الفهرس | Only 14 pages are availabe for public view |
Abstract Natural gas (NG) is considered to be the most environmentally attractive fuel compared to others. The global demand of liquefied natural gas (LNG) has risen rapidly in recent years for the reasons of energy security and sustainable development (Ikealumba & Wu, 2014). Natural gas, abundant around the world, has a clean reputation compared to other fossil fuels since it burns less carbon when used (Finkel et al., 2013) It constitutes types of fossil fuel known as ―hydrocarbons‖ because these fuels contain chemical combinations of hydrogen and carbon atoms. It is a mixture of methane, ethane, propane and butane with small amounts of heavier hydrocarbons and some impurities, notably nitrogen and complex sulphuar compounds and water, carbon dioxide and hydrogen sulphide which are removed before liquefaction. Methane is the major component, usually over 85% by volume (The International group of Liquefied Natural Gas Importers [GILGNL], 2019). Therefore workers at LNG industry may be exposed to petroleum hydrocarbons, such as aromatics BTEX, H2S, SOx, formaldehyde, CO, VOC, NOx and PM. Respiratory symptoms may occur due to exposure to irritant impurities which can cause cough, wheezes, shortness of breath, aggravation of asthma and reduction of lung functions (Gorguner & Akgun, 2010). On the other hand some cardiovascular symptoms can result from exposure to hazards related to NG which lead to range of symptoms as disturbance of cardiac rate and rhythm, hypertension, dilated cardiomyopathy and even cardiac death. The study was conducted in one of LNG companies in Egypt. Investigations were conducted at the laboratories of Occupational Health and Air Pollution department High Institute of Public Health, Alexandria University. The main aim of the study is to assess some cardiopulmonary effects among workers exposed to LNG in Egypt. In this study, pulmonary function tests and resting 12 leads ECG were done to assess effects of exposure to natural gas and its components on respiratory and cardiovascular systems respectively and the results were correlated with duration of exposure. All the workers were male. The median of the age for the exposed workers was 40.45 ± 7.89years comparing to 42.39 ± 7.72among the controls. About 49.1% of the exposed workers were smokers comparing to 59.7% of the controls The results of the study revealed that 70.4% of the exposed group and 54.8% of the non-exposed group had reduction of FVC less than 80% of predicted values with significant difference among two groups regardless duration of exposure in regression analysis model (P-value < 0.05). Also, there were significant differences between both groups regarding arrhythmias. PR interval was significantly longer when compared to duration of exposure (<20 versus ≥ 20 years) among the exposed group in regression analysis model. There was no significant difference between two groups regarding serum cholesterol and triglycerides. 6.2. Conclusion 1. Exposure to natural gas in LNG industry may lead to significant cardio-pulmonary changes among exposed workers. 2. Pulmonary function tests and ECG are easy tools for detection of respiratory and cardiac changes in the current occupational exposure to LNG. 3. Reduction of FVC% below 80% of predicted is the most frequent significant change in pulmonary function testing among workers exposed to NG in LNG industry regardless to duration of exposure. 4. There is prolongation in PR interval among exposed group when it was compared according to duration of exposure (<20 VS ≥ 20 years). Also arrhythmias are significant findings among the exposed group. 5. There was no statistically significant difference between the two groups regarding cardiovascular risk factors including cholesterol and triglycerides. It is recommended that all workers exposed to LNG should be investigated regularly for lung functions regardless their duration of exposure to detect any deterioration in their lung function which may affect performance especially if these workers have health conditions that may be deteriorated due to exposures with comorbidities such as allergy, asthma and COPD. 2. Workers engaged in LNG industry should do ECG at preplacement and periodic medical examinations with a special focus on cardiac arrhythmias and P-R interval. Workers with any cardiac problem should benefit from relocating in a suitable place to avoid exacerbation of their conditions by exposures. 3. Follow-up studies to investigate the prognosis of pulmonary and cardiac disorders among workers in LNG industry. 4. Apply personal protective equipment for workers exposed to NG with preventing and control of environmental emissions at the source to the acceptable threshold limit value (TLV). 5. Strengthen efforts to implement legislation to reduce the harmful effects of exposure to NG. 6. Need of further studies for flow rates and detect cause of restrictive effect in pulmonary functions. |