Syllabus: GS 3 / Environment
In Context
- The Global E-waste Monitor 2024, brought out by United Nations Institute for Training and Research (UNITAR), International Telecommunication Union (ITU), and Fondation Carmignac, a corporate foundation.
Key findings
- The world produced 62 billion kg of electronic waste (e-waste) in 2022.
- That number is projected to rise to 82 billion kg in 2030
- The world’s generation of electronic waste is rising five times faster than documented e-waste recycling
- The report also highlighted the composition of the 62 billion kg of e-waste.
- It contained 31 billion kg of metals, 17 billion kg of plastics and 14 billion kg of other materials (minerals, glass, composite materials, etc.)
- Region wise : Among regions, Europe has the highest rate of documented formal collection and recycling of e-waste at 42.8 percent.
- Meanwhile, Africa generates the lowest rates of e-waste but struggles to recycle it.
- Countries in Asia generate almost half of the world’s e-waste (30 billion kg) but have made limited advances in e-waste management; moreover, relatively few of them have enacted legislation or established clear e-waste collection targets.
Impacts and Challenges
- E-waste, any discarded product with a plug or battery, is a health and environmental hazard, containing toxic additives or hazardous substances such as mercury, which can damage the human brain and coordination system
- Challenges contributing to the widening gap include technological progress, higher consumption, limited repair options, shorter product life cycles, society’s growing electronification, design shortcomings, and inadequate e-waste management infrastructure.
Global policy
- On the policy front, 81 countries have adopted e-waste policy, legislation or regulation. Sixty-seven countries have legal provisions on EPR for e-waste.
- Another 46 have provisions on e-waste collection rate targets. Finally, 36 countries have provisions on e-waste recycling rate targets.
Status in India
- The Ministry of Environment, Forest and Climate Change has comprehensively revised the E-Waste (Management) Rules, 2016 and notified the E-Waste (Management) Rules, 2022 in November, 2022 and the same is in force since 1st April, 2023.
- These new rules intend to manage e-waste in an environmentally sound manner and put in place an improved Extended Producer Responsibility (EPR) regime for e-waste recycling wherein all the manufacturer, producer, refurbisher and recycler are required to register on a portal developed by the CPCB.
- The new provisions would facilitate and channelize the informal sector to the formal sector for doing business and ensure recycling of E-waste in an environmentally sound manner.
- Provisions for environmental compensation and verification & audit have also been introduced.
Suggestions
- Amidst the hopeful embrace of solar panels and electronic equipment to combat the climate crisis and drive digital progress, the surge in e-waste requires urgent attention.
- There is an immediate call for greater investment in infrastructure development, more promotion of repair and reuse, capacity building, and measures to stop illegal e-waste shipments.
- Concrete steps are urgently needed to address and reduce e-waste.
- Improved e-waste management could result in a global net positive of US $38 billion, representing a significant economic opportunity while addressing climate change and health impacts.
- We must seize the economic and environmental benefits of proper e-waste management; otherwise, the digital ambitions of our future generations will face significant risks.
- Monitoring the quantities and flows of e-waste is essential for evaluating developments over time, and to set and assess targets towards a sustainable society and circular economy.
| Daily Mains Practice Question[Q] The enforcement of e-waste policy, legislation and regulation remains a genuine challenge globally.Elucidate |
2.Pain-sensing cells are either male or female, finds study
Introduction
This unwanted yet necessary sensory experience most living beings share is pain. It is an essential component of our body’s warning system that directs our attention to potential external or internal harm.
The definition of ‘Pain’
- The International Association for the Study of Pain defines pain as, “An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.”
- The way people perceive pain is highly personal and subjective in nature.
- In fact, scientists have suspected for some time now that the perception of pain might be sexually dimorphic: that is, different between (biological) men and women. But the particulars have been a mystery.
- A study led by University of Arizona Health Sciences researchers, recently published in the journal Brain, demonstrated for the first time functional sexual dimorphism in nociceptors, the nerve cells responsible for perceiving pain.
Why do we perceive pain?
- Nociceptor cells have bare nerve endings, and they are found across our skin, bones, joints, and muscles.
- The receptors detect extreme pressure, temperature, and chemical signals released by the body when it is injured, turn them into electrical signals, and relay them to the brain via the spinal cord. The brain finally reads the message and perceives pain.
- Activation of nociceptors likely produces the same perception of pain in men and women.
- While the nociceptors are normally activated by high-intensity stimuli, under some circumstances the threshold for their activation may be decreased, allowing low intensity and normally physiological stimuli to activate them and produce pain.
The nociceptor response threshold
- Previous studies have reported that the nociceptor response threshold in females is lower than that in males.
- One possible biological mechanism underlying this difference could be peripheral nociceptor sensitisation: a phenomenon in which the threshold for pain is lowered by external factors, causing the receptors to respond to stimuli that they’d otherwise ignore.
- To understand sexual dimorphism in nociceptors sensitisation, the research team investigated how easily pain receptors in the dorsal root ganglion — a cluster of nerve cells located near the spinal cord — could be excited.
- The team found that prolactin, a hormone responsible for the growth of breast tissue, also selectively promoted pain responses in female rodents.
- Later, the researchers found receptors for prolactin were expressed more in female-specific pain disorders such as endometriosis.
- Their studies of sleep and chronic pain also established that orexin B, a neurotransmitter that regulates wakefulness, produced sensitisation in male rodents but not female rodents.
‘Differentially sensitised’
- In the new study, the researchers studied how prolactin and orexin-B affect nociceptor activation thresholds in the nerve cell samples they had.
- They cultured the nerve cells overnight in the presence of mouse prolactin for the mice and human prolactin for both the monkey and the human samples.
- For orexin-B, they applied the neurotransmitter to cultured nerve cells of all three species.
- In the mice cohort, a technique to separate and identify proteins revealed prolactin had increased the firing-up of nociceptors in females and orexin-B had done the same thing in males.
- Immunohistochemistry analyses of monkeys and humans also revealed similar effects.
The devil’s in the differences
- When doctors prescribe medicine to help manage pain, they typically overlook the sex of the patient.
- In fact, other than certain female-specific hormonal therapies, health workers generally treat pain the same way among both men and women — even though we also know the rate at which different pain conditions occur differs between the sexes.
- For example, pain arising from conditions not linked to visible tissue damage, such as irritable bowel syndrome, migraines, and painful bladder syndrome, is more common in women, alongside female-specific issues such as endometriosis and dysmenorrhea.
- On the other hand, cluster headaches and gout are more common in men, together with male-specific ailments like prostatitis.
Conclusion
Unravelling the different mechanisms that drive nociceptor sensitisation and activation will bring us a step closer to understanding qualitative sex differences in pain perception, which in turn is essential to designing precise and sex-specific pain therapies.
Editorial 3 : In an electric vehicle, what is regenerative braking?
Context
The impulse to be sustainable — driven by the incessant pressure to lower our emissions — often manifests as lowering consumption and increasing reuse alongside reforms like tweaking consumer behaviour. Electric vehicles are the site of many of these changes, aided by state-led incentives and subsidies. Regenerative braking is an important mechanism in these vehicles that increases their energy use efficiency.
What is braking?
- Braking is the mechanism by which an automotive vehicle in motion slows down.
- A vehicle moving faster has more kinetic energy than a vehicle moving slower, so the process of braking removes (mostly) kinetic energy from the vehicle.
- The law of energy conservation means this removed energy has to go somewhere.
- The disc brake is one type of mechanical brake: it works by pressing brake pads against a disc attached to spinning wheels, and uses friction to convert some of the wheels’ kinetic energy into heat. This is why the discs of disc brakes have holes cut into them, to dissipate heat better.
- Another type is the induction brake, often used in trains: a magnet induces circular electric currents in a spinning wheel.
- These currents produce their own magnetic field, which opposes that of the external magnet.
- The opposition acts like a drag on the wheel and forces it to slow down. In terms of energy: the metal resists the flow of the circular currents and dissipates heat.
What is regenerative braking?
- Regenerative braking is a brake system designed to convert the kinetic energy of the wheels to a form that can be stored and used for other purposes.
- As such, it creates a process in which at least part of the energy delivered to the vehicle’s wheels can be recovered in a situation when the vehicle doesn’t need it.
- Regenerative braking is one type of dynamic braking. In an electric vehicle, of the types becoming common on Indian roads, a battery onboard the vehicle draws electric power from the grid and stores it.
- When the vehicle moves, the battery powers an electric motor that propels the vehicle, converting electrical to mechanical energy. This motor is called the traction motor.
- During regenerative braking, the motor operates as a generator, turning mechanical energy back to electrical energy. In the vehicle, this means an electric current will be produced as the vehicle brakes, which is stored separately in a battery.
- In some other vehicles, especially trains, the current is fed back into the traction motor.
- The other type of dynamic braking is rheostatic braking, where the current is sent to an array of resistors that dissipate the electrical energy as heat.
- It is often necessary for a vehicle to have both regenerative and rheostatic braking in case the electrical energy recovered can’t be stored or used right away.
How does motor become a generator?
- A motor has two essential parts: a rotor (the thing that rotates) and a stator (the thing that’s stationary).
- In a rudimentary design, the stator consists of permanent magnets or electromagnets while the rotor consists of current-carrying wires coiled around in loops. The stator surrounds the rotor.
- When a charged particle, like an electron, moves inside a magnetic field, the field exerts a force on the particle called the Lorentz force.
- Whether the force will push or pull the wire in which the electron is moving depends on the direction of the electric current.
- This is when the coiling helps. The current at the coil’s two ends moves in opposite directions, so the magnetic fields imposed by the stator will push on one end of the coil and pull on the other.
Does regenerative braking have downsides?
- While it is a simple energy recovery mechanism, regenerative braking has some downsides. For example, it alone often doesn’t suffice to bring an electric vehicle to a halt.
- It has to be used together with a conventional system that dissipates some of the kinetic energy as heat.
- Such a system is also required to prevent vehicles from backsliding downhill, which many regenerative brakes won’t prevent.
- Another example is that the amount of energy a regenerative brake can recover drops as the vehicle’s velocity drops as well.
- This said, a regenerative brake can be beneficial for an electric vehicle’s energy-use efficiency in stop-start traffic.
Are there other ways to recover energy?
- The design of a regenerative brake depends on the energy form to which the mechanical energy from the wheels is to be converted.
- An electric vehicle funnels it into a generator and obtains a current, which is stored in a battery or a supercapacitor.
- Similarly, the mechanical energy can be used to increase the angular momentum of a rotating flywheel.
- Flywheels are especially useful because they can receive energy much faster than other such systems.
Conclusion
For every unit increase in speed, they also store exponentially more energy. Engineers have been able to build flywheels with carbon-composites that, in a vacuum, can spin at up to 50,000 rpm. The flywheel can be linked to a reciprocating engine to manage or augment its output, like in Formula One racing, or to a gyroscope to help submarines and satellites navigate.
