The right to clean water is read as part of the 'Right to life' under Article 21 of the Indian Constitution (judicial interpretations).
Ozone column 'thickness' is expressed in Dobson Units (DU): 1 DU = 0.01 mm thickness at STP. It quantifies total ozone overhead.
In 2017, smaller, energy‑intensive countries like Qatar had the highest per capita CO2 emissions (Qatar leads due to energy production and small population).
Bioremediation uses microorganisms (bacteria, fungi) or their enzymes to degrade or transform pollutants (e.g., oil) into less harmful substances.
Energy decreases at successive trophic levels due to metabolic loss (Second law of thermodynamics); only a small fraction (~10%) is transferred to the next level.
Copper is the most abundant metal in mobile phone e‑waste (used in wiring and components); precious metals like gold and palladium are present in smaller amounts.
Ozonisation is considered an ideal disinfectant for wastewater because ozone is a strong oxidant that inactivates bacteria, viruses and removes odour without forming long-lived halogenated byproducts.
The word 'smog' is a blend of smoke and fog. Smog contains pollutants (particulates, ozone, PAN) formed from smoke trapped in fog or stable air.
Excess fluoride in drinking water causes fluorosis — dental fluorosis (mottling of teeth) and skeletal fluorosis affecting bones and joints.
CFC: Chlorofluorocarbon (ozone-depleting halogenated compound). AQI: Air Quality Index (numeric index of air pollution levels). PAN: Peroxyacetyl nitrate (a photochemical oxidant component of photochemical smog).
CFC = Chlorofluorocarbon; AQI = Air Quality Index; PAN = Peroxyacetyl nitrate (Peroxyacyl nitrates).
Smog arises when emissions (NOx, VOCs, particulates) react in sunlight producing photochemical oxidants (ozone, PAN) and aerosols. Health impacts include coughing, throat irritation, exacerbation of asthma/COPD, increased hospital visits and long-term lung damage; environmental effects include reduced photosynthesis and crop yield.
Smog is an air pollution mixture formed from smoke, fog and photochemical pollutants (ozone, PAN, particulates); it causes respiratory and eye irritation, aggravates asthma and bronchitis, reduces lung function and visibility, and can damage vegetation.
Apply the 3Rs: Reduce (buy less, avoid disposables), Reuse (containers, bags), Recycle (segregate and send recyclables). Compost organic waste. Replace disposable items with durable alternatives. E‑waste and some hazardous wastes require proper collection and recycling systems; full elimination is difficult without systemic changes.
Common wastes: organic (kitchen scraps, food leftovers), paper, plastics (bags, bottles), glass, metals, e‑waste (batteries, chargers), sanitary waste, textiles, and hazardous household chemicals. Easily reduced: single‑use plastics, paper (by reusing/digital options), food waste (composting/meal planning), packaging (carry reusable containers). Difficult to reduce: some e‑waste, unavoidable medical/sanitary waste, certain packaged goods due to current infrastructure/manufacturing practices.
Eutrophication stages: nutrient input (fertilizers, sewage) → algal bloom → death of biomass → microbial decomposition consumes dissolved oxygen → hypoxia/anoxia → fish kills and biodiversity loss. Algal blooms reduce light penetration, alter food webs and, if toxin-producing, pose risks to humans and animals; management requires reducing nutrient loading and improving wastewater treatment.
a) Eutrophication: Enrichment of aquatic systems by nutrients (mainly N and P) leading to excessive plant/algal growth, oxygen depletion and ecosystem degradation. b) Algal bloom: Rapid proliferation of algae or cyanobacteria in water bodies often due to nutrient input; may form dense surface scums and some blooms produce toxins (HABs).
Nutrient enrichment stimulates primary production; subsequent decomposition by microbes increases Biological Oxygen Demand (BOD) and decreases dissolved oxygen, harming aerobic aquatic life. Long-term effects include habitat degradation, reduced water quality and harmful algal blooms.
Fertilizer runoff supplies excess nitrogen and phosphorus to water bodies, causing eutrophication and algal blooms that reduce oxygen (hypoxia), cause fish kills, loss of biodiversity, altered food webs and possible toxin production.
Preventive measures (source control) are most effective: advanced wastewater treatment (tertiary nutrient removal), agricultural best practices (slow-release fertilizers, timing, contour farming), sediment control, and community awareness. Remedial actions (aeration, algicide) provide short-term relief but do not replace nutrient reduction.
Control eutrophication by reducing nutrient inputs: treat sewage (remove N & P), limit fertilizer runoff (precision application, buffer strips), promote riparian vegetation, construct wetlands, control livestock waste, encourage septic system maintenance and reduce detergen phosphates; aeration and dredging may mitigate symptoms.
Personal actions aggregated have large impacts: lower emissions, reduced resource extraction and waste generation. Participation in community cleanups, awareness campaigns and responsible consumer choices (sustainable goods) further amplifies effect. Proper segregation and disposal prevent land and water contamination.
Individuals can reduce pollution by using public transport, carpooling, cycling or walking; conserving energy (LEDs, efficient appliances), reducing waste (reduce, reuse, recycle), proper disposal of hazardous and e‑waste, avoiding single‑use plastics, choosing eco-friendly products, conserving water, planting trees and supporting clean technologies and policies.
By converting waste into raw material, recycling conserves natural resources (timber, minerals), saves energy (e.g., recycling aluminium uses far less energy than primary production), and reduces pollutant emissions and habitat destruction associated with mining and manufacturing.
Recycling reduces pollution by lowering raw material extraction, decreasing energy consumption and greenhouse gas emissions, reducing landfill use and leachate, and minimizing air and water pollution from manufacturing and waste incineration.
Catalytic converters use oxidation and reduction reactions to lower toxic emissions and are key in meeting emission standards. Ecosan systems emphasize nutrient recycling, water conservation and on-site treatment, making sanitation sustainable where sewerage is limited.
a) Catalytic converter: An automobile exhaust device containing catalysts (platinum, palladium, rhodium) that convert CO, hydrocarbons (HC) and NOx into less harmful CO2, H2O and N2, reducing vehicular air pollution. b) Ecosan toilets: Ecological sanitation toilets that separate urine and feces, minimize water use, reduce pathogen transmission and allow nutrient recovery (compost or urine fertilizer) for safe reuse after treatment.
Preventive measures (treatment at source, substitution of hazardous chemicals), legal frameworks, surveillance (satellite/ships), and international cooperation are essential. Public awareness, corporate responsibility and investments in waste management infrastructure reduce oceanic toxic dumping.
Solutions: enforce international conventions (MARPOL, London Convention), strengthen monitoring and penalties, improve industrial waste treatment, promote safe disposal and land‑based treatment, implement extended producer responsibility, develop port reception facilities, prevent illegal dumping, and support cleanup and remediation programs.
Explanation: Echinoderm adults (e.g., sea stars, sea urchins) display radial (usually pentaradial) symmetry, whereas their larvae (for example, bipinnaria or pluteus larvae) are bilaterally symmetrical. This change reflects their planktonic larval stage and sedentary/adult body plan.
Biomagnification (also called biological magnification) occurs when persistent, non-biodegradable chemicals (for example DDT, mercury, PCBs) are absorbed or ingested by organisms and are not efficiently excreted. These substances bioaccumulate in individual organisms and become more concentrated as predators eat contaminated prey. As a result, top predators have the highest concentrations. Consequences include reproductive failure (eggshell thinning in birds due to DDT), neurotoxicity and chronic poisoning in fishes, birds and mammals. Key terms: biomagnification, bioaccumulation, trophic level, persistent organic pollutants (POPs).
Biomagnification is the progressive increase in the concentration of persistent toxic substances in organisms at successive higher trophic levels of a food chain.
Effects of noise pollution: 1) Auditory effects — temporary or permanent hearing loss and tinnitus; prolonged exposure above ~85 decibel (dB) causes noise-induced hearing loss and threshold shift. 2) Physiological effects — elevated heart rate, hypertension, increased stress hormones (cortisol), cardiovascular problems. 3) Psychological effects — irritability, anxiety, reduced concentration and productivity. 4) Sleep disturbance — insomnia and impaired recovery. 5) Social effects — communication interference and reduced quality of life. 6) Ecological impacts — disruption of animal communication, altered behaviour, impaired mating and navigation in wildlife. Key terms: decibel (dB), threshold shift, tinnitus, chronic exposure.
Noise pollution causes auditory effects (hearing loss, tinnitus), physiological stress (elevated blood pressure, increased cortisol), sleep disturbance, reduced work efficiency and behavioral impacts on humans and wildlife.