Answer to Question 1
Waterborne disease (pathogens) reaches water through animal (including human) wastes being discharged to land or water; the basic impact is disease. Human and animal wastes reach water by either direct discharge or runoff from land; the basic impact is the addition of nutrients (limiting factors) and disease to water. Chemicals pollute water by either direct discharge to water or runoff from land; the basic impacts are rendering water unpalatable (or dangerous) for humans and dangerous for aquatic life. Sediments reach water as a result of erosion; the basic impact is to increase turbidity and increase the nutrient load.
Answer to Question 2
Social modernization does not require the economic trappings of a developed country. Instead, what is needed are efforts made on behalf of the poor, with particular emphasis on the following: (1) education, especially improving literacy and education of girls and women equally with boys and men; (2) improving health, especially lowering infant mortality; (3) making family planning accessible; (4) enhancing income through employment opportunities; and (5) improving resource management (reversing environmental degradation).
The relationship between air temperature and two measures of water vapour saturation of air.
Hydrogen bonding of water with itself and with other compounds
Water caltrop
Using a water-based cleaning system helps reduce the hazards from using strong chemicals.
The chemical structure of the water molecule
Water Molecule