern that have arisen from acute or chronic exposure to low levels of CO in experi mental and epidemiological research in animal and man are: its role in the aggrevation of symptoms of car diovascular diseases; its contribution to performance deficits In certain psychomotor tasks; and its role in limiting the working capacity of exercising man. The use of tobacco by workers and the general population continues to increase world-wide. Smoking is thought to be one important factor in the development of many disorders of public health importance, including a number of disorders in which exposure to various chemi cal and physical factors plays an aetiological role. Prospective and retrospective epidemiological studies have identified cigarette smoking as one of the major factors in the development or coronary heart disease. It has been suggested that the risk of developing ar terial disease from intermittent exposure to CO may be much higher for smokers than non smokers. The present study has been carried out in a trial to find a relationship between exposure to CO and some biochemical and haematological parameters namely those concerned with liver functions, lipid profile, serum protein fractions, trace metals and complete blood picture. Also to evaluate the substantial effect of smoking on the assessed parameters. A total number of 117 male workers, smokers and non smokers, occupationally exposed to CO from Misr Chemical Industries Company have been selected for this study. A matched comparison group of 58 workers, smok ers and non smokers, was selected from the administra tive department of the factory, with no occupational ex posure to CO, but with the same demographic characteris tics as the exposed group. Exposed workers have been classified into exposed smokers and exposed non smokers. Similarly, control subjects were classified into control smokers and con trol non smokers. Results were presented as follows: a) effect of occupational exposure to CO. b) effect of smoking. c) effect of combined exposure to CO and smoking. I I The determination of the indices of exposure re vealed that COHb levels increased by both exposure to CO and smoking, but the levels of serum thiocyanate were found to be higher only among smokers, either exposed to CO or not. Also, it has been found that there is a pos itive correlation coefficient during the entire life and serum thiocyanate levels among all examined subjects and with COHb levels among smoking workers exposed to CO. This strengthens the validity of the use of thio cyanate as a smoking index. Liver functions were found to be affected by ex posure to CO. This has been demonstrated by the in creased levels of activity of serum transaminases ( AST andALT ). This suggests some dame,ge in the liver tissue due to CO exposure. Lipid metabolism was found to be affected by smoking more strongly than CO. This is evi dent by the fact that only total lipids and cholesterol were affected by CO exposure, while HDLchol., LDLcho 1 . , HDLchol./Chol ratio and LDLchol./HDLchol. ratio were all affected by smoking. Some of these parameters showed some significant correlation with COHb levels and smok ing habit expressed as number of packs of cigarettes smoked during the entire life. Also smoking had been found to affect the haematological parameters more potently than CO exposure. A trend of increase in the mean levels of haemoglobin, haematocrit, RBCs count, WBCs count and platelets count was detected among smokers when compared with non smokers. Also, Lower levels of neutrophils and higher levels of lymphocytes count had been detected due to smoking. Concerning trace elements metabol ism, CO decr eased the levels of serum Cu and increased the levels of serum Zn. It has been concluded that smoking has a del eterious effect stronger than that of CO exposure as concerns lipid metabolism and haematology, while CO ex posure has an adverse effect on liver functions and trace element metabolism.^leng