esses are called Non-biodegradable substances.
While Biodegradable waste will eventually break down and become part of the earth and soil, like food scraps and paper, Non-biodegradable waste does not break down but remain stable indefinitely.
Harmful effects of Non-biodegradable Waste Materials:
- Non-biodegradable materials are the main contributors to pollution and ecological instability.
- Non-biodegradable waste is an environmental concern, as it threatens to overwhelm landfills and create disposal problems
- Non-biodegradable wastes remain unchanged over a long period of time and persist in the environment for a long time and may harm the various members of the ecosystem in the long run.
- Some of them remain inert and begin to accumulate in our surroundings, and hence continue to pollute the environment.
- These wastes are very harmful. They enter the food chains and their concentration goes on increasing from one trophic level to the next. This leads to biological magnification and results in harmful effects on human beings and animals.
- Dumping these wastes affects the soil fertility and subsequently reduces the crop yield.
- Glass, metals, plastics, electronic devices, medical wastes are some of the non-biodegradable waste materials.
Incineration is a disposal method which is widely recognized as a practical method of disposing of certain hazardous waste materials such as biological medical waste, is now being considered as a controversial method of waste disposal, due to issues such as emission of gaseous pollutants.
Ecosystem refers to a system that includes all living organisms ( Biotic factors) such as plants, animals, microorganisms etc in a habitat as well as its physical environment ( Abiotic factors) such as weather, soil, earth, sun, climate, rocks minerals etc, functioning together as a unit.
Ecosystems maintain a very delicate balance. Various human activities threaten to destroy this balance. Natural disasters such as fires, floods, storms and volcanic eruptions also have an effect on the ecosystems. Population growth, climate changes, resources exploitation etc, add to the destruction of the ecosystem. An increase or decrease in population of any organism can also disturb this balance.
An ecosystem is a community of plants and animals interacting with each other in a given area, and also with their physical environment. Both living and non-living things within a particular area make up the ecosystem.
Components of Ecosystem
- Biotic components: are the living components of an eco system.
- Abiotic components: are the non living components of an eco system.
There is a mutual dependence of biotic members and abiotic members on one another in an eco system…This means the absence of one member can affect all other parties of the eco system.
Types of Eco- systems:
- Natural eco system: A natural ecosystem is a biological environment that is found in nature rather than created or altered by man.
Examples: Forests rivers lakes,ponds,coral reefs, deserts, grasslands etc.
- Artificial eco system: Humans have modified some ecosystems for their own benefit. These are artificial ecosystems.
Examples: crop fields,gardens,aquariums,dams,man-made ponds etc
Food chain and Food web:
FOOD CHAIN : A food chain describes how energy and nutrients move through an ecosystem.
- In the food chain, food, nutrients, and energy are transferred from one living organism through another in the form of food .
- Food chains begin with plant life, and end with animal life.
- In a food chain, each organism occupies a different trophic level, defined by how many energy transfers separate it from the basic input of the chain
- The number of steps an organism takes from the start of the chain is a measure of its trophic level.
- Autotrophs or producers are at the first trophic level. They use solar energy to produce food and make it available for heterotrophs or consumers.
- Herbivores are primary consumers and form the second trophic level; small carnivores form the third trophic level and larger carnivores form the fourth trophic level of the food chain.
- Energy flow in a food chain is unidirectional. Energy is passed from organisms at one trophic level or energy level to organisms in the next trophic level.
Food Web: consists of many inter connected food chains. In any eco system, there can be many food chains which are inter linked at various levels.
Uncontrolled human activities and rapid population explosion are the major causes of environmental degradation. Human beings perform various activities utilizing the environmental components. Though these activities make the life comfortable, they adversely affect the environment.
Human activities contribute to climate change by causing changes in Earth's atmosphere in the form of greenhouse gases, aerosols etc. Greenhouse gases and aerosols affect climate by altering incoming solar radiation and out going infrared (thermal) radiation that is part of Earth’s energy balance.
Burning of fossil fuels such as coal, oil and natural gas to generate large amounts of energy is the human activity that has the greatest impact on global warming. Deforestation for housing, farming, and industry has a direct effect on ecosystems and endangered species. Trees absorb carbon dioxide emissions from the environment, and when large areas are cleared through deforestation, stored carbon is also released into the atmosphere.
Evidence of climate change is observed in rising sea levels over the last century, the rise in global temperature since 1880, warming oceans, shrinking Greenland and Antarctic ice sheets, declining arctic sea ice, glacial retreat, extreme high-temperature events, ocean acidification, and decreased snow cover.
Bio-magnification:
- Bio-magnification is the increasing concentration of a substance, such as a toxic chemical in the tissues of organisms at successively higher levels in a food chain.
- Biological magnification often refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The substances become concentrated in tissues or internal organs as they move up the chain
- This occurs when agricultural, industrial, or human waste pours into the ocean directly or via rivers, sewage, etc. Some of the most dangerous of these toxins settle in the sediment of the sea floor and are consumed by bottom feeders. With each step up the food chain, there is an increase in the concentration of these chemicals. This affects humans because a large percentage of the fish we consume are higher on the food chain and therefore likely to carry a high concentration of potentially harmful chemicals.
Ozone Depletion:
- The ozone layer is a deep layer in the stratosphere. encircling the Earth, which has large amounts of ozone in it. The layer shields the entire Earth from much of the harmful ultraviolet radiation that comes from the sun. Ozone is a special form of oxygen, made up of three oxygen atoms rather than the usual two oxygen atoms.
- Ozone layer filters out most of the sun's potentially harmful shortwave ultraviolet (UV) radiation. If this ozone becomes depleted, then more UV rays will reach the earth.
- Exposure to higher amounts of UV radiation could have serious impacts on human beings, such as skin cancers, Sun burns, premature ageing of the skin, eye diseases, and weakening of the human immune system. It can cause abnormalities in a growing foetus in pregnant women resulting in birth abnormalities.
- It has adverse effects on agriculture, terrestrial plant life, natural ecosystems etc.It also causes damage to marine life, In particular, plankton (tiny organisms in the surface layer of oceans) are threatened by increased UV radiation. Plankton is the first vital step in aquatic food chains.
Causes for ozone depletion:
Scientific studies have substantiated that the cause of ozone layer depletion is human activity, specifically, human-made chemicals that contain chlorine or bromine. These chemicals are widely known as ODS, an acronym for Ozone-Depleting Substances.
- The chief ozone-depleting substances include chlorofluorocarbons (CFCs), carbon tetrachloride, hydrochlorofluorocarbons (HCFCs) and methyl chloroform. Chemicals like chlorofluorocarbons (CFCs) are released from excessive use of aerosols, propellants, refrigerants. These act with ozone and break it down to oxygen and chlorine monoxide.
- NO2 released from the burning of fuels in planes react with ozone to form NO3 and oxygen.
- This has resulted in depletion of ozone layer and the formation of the Ozone hole in the region above Antarctica. Australia is also affected.
Waste Management:
- Waste management is the collection, transportation, and disposal of garbage, sewage, and other waste products.
- Some of the most commonly used methods that are used for waste management landfills, combustion, composting, avoidance and waste minimization.
- All non – biodegradable like plastic bags, glass bottles cannot be broken down by decomposers, so their disposal poses a big problem. They can be managed by practising the concept of 3R’s. Reduce, Reuse, Recycle.
The three R's – reduce, reuse and recycle – help to cut down on the amount of waste we throw away.
Alternative Ways of waste management:
- Avoiding use of plastics. Use of earthen cups,carry bags made of cloth or paper instead.
- Use of CFC-free refrigerators
- Use of organic manure instead of chemical fertilisers.
- Use of eco-friendly products.
Green House effect:
The Green House Effect is the effect of atmospheric gases like carbon dioxide absorbing energy from the Sun and Earth and trapping it near the Earth's surface warming the Earth to a temperature range that is hospitable for life.
