My Science School

The United Nations (the U.N.) declared 2010 the International Year of Biodiversity. Throughout the year, several key initiatives were organized to spread awareness on the need to promote biodiversity conversation and encourage everyone – as individuals and groups – worldwide to take mindful steps to stop the loss of biodiversity. That year, the U.N.’s Convention on Biological Diversity held its 10th biannual meeting in Nagoya, Japan. This international legally binding treaty, which came into force in 1993, aims to encourage actions that will lead to a sustainable future.

Biodiversity — the variety of all life forms, from genes up — is vital because diversity makes for healthy, stable ecosystems. From coral reefs to the Kalahari, these natural 'balancing acts' are intrinsically valuable. But beyond beauty and amenity, ecosystems also provide essential 'services' such as breathable air, clean water and fertile soils. Fisheries, agriculture, medicine and many traditions and ways of life all depend on biodiverse ecosystems.

Clearly, biodiversity is key not just to life on Earth, but to economies and cultures. And for the poor, who often depend directly on land and sea for subsistence, it is literally a lifeline.

 

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Also called the Gulf of Mexico oil spill, Deepwater Horizon oil spill is considered to be the largest marine oil spill in history. It occurred on April 20, 2010 when the Deep Horizon oil rig exploded in the Gulf of Mexico and off the coast of Louisiana, the U.S. The rig was leased by London-based oil company BP. By the time the leak from the exploratory well was capped 87 days later, more than three million barrels of oil had leaked into the waters while the explosion itself had claimed 11 lives. The disaster has had environmental, health and economic impacts.

An estimated 53,000 barrels were flowing into the Gulf of Mexico every day.

The accident also made extensive damages to the marine environment. According to the Centre for Biological Diversity, the oil spill killed over 82,000 birds, 25,900 marine mammals, 6,000 sea turtles and tens of thousands of fish, among others.

 

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Over the last few decades, there has been a significant spike in the number of wildfires. Greenhouse gas emissions have led to an increase in global temperature. As warmer temperatures hasten evaporation, the land subsequently turns drier, enhancing the chances of wildfires.

A 2019 Australian government report on wildfires and climate change said human-caused climate change has resulted in more dangerous weather conditions for bushfires in recent decades for many regions of Australia.

 Heatwave and drought

Fire season in Australia is always dangerous. But conditions have been unusually severe this year. Australia is experiencing one of its worst droughts in decades. Meanwhile, a heatwave last December broke the record for highest nationwide average temperature, with some places sweltering under temperatures well above 40 degrees Celsius.

Fire season has changed

With climate change, weather conditions are growing more extreme, and for years, the fires have been starting earlier in the season and spreading with greater intensity in Australia. The fire season is starting earlier and is about two to four months longer, especially in south and east Australia. The normal peak fire season is later in summer, which is January and February. Australia is just entering its summer season, meaning the country could be months away from finding relief.

 

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 Though it is estimated that nearly half-a-billion animals have been affected in one State alone, it is difficult to get the exact number until fires subside enough to allow surveys of the burned areas. Fires have been part of the Australian landscape for thousands of years. Many species and ecosystems have evolved to cope and later populate nearby unaffected land. But as climate change fuels longer five seasons and more frequent, intense fires, it could become increasingly difficult for animals to adapt newer escape strategies and for ecosystem to bounce back.

In the line of fire

Smaller mammals and reptiles can escape the blazes by burrowing underground or hiding in rocks.

But some are not good at coping heat or stress. Wombat, the small, stubby-legged marsupial, can’t run very fast or far. Kolas are particularly vulnerable to bushfires as their slow movement and tree-dwelling lifestyle make it difficult for them to escape. Koalas and kangaroos are primarily killed directly by the fires. In this season, nearly a third of all koalas in New South Wales have died and about a third of their habitat has been destroyed according to a government estimate.

Ecosystems are built on balance – once one element is thrown off, everything is affected. Even if animals don’t die from the flames or smoke, they would eventually do from the fire’s aftermath. After their habitat is destructed, there will be no shelter or food left to survive on. These animals’ recovery depends not only on their population size, but also on the condition of their habitat.

 

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An uncontrolled fire in an area of combustible vegetation that spreads quickly, wiping out large areas of land is called a wildfire. A wildfire can also be termed a forest fire, a grass fire, a peat fire or a bushfire depending on the type of vegetation.

During summer, when there is no rain for months, the forests become littered with dry leaves and twigs, which could burst into flames ignited by the slightest spark.

Natural causes: Lightening is the most common cause of bushfire. There are three conditions for a bushfire to spread – fuel, oxygen and a heat source. In the forest, anything that is flammable is a fuel. This includes tall, dry grass, bushes and trees. High temperature, drought and dry vegetation are a perfect combination for igniting a forest fire.

Human-made disaster: Human neglect such as downed powerlines, sparks from tools or forest machinery, abandoned campfires and discarded cigarette butts can spark fires. People also tend to clear forests by setting them on fire to pave way for cultivation. Sometimes they set fire to scare away wild animals and the fire could spread and turn disastrous.

In Australia:

Summer is the season of fire in Australia with hot, dry weather making it easy for blazes to start and spread. Most of the time, it is natural causes such as lightning that trigger a fire, but sometimes human are also to blame. New South Wales police have charged at least 24 people with deliberately starting bushfires, and have taken legal action against 183 people for fire-related offences since November, according to reports.

 

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Bushfires are almost an annual affair in Australia, but this fire season has been unprecedented in scale and intensity.

A series of massive bushfires has been burning across Australia since September 2019 and they intensified early this month, with a number of towns evacuated.

At least 27 people have been killed, 1200 homes destroyed, and 18 million acres of land – bush, forest and parks – have been burned. Of all the States, New South Wales has been the hardest-hit. Nearly half-a-billion creatures, including birds, mammals and reptiles, have been affected by the fires in New South Wales alone and millions of them are possibly dead, according to scientists. Many large cities have been shrouded in smoke for weeks. State and federal authorities are struggling to contain the massive blazes, even with firefighting assistance from other countries.

Why are the fires so bad? Persistent drought and record temperatures are the major drivers of the fire, but the role played by climate change in making natural disasters go from bad to worse should not be overlooked, say scientists.

 

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• Dumping of medical waste in the open or disposal of untreated waste can be dangerous.


• A host of infectious diseases is linked to toxic medical waste while garbage collectors, along with those living close to medical centres, are especially at risk.


• The disposal of untreated waste in landfills can lead to the contamination of drinking, surface and ground water if those landfills are not properly constructed.


• The disposal of untreated waste in landfills can cause diseases in animals as well. Animals may consume infected waste and eventually, these infections can be passed on to humans who come in contact with them.


• It is often found that biomedical waste is dumped into the ocean, where it eventually washes up on shore.


• The treatment of healthcare waste with chemical disinfectants can result in the release of chemical substances into the environment if those substances are not handled properly.


• Inadequate incineration or the incineration of unsuitable materials results in the release of pollutants, including carcinogens (cancer-causing chemicals) into the air.


• Incineration of medical devices with heavy metals (in particular lead, mercury and cadmium) can lead to the spread of toxic in the environment.


• If safety measures are not followed, health workers, laboratory personnel and transport workers will also be affected.

 

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• As of 2016, India was generating about 484 tonnes of bio-medical waste per day, from its 1,60,000 health-care centres. It was estimated that the country would generate 77.5 tonnes of medical waste per day by 2022. A 100-bed hospital generates 100-200 kg of hospital waste every day, according to a study.


• Of the total amount of waste generated by health-care activities, 15% is considered hazardous that may be infectious, toxic or radioactive.


• Segregation, treatment and transportation, depends on the type of bio-medical waste. Incineration, deep burial, local autoclaving, microwaving, chemical disinfection, mutilation and shredding and discharge into the drains, followed by disinfection are some of the ways that medical wastes are managed in India.


• Colour-coded containers are used for disposal of biomedical waste.


• India’s bio-medical waste management is ruled by the Bio-medical Waste Management Rules 2016. According to the rules, blood samples and microbiological waste should be pre-treated on-site before being disposed of. It also planned to introduce a bar-coding system, where all biomedical waste containers or bags are going to be tracked by the government. This is to ensure that the movement from its manufacturing to treatment facilities is monitored.


• Common bio-medical waste treatment facilities (CBWTFs) are involved in managing waste. According to the 2016 rules, a CBWTF within 75 km of a healthcare centre has to ensure that waste is collected routinely and regularly.


• The ruling also extends to vaccination camps, blood donation centres and surgical camps.

 

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Infectious medical waste: These are waste materials that can pose a risk of infection to humans, animals, and the overall environment. This includes blood-stained bandages, surgical waste, human or animal body parts, cultures and swabs.

Sharps waste: This includes syringes, needles, disposable scalpels and blades.

Chemical waste: Solvents and re-agents used for laboratory preparations, disinfectants, metals such as mercury in devices such as broken thermometers and batteries.

Pharmaceutical waste: Unused, expired and contaminated medicines.

Radioactive waste: Products contaminated by radionuclides, including radioactive diagnostic material or radiotherapeutic materials.

 

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Morning walkers of Clifton Beach, Karachi, Pakistan, were in for a shock recently as the golden sand was covered in garbage, which included a large amount of bio-medical waste. The tide had brought with it several blood vials and open syringes to the shoreline. Pakistani media criticised the government for going easy on hospitals and research centres that continue to dump toxic waste in the open or directly into water bodies.

To story is not different in India. Despite regulations against the dumping of medical waste in the open, loads of them are disposed of in landfills along with other garbage every day. Other rules of segregation and safety measures are also flouted in some places. Coming in contact with such waster or open burning can prove harmful to the environment and our health.

Waste generated during the diagnosis, treatment or immunisation of human beings or animals in hospitals and clinics and during experiments in research labs are all biomedical waste. It includes used syringes, blood-stained cotton bandages, used I-V tubes, scalpels, blades, glass, microbiological cultures, discarded gloves, and linen. It also includes human or animal tissues, organs and body parts and fluids. Biomedical waste may be solid or liquid.

 

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Farmers are not the only reason for air pollution.  Stubble burning does contribute to Delhi’s pollution in a major way, but it is episodic and depends a lot on wind direction and other meteorological factors. According to the Centre for Science and Environment (CSE), about 65% of pollution in Delhi is due to local sources.

Dust is a major contributor to air pollution. Unpaved roads, and digging for various infrastructural construction expose the loose soil, contributing as much as 17% of the particulate matter (PM) in the air. A TERI-ARAI study published in 2018 on PM 2.5 emissions showed that transport contributed 39%, road dust 18%, construction activities 8%, followed by power plants 11% to the air pollution in Delhi. Pollution mitigation efforts should take these factors into account.

 

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On November 6, the Supreme Court of India ordered an incentive of Rs 100 per quintal for small and marginal farmers who engage in the management of the residue of their non-Basmati variety rice crop in Punjab, Haryana and Uttar Pradesh.

The SC Bench also ordered the States to distribute crop residue management tools and machines to small and marginal farmers free of cost. The States need to use their own funds to finance the scheme, it said.

Meanwhile, it asked the Delhi government to submit an action plan to deal with issues of garbage dumping and burning, pock-marked roads and the state of traffic congestion in the capital city. The court gave the government three weeks to repair the potholes.

 

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• Even with capital subsidy, machines like Happy Seeder are not considered economical, as their demand is seasonal. The high cost of the machines and the rising price of diesel put pressure on farmers. For them, stubble burning is a cheaper option. A Happy Seeder machine is priced at Rs 1.5 lakhs. Though the government offers a 50% subsidy on the purchase of Happy Seeders to individual farmers, the machine still remains unaffordable. Also not all tractors are capable of pulling a happy seeder along, only those with a capacity of 65 horsepower would be able to drag an additional device mounted on it.


• Farmers remain sceptical about the efficiency of these machines. They fear the machines will affect productivity and damage the soil. Besides, they feel using machinery is time-consuming.


• The farmers have expressed that the number of machines provided is extremely inadequate.

How can stubble burning problem be solved?

• The equipment has to be supplied quickly and in good numbers. There are reports that subsidized agromachines being provided by the government have not reached many villages and whenever given, the number is too low.


• It is important to find other uses for stubble such as biomass, which may encourage farmers to look for alternative sources of income.

 

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Farmers can use devices such as mulchers (that cut up grass, leaves, etc., for use as mulch), rotavators (a machine with rotating blades for breaking up or tilling the soil), Happy Seeders and straw management system to manage and utilise stubble.

Happy Seeder is nothing but a tractor-mounted device which can cut and lift the previous crop (in this case the rice straw) and sow a new (wheat) crop in its place simultaneously. It also deposits the straw over the sown area as mulch. Mulch enriches and insulates the soil.

The straw management system involves the use of a machine attached to a harvester chopper, which spreads loose straw uniformly. Here, the straw serves as mulch.

Straw could also be used as feeder.

(However, farmers in these regions report a lower preference for paddy straw because of the comparatively high silica content in it. There are also reports of wheat straw rejection due to fuel spillover during harvesting by machines.)

 

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Farmers have to clear the stubble soon after harvest so as to prepare the field for sowing the next crop.

For clearing the farm waste, they usually have a short span of 10 to 15 days during which they prefer burning the stubble to other methods as it is considered the cheapest and least time-consuming solution. The residue and stubble are an important source of organic matter for the soil. Burning off this organic matter will gradually reduce soil organic matter levels. Burning can made the soil hotter and drier on the surface, creating a hard seedbed. Burning can temporarily seal the soil surface to some extent. Burning will result in the loss of some of the volatile nutrients, such as nitrogen, in the residue. Phosphorus and other minerals are not volatilized by burning and will remain on the field in the ash, unless the ash is blown away.

 

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