Water pollution and human health

Health is wealth. It is a multi-dimensional issue where agent, host and environment, all play their part to maintain its homeostasis. Water pollution is a growing issue threatening human health.

1. Water Pollution and Human Health Presented by: Shisam Neupane

2. Water It is one of the most important natural resources on earth. Most common liquid Covers 71.4% of earth’s surface Pure water has no smell, taste or color 2

3. Importance (for human) The human body is approximately 70% water. It helps in thermoregulation, transportation (within body as well as outside for water vehicles), detoxification in living beings. It is main components for other fluids like; milk, juice etc. Water is needed not only for drinking, but also for washing, cleaning, irrigation, transportation, recreation etc. #People can survive a few months without food but they can survive a day or two without water. 3

4. Water quality Water quality refers to the chemical, physical, biological, and radiological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. The most common standards used to assess water quality relate to health of ecosystems , safety of human contact , and drinking water . 4

5. Water Quality Standards Safe drinking water is essential to health, a basic human right and component of effective policy for health protection. Access to safe drinking water is important as a health and development issue at a national, regional and local level. The primary purpose of guidelines for drinking water quality is the protection of public health

6. Improving access to safe drinking water to result in benefits to health. Every efforts should be made to achieve a drinking water quality as safe as practicable. Diseases related to contamination of drinking water constitute a major burden on human health . Interventions to improve the quality of drinking water provide significant benefits to health

7. WHO Guidelines The guidelines for drinking water quality recommended by WHO relates to following variables: a. Acceptability Aspects b. Microbiological aspects c. Chemical aspects

8. a)Acceptability Aspects Turbidity <5NTU (Nephelometric turbidity Unit ) Colour < 15 TCU (True colour unit) Taste and odour: No unusual taste or odour Temperature: Cool water is more platable (Source: National Drinking Water Quality Standards, 2062)

9. b ) Chemical Aspects Chlorides or salinity- 200mg/l and maximum 500mg/l Ammonia Usually <0.2mg/l PH 6.5-8.5 Hydrogen sulphide Up to 0.1mg/l Iron 0.3mg/l Sodium <200mg/l Sulphate <250mg/l Total dissolved solid <1000mg/l Zinc <3mg/l Manganese <0.1mg/l Copper <1mg/l Aluminium < 0.2mg/l (Source: National Drinking Water Quality Standards, 2062)

10. c) Microbiological Aspects Water should not contain any pathogenic micro-organisms like bacteria virus or parasite free living organisms such as fungi, algae etc. water is most common medium for transmission of communicable disease so it should filtered or made free from microbes. (Source: National Drinking Water Quality Standards, 2062)

11. Human health From the public health aspect, we have to prevent and promote human health in every way. The water quality also plays a great role in human health. High water temperatures can increase rate of photosynthesis; metabolic rates in aquatic organisms; solubility and thus toxicity of certain compounds. Water supply with pH values greater than 11 can cause skin & eye irritations, as does a pH below 4. Presence of excess of iron and manganese in water causes discoloration, turbidity and deposits. Iron and manganese bearing water have astringent metallic or bitter taste. Precipitation of iron and manganese imparts colour to water from yellow to brownish black, which becomes objectionable to consumers. 11

12. Dissolved solids in water causes decreasement in palatability and gastrointestinal irritation Presence of ammonia indicates the possibility of sewage pollution and the consequent possible presence of pathogenic micro-organisms, which may cause several water borne infections Arsenic in water causes acute poisoning; Skin, bladder and lung cancer; Clastogenic effects Excess nitrate in water causes Methaemoglobinaemia -blue baby syndrome; Nitrosamines - cancercausing substances 12

13. All the things that causes change in water quality are responsible for changes in human health as people are in direct contact with water either by consuming directly or by using for domestic purpose, industrial purpose or for recreational or other purposes. 13