Erbil-Gwer Road refineries were not built according to the standard regulations. Hence, distillation tower, storage tanks, and flare sections of the refinery release the hydrogen sulfide (H2S) and carbon monoxide (CO). At present, the measurements of H2S and CO were taken in one of the Erbil-Gwer Road refineries to determine the risk level of these gases to human health and environment. Khurmala, Tawke, and Demir dagh crude oils having different properties, were utilized. According to the study performed, one could conclude that (i) several poisonous gases like H2S and CO are released by the Refineries into the atmosphere of refinery and nearby the refinery that have the dangerous impact on the health and environment; (ii) the hydrogen sulfide and carbon monoxide diffusion rate from flare, storage tank and distillation tower is higher than the standard rate; (iii) As Iraqi crude oil has high sulfur content than other crude oil and the proportion of sulfur is differ from one location to another, the utilization of this kind petroleum in Refinery is the cause the production of poisonous gases; (iv) wind highly impacts the diffusion of hydrogen sulfide and carbon monoxide. Hydrogen sulfide and carbon monoxide spread further from the source of these gases by increasing wind speed, (v) the effect of atmospheric temperature cannot be neglected. The diffusion rate of H2S and CO gas is increased in higher atmospheric temperature.