Environmental issues in Syria Attacks on oil refineries can cause oil fires which release harmful chemicals into the air, such as sulfur dioxide, nitrogen dioxide, carbon monoxide and polycyclic aromatic hydrocarbons (PAHs). The sulphur and nitrogen compounds are linked to acid rain which can have dire impacts on vegetation as well as cause soil acidification. PAHs persist in the environment for long periods of time and are known carcinogens. Syria also extracts heavy crude oil, which generally has a higher proportion of noxious substances, including heavy metals, making it especially dangerous when these substances seep into the soil. Syria has two oil refineries. The
Environmental impact of aviation Environmental impact of aviation The environmental impact of aviation occurs because aircraft engines emit heat, noise, particulates and gases which contribute to climate change and global dimming. Airplanes emit particles and gases such as carbon dioxide (), water vapor, hydrocarbons, carbon monoxide, nitrogen oxides, sulfur oxides, lead, and black carbon which interact among themselves and with the atmosphere. Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines, the rapid growth of air travel in the past years contributes to an increase in total pollution attributable to aviation. From 1992 to 2005, passenger kilometers increased