Environmental Hazards & Remedial Measures | Geography Optional for UPSC (Notes) PDF Download

Introduction

Environmental hazards refer to events, substances, or conditions that have the potential to harm the natural environment or adversely affect human health. These hazards can be natural, like storms and earthquakes, or human-induced, such as pollution. They are considered extreme events that go beyond tolerable limits, making it difficult for humans, animals, and plants to adjust, and often resulting in significant damage and loss of life.

• The term "environmental hazard" is different from "environmental disaster," as hazards refer to the processes or dangers that cause an accident or extreme event, while disasters are the sudden, adverse, and unfortunate consequences of these hazards. Disasters impact humans, plants, and animals severely and indiscriminately.
• Environmental hazards have direct effects on people, businesses, and wildlife, as society relies on agricultural production, energy supply, chemical usage, and transport and communication infrastructures. Consequently, enhancing resilience to environmental hazards is a high priority. Examples of hazards include floods, droughts, emerging diseases, invasive species, and pollution of land, water, and air.
• Scientific data plays a vital role in identifying and characterizing natural and human-induced hazards. This evidence-based information helps assess the threats and develop appropriate mitigation strategies. The severity of impacts from environmental hazards depends on the nature of the hazard, as well as the level of exposure and vulnerability.
• Quantifying the risks posed by environmental hazards and predicting their future implications is crucial. However, an even greater challenge lies in understanding how these hazards interact with other environmental factors, such as land use, climate change, and increasing human populations.
• By evaluating the risks associated with natural and human-made environmental hazards, we can better predict and create strategies to address the threats they pose to society, the economy, and the environment.

On the basis of main causative factors, the environmental hazards and disaster are of two types:

• Natural hazards and disaster and
• Anthropogenic hazards and disaster.

Natural hazards are further subdivided into two categories:

• Planetary hazards and
• Extra planetary hazards and disasters.

Planetary hazards and disasters are of two types:

• Terrestrial or endogenous hazards, (volcanic eruption, Earthquake) and
• Atmospheric or exogenous hazard (Cyclone, Flood, drought)

Anthropogenic hazards and disasters are of three types:

• Physical hazards (landslides, soil erosion, Earthquakes)
• Chemical hazards and disasters (sudden outbreak of lethal poisonous gases from industries, nuclear explosion, leakage of radioactive elements,
• Biological hazards and disaster (sudden rise in population of species in a given habited).

Earthquake and its Management

• An earthquake is a sudden and unexpected movement of the Earth's surface that can range from a gentle tremor to a violent shaking, capable of destroying buildings and creating massive cracks in the ground. The cause of an earthquake is the sudden release of accumulated stress within the Earth's crust. The energy released by an earthquake travels in the form of waves and can be measured using the Richter scale, named after scientist C.F. Richter. This scale ranges from 0 to 9, but there is no upper limit since it is a logarithmic scale. Another method of measuring earthquake intensity is the Mercalli scale.
• The intensity of an earthquake is influenced by various factors, such as magnitude, distance from the epicenter, acceleration, duration, amplitude of the wave, type of surface, water table, geological conditions of the region, and the construction type of buildings. The table compares the Mercalli intensity with the Richter magnitude scale and their corresponding effects.
• Earthquakes are triggered by an imbalance within the Earth's crust, resulting from volcanic eruptions, faulting, folding, uplifting, subsidence, hydrostatic pressure from manmade water bodies like reservoirs and lakes, and plate movement. The Plate Tectonic Theory has been proposed to explain the occurrence of earthquakes. According to this theory, the Earth's crust consists of solid, moving plates, which include continental crust, oceanic crust, or both. There are six major plates (Eurasian, Indian, American, African, Pacific, and Antarctic) and twenty minor plates. These plates move relative to one another due to thermal convective currents originating deep within the Earth, causing tectonic events to occur along plate boundaries.

While earthquakes cannot be prevented, their impact can be minimized by implementing effective management strategies to reduce their severity, frequency, and potential magnitude. Some of these strategies include:

• Constructing earthquake-resistant buildings in earthquake-prone areas, either by incorporating weak spots to absorb vibrations or by placing pads or floats beneath the structures.
• Avoiding settlement and construction of infrastructure in earthquake-prone zones.
• Preferring wooden houses in seismic areas, as they are more resilient to earthquakes.
• Using reinforced concrete columns to support long walls in structures.
• Providing reinforced concrete footings for each building.
• Predicting earthquakes well in advance to save lives and property, by monitoring and analyzing seismic activity.

Through these measures, we can better prepare for and mitigate the devastating effects of earthquakes, protecting lives and property.

Flood and its Management:
A flood occurs when a river overflows its banks and inundates the surrounding areas. This natural disaster can be caused by various factors, including heavy rainfall, deforestation, poor agricultural practices, inadequate drainage systems, and unplanned urbanization. Floods can cause significant damage to homes, buildings, industries, and crops, as well as lower soil fertility and lead to the outbreak of epidemics. Each year, thousands of living organisms and a vast amount of property are lost due to flooding in different rivers. Therefore, it is essential to adopt preventive measures to minimize the impact of floods.

India, being a tropical country with numerous rivers, is highly susceptible to floods. Heavy monsoon rains often cause rivers to overflow, leading to flooding in surrounding areas. Additionally, regions with poor drainage systems are prone to water accumulation and flooding. Almost all Indian states have experienced severe floods, resulting in the loss of human and animal lives, as well as damage to crops, houses, and public utilities. Intriguingly, while floods can be highly destructive, they can also benefit agriculture by enriching soil quality.

Several flood abatement measures can be implemented to reduce the severity of floods:

• Constructing dams and barrages on riverbeds can help control water flow and prevent flooding.
• Restoring wetlands and implementing watershed management programs can improve water retention and reduce the risk of flooding.
• Building flood walls, embankments, and dikes can act as physical barriers to protect areas from flooding.
• Interconnecting rivers can help distribute excess water and reduce the pressure on individual waterways.
• Undertaking massive afforestation efforts in deforested areas can help prevent soil erosion and reduce the risk of flooding.
• Providing timely flood warnings through various media can help communities prepare for and respond to potential flooding events.
• Governments should collaborate with NGOs and local communities to implement emergency flood control measures.
• Diverting floodwater from low-lying areas using artificial channels and dikes can help reduce the impact of flooding on vulnerable regions.

Cyclone and its Management:

• A cyclone is a powerful, circular or oval-shaped swirling storm with a diameter of approximately 650 km, capable of causing widespread destruction. Tropical cyclones are particularly dangerous due to their high wind speeds of 180 to 400 km per hour, significant tidal surges, intense rainfall, abnormally low atmospheric pressures causing unusual rises in sea levels, and their ability to persist for extended periods. The combined effects of these factors result in severe damage to affected areas, leading to significant loss of life and property.
• Cyclones are referred to by different names in various parts of the world, such as Hurricanes in the North Atlantic Ocean, Typhoons in the North Pacific Ocean, and Willy-Willy in Australia. A catastrophic cyclone struck the coast of Orissa on October 29, 1999, causing more than 10,000 deaths and property damage of over 2000 crore rupees. Environmental scientists believe that tropical cyclones are a result of global climate change and that their frequency will continue to increase.

India has an extensive coastline that is susceptible to tropical cyclones in both the Bay of Bengal and the Arabian Sea. The Bay of Bengal region is particularly prone to storms and cyclones. Cyclones are characterized by intense low-pressure areas, taking the form of depressions or cyclonic storms, and severe cyclones are associated with hurricane-force winds. India experiences two cyclone seasons, the pre-monsoon season (April-May) and the post-monsoon season (October-December). The states most affected by cyclones are Orissa, Andhra Pradesh, Tamil Nadu, and West Bengal.

To minimize the loss of life and property from cyclones, the following preventive measures should be implemented by society:

• Undertake large-scale planting along the coastal belt.
• Provide timely warnings about anticipated cyclones through various media outlets.
• Temporarily evacuate populations from affected or soon-to-be-affected areas to safer locations.
• Preserve, maintain, and replace coastal sand dunes.
• Preserve and maintain barrier islands and coastal wetlands.
• Construct cyclone-resistant structures and shelters in areas vulnerable to cyclones.
• Build dams, embankments, and windbreakers to protect localities from the severity of cyclones.
• Ensure that the government takes immediate action to provide relief and rehabilitation measures to those affected by cyclones.

Landslides:
Landslides refer to the rapid movement of large masses of rocks, soil, and mud down a slope, such as a hill, mountain, or highland. They can be caused by heavy rainfall on slopes with loose soil and debris, excavation, or the deposit of loose ash after a volcanic eruption. Earthquakes and sudden rock failures can also trigger landslides.

Landslides can result from various factors, including water saturation, slope modifications, and earthquakes. To reduce the risk of landslides and mudslides affecting structures, it is advisable to select flat land or stable slopes for construction. Other methods include building channels, drainage systems, retention structures, and walls; planting groundcover; reinforcing soil with geo-synthetic materials; and avoiding cut-and-fill building sites. Redirecting water that might impact steep slopes can significantly reduce the risk of landslides, as water can loosen soil, which is necessary for sustaining land.

There are several high-risk areas for landslides, including:

• Areas where wildfires or human activities have destroyed vegetation;
• Areas with a history of landslides;
• Steep slopes and areas at the bottom of slopes or canyons;
• Slopes that have been modified for construction purposes, such as buildings and roads;
• Channels along streams or rivers; and
• Areas where surface runoff is directed.

Building structures away from these high-risk areas can help reduce the impact of landslides. Additionally, there are precautions that can be taken before intense storms and rainfalls, such as:

• Recognizing that steep slopes and areas affected by wildfires are vulnerable to landslides and debris flows.
• Researching whether landslides or debris flows have previously occurred in your area by contacting local authorities, county geologists, county planning departments, state geological surveys, departments of natural resources, or university geology departments.
• Learning about local emergency and evacuation plans.
• Developing emergency and evacuation plans for your family and business.
• Establishing an emergency communication plan in case family members become separated.

By taking these precautions, individuals and communities can better prepare for and mitigate the impacts of landslides.

Drought and its Management

Drought refers to an extended period of dry weather that is particularly damaging to crops. Different fields have varying perspectives on drought. Meteorologists define it as a period without rain or with a rain deficit, while agronomists see it as a lack of moisture for crop production. Economists view drought as a shortage of rainfall that negatively impacts agricultural production. Farmers perceive drought as a lack of rainfall for crucial crop growth stages and operations.

• If drought is not managed effectively and persists for more than two to three consecutive years, it can lead to a famine-like situation. Drought negatively affects the economic and social lives of people, exacerbating poverty, water scarcity, famine, internal displacement, migration, and social breakdown. Additionally, reduced crop production increases commodity prices and affects relative prices.
• At the household level, a significant drop in production results in a considerable reduction in farm employment and income. The decrease in income, combined with rapidly increasing food prices, leads to a severe and widespread decline in purchasing power. This often results in migration, with people becoming environmental refugees. Furthermore, low income and reduced food production contribute to malnutrition among children, causing significant social costs and a substantial drain on economic resources.
• According to Prof. Amartya Sen, malnutrition and famine can occur on a massive scale even when there is adequate food availability. A shortage in food grain production leads to a prolonged decrease in food grain intake, and massive starvation leads to an excessive increase in death rates.

Drought Control Measures:
Predicting drought is challenging, but computer-based studies can help to provide some insights.
Some measures that can be taken to mitigate drought include:

• Efficient use of rainwater and rainwater harvesting
• Implementation of dry farming techniques
• Lining canals to prevent water loss
• Avoiding overcropping
• Limiting settlements in drought-prone areas
• Promoting horticulture plantations
• Controlling desert migration.

Environmental Pollution

Environmental pollution poses a significant threat to our planet. It refers to the release of materials or energy into water, land, or air that may cause short-term or long-term harm to the Earth's ecological balance or decrease the quality of life. In simpler terms, environmental pollution contaminates the environment, making it unsafe to use. This pollution has detrimental effects on plants, animals, and humans.

• A substance that causes pollution is called a pollutant. These can be solid, liquid, or gaseous substances that are present in higher concentrations than their natural abundance. They are produced either due to human activity or natural occurrences. 
• Pollutants can cause primary damage with direct, identifiable impacts on the environment, or secondary damage in the form of subtle disruptions in the delicate balance of the biological food web, which can only be detected over long periods. Factors such as industrialization, motorized vehicles, rapid urbanization, population growth, exploitation of natural resources, and improper sewage and waste disposal from industries and cities have led to a significant increase in waste byproducts. 
• Consequently, environmental pollution usually occurs as a result of energy conversions and resource use, leaving their byproducts in water, soil, or air.

Natural resources that were once freely available as a gift from nature are now highly polluted. Depending on the area or part of the environment affected, pollution can be classified into the following types:

• Air pollution
• Water pollution
• Land pollution
• Noise pollution
• Radiation pollution
• Thermal pollution

Air Pollution

Air pollution is a significant issue facing humanity today. It refers to the presence of harmful substances or properties in the air that decrease its usefulness and have detrimental effects on human health and the environment. Air pollution can be categorized into outdoor atmospheric conditions, localized air conditions, and enclosed space conditions. It occurs due to natural causes, such as volcanic eruptions releasing ash, dust, sulfur, and other gases, or human activities. However, pollutants from natural sources tend to remain in the atmosphere for a shorter duration and do not cause permanent atmospheric changes, unlike those from human activities.

Sources of Air Pollution
Major sources of air pollution include power and heat generation, solid waste burning, industrial processes, and transportation. Domestic burning of coal, kerosene oil, firewood, cow dung cakes, and cigarette smoke releases pollutants such as carbon monoxide (CO), carbon dioxide (CO₂), and sulfur dioxide (SO₂). Approximately 90% of global air pollution consists of the following pollutants:

• Carbon dioxide: This gas is a significant contributor to air pollution, mainly produced during fuel combustion in factories, power stations, and households.
• Carbon monoxide: Generated from incomplete combustion of fossil fuels like coal, petroleum, and wood charcoal, automobiles using diesel and petroleum are the primary sources of carbon monoxide.
• Sulfur dioxide: Accounting for about 18% of all air pollution, it is produced by chemical industries, metal smelting, pulp and paper mills, and oil refineries.
• Oxides of nitrogen: A few nitrogen oxides (NOx) are produced by natural processes and human activities, such as thermal power stations, factories, automobiles, and aircraft, contributing to about 6% of air pollution.
• Hydrocarbons: These compounds comprise carbon and hydrogen atoms, which either evaporate from fuel supplies or remain as unburned residues in the fuel.
• Particulate matter: These are small solid particles (e.g., smoke particles from fires, asbestos, dust particles, and industrial ash) dispersed into the atmosphere.

Effects of Air Pollution

• Effects on human health: Exposure to air pollution can cause various health problems, including pulmonary, cardiac, vascular, and neurological impairments. Health effects can differ significantly among individuals, with high-risk groups such as the elderly, infants, pregnant women, and those with chronic heart and lung diseases being more susceptible. Children are at greater risk due to their outdoor activity levels and developing lungs. Air pollution can cause both acute (short-term) and chronic (long-term) health effects.
• Effects on plants: Gaseous pollutants can damage crop leaves by entering leaf pores, leading to reduced photosynthesis, nutrient uptake, and plant growth. Chronic exposure can also weaken the waxy coating that prevents excessive water loss, making plants more vulnerable to diseases, pests, drought, and frost.
• Effects on materials: Air pollutants cause significant material damage worldwide, including breaking down exterior paint on cars and buildings, and discoloring irreplaceable monuments, historic buildings, and marble statues.
• Effects on climate: Air pollution contributes to global warming by increasing the concentration of gases like carbon dioxide, nitrogen oxides, methane, and CFCs. Global warming can have various adverse effects, such as rising ocean levels due to melting polar ice caps, flooding coastal areas, and the complete submersion of countries like Bangladesh and the Maldives.

Control Measures for Air Pollution
Two fundamental approaches to control air pollution include preventive techniques and effluent control. Installing proper equipment, such as scrubbers, closed collection recovery systems, dry and wet collectors, filters, and electrostatic precipitators, can effectively reduce pollutants. Increasing the height of industrial stacks can help disperse pollutants further away from the ground. Industries should be strategically located to minimize pollution effects based on topography and wind patterns. Additionally, substituting raw materials that cause more pollution with less harmful alternatives can help reduce pollution.

Water Pollution

Water is one of the most important biological components that sustain life. However, nowadays water is highly polluted and is one of the pivotal issues in the world. The water is said to be polluted when it has more “negative‖ qualities than “positive‖ ones. Water quality refers to the physical, chemical, and biological characteristics of water. Thus, in simple words, we can that polluted water is that water that has been abused, defiled in some way, so that it is no longer fit for use. Water pollution can be defined as “the presence of too much of undesirable substances in the water which tend to degrade the quality of water‘s physical, chemical and biological characteristics, making it unsuitable for beneficial use”.

Sources of Water Pollution
Water pollution is one of the most serious environmental problems. Water pollution is caused by a variety of human activities such as,

• Domestic sewage discharged into rivers from areas located on its banks.
• Excretory wastes of humans and animals in water bodies.
• Disposal of urban and industrial waste matter into water bodies.
• Industrial wastes effluents from urban areas containing high concentration of oil, heavy metals and detergents.
• Minerals, organic wastes, and crop dusting from agricultural fields with phosphate and nitrogen fertilizers that reach lakes, rivers, and sea (water becomes deoxygenated and poisonous, thus, cannot support aquatic life).
• Chemical fertilizers, pesticides, insecticides, herbicides and plant remains.
• Industrial waste water containing several chemical pollutants, such as calcium, magnesium, chlorides, sulphide, carbonates, nitrates, nitrites, heavy metals, and radioactive waste from nuclear reactor.
• Natural sources of pollution of water are soil erosion, leaching of minerals from rocks, and decaying of organic matter.

Water pollutants are categorized as point source pollution and non-point source pollution.

• Point source pollution: When pollutants are discharged from a specific location such as a drain pipe carrying industrial effluents discharged directly into water body it represents point source pollution. In other words, point source pollution is defined as any single identifiable source of pollution from which pollutants are discharged.
• Non-Point source pollution: Those sources which do not have any specific location for discharging pollutants, in the water body are known as non-point sources of water pollution. For example, run off from agricultural fields, grazing lands, construction sites, abandoned mines and pits etc.

Effects of Water Pollution
Water pollution is the second major source of waterborne diseases and health problems after air pollution.

• Effects on humans: On consuming polluted water, humans can suffer from diseases like amoebic dysentery, skin cancers, cholera, typhoid fever, damage of nervous system, genetic mutations/ birth defects, hepatitis, malaria. Metals like lead, zinc, arsenic, copper, mercury and cadmium in industrial waste waters adversely affect humans and other animals. Consumption of arsenic polluted water leads to skin lesions, rough skin, dry and thickening of skin and ultimately skin cancer. Pollution of water bodies by mercury causes Minamata disease in humans and dropsy in fishes. Lead causes displexia; cadmium poisoning causes Itai – Itai disease etc.
• Effects on plants and animals: Water pollution results in lower crop yields, excess growth of algae can kill aquatic life, reduce photosynthesis, disrupts the food chain and food web. Oil spills are a major problem near coastal waters and can kill or adversely affect fish, other aquatic organisms, and birds and mammals. Spills can kill or reduce populations of organisms living in coastal sands and rocks and may kill the worms and insects that serve as food to birds and other animals.
  Fertilizers and pesticides are widely used in agriculture. Their excessive use to increase agricultural yield has led to the phenomenon of eutrophication and biomagnifications, which are serious consequences of water pollution.
  (i) Eutrophication: With the use of high-yielding varieties of crops application of fertilizers and pesticides has increased. Excess fertilizers may mix with surface water bodies (surface runoff). The enrichment of water with nutrients such as nitrates and phosphates that triggers the growth of green algae is called eutrophication. This fast growth of algae followed by their decomposition depletes the water body of the dissolved oxygen. As a result, aquatic animals die of oxygen shortage.
  (ii) Biomagnification: Entry of harmful, non-biodegradable chemicals in small concentration and their accumulation in greater concentration in the various levels of a food chain is called biomagnification. Nonbiodegradable pesticides, such as DDT are widely used for crop protection. Once they enter the food chain, their concentration keeps on increasing with each trophic level (steps of a food chain). As a result, accumulation of these compounds takes place in the body of top consumers over a period of time.

Control measures for preventing water pollution

• Setting up effluent treatment plans to treat waste.
• Industrial wastes must be treated before discharge.
• Educate Public for preventing water pollution and the consequences of water pollution Strict enforcement of Water Pollution Control Act.
• Continuous monitoring of water pollution at different places.
• Developing economical method of water treatment.

Land Pollution

Land pollution is the degradation of the earth’s land surface through misuse of the soil by poor agricultural practices, mineral exploitation, industrial waste dumping, and indiscriminate disposal of urban and toxic wastes. In simple terms, land pollution is the degradation of the earth’s surface caused by a misuse of resources and improper disposal of waste. Land pollution is responsible for damage done to natural habitat of animals, deforestation and damage done to natural resources, and the general uglying up of our communities. Polluting the land by harmful chemicals can lead to entry of pollutants into food chain. This is commonly caused by excess use of fertilizers in agriculture, irresponsible disposable of industrial wastes etc. Even defecating in the open spaces also causes pollution.

Sources of Land Pollution
The major sources of land pollution are highlighted below:

• Soil erosion: Soil erosion can be defined as the movement of topsoil from one place to another. Soil erosion removes rich humus topsoil developed over many years through vegetative decay and microbial degradation and thus strips the land of valuable nutrients for crop growth. Strip mining for minerals and coal lays waste thousands of acres of land each year, denuding the earth and subjecting the mined area to widespread erosion problems. The increase in urbanization due to population pressure presents additional soil-erosion problems; sediment loads in nearby streams may increase as much as 500 to 1,000 times.
• Industrial Waste: Large number of industrial chemicals, dyes, acids, fertilizer companies, pharmaceutical companies etc. find their way into the soil and are known to create many health hazards including cancer.
• Urban Wastes: Because of modem lifestyle and eating habits the urban wastes are becoming very dangerous to human beings. Urban wastes include both which is a nondegradable material and harmful to the society in long run.
• Agricultural sources: Agricultural chemicals especially fertilizers and pesticides pollute the soil. Fertilizers in the runoff water from these fields can cause eutrophication in water bodies. Pesticides are highly toxic chemicals that affect humans and other animals adversely causing respiratory problems, cancer, and death.
• Plastic bags: Plastic bags made from low density polyethylene, is virtually indestructible, create colossal environmental hazard like land pollution. The discarded bags block drains and sewage systems.

Effects of land pollution

• Toxic compounds affect plant growth and human life also.
• Water logging and salinity makes soil infertile.
• Hazardous chemicals enter into food chain from soil disturbing the biochemical process.
• Nervous disorders, gastrointestinal disorder, joint pain, respiratory problems are the effects seen on human beings.

Control measures for preventing soil pollution

• Soil erosion must be prevented or controlled by proper tree plantation.
• All the wastes from industry, domestic, must be dumped with proper treatment.
• Use of synthetic fertilizers must be avoided instead natural fertilizers must be preferred.
• Educate people regarding consequences of soil pollution and to prevent soil pollution.
• Toxic and non-degradable materials must be totally banned.
• Recycling and reuse of industrial and domestic wastes can minimize soil pollution considerably

Noise Pollution

Noise pollution has a relatively recent origin and is one of the least discussed problems. Noise is one of the most pervasive pollutant. People tend to underestimate this problem because it is not possible to smell, see or touch it. Noise Pollution is any loud sounds that are either harmful or annoying to humans and animals. To be more precise, noise by definition is “sound without value‖ or “any noise that is unwanted by the recipient”. Noise like other pollutants is a byproduct of industrialization, urbanization and modern civilization. Noise level is measured in terms of decibels (dB). W.H.O. has prescribed optimum noise level as 45 dB by day and 35 dB by night. Anything above 80 dB is hazardous.

Sources of Noise Pollution
Noise pollution is a growing problem. It is a composite of sounds generated by human activities ranging from blasting stereo systems to the roar of supersonic transport jets. All human activities contribute to noise pollution to varying extent. Noise pollution is more intense in the work environment than in the general environment. Sources of noise pollution are many and may be located indoors or outdoors.

• Indoor sources include noise produced by household gadgets like radio, television, generators, electric fans, washing machine, vacuum cleaners, air coolers, air conditioners and family conflict. The average background noise in a typical home today is between 40 and 50 decibels. Noise pollution is more in cities due to a higher concentration of population and industries and activities such as transportation.
• Outdoor sources of noise pollution include indiscriminate use of loudspeakers, industrial activities, automobiles, rail traffic, aeroplanes and activities such as those at market place, religious, social, and cultural functions, sports and political rallies. During festivals, marriage and many other occasions, use of fire crackers contribute to noise pollution.

Effects of Noise Pollution

• The research shows that many illnesses are connected to noise pollution, such as hearing loss, high blood pressure, coronary heart diseases, loss of temper, and decrease in work efficiency, sleeplessness, anxiety, and speech interference. 
• The effect is variable, depending upon individual susceptibility, duration of exposure, nature of noise, and time distribution of exposure. On average, an individual will experience a threshold shift (a shift in an individual’s upper limit of sound detectability) when exposed to noise levels of 75 to 80 dB for several hours. This shift will last only several hours once the source of noise pollution is removed. 
• A second physiologically important level is the threshold of pain, at which even short-term exposure will cause physical pain (130 to 140 dB). Any noise sustained at this level will cause a permanent threshold shift or permanent partial hearing loss. At the uppermost level of noise (greater than 150 dB), even a single short-term blast may cause traumatic hearing loss and physical damage inside the ear. Industrial noises also affect the lives of animals. For example, whales‘ navigation system breaks down due to the sounds of ships.

Preventive Measures
Noise is everywhere, it is not as easy to control as other pollutions. Reducing noise pollution by muffling the sounds at the source is one of the best methods in industry and for urban living. Using earplugs where abnormal noise is produced. Banning noise polluting vehicles, controlling vibration of machines by proper lubricating machine, plantation of trees on road sides and near building can absorb noise, constructing sound proof rooms, enforcing noise pollution control act and educating people about noise pollution and its consequences. Creation of green cover adjacent to municipal roads and in mines is the way to mitigate noise pollution. It has been observed that noise level reduces by 10 decibels per every 10m wide green belt development.

Radiation Pollution

Radiation pollution is one of the serious types of pollution and also neglected one. This is the pollution due to abnormal radiation in the environment. Radiation pollution is any form of ionizing or non-ionizing radiation that results from human activities. The radiations emanating from the decay of radioactive nuclides are major sources of radiation pollution. The most well-known radiation results from the detonation of nuclear devices and the controlled release of energy by nuclear-power generating plants, from the cell and mobile towers, by use of wireless Internet access modems, etc. Other sources of radiation include spent-fuel reprocessing plants, byproducts of mining operations, and experimental research laboratories. Increased exposure to medical X-rays and to radiation emissions from microwave ovens and other household appliances, although of considerably less magnitude, all constitute sources of environmental radiation.

Effects of Radiation Pollution
Public concern over the release of radiation into the environment greatly increased following the disclosure of possible harmful effects to the public from nuclear weapons testing, the accident (1979) at the Three Mile Island nuclear power generating plant near Harrisburg, and the catastrophic 1986 explosion at Chernobyl, A Soviet nuclear power plant. In the late 1980s, revelations of major pollution problems at U.S. nuclear weapons reactors raised apprehensions even higher. The environmental effects of exposure to high-level ionizing radiation have been extensively documented through post-war studies on individuals who were exposed to nuclear radiation in Japan. Some forms of cancer show up immediately.

Preventive Measures
Radioactive nuclear wastes cannot be treated by conventional chemical methods and must be stored in heavily shielded containers in areas remote from biological habitats. The safest of storage sites currently used are impervious deep caves or abandoned salt mines. Most radioactive wastes, however, have half-lives of hundreds to thousands of years, and to date no storage method has been found that is absolutely infallible.

Thermal Pollution

Thermal pollution refers to the release of excess heat into the environment, primarily from thermal power plants, industries involved in metal molding, and other heat-generating processes. This excess heat is often released into the air, causing a significant increase in the local temperature. Major contributors to thermal pollution include fossil-fuel and nuclear power plants, as well as industrial manufacturing processes such as steel foundries, metal manufacturers, and chemical and petrochemical production.

• These power plants and industries consume a large amount of water (around 30% of all abstracted water and 90% of all water consumption, excluding agricultural uses) for cooling purposes. The heated water is then discharged into rivers, streams, or oceans, raising the temperature of the receiving water by 5 to 11°C above the ambient water temperature. This can result in ecological imbalances and even massive fish kills near the discharge source. The increased temperature also accelerates chemical-biological processes and reduces the water's ability to hold dissolved oxygen.
• Aquatic organisms are adapted to a stable, uniform water temperature, so any fluctuation can have severe consequences for aquatic plants and animals. In particular, organisms in warm tropical waters live close to their upper temperature limit, making them especially vulnerable to even slight temperature increases. Thermal pollution can cause stress in aquatic organisms, affecting their feeding, metabolism, and growth. It can also reduce their swimming efficiency and ability to escape predators or catch prey, as well as decrease their resistance to diseases and parasites. This can lead to a reduction in biological diversity and significant changes in biological communities near heated discharge points.
• One effective method for reducing thermal pollution is to store hot water in cooling ponds, allowing it to cool down before being released into receiving water bodies. This helps to mitigate the negative effects of thermal pollution on aquatic ecosystems.

Conclusion

In conclusion, environmental hazards pose significant threats to human health, wildlife, and the planet as a whole. These hazards can be natural, like earthquakes, floods, and cyclones, or human-induced, such as pollution. Understanding and addressing the risks associated with these hazards is crucial for the well-being of society, the economy, and the environment. By adopting effective management strategies, such as constructing earthquake-resistant buildings, implementing flood abatement measures, and controlling pollution sources, we can mitigate the impacts of these hazards and preserve our environment for future generations.

Frequently Asked Questions (FAQs) of Environmental Hazards & Remedial Measures

What are the main types of environmental hazards and disasters?

Environmental hazards and disasters can be categorized into two main types: natural hazards and disasters, and anthropogenic hazards and disasters. Natural hazards are further subdivided into planetary hazards (terrestrial or endogenous, and atmospheric or exogenous) and extra-planetary hazards. Anthropogenic hazards and disasters can be classified into physical, chemical, and biological hazards.

How can we minimize the impact of earthquakes on infrastructure and human lives?

Some strategies to minimize the impact of earthquakes include constructing earthquake-resistant buildings in earthquake-prone areas, avoiding settlements in such zones, preferring wooden houses in seismic areas, using reinforced concrete columns and footings in structures, and predicting earthquakes well in advance to save lives and property.

What are the primary sources of air pollution, and how can they be controlled?

Major sources of air pollution include power and heat generation, solid waste burning, industrial processes, and transportation. Control measures include installing proper equipment (such as scrubbers and filters), increasing the height of industrial stacks, strategically locating industries, and substituting raw materials that cause more pollution with less harmful alternatives.

What are the effects of water pollution on human health and the environment?

Water pollution can cause various health problems in humans, such as gastrointestinal disorders, skin diseases, and neurological impairments. It can also negatively impact the environment by damaging aquatic ecosystems, causing eutrophication, and leading to biomagnification of harmful substances in the food chain.

How can we prevent soil erosion and land pollution?

Preventing soil erosion and land pollution can be achieved through proper tree plantation, responsible dumping of industrial and domestic wastes, avoiding the excessive use of synthetic fertilizers, educating people about the consequences of soil pollution, banning toxic and non-degradable materials, and recycling and reusing industrial and domestic wastes.