Pollution Environmental aspects 38 Health aspects 38 Environmental health 37 Gezondheid 36 Public Health 36 Quality Control 36 Water 36 Water Microbiology 36 Water Pollution 36 Water Supply 36 Water quality 36 Water quality management 36 prevention & control 36 standards 36 Air 1 Factory and trade waste 1 Heavy metal 1 Kathmandu Valley 1 Social aspects 1 Transportation 1 water and waste 1