الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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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.