My Science School

The air quality is measured by the Air Quality Index. Air quality indices have been created in different countries for the measurement of air quality. These indices measure the air quality in the country and indicate whether the amount of nitrogen dioxide, carbon monoxide and sulfur dioxide in the air exceeds the criteria set by the World Health Organization or not.

The Air Quality Index measures the quality of air. It shows the amount and types of gases dissolved in the air. There are 6 categories of the air have been created in this air quality index. 

These categories are based on air quality. These categories are; good, satisfactory, moderate, poor, very poor and severe. 

 

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New infectious diseases are a sign of how the world is changing, say experts. The more we change the environment, the more we disrupt ecosystems and provide opportunities for diseases to emerge.

Deforestation and human-animal conflict

Clearning of forests may bring wildlife out of the forest to nearby human settlement. ,amu viruses exist harmlessly with their host animals in forests because the animals have co-evolved with them. But humans can become unwitting hosts for these pathogens when they venture into or change forest habitat and come in contact with the host animals directly or indirectly.

New infections can spread rapidly in big cities as population density is higher – people are packed tightly, breathing the same air and touching the same surfaces.

Wildlife trade

Wildlife trade increases the chances of human-animals contact, putting humans at the risk of contracting diseases. For instance, SARS was linked to wildlife trade and eating of wildlife. People who handle, killed and sold wild animals made up early 40% of the first cases. Poorly regulated wet markets (a market selling fresh meat, fish, produce and other perishable goods) and illegal wildlife trade offer a unique opportunity for viruses to spill over from wildlife hosts into the human population. Bird flu’s – H7N9 and H5N9 – too originated in wet markets.

Mobility of people

Increased movement of people, faster transport and international travel and greater inter-connectivity among megacities pose greater risks of disease transmission.

Climate change

Climate change is altering the way animals live and eat. For instance, unusually heavy rains may create favorable environments for bats hosting the virus to reproduce and multiply. Similarly, food scarcity brought about by drought, may lead to more bush meat hunting, raising the risk of outbreaks such as Ebola.

In the American Southwest, years of drought led to a boom in rodent populations as predators suffered. This led to the deadly hanta virus outbreaks in 1993.

 

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As the world grapples with the new coronavirus, which is thought to have spread from bats. Let’s take a look at some of the major zoonotic diseases and their outbreaks:

Bubonic plague

Bubonic plague was the cause of the Black Death that swept through Asia, Europe and Africa in the 14th Century and killed an estimated 50 million people. It took centuries for some societies to recover. Plague is a bacterial disease caused by rodents and cats. The infection in humans is caused by the bite of an infected flea.

HIV AIDS

HIV, the virus that causes AIDS, originated from chimps and other primates and is thought to have first infected humans at least a century ago. However, it was first recognised only in 1981. By the end of that year, there were 270 reported cases and 121 deaths. HIV destroys the door to a host of deadly infections. The virus has now mutated to a separate human-only disease. HIV –AIDS is considered a pandemic. Between 1981 and 2018, the disease caused an estimated 32 million deaths worldwide.

SARS

An epidemic of SARS, caused by a train of coronavirus SARS-CoV, affected 26 countries and resulted in more than 8,000 cases in 2003, SARS-CoV is thought to have spread from bats, which, in turn, spread to other animals (civet cats) and pethaps first infected humans in southern China in 2002. China is considered a potential zone of the re-emergence of SARS-CoV.

Ebola

The 2014-16 outbreak in West Africa was the largest Ebola outbreak since the virus was first discovered in 1976. The outbreak started in Guinea and then spread to other parts of the continent. The virus is transmitted to people from wild animals (such as chimpanzees, gorillas, monkeys, antelopes or porcupines). Human-to-human transmission happens through direct to indirect contact with the blood or bodily fluids of infected people. It is thought that fruit bats of the Pteropodidae family are natural Ebola virus hosts.

Nipah

Nipah virus (NiV) infection severely affects both animals and humans. The natural host of the virus are fruit bats (Indian flying fox).

It can spread from bats to other animals to people or directly from bat to and between people. Even eating a fruit bitten by an infected bat can transfer Nipah to humans. The disease was first identified in 1998 during an outbreak in Malaysia. Indi has reported three NiV outbreaks in the past. The first two were in West Bengal: Siliguri in 2001 and Nadia in 2007. The third outbreak occurred in Kerala in May 2018.

 

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So you know what’s common among 2019-nCoV (new or novel coronavirus), HIV AIDS, Ebola, SARS, MERS, Nipah, H1N1 flu (swine flu) and HSN1 flu (bird flu)? Yes, all of these are zoonosis – that is, they are animal-borne diseases.

Zoonoses have different modes of transmission. In direct zoonosis, the disease is transmitted from animals to human through air, bites or saliva. In indirect zoonoses, the transmission occurs via an intermediate species (referred to as a vector), which carries the disease pathogen. These pathogens can be viruses, bacteria, fungi or parasites.

Though the world has seen the emergence of diseases throughout history, in the last 50 years, a host of new infections diseases has spread rapidly after making the evolutionary jump from animals to humans.

According to the World Health Organisation (WHO), 70% of emerging human pathogens come from animals. In the last century, at least 10 infectious diseases jumped from animals to humans, it says.

What had led to this?

Globalisation, urbanisation, deforestation, encroachment of wild environments, human-animal conflicts and wildlife trade have led to the spike in zoonosis outbreak, says a report by the Global Preparedness Monitoring Board, an independent panel of experts convened by the World Bank and the WHO, released in September 2019. It has also warned that the risk of a global pandemic is growing and that zoonotic diseases will continue to emerge and re-emerge.

 

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By now, it is common knowledge that human activities have a significant impact on the world’s ecosystem. Human beings have deeply altered the environment. They have directly or indirectly contributed to pollution, global warming, climate change and the destruction of biodiversity. It is high time we took measures to save the planet from further degradation. Some of you may have already resolved to adopt a sustainable lifestyle. But where should you start? Well, the best place to begin is your own home!

Many everyday items in your house can be contributing to environmental degradation because of what they are made of, how they are produced, or how they are disposed of. We are not just talking about ‘single-use’ plastic items. Of course, they are among the biggest concerns. But today, we are going to focus on the less obvious ones.

Here is a list of common things harming the environment. Next time you reach for any of these items, remember the three Rs – Reduce, Reuse and Recycle.

Wet wipes

Whether it’s wiping your face or cleaning a spill on the table, wet wipes bring ease and convenience to our lives. But the same can’t be said for the environment. Because the single-use wipes are made of synthetic cellulosic fibre and plastic fibre that don’t break down easily. When disposed of via the toilet, the non-biodegradable products block sewers. They also end up in oceans and harm marine life. Remember, paper tissues are not any better, because trees are felled to make them.

Tooth brush and face wash

Some varieties of toothpaste contain plastic microbeads, a leading contributor to the eight million tones of plastic that enter the ocean each year. Microbeads are tiny pieces of polyethylene plastic added to products such as face washes, body scrubs, abrasive cleaners and toothpastes. Microbeads can easily pass water filtration systems and end up in the sea, posing a serious threat to marine life. They do not biodegrade and as they travel, attract toxic chemicals. According to a study, a single shower using such products can result in 1, 00,000 plastic particles in the ocean. So, when you purchase a product, always check its ingredients and avoid ones with microbeads. (Look for words such as “polypropylene” and “polyethylene” on the label. They indicate the presence of plastic microbeads.)

Deodorant sprays

Aerosols sprays cans such as deodorant, air fresheners and spray paint use certain gases to propel the content from the nozzle. These gases could be hydrocarbons and nitrous oxide – both of which are greenhouse gases. The use of aerosol-coated products also results in volatile organic compounds (VOCs) emissions from the propellants and solvents contained in them. Once airborne, VOCs, in the presence of sunlight, react with nitrogen oxides to form ozone, a key cog in smog. Many sprays also contain highly toxic chemicals such as xylene and formaldehyde, which are cancer-causing agents. They also affect our neurons.

Sunscreen lotion

Common chemicals used in sunscreen creams and lotions to protect against harmful affects of ultraviolet light threaten corals and other marine life. They include oxybenzone, benzophenone-1, benzophenone-8, OD-PABA, 4-methylbenzylidene camphor, 3-benzylidene camphor, nano-titanium dioxide and nano-zinc oxide. Some of these compounds are found in more than 3,500 skin care products worldwide for protection against the sun’s harmful effects. The chemicals enter the environment through wastewater effluent or directly from swimmers wearing sunscreen. The chemicals impair growth and photosynthesis in algae; accumulate in tissues of corals and induce bleaching; and deform the young of mussels, sea urchins and dolphins.

Clothes

Apparel production is linked to environmental problems such as water and air pollution. Every year, global emissions from textile production are equivalent to 1.2 billion tones of CO2, a figure that outweighs the carbon footprint of international flights and shipping combined. Further, dyeing of apparel contributes to about 20% of global water pollution.

While production of natural fibre is linked to pesticide use and heavy water consumption, synthetic textiles contain microplastic known as microfibers, which find their way to the ocean, affecting marine life.

By keeping your clothes until they wear out, and not shopping often, you can reduce your impact.

Glitter

Glitter is made from plastic and used in a wide array of products, including in art and craft, jewellery and cosmetics. But when it is washed down the drain, it becomes part of the growing problem of microplastics, which are consumed by plankton, fish and birds. Animals die from starvation when microplastics collect in their systems, and the material can even make its way up the food chain to end up on our plates.

Paper cups

Increasing awareness and ban against plastic use have led to the shift to alternatives such as paper bags and cups. But how environment-friendly are they? Cups are technically recyclable, but due to the complicated way in which they are produced, the vast majority of coffee cups do not end up being recycled. Indeed, they are made largely of paper, but disposable coffee cups are lined with plastic polyethylene, making the cups waterproof and therefore able to contain liquid. In addition, the difficulty of recycling coffee cups is increased by the fact they are contaminated with drink. This means cups cannot be recycled at standard recycling plants, and must instead be taken to special facilities, which are minimal in number all over the world. Further, many paper cups are made from virgin paper pulp. That means trees are felled to produce them.

 

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There are birds like the piping plovers (Charadrius melodus) that lay their eggs directly on the sand of a beach in a shallow depression. When sea-levels rise, beaches are washed away. When temperatures rise, and wetlands dry out, ducks that live and lay eggs on them will have nowhere to go.

Same is the fate of birds that depend on coral reefs. About one third of the carbon dioxide in the atmosphere is absorbed by the ocean. When CO2 increases and the weather gets warm, more CO2 is absorbed and water becomes more acidic. Increased acidity reduces the ability of the corals to secrete calcium carbonate, which forms the structure of the reef. As a result, they become brittle and break easily. The reef structures shrink (something that happened to the Great Barrier Reef). For many birds in the tropics, corals reefs provide an important food source and are critical habitats for survival.

In Hawaii, mosquitoes that carry malaria breed in lower attitudes. Mountaintops provide protection for birds from mosquitoes since they cannot reach the area. Increasing temperatures have led mosquitoes to move further up the mountain slopes, threatening the birds that live at the top of the mountain. Avian malaria is a major reason for the decline of Hawaiian birds.

When birds move out of their habitats in search of new places to occupy, they over-exploit prey sources, leading to destruction of the entire ecosystem. Ospreys have been seen hunting other birds, so they may pose a threat to birds in the area, particularly if fish become scarce.

Recently, peafowl were found across Kerala, surprising bird-watchers. Why did they move from their habitat? Obviously in search of food and shelter. Studies also show that some species of birds are developing shorter wing spans and have less density in their bones.

 

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[1] Stop climate change. Even if we end releasing greenhouse gases now, there will be continued warming by the gases released earlier. Birds will have to face a warmer planet in the coming years.

[2] Preserve bird habitats. Restore them where they have been lost. Build artificial nesting sites (simple cages for sparrows to bring them back).

[3] Continues to observe and collect data on when birds arrive at certain spots, when their numbers decline, and the connection between their numbers and the year’s temperature patterns.

[4] Grow more trees. They help to balance climate changes, keep CO2 level low and give the birds a chance to nest and survive.

[5] Keep your cat indoors. Each year, outdoor cats kill more than a billion birds in the U.S. and Canada; keeping cats inside is safer for them and better for birds.

[6] Make the spaces around your house friendly for birds. Gardens, trees, and native flowers are good for people and birds.

[7] In a factory outside Chennai, migratory birds hit the glass windows often and crashed to the ground. The management built large nets under every window to save the birds.

[8] Wherever you find a place and time, talk about birds and the need to protect them. More than 30% of our breeding birds are already declining and are in need of conservation action.

 

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A good example is the study of great tits (Parus major) in Europe. These birds reproduce when caterpillars come out in spring when the buds burst out. The caterpillars gorge on the new leaves, great tits pick up the caterpillars to feed the nestlings. This maintains the bird’s survival rates.

Bird reproduction takes place just when the caterpillars are in abundance before they form their cocoons. Warmer temperatures have led to caterpillars emerging sooner. The birds lay eggs too late, and the caterpillars are gone. The cues the birds use to reproduce are not matching up with the peak prey availability. This can reduce the number of eggs they lay.

Pied flycatchers (Ficedula hypoleuca) spend the winter in tropical Africa before migrating to Europe in the spring to breed, They use day-length change in their wintering grounds as a cue for migration. But prey availability is based on temperature, and due to climate change, it starts earlier in the year. The birds do not arrive at breeding grounds in time to take advantage of peak prey. See the mismatch? The fly-catcher population has declined more than 90% in some areas.

The snow bunting is adapted to very specific mountain habitats. When climate changes, they cannot find food. The ranges of boreal birds in Northern Europe are predicted to decrease by more than 73% over the next century.

 

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Billions of locusts have been swarming through East Africa, particularly Kenya, which saw the worst outbreak in 70 years. They spread from Ethiopia and Somalia. The massive swarms entered Kenya in December and tore through pastureland in the north and centre of the country. Left unchecked, locust numbers could increase 500 times by this June, spreading to Uganda and South Sudan. It could become a plague that will devastate crops and pasture in a region which is already hit by series of droughts and floods. This could lead to a major food security problem, says the UN. The FAO says the current invasion is known as an “upsurge” – when an entire region is affected. However, if it gets worse and cannot be contained, over a year or more, it would become which is known as a “plague” of locusts.

 

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The current attack began in January 2019. According to the Food and Agriculture Organisation (FAO) of the United Nations, which monitors and manages locust invasions, between February and June, widespread breeding in Yemen, Saudi Arabia and Iran caused the formation of large numbers of locust swarms. (These areas reported heavy rains in January.)

Control operations were less successful in Iran and Yemen and swarms invaded the India-Pakistan border between June and December. In India, the monsoon provided a favourable environment for the locusts to multiply. The outbreak began late last year in Gujarat and Rajasthan, where more than 3.5 lakh hectares of crop were affected in various districts. Crops of mustard, cumin and wheat were damaged. But a number of timely measures such as spraying of insecticides and a change in wind direction prevented the spread and larger damage. However, some farmers have lost their entire crops and may need replanting.

 

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Controlling locust swarms is no easy task. The larger the swarms, the more difficult the task becomes.

• At present, the primary method of controlling desert locust swarms and hopper bands is to use pesticides, which is applied in small concentrated doses by vehicle-mounted and aerial sprayers. (However, this led to environmental concerns).


• Natural predators such as wasps, birds and reptiles may prove effective at keeping small swarms at bay.


• Other strategies include catching them in nets, driving them away by burning tyres, collecting hoppers with catching machines, trapping them in duties, and other mechanical methods.


• One of the most effective ways to avoid the devastating effects of locust players is to prevent them from happening in the first place. Early warning and preventative control strategies are in place in some places. Locust monitoring stations collect data on weather, ecological conditions and locust numbers, making forecasts of the timing and location of breeding.

 

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• The desert locust is potentially the most dangerous of the locusts because of the ability of swarms to fly rapidly across great distances. Plagues of the desert locust have threatened agricultural production in Africa, the Middle East and Asia for centuries.


• During quiet periods (known as recessions) the desert locust is usually restricted to the semi-arid and arid deserts of Africa, the Near East and South-West Asia, inhabiting some 30 countries (including India) but during plagues, they may spread over an enormous area of nearly 30 million sq. km., extending over 60 countries.


• According to the National Geographic, a single swarm of the desert locust can be 460 square miles in size and pack between 40 and 80 million individuals into less than half-a-square mile. Each locust can eat its weight in plants each day, so a swarm of such size would eat 423 million pounds of plants every day.


• The desert locust flies with the wind and swarms can travel from about five to 130 km or more in a day. Solitary adults usually fly at night whereas gregarious adults fly during the day. The locust can live between three and six months, and there is a 10- to 16-fold increase in locust numbers from one generation to the next.

When conditions are right

• The desert locust reproduces and increases in numbers, when conditions are favourable. It needs moist, sandy soil to lay eggs and fresh vegetation for hoppers (nymphs) to grow into adults. A good monsoon is therefore a cause for concern.


• Females lay about 95 to 158 eggs in an egg pod in soft soils at a depth of 10 to 15 cm below the surface. The location needs to be at the night temperature and right degree of dampness.


• Thought it’s still a mystery what triggers solitary insects to become gregarious, scientists have theorised that a primary cause of the switch happens when individuals regularly touch others on the hind legs within populations. When population starts to build up following a period of drought, individuals concentrate in an environment while foraging. As young insects get more crowded, the close physical contact causes the insects’ hind legs to bump against one another. This triggers a change in behaviour, they say.

 

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Locusts are solitary insects. They are related to grasshoppers, they look and behave like them. But locusts have another behavioural phase called the gregarious phase, which is when they turn out to be a nightmare for farmers. The desert locust is the most destructive of all food-eating locust species because of its speed and ability to multiply rapidly. The recent outbreak in India is believed to be among the worst. Crops in more than 3.5 lakh hectares in various districts of Rajasthan and Gujarat were damaged. Thanks to a number of timely measures and a change in wind direction, a larger damage was averted. But Eastern Africa is experiencing the worst outbreak of the desert locust in 70 years and the U.N. has sought $70 million from international donors to scale up control measures.

Two phased locusts

• Locusts are a group of short-horned grasshoppers that belong to the family called Acrididae. The main difference between grasshoppers and locusts is that the latter can exist in two different behavioural states – solitary and gregarious (gregarious; Become social and live in groups/herds/flocks/swarms). When the population density is high, individuals undergo physiological and behavioural changes. They form bands of nymphs (hoppers or young ones) or swarms of adults and congregate into thick, mobile, ravenous swarms.


• In the case of the desert locust, the solitary brown adults become pink in the gregarious phase, while the immature ones become yellow. These changes are so dramatic that the swarming and non-swarming forms were once considered to be different species.


• The locusts travel long distances in swarms, multiply in numbers as they migrate and devour vegetation wherever they settle. They eat leaves, flowers, fruits, seeds and bark, and also destroy plants by their sheer weight as they descend on them in massive numbers.

 

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The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal was adopted in 1989 and it came into force in 1992. The convention aims to protect human health and the environment against the adverse effects resulting from the generation, transboundary movements and management of hazardous waste and other waste.

In May 2019, 187 countries agreed to amend the Basel Convention to subject shipments of scrap plastic to tighter controls and greater transparency. Set to come into effect in 2021, this amendment would prohibit nations from exporting hazardous plastic waste to other countries.

 

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The Southeast Asian importers became swamped with waste posing significant threat to the environment. The sheer quantity of imported scrap not only overwhelmed ports, but also caused a sharp uptick in illegal recycling operations. Illegal recyclers dumped toxic wastewater into waterways and polluted the air with fumes from burning plastic.

These countries began to face backlash from the public and environmental groups, who used officials to permanently ban the import of plastic waste. This made countries send unwanted and contaminated waste back to the countries it came from and to impose new controls.

• In 2018, Malaysia announced bans on imports of plastic scrap by 2021. Malaysia has revoked import permits and has been clamping down on illegal processing plants.


• Thailand has temporarily prohibited plastic waste import.


• Indonesia has restricted the import of non-recyclable waste and Vietnam will bar all imports of plastic scrap by 2025.


• India announced that a ban on import of plastic waste would began in August, 2019.

 

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