الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Natural Gas (NG) continues to be favoured as an ecologically attractive fuel. It has lower impacts on environmental pollution and it was announced that Egypt is going to cooperate with other countries in the region to receive gas, liquefy it and re-export to Europe and to be a regional centre for trading energy in the Eastern Mediterranean region. Therefore, a great number of workers is expected to be included in LNG industry. Liquefied Natural Gas (LNG) consists primarily of methane, ethane and propane. Other constituents also present at different concentrations: iso-butane, normal butane, pentanes, hexanes, heavier hydrocarbons, and nitrogen, in addition to some contaminants as hydrogen sulphide, carbon-monoxide, and mercury. Moreover, workers are exposed to many other hazardous factors during work, which might be mechanical (slips, falls), physical (noise, vibration, cold surfaces), chemical (constituents and contaminants of natural gas) and psychosocial factors, in addition to fires and explosions. Many studies were conducted to assess the risks of fires and explosions in LNG industry, but unfortunately without focusing on the health status of the exposed workers and on changes in their haematological and biochemical parameters.
The present study aimed to investigate the impact of LNG environment on the health of workers and to measure some of their haematological and biochemical parameters. A point which should be taken in consideration is that exposed workers are engaged in the different processes of LNG industry according to work needs without a specific exposure. Our final goal is to control the adverse health effects of any exposure in LNG industry in Egypt.
In order to fulfil this aim, a cross-sectional study was conducted. The study Population included all male workers employed for more than one year and accepting to participate in the present study.Female workers were excluded as they were not involved in the exposed sector.
A pre-designed pre-coded structured interviewing questionnaire was used to collect data from workers including their socio-demographic characteristics, a detailed occupational history about their previous and current job regarding nature and duration of exposure. The use of personal protective equipment and safety measures were also investigated. Detailed information about their smoking history, their current and previous medical conditions and investigations were collected. Finally, fasting blood samples were obtained from the participants using appropriate standard procedures and they were subjected to the following laboratory tests: Complete blood count (CBC), fasting blood glucose (FBG), renal function tests (urea, creatinine), liver function tests (ALT, AST). lipid profile (Cholesterol and triglycerides) and tumor Markers (CEA, PSA, CA19.9, CA125, CA15.3).
Appropriate statistical procedures were then applied to process the data and the following results were obtained:
• Regarding sociodemograpghic data, insignificant differences regarding age, gender and smoking history were observed among exposed and non-exposed workers.
• Concerning occupational history, differences between the two groups were insignificant regarding work duration, but significant regarding daily working hours.
• Medical history showed that hypertension was more prevalent among exposed workers compared to controls.
• Medical examination revealed insignificant differences between the two exposed groups regarding their blood pressure measurements, pulse and BMI.
• As regards CBC parameters, significant differences betweenthe two groups were observed concerningHaemoglobin (g/dl), Haemoglobin %, R.B.Cs count, Haematocrit value and Lymphocytic count. This might be attributed to gas impurities or due to other air pollutants emitted during incomplete combustion of gas flare or due to haematotoxic effects induced by benzene.
• Concerning biochemical parameters, values of serum creatinine, ALT, AST and triglycerides were observed to be higher among exposed workers while the values of fasting blood sugar, blood urea and serum cholesterol were found to be higher among non-exposed workers. However, the differences were insignificant for all parameters except for AST.
• With regard to tumor markers, CEA values were significantly higher among exposed workers, while Ca125 values were significantly higher among non-exposed workers. No significant differences were observed regarding the other tumor markers.
• No correlation between significantly increased CBC parameters among exposed workers and some variables (age, duration of exposure, smoking index, duration of current and past work, CEA, CA125) was observed. The same was observed between AST and other variables (age, duration of current and past work, triglycerides). The only significant correlation was between AST and cholesterol. Some hepatic disorders may have a role in this relationship.
• All measured air contaminants were below TLV level, except for benzene.
Based on the findings of this study, the following recommendations can be suggested:
• Pre-placement medical examination for proper selection of workers should include: a proper medical history, a thorough medical physical examination carried out by occupational medical specialists and blood tests including complete blood count, kidney, liver and some tumor markers assessment.
• Periodic medical examination for early detection of health impairment.
• Application of personal protective equipment (PPE) for exposed workers.
• Initiating a health education program for workers.
• Periodic assessment of the environmental contaminants and making sure of keeping them below their TLV levels.
• Control of benzene emitted as an environmental contaminant from nearby industries.
• More studies are needed for further evaluation of the results.
Conclusion
• Some haematological and biochemical changes were detected among exposed workers, mainly in their CBC parameters (Haemoglobin (g/dl), Haemoglobin %, R.B.Cs count, Haematocrit value and Lymphocytic count) which were higher in exposed workers. As regards biochemical parameters, the differences were insignificant except for AST. Concerning tumor markers, CEA values were significantly higher among exposed workers.
• Medical history revealed that hypertension was more prevalent among exposed workers compared to controls.
• Assessment of air contaminants showed that the measured values were below TLV levels except for benzene.
• It is difficult to attribute these adverse health effects to a certain exposure due to the fact that exposed workers are engaged in the different processes of LNG industry according to work needs.
• Moreover, it is difficult to attribute these effects to any of the constituents of LNG as all the measured values in air were below their TLV.
• Gas impurities, air pollutants emitted during incomplete combustion of gas flare and exposure to factors outside the work environment as exposure to benzene from a nearby industry might be blamed as the offensive pollutants.