Introduction to Environmental Pollution and their Impacts on Public Health

Introduction to Environmental Pollution and their Impacts on Public Health

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  Introduction to EnvironmentalPollutions and their Impacts on Public Health Amjad Khan Afridi Lecturer, Department of Health & Biological Sciences
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  Environmental Pollutions andtheir Hazardous Impacts Environment Pollution may be defined as, the physical and biological factors along with their chemical interactions that affect an organism or a group of organisms. From last three decades (30 years), environmental pollution has become a major threat to public health, specially increasing of diseases worldwide due to environmental pollution . Developmental activities such as construction, transportation and manufacturing not only deplete the natural resources but also produce large amount of wastes that leads to pollution of air, water, soil, and oceans; global warming and acid rains. Untreated or improperly treated waste is a major cause of pollution of rivers and environmental degradation causing ill health and loss of crop productivity.
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  Cont… The World HealthOrganization (WHO) estimates that about a quarter (25%) of the diseases facing mankind today occur due to prolonged exposure to environmental pollution. Most of these environment-related diseases are however not easily detected and may be developed during childhood and showed later in adulthood. Improper management of solid waste is one of the main causes of environmental pollution. Many of the cities has lack solid waste regulations and improper disposal facilities, including for harmful waste. Such waste may be infectious, toxic or radioactive.
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  Cont… Municipal waste dumpingsites are designated places set aside for waste disposal. Depending on a city’s level of waste management, such waste may be dumped in an uncontrolled manner, segregated for recycling purposes, or simply burnt. Poor waste management poses a great challenge to the well-being of city residents, particularly those living adjacent the dump sites due to the potential of the waste to pollute water, food sources, land, and vegetation. The poor disposal and handling of waste thus leads to environmental degradation, destruction of the ecosystem and poses great risks to public health.
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  Composition: Determinants  OrganicPollution – BOD5 (Biological Oxygen Demand) – COD (Chemical Oxygen Demand) – TOC (Total Organic Carbon), – TSS (Total Suspended Solids), – TDS (Total Dissolved Solids)  Nitrogen Pollution – NH4, NO3, NO2  Phosphorous Pollution – Phosphorous  Heavy metals – Hg, Ag – Cd, Zn – Cu, Ni – Pb, As – Cr  Microorganisms – Fecal Coliforms (E.coli, Salmonella, Shigella, K. pneumonae, P. valgurous, Enterobacter etc).
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  Pollution and Pollutants.. Pollutionmay be defined as “addition of undesirable material into the environment due to human activities” while the agents which cause environmental pollution are called pollutants. A pollutant may be defined as “a physical, chemical or biological substance unintentionally released into the environment which is directly or indirectly harmful to humans and other living organisms”. Human activities directly or indirectly affect the environment harmfully. A stone crusher adds a lot of suspended particulate matter and noise into the atmosphere.
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  Cont… Automobiles release variousdangerous gases like, oxides of nitrogen, sulphur dioxide, carbon dioxide, carbon monoxide and a complex mixture of unburnt hydrocarbons and black soot which pollute the atmosphere. Domestic sewage and run off from agricultural fields, laden with pesticides and fertilizers, pollute ground and surface water resources. Effluents from tanneries (process of treating skins and hides of animals to produce leather) contain many harmful chemicals and emit foul smell.
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  Types of Pollution.. a)Noise pollution b) Soil pollution c) Air pollution d) Water pollution e) Radiation pollution
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  a) Air Pollution.. Airpollution may be defined as the presence of any solid, liquid or gaseous substance including noise and radioactive radiation in the atmosphere in such concentration that may be directly and indirectly injurious to humans or other living organisms, plants, property or interferes with the normal environmental processes. An ever-increasing use of fossil fuels in power plants, industries, transportation, mining, construction of buildings, stone quarries cause air pollution. Air pollutants are of two types (1) suspended particulate matter, and (2) gaseous pollutants like carbon dioxide (CO2), NO3, NO2, NH4 etc.
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  Pollutant Source HarmfulEffect Carbon Compounds (CO and CO2)  Automobile exhaust  burning of wood and coal  Respiratory Problems,  Green house effects Sulfur compounds (SO4)  Power plants and refineries  Respiratory problems,  Loss of photosynthesis  Acid rain Nitrogenous compounds (NO3, NO2, NH4)  Motor vehicle exhaust,  Atmospheric reaction  Irritation in eyes and lungs,  Low agricultural productivity, Acid rain damages materials Hydrocarbons and Suspended particulate materials  Automobile and petroleum industries,  Thermal power plants  Respiratory problem,  Cancer causing properties,  Poor visibility,  Breathing problems. Fibers (Cotton, wool)  Textiles and carpet weaving industries  Lung disorders
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  b) Noise Pollution.. “Noiseis a sound without value” or “any noise that is unwanted by the recipient”. Source of Noise are industries such as stone cutting and crushing, steel forgings , loudspeakers, movement of heavy transport vehicles, railways and airports. Excessive Noise leads to irritation and an increased blood pressure, decrease in work efficiency, loss of hearing which may be first temporary but can become permanent in the noise stress conditions. Therefore, its important that excessive noise should be controlled.
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  c) Water Pollution.. Additionor presence of undesirable substances in water is called water pollution, which is one of the most serious environmental problems. Agricultural run-off laden with excess fertilizers and pesticides, industrial effluents with toxic substances and sewage water with human and animal wastes pollute ground and surface water resources. Rivers, lakes, seas, oceans and ground water sources may be polluted by point or non-point sources. When pollutants are discharged from a specific location such as a drain pipe carrying industrial effluents discharged directly into a water body it represents point source pollution.
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  In contrast non-pointsources include discharge of pollutants from diffused sources or from a larger area such as run-off from agricultural fields, grazing lands, construction sites, uncontrolled mines and pits, roads and streets. Water Pollution due to pesticides and inorganic chemicals pose serious threats as; may contaminate water bodies or aquatic organisms take up pesticides from water and become effected or died. Metals like lead, zinc, arsenic, copper, mercury and cadmium in industrial waste waters adversely affect humans and other animals, causing skin lesions, rough skin, dry and thickening of skin and ultimately skin cancer. Oil pollution of sea occurs kills marine birds and adversely affects other marine life and beaches.
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  d) Soil Pollution.. Additionof substances which adversely affect the quality of soil or its fertility is known as soil pollution. Generally polluted water also pollute soil. Solid waste is a mixture of plastics, cloth, glass, metal and organic matter, sewage, sewage sludge, building debris, generated from households, commercial and industries establishments add to soil pollution. In addition, fertilizers and pesticides from agricultural use which reach soil as run-off and land filling by municipal waste are growing cause of soil pollution. Acid rain and dry deposition of pollutants on land surface also contribute to soil pollution.
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  e) Radiation Pollution.. Radiationis a form of energy travelling through space. The radiation emitting from the decay of radioactive compounds are a major sources of radiation pollution. Radiations can be categorized into two groups i.e. 1) non-ionizing radiations 2) Ionizing radiations.
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  Cont… a) Non-ionizing radiations: •Non-ionizing radiations are constituted by the electromagnetic waves at the longer wavelength of the spectrum ranging from near infra-red rays to radio waves. • These waves have energies enough to excite the atoms and molecules of the medium through which they pass, causing them to vibrate faster but not strong enough to ionize them. • In a microwave oven the radiation causes water molecules in the cooking medium to vibrate faster and thus raising its temperature. • Non-ionizing radiation does not penetrate deep into the tissues but increases the risk of damage to the skin and eyes. Dependent on the energy and exposure time, non- ionizing radiation can cause localized heating, or photochemical reactions can occur with possible permanent harm. Exposure should therefore be minimized.
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  Cont… b) Ionizing radiations: •Ionizing radiation cause ionization of atoms and molecules of the medium through which they pass. Electromagnetic radiations such as a) Short wavelength ultra violet radiations (UV), X-rays and gamma rays and b) Energetic particles produced in nuclear processes, c) Electrically charged particles like alpha and beta particles produced in radioactive decay and d) Neutrons produced in nuclear fission, are highly damaging to living organisms. • Electrically charged particles produced in the nuclear processes can have sufficient energy to knock electrons out of the atoms or molecules of the medium, thereby producing ions. • They can cause chemical changes by breaking the chemical bonds, which can damage living tissues.
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  Thank You