environmental Hazards

An environmental hazard is a substance, a state or an event which has the potential to threaten the surrounding natural environment/ adversely affect people’s health, including pollution and natural disasters such as storms and earthquakes. The environmental hazards deals with the concept that are caused by air, water, soil and radioisotopes. Air pollution occurs when the air contains gases, dust, fumes or odor in harmful amounts. Water pollution is the contamination of water bodies. Contamination of soil by human and natural activities which may cause harmful effects on living beings.

1. ENVIRONMENTAL HAZARDS Shreyas B.R MPHARM QA

2. CONTENTS Introduction Hazards based on Air Water Soil Radioactive isotopes Conclusion References 2

3. Introduction An environmental hazard is a substance, a state or an event w hich has the potential to threaten the surrounding natural environment/ adversely affect people’s health, including pollution and natural disasters such as storms and earthquakes. Any undesirable change in the physical, chemical or biological features of air, land and water is called pollution. Any physical, chemical or biotic component/ agent or non-living substance that is responsible to bring about an undesirable change in the environment is called pollutant. 3

4. Air pollution Definition: Any atmospheric condition in which substances are present at concentrations high enough above their normal ambient levels to produce a measurable effect on man, animals, vegetation or materials is called air pollution. It is when concentrated gases exceed safe limits. Air pollutant: It is a substance or effect dwelling temporarily or permanently in the air , which adversely alters the environment by interfering with the health, the comfort, or the food chain, or by interfering with the property values of people. 4

5. Classification 5

6. Sources of air pollution Air Pollution may originate from a natural or anthropogenic source or from both sources. natural source – an erupting volcano, accidental fire etc . Man- made - industrial units, thermal power plants, automobile exhausts, fossil fuel burning, mining, nuclear explosions. 6

7. Causes of air pollution 7 Primary air pollutants

8. Secondary air pollutants Smog: Air pollution in urban and industrial areas. Photochemical smog: a noxious mixture of gases and particles, is produced when strong sunlight triggers photochemical reactions in the atmosphere. The major component of photochemical smog is ozone. 8

9. Effects of air pollution Human effects: eg : diseases Environmental Effects Acid rain Ozone Depletion Global Climate Change Green- house effect Global warming 9

10. Water pollution Water pollution is defined as alteration in physical, chemical or biological characteristics of water, making it unsuitable for designating best use in its natural states. 10

11. Causes of water pollution Industrial wastes: All the industries discharge the waste by-products from the manufacturing processes into rivers or other water bodies . Domestic sewage: It consists of water borne wastes of the human community. Mostly it is disposed off as such in treated, partly or untreated form in nearby lakes, rivers or sea, where it causes pollution. 11

12. 3. Thermal and Radioactive Waste: Different industries and nuclear power plants use water and discharge the heated water into nearby water bodies . 4.Biodegradable and Non-Biodegradable Waste: Biodegradable pollutants consist mainly of organic matter from domestic sewage . Non-biodegradable wastes includes plastic bags, long chain detergents, aluminium cans, glass etc. 12

13. Effects of water pollution Physical effects: Settled particles may slowly accumulate on vegetation foliage and produce a deposit on the river bed. Small suspended particles make water turbid and reduces light penetration, reduces photosynthesis and restricts plant growth. Chemical toxic wastes: Toxic metals: Heavy metals eg : Iron, lead, mercury, cadmium, zinc etc Acid and alkali toxins: These may be regarded as hazardous because they lower or raise the pH value of water. 13

14. c. Pesticide toxins: Hazardous pesticides are the organochloride compounds because of their stability and persistence in the environment. Chemical nutrient effects: In water pollution, the two most important nutrients are nitrogen and phosphorous usually present in nitrates and phosphates. Microorganism effect: Wastes that are discharged into water contain pathogenic organisms that are capable of causing human diseases. Eg : cholera, typhoid fever, bacillary dysentery etc 14

15. Control measures for water pollution Prevent or minimize the mixing of pollutants into water bodies . Maintenance and restoration of water of all types, such as surface water and ground water . Industries should treat their effluents before they dispose it into water bodies. 15

16. Soil pollution Contamination of soil by human and natural activities which may cause harmful effects on living beings. 16

17. Causes for soil pollution Natural causes : Landslides, Hurricanes Man-made causes Urbanization : Contamination of soil due to waste water. Unfit for agricultural land due to construction of dams , project in near by places . 17

18. Industrial wastes : Discharge of large quantities of toxic, flammable, non-biodegradable substances on land results in soil pollution. Mining : Mining refers to process by which nonrenewable substances and valuable minerals are extracted from earth. It leads to change in composition of soil. 18

19. Domestic waste : It includes wastes such as food wastes, paper, g lass, plastic materials. Contribute to soil pollution. Radioactive waste : Nuclear power plants, nuclear testing, and explosion. 19

20. Effects of soil pollution Disposal of industries wastes on fertile lands degrades the quality of soil. Urban waste slowly poison the soil, damaging its fertility. Radioactive elements that present in polluted soil enter food chain through plants. Causes Planting of trees must be encouraged. Solid waste can also be used for electricity generation. Use of chemical fertilizers and pesticides should be minimized. 20

21. Methods to control soil pollution Reducing chemical fertilizer and pesticide use. Recycling is another way to reduce and control soil pollution. Reusing of materials De-forestation, the cutting down of trees, causes erosion, pollution and the loss of fertility in the topsoil. 21

22. Radioactive pollution Addition of radiation to environment by using radioactive elements . 22

23. Sources of radioactive pollution Natural sources Cosmic Radiation Terrestrial Radiation Internal Radiation Man-made sources Production and research of nuclear weapons Mining of radioactive ore Medical waste Nuclear power plants Industrial radiography 23

24. Production of nuclear weapons: Radioactive materials used in this production have high health risks and release a small amount of radioactive pollution . Mining of radioactive ore: Mining of these involves crushing and processing of the radioactive ores and this generates radioactive waste which emits alpha particles. 24

25. Medical waste: A number of radioactive isotopes are used in medicine, either for treatment or diagnostics. Nuclear power plants : Nuclear power plants under current standards produce little radioactive pollution due to safety precautions that must be adhered. 25

26. Control of radioactive pollution Prevention of leakage of radioactive elements from the nuclear reactor. Proper storage and disposal of nuclear wastes . Regular monitoring and high risk analysis . Global understanding about nuclear exposure. 26

27. Conclusion A hazard is a situation that poses a level of threat to life, health, property, or environment. 'Environmental hazard' is the state of events which has the potential to threaten the surrounding natural environment and adversely affect people's health. Air pollution has long been a serious problem in the world. 27

28. Reference https:// www.ncbi.nlm.nih.gov/pmc/articles (accessed on 6 march 2019) https:// www.jacionline.org/article (accessed on 5 march 2019) https:// www.pharmatutor.org/articles/discussion-radiosotope-radiopharmaceutical-uses (accessed on 7 march 2019) https :// www.omicsonline.org/scholarly/water-pollution-journals-articles-ppts-list.php (accessed on 6 march 2019) 28

29. Dr. M.K Gupta, Dr. Manish Jaimini, Vikas Pandey, Environmental Science, Nirali Prakashan, 1 st edition, P: 3.1-3.23 Dr. Kishore R. Pawar , Dr. Sachin B. Narkhede , environmental sciences, Vandana publications, 2 nd edition, P: 3.1-3.3 29

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