Petroleum industry Trade 5 Economic conditions 2 Aerosols 1 Arab countries 1 Cadmium 1 Chernobyl accident 1 Coal 1 Desert 1 Earthquake 1 Estuary 1 Finances 1 Flood control 1 Fluorine 1 Fuels 1 Gaseous fuel 1 Global warming 1 Heating of rivers 1 India 1 International economic relations 1 Investment 1 Mercury ,Health damage 1 Middle East 1 Near East 1 Near east 1 Nuclear energy 1 Oceanography 1 Oil politics 1 Ozone hole 1 Political aspects 1