What is waste? 

• Any substance or liquid that is left over after productive usage or is unusable in its current state and is often discarded; and Material associated with human activity as opposed to nature, which has its own mechanism for recycling trash so that it finally becomes a resource: for instance, leaves, branches, and other organic stuff decay into manure.
• Health benefits from the safe disposal of waste that would otherwise harm the environment; Economic benefits from the reuse/recycling of things that would have been disposed as waste; and Aesthetic benefits from a clean environment devoid of rotting garbage dumped in the open.

Types of Waste

Based on its physical properties

On the basis of their physical features, trash can be classified as solid waste (such as garbage), liquid waste (such as wastewater), and gaseous waste.

1. Solid wastes – These are the undesirable substances that human society discards. This includes municipal, industrial, agricultural, biomedical, and radioactive wastes.
2. Liquid wastes – Wastes generated by industrial washing, flushing, or production processes are known as liquid wastes.
3. Gaseous wastes – These are the wastes generated in the form of gases by automobiles, industry, and the combustion of fossil fuels such as petroleum. They interact with the other gases in the atmosphere and occasionally generate smog and acid rain.

Based on pattern of use

Based on the pattern of use, it can be classified into 

1. human waste (feces, urine). 
2. animal waste. 
3. farm waste.
4. industrial as well as commercial waste.

Based on source

Based on source, waste can be categorized as 

1. municipal waste (for example, household waste, commercial waste, and demolition waste), 
2. hazardous or toxic waste (for example, radioactive waste, explosives waste and e-waste)
3. Biomedical waste (for example, hospital waste). 

Based on Degradation

Typically, trash is divided into two categories biodegradable and non-biodegradable. These two types of trash are described in detail below:

1. Biodegradable waste: Biodegradable waste consists of food scraps, yard clippings, etc. that originate from our kitchen. Moisture-based waste is another name for biodegradable trash. This can be composted to produce fertiliser. Depending on the type of substance, biodegradable wastes disintegrate over a period of time.
2. Non-biodegradable waste: Non-biodegradable waste consists of items such as old newspapers, shattered glass, plastics, etc. Waste that is not biodegradable is known as dry waste. Dry wastes are recyclable and reusable. Non-biodegradable wastes do not degrade on their own and are therefore significant pollutants.

Sources Of Wastes

The production of garbage is an integral component of daily living. Wastes can be produced by a variety of sources.

This includes waste from homes, schools, offices, markets, restaurants, and other public locations. The wastes generated by such sources include common objects such as food debris, old plastic bags, soda cans and plastic water bottles, damaged furniture, broken home appliances, and clothing, among others.

1. Medical or Clinical sources of wastes

• Medical/clinical waste refers to the wastes generated by health care facilities such as hospitals, clinics, surgical theatres, veterinary hospitals, and laboratories.
• This includes surgical instruments, drugs, blood, body parts, wound dressing materials, needles, and syringes.

2. Agricultural sources of wastes

• Agricultural regions generate both plant and animal waste. Land and water pollution is caused by the excessive use of fertilisers, insecticides, and other agricultural chemicals, as well as their byproducts.
• Additionally, they pollute the soil. Important chlorinated hydrocarbon pesticides include DDT, BHC, endrin, dieldrin, lindane, parathion, malathion, and endosulphon, which are absorbed by the soil and harm soil-grown crops.
• Other agricultural wastes are generated by sugar mills, tobacco processing facilities, slaughterhouses, cattle, and poultry, among others.

3. Industrial Sources of Wastes

• These are the wastes produced by manufacturing and processing businesses, such as chemical plants, cement factories, power plants, textile and food processing industries, and petroleum industries.
• These industries generate a variety of waste items.
• Industrial solid wastes can be divided into two categories.

a. Non-hazardous wastes

• Food processing factories, cotton mills, paper mills, sugar mills, and textile businesses generate these wastes.

b. Hazardous wastes

• Nearly every industry produces hazardous wastes. Important examples are metals, chemicals, pharmaceuticals, lather, pulp, electroplating, dye, and rubber.
• A factory’s liquid industrial waste that flows into a stream can destroy aquatic life and cause human health problems.

4. Wastes from Construction or Demolition

• As a result of the construction of roads and buildings, construction waste consists of concrete debris, wood, large packaging boxes, and plastics from the building supplies.
• The garbage produced by the destruction of ancient buildings and structures is known as demolition waste.

5. Commercial Sources

• Due to the development of modern cities, industries, and automobiles, enormous quantities of waste are produced daily. These include markets, highways, structures, hotels, business complexes, hostels, car shops, and printing presses, among others.
• Hospitals, nursing homes, and medical institutions also generate a substantial volume of dangerous and highly poisonous waste.
• In addition to producing several chemicals and throwaway objects, these units also create a variety of other substances. These wastes are deposited in populated regions, where they pose a significant threat to human health and cause a variety of infectious diseases.
• In addition to the wastes generated by the sources listed above, there are also wastes produced by mining activities and radioactive chemicals that pose significant harm to society and the environment.

6. Mining Sources

• The mining wastes alter the physical, chemical, and biological characteristics of the land and atmosphere.
• The wastes include overburden, mine tailings (the trash remaining after mining has been removed from rock), and toxic gases emitted by blasting, among others.

7. Radioactive Sources

• Even though every precaution is taken in the operation and maintenance of nuclear reactors, a quantifiable amount of radioactive waste has been detected to escape into the environment.
• Other sources of radioactive waste include radioactive substance mining and atomic explosions, among others.

8. Electronic sources of waste

• The DVD and music players, televisions, telephones, computers, and other electrical items in your home that are no longer useful are considered electronic wastes.
• Also known as e-waste, e-scrap, and trash electrical and electronic equipment (WEEE). Some electronic waste (such as televisions) contains toxic substances that are dangerous to humans and the environment.

9. Municipal Solid Waste

• Municipal solid wastes are the garbage collected from residential homes, markets, streets, and other urban locations and disposed of by municipal entities (MSW). Typically, urban solid wastes are referred to as garbage.
• Municipal solid wastes are a mixture of paper, plastic, clothing, metals, glass, organic matter, and other materials generated by households, businesses, and markets.
• The quantities of various constituents fluctuate from season to season and location to location based on lifestyle, dietary habits, standard of living, and the extent of commercial and industrial operations in the region.
• Municipal solid wastes are collected locally, and the amount collected is proportional to population size and consumption.

Hazardous wastes

• Numerous chemical, biological, explosive, and radioactive wastes that are highly reactive and poisonous pose a grave threat to human, plant, and animal life and are referred to as hazardous wastes.
• They are naturally extremely poisonous. When managed improperly, hazardous wastes can cause severe harm to human health and the environment. Dangerous wastes may exist as solids, liquids, sludges, or gases.
• They are primarily produced by chemical production, industrial production, and other industrial operations. Important hazardous wastes include lead, mercury, cadmium, chromium, several medications, leather, pesticides, dye, and rubber, as well as effluents from other industries.
• They may pose a threat if they are improperly stored, transported, treated, or disposed of. Toxic, reactive, ignitable, explosive, corrosive, infectious, or radioactive waste materials may exist.

1. Ignitability

• These are wastes with a flash point below sixty degrees Celsius. In addition to posing immediate threats, such fires can also disperse dangerous particles over large areas.

2. Corrosiveness

• These wastes are predominantly acidic or alkaline and damage other materials. As they discharge dangerous substances, they must be disposed of in particular containers and kept away from ordinary trash.

3. Reactivity

• These are extremely reactive or explosive wastes. These undergo violent chemical reactions and are afterwards exploded to produce heat and poisonous fumes.

4. Toxicity

• These wastes emit poisons and pose threats to human health and the environment.

What is solid waste? 

• Solid waste is any waste other than human excreta, urine, and wastewater. There are two categories of solid waste: biodegradable and nonbiodegradable.
• Biodegradable: Biodegradable garbage is waste that can be broken down by biological processes, such as vegetable peels, food, and farm waste, among others. Organic trash is biodegradable and can be recycled; and
• Nonbiodegradable: Nonbiodegradable garbage, such as paper, glass, and metal, cannot be broken down through biological processes. Nonbiodegradable garbage can be subdivided into two categories: recyclable and nonrecyclable materials
  • Recyclable rubbish: Recyclable waste is that waste which has economic value that may be recovered, for example, metal, paper, glass, plastic bottle, and so on
  • Nonrecyclable waste: Nonrecyclable waste is that waste which does not have economic worth of recovery, for example, tetra packs, thermocol, and so on.

What is liquid waste?

• Liquid waste is once-used water that is no longer suitable for human consumption or other applications requiring clean water. Two broad categories of liquid waste or wastewater exist:
• Gray water or sullage is wastewater from bathrooms or kitchens. Black water is wastewater from toilets that contains faeces. Gray water is typically less contaminated than black water.

Impacts of Waste Accumulation

Massive industrialization, increased urbanisation, advanced agricultural technology, and shifting life patterns have led to the production of enormous amounts of trash. As an example, accumulation of wastes in densely populated areas, disposal of urban sewage and industrial wastes discharged into rivers, etc. impact the soil, air, and water ecosystems due to poor waste disposal. Chemical, biological, and explosive wastes offer an immediate or long-term threat to human and animal life.

Solid waste disposal is detrimental to human health. It is estimated that around twenty-five human diseases are linked to solid waste. Due to the dumping of garbage in open areas, there is an increase in the number of rats and flies, which are carriers of other organisms responsible for various terrible diseases.

The pathogen-carrying flies are responsible for the spread of diseases such as dysentery and diarrhoea. An estimated seventy thousand flies are produced each cubic foot of waste. The disposal of solid waste has a lot of negative consequences on all the components of an ecosystem, as well as on the aesthetics.

Some of the effects of garbage accumulation are listed below:

Spoilage of Landscape

• It is usual practise to dispose of plastic bags, containers, vegetables, fruit peels, cans, etc. in an open place without considering the repercussions.
• We must recognise that incorrect rubbish disposal detracts from the attractiveness of the area.

Pollution

• Random and improper trash disposal has major environmental consequences. 
• The majority of wastes contain organic compounds, a variety of inorganic minerals, and other harmful substances, which contaminate the environment and lead to: the degradation of land, the contamination of drinking water, the extinction of aquatic life, the degradation of ground and surface water used for irrigation and industry, and the improper disposal of wastes, which causes soil, air, and water pollution.

Health Hazards

Random and improper trash disposal has major environmental consequences. The majority of wastes contain organic compounds, a variety of inorganic minerals, and other harmful substances, which contaminate the environment and lead to: the degradation of land, the contamination of drinking water, the extinction of aquatic life, the degradation of ground and surface water used for irrigation and industry, and the improper disposal of wastes, which causes soil, air, and water pollution.

Health hazards due to air pollution

Hazardous air pollutants present in the atmosphere affect human health both directly and indirectly. It may be a short-term or long-term effect.

The following are the negative health effects:

• noxious gas Carbon monoxide lowers blood oxygen and haemoglobin formation, resulting in damage to the heart and central nervous system.
• Both sulphur dioxide and sulphuric acid irritate the respiratory tracts of humans, and excessive quantities of sulphur dioxide result in serious heart and lung disorders such as bronchitis, asthma, etc.
• Higher concentrations of nitrogen oxide harm the respiratory organs, liver, and kidneys.
• Ozone can significantly impair lung functions.
• Lead can cause damage to the blood-forming organs and nervous system, particularly affecting the brain functions of newborns.
• Pesticides and radiation are additional harmful air pollutants that pose a significant threat to human health.
• Metal, dusts, asbestos, and hydrocarbons diminish life expectancy, cause nervous system degradation, and increase the chance of cancer.
• In mining activities, silica and dust cause pneumoconiosis (common disease in mine workers).
• Components of petroleum can impact blood-forming organs, the brain, teeth, and bones, among others.
• Mercury and cadmium are known kidney and brain toxins.

It is argued that water is contaminated when its quality or composition is altered, either naturally or due to human actions. Nearly 80% of human diseases in underdeveloped nations are caused solely by dirty water.

Impacts of water pollutants

The following are well-known effects of water pollutants:

• Numerous industrial contaminants that enter the human body through contaminated water and food pose a hazard to life and health. Due to mercury and cadmium from industrial effluents in the aquatic ecosystem, the infamous MINAMATA and ITAI-ITAI diseases claimed a large number of lives in Japan.
• Certain agrochemicals, such as chlorinated pesticides, which are disposed of in water accumulate in aquatic food chains and reach the human body, causing severe sickness. Several individuals in coastal Karnataka perished after devouring crabs infected with chemicals.
• Changes in water quality caused by iodine deficiency result in goitre, which is endemic in many regions of India.
• Many water-borne diseases widespread in India, such as cholera, typhoid, gastroenteritis, and hepatitis, are caused by water pollution.
• In Andhra Pradesh, the KNOCK-KNEE syndrome is the most serious sickness caused by excessive levels of fluorine in the drinking water.

Health Hazards due to Soil or Land Pollution

The accumulation of hazardous chemical compounds, salts, disease-causing organisms, and radioactive substances in the soil causes a variety of health issues. Impacts of trash accumulation in soil/land on human health include the following:

• Indirectly, land contamination has an effect on human health. Through the food chain, the contaminants contributed to the soil enter the human body via water or air.
• Several agrochemicals, such as DDT, fluorine, arsenic, lead compounds, and organ phosphorus compounds, are extremely hazardous and cause symptoms such as nausea, vomiting, diarrhoea, perspiration, salivation, and tremors of the muscles.
• Certain rodenticides, including strychnine, sodium fluoroacetate, and others, are blood coagulants.
• The accumulation of ethylene dichloride, ethylene dibromide, and methyl dibromide in the liver, kidney, heart, and spleen results in degenerative lesions.

Impact of Waste Accumulation on Terrestrial Life

Toxic wastes can contaminate soil, air, surface water, and groundwater. The oil pollutants may have adverse effects on humans, plants, and animals. Through the food chain, these harmful compounds are transported to various creatures and create a variety of difficulties in living things. Among these are the following:

• Numerous harmful chemicals, pesticides, and other agricultural wastes are released into the environment, and plants absorb them from the air, water, and soil. These poisonous compounds have a devastating impact on plants growing in such settings.
• Acute damage including chlorosis, discoloration, and even plant death may result from exposure to high concentrations of pollutants.
• Reduced crop productivity and yield are seen. Additionally, the quality of plant nutrients is diminished.
• Sulfur dioxide is a highly hazardous pollutant that harms crops.
• Fluoride-related losses to agriculture and animal life have increased dramatically in recent years.
• In addition to physical changes, biochemical and physiological modifications have been reported in numerous mammals, including humans.
• An excessive accumulation of wastes disrupts the behaviour of both wild and domesticated animals and causes health issues.
• Some extremely toxic chemicals cause genetic defects in animals.
• Several domesticated animals, such as cows, buffaloes, goats, etc., frequently consume polythene and plastic bags together with their food, which ultimately reaches their alimentary canal and causes several diseases and even death.

Impact of Waste Accumulation on Fresh Water

Large quantities of human garbage are dumped in rivers, lakes, ponds, and other aquatic bodies, polluting the water and rendering it unfit for drinking and other domestic uses. The following are the implications of garbage disposal on aquatic life:

• The hazardous pollutants that enter water bodies have a detrimental effect on aquatic life.
• The sewage of cities is frequently discharged into rivers, which poses a threat to plant, animal, and human life.
• Due to the accumulation of pollutants in canals, lakes, and rivers, the oxygen concentration is drastically lowered, threatening the existence of fish and other aquatic species. In high oxygen shortage, the majority of fishes perish.
• The sewage from towns, sanatoria, and tanneries that is released into rivers, canals, and lakes, etc. carries numerous kinds of disease-causing bacteria and germs.
• Some contaminants, such as heavy metals, cyanides, and a number of other organic and inorganic chemicals, are toxic to aquatic species. Many of them, especially those that are not biodegradable, accumulate in the bodies of creatures and have long-term impacts.
• In heavily contaminated aquatic environments, biodiversity declines.
• DDT and other pesticides that are present in extremely low amounts in water may accumulate in algae, insects, and fish. The birds or humans who consume these fish are thus exposed to extremely high doses of toxic chemicals. These compounds can alter egg production and bone growth in birds.

Impact of Waste Accumulation on Marine Life

One of the least recognised but most significant uses of the ocean is as a vast landfill. In the past, the oceans were able to absorb human trash without observable negative consequences. However, industrialisation and other accompanying advances, as well as a dramatic rise in the world’s population, have produced enormous volumes of trash that are now exceeding the seas’ capacity to absorb them. The seashores have been severely polluted by a variety of human wastes, including urban sewage, obsolete equipment, and automobiles. The disposal of garbage has the following effects on marine life:

• The development of marine algae is inhibited.
• Massive oil spills not only contaminate a large number of beaches and estuaries, but they also cause extensive harm to marine life.
• Wind and rivers transport herbicides and pesticides (particularly organ chlorides) to the oceans, where they contaminate marine water.
• It is of grave worry that mangrove forests are being degraded at an alarming rate as a result of rubbish disposal along coastlines.
• Thermal and radioactive contamination have disrupted estuaries and coastal ecosystems’ fish populations. Their reproduction is also negatively harmed.

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