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Environmental Degradation And Human Health. Environmental Degradation. Environment: The environment is the sum total of physical and biotic conditions influencing the responses of the organisms. Biosphere-(Air, Water & Soil) Atmosphere Hydrosphere lithosphere .
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Environmental Degradation Environment: The environment is the sum total of physical and biotic conditions influencing the responses of the organisms. • Biosphere-(Air, Water & Soil) Atmosphere Hydrosphere lithosphere
Atmosphere The multilayered gaseous envelope surrounding the planet earth is called as atmosphere. Zones of Atmosphere- • Troposphere - • lowest layer, 8-10 km from earth surface. • Climatic events- cloud formation, lightenning, thundering, storm formation. • Air temperature decreases with increase in height. • Upper layer temp(- 60 o C ).
2.Stratosphere- i. 50-55 Km in height ii. Free from clouds iii. Aeroplanes usually fly in its lower zone. iv. Temp increases up to 90 oC. v. Ozone layer is present in this zone.3. Mesosphere – i. 50 km up to 100km ii. Temp decreases up to – 80 oC.
4. Ionosphere(Thermosphere) – i. Extends up to height of 400 km ii. Temp rises up to 1000 oC. iii. Contains large no of ions & free electrons. iv. It reflects radio wave signals & helps in long distance radio communication & telecommunication.5. Exosphere – i . Lies beyond 400 km. ii. Air density is very low. iii Temp. increases.
Environmental Degradation • Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystemsand the extinction of wildlife. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. • The United Nations International Strategy for Disaster Reduction defines environmental degradation as “The reduction of the capacity of the environment to meet social and ecological objectives, and needs”.
One of the greatest challenges facing humanity is environmental degradation, including deforestation, desertification, pollution, and climate change – an issue of increasing concern for the international community. Environmental degradation increases the vulnerability of the societies it affects and contributes to the scarcity of resources.
Climate change will lead to an increase in the intensity and frequency of weather extremes, such as heat waves, floods, droughts and tropical cyclones. The people hardest hit by climate change and environmental degradation are those living in the most vulnerable areas, including coastal communities, small island nations, Sub-Saharan Africa and Asian delta regions. It is the poorest of the poor, who lack the resources to prepare, adapt and rebuild, are most affected.
Environmental Change and Human Health, a special section of World Resources 1998-99 in this report describes how preventable illnesses and premature deaths are still occurring in very large numbers. If vast improvements are made in human health, millions of people will be living longer, healthier lives than ever before. In these poorest regions of the world an estimated 11 million children, or about one in five, will not live to see their fifth birthday, primarily because of environment-related diseases. Child mortality is larger than the combined populations of Norway and Switzerland, and mostly due to malaria, acute respiratory infections or diarrhea — illnesses that are largely preventable.
Effects of the major environmental problems on both health and productivity • A.Water pollution and water scarcity: As per the estimation of UN, more than two million deaths and billions of illnesses a year are attributable to water pollution. Water scarcity compounds these health problems. Productivity is affected by the costs of providing safe water, by constraints on economic activity caused by water shortages, and by the adverse effects of water pollution and shortages on other environmental resources such as, declining fisheries and acquifer depletion leading to irreversible compaction.
B.Air pollution: As per the estimation of UN, urban air pollution is responsible for 300,000—700,000 deaths annually and creates chronic health problems for many more people. Restrictions on vehicles and industrial activity during critical periods affect productivity, as does the effect of acid rain on forests and water bodies.C.Solid and hazardous wastes: Diseases are spread by uncollected garbage and blocked drains; the health risks from hazardous wastes are typically more localized, but often acute. Wastes affect productivity through the pollution of groundwater resources.
D.Soil degradation: Depleted soils increase the risks of malnutrition for farmers. Productivity losses on tropical soils are estimated to be in the range of 0.5-1.5 per cent of GNP, while secondary productivity losses are due to siltation of reservoirs, transportation channels and other hydrologic investments.E. Deforestation: Death and disease can result from the localized flooding caused by deforestation. Loss of sustainable logging potential and of erosion prevention, watershed stability and carbon sequestration provided by forests are among the productivity impacts of deforestation.
F. Loss of biodiversity: The extinction of plant and animal species will potentially affect the development of new drugs; it will reduce ecosystem adaptability and lead to the loss of genetic resources.G. Atmospheric changes: Ozone depletion is responsible for perhaps 300,000 additional cases of skin cancer a year and 1.7 million cases of cataracts. Global warming may lead to increase in the risk of climatic natural disasters. Productivity impacts may include sea-rise damage to coastal investments, regional changes in agricultural productivity and disruption of the marine food chain.
Environmental Pollution An undesirable change in the physical, chemical or biological characteristics of our air, water and soil harmfully affect human life or create a potential health hazard of any living organism. Types – 1. Air pollution 2. Water pollution 3. Soil pollution 4. Noise pollution
Air Pollution • Sources • Natural pollutant – Natural fog, pollen grain, bacteria, products of volcanic eruption. • Aerosol or particulate matter- dust, smoke, mists , fog& fumes. • Gases &Vapours – Organic & radioactive compounds,S,N,O2,
Gas phase chemistryIn the gas phase sulfur dioxide is oxidized by reaction with the hydroxyl radical via an intermolecular reaction:SO2+ OH → HOSO2which is followed by:HOSO2· + O2 → HO2+ SO3In the presence of water, sulfur trioxide (SO3) is converted rapidly to sulfuric acid:SO3 (g) + H2O (l) → H2SO4 (l)Nitrogen dioxide reacts with OH to form nitric acid:NO2 + OH· → HNO3
Since 1998, Harvard University wraps some of the bronze and marble statues on its campus, such as this "Chinese stele", with waterproof covers every winter, in order to protect them from erosion caused by acid rain (or, actually, acid snow)
Green House Effect • Greenhouse gases • water vapor, 36–70% • carbon dioxide ,9–26% • methane, 4–9% • ozone, 3–7%
Effect of Green House effect • Temp is going to increase, about 3.6 oC. • All the glaciers will recede & ice cap in the Antarctica & the Arctic will begin to melt. • The sea level will rise by a few meter. • Most of the cities on the sea shore may be submerged.
Photochemical Smog • Smog = smoke + fog • Photochemical smog is secondary pollutant which is produced in the air by interaction among two or more primary pollutant • Action of sunlight on hydrocarbons & nitrogen oxides • Main constituents of photochemical smog are Peroxy acetyl nitrate (PAN),nitrogen oxide,hydrocarbon,CO,& Ozone.
Photochemical Smog • Photochemical smog is a mixture of pollutants which includes particulates, nitrogen oxides, ozone, aldehydes, peroxyethanoyl nitrate (PAN), unreactedhydrocarbons, etc. The smog often has a brown haze due to the presence of nitrogen dioxide. It causes painful eyes.
Water Pollution • Sources • 1. Domestic waste water & sewage • 2. Industrial waste • 3. Agricultural Waste • 4.physical pollutants(thermal & radioactive)
Case Study • On 9 December 1952, foggy conditions developed over London. Being very cold, most houses kept fires burning, with coal as the major fuel. The smoke from these fires mixed with the fog and was unable to disperse, resulting in a smog which persisted for 4 days. The pH of air during the Great London Smog was as low as 1.6. During this period some 4000 more people died than would expected at this time of the year. Most of these additional deaths were due to respiratory disorders
Effect of Photochemical Smog • Eye irritation • Vegetation damage • Visibility reduction • Cracking of rubber • Fading of Dyes- affects colour of dyes.
Water Pollution • Sources • 1. Domestic waste water & sewage • 2. Industrial waste • 3. Agricultural Waste • 4.physical pollutants(thermal & radioactive)
Effect of Water Pollution • Eutrophication- The enrichment of water body by input of organic waste containing nutrients, chiefly nitrates & phosphates. Due to nitrates & phosphates the water body becomes highly productive or eutrophic, which is called as Eutrophication.
