The main objectives were to identify the source and assess the level of air pollution, in accordance with national and international legislation and standards relating to ambient air quality. This work focused on the impact of carbon dioxide (CO₂) emissions generated by industrial activities of petroleum refining, liquefied natural gas processing and petrochemicals, on the quality of ambient air in the region of Arzew, Algeria in 2017. The study revealed that the average annual CO₂ concentration did not exceed the limit value recommended by the European standard EN 13779. This study also demonstrated that the CO₂ content levels depended on the emission rates industrial and weather seasons, peaking in summer mainly due to relatively stable weather conditions.