TP Chemical technology 65 TA Engineering (General). Civil engineering (General) 52 TD Environmental technology. Sanitary engineering 37 TJ Mechanical engineering and machinery 26 Environmental pollution 21 GE Environmental Sciences 16 QD Chemistry 14 HD28 Management. Industrial Management 9 TK Electrical engineering. Electronics Nuclear engineering 9 Air pollution and its control 8 T Technology (General) 8 Malaysia 7 QC Physics 6 Water pollution 6 Enviromental management 5 Environmental health. Including sewage disposal, air pollution, nuisances, water supply 5 NA Architecture 5 QH Natural history 5 TC Hydraulic engineering. Ocean engineering 5 Environmental conditions. Environmental quality. Environmental indicators. Environmental degradation 4 Environmental effects of industries and plants 4 Environmental protection 4 H Social Sciences (General) 4 HC79 Special topics-Including air pollution, automation,consumer demand, famines, flow of funds,etc 4 HD1394-1394.5 Real estate management 4 Q Science (General) 4 Qualities of water. Water quality 4 TH Building construction 4 HD Industries. Land use. Labor 3 HT101-395 Sociology, Urban 3