Table of Contents
LEVEL 1 (CLASSES 4 AND 5) QN 1 TO 50.
1. As an environment-conscious citizen, how can you reduce your carbon footprint?
a) Walking to school (500 m)
b) Using natural air and switching off AC
c) Defrosting refrigerator regularly
d) All of the above
Answer: d) All of the above
2. What is the molecular formula of ozone gas?
a) O
b) O₂
c) O₃
d) O₄
Answer: c) O₃
3. Which atmospheric molecule protects us by absorbing harmful UV rays?
a) Ozone
b) Oxygen
c) Hydrogen
d) Nitrogen
Answer: a) Ozone
4. What does deforestation mean?
a) Cutting down of trees
b) Planting trees
c) Landslides in forests
d) All of the above
Answer: a) Cutting down of trees
5. Cyclones, droughts, and coral disasters are mostly found:
a) Under water
b) In forests
c) On snow-clad mountains
d) In desert regions
Answer: a) Under water
6. How can CO₂ concentration be reduced?
a) Planting trees
b) Cutting down trees
c) Using plastic
d) Burning fossil fuels
Answer: a) Planting trees
7. Shinkansen in Japan refers to which transport?
a) Bus Rapid Transit System
b) Bullet trains
c) Mono rails
d) Metro trains
Answer: b) Bullet trains
8. Benefits of recycling include:
a) Resource conservation
b) Job creation
c) Energy conservation
d) All of the above
Answer: d) All of the above
9. Which waste is broken down by fungi and bacteria?
a) Chemical waste
b) Plastic waste
c) Organic waste
d) Electronic waste
Answer: c) Organic waste
10. Which Delhi site collapsed in 2017 and now has a waste-to-energy plant?
a) Ghazipur dumpsite
b) Baddi dumpsite
c) Narela-Bawana landfill
d) Bandhwari dumpsite
Answer: a) Ghazipur dumpsite
11. Onsite composting is used mainly for:
a) Rubber
b) Food
c) Plastic
d) Electronics
Answer: b) Food
12. Recycling helps to ______ resources.
a) Conserve
b) Consume
c) Dissipate
d) Exhaust
Answer: a) Conserve
13. This liquid forms lakes, rivers, seas and is essential for all life:
a) Water
b) Lava
c) Nitrogen
d) Gelatin
Answer: a) Water
14. A massive floating piece of freshwater ice is called:
a) Ice cube
b) Iceberg
c) Ice piece
d) Ice bag
Answer: b) Iceberg
15. Mercury vapour lamps produce which colour light?
a) Yellow
b) White
c) Red
d) Orange
Answer: b) White
16. Most economical way to increase lamp brightness:
a) Replace the lamp
b) Clean the light surface
c) Switch off the bulb
d) None of the above
Answer: b) Clean the light surface
17. The ultimate source of all energy is:
a) Fire
b) Water
c) Wind
d) Sun
Answer: d) Sun
18. Which is a transboundary river of India?
a) Ganga
b) Kaveri
c) Narmada
d) Yamuna
Answer: a) Ganga
19. Major cause of hidden household water loss:
a) Shower
b) Hosepipe
c) Leaks
d) Running taps
Answer: c) Leaks
20. The process that renews Earth’s water supply is:
a) Photosynthesis
b) Evaporation
c) Water cycle
d) Tides
Answer: c) Water cycle
21. First national park of India:
a) Hazaribagh National Park
b) Similipal National Park
c) Dachigam National Park
d) Jim Corbett National Park
Answer: d) Jim Corbett National Park
22. World Turtle Day is celebrated on:
a) 23rd March
b) 23rd April
c) 23rd May
d) 23rd June
Answer: c) 23rd May
23. Substance used to prevent or kill pests:
a) Pesticide
b) Insecticide
c) Compost
d) None of the above
Answer: a) Pesticide
24. International Yoga Day is observed on:
a) 21st June
b) 22nd June
c) 6th June
Answer: a) 21st June
25. Anthropogenic activities lead to:
a) Air pollution
b) Water pollution
c) Land pollution
d) All of the above
Answer: d) All of the above
26. CO₂, methane, and water vapour are known as:
a) Saturated gases
b) Greenhouse gases
c) Natural gases
d) Noble gases
Answer: b) Greenhouse gases
27. Which is an example of reuse?
a) Using old clothes for dusting
b) Selling newspapers
c) Throwing old books
d) Taking cartons to recycling centres
Answer: a) Using old clothes for dusting
28. Converting an old product into a new, better one is called:
a) Recycling
b) Upcycling
c) Reducing
d) Incinerating
Answer: b) Upcycling
29. Which resource is renewable?
a) Coal
b) Diamond
c) Silver
d) Wind
Answer: d) Wind
30. Which is an example of pollution?
a) Oil spill
b) Burning fossil fuels
c) Littering
d) All of the above
Answer: d) All of the above
31. Which sentence shows humans changing Earth’s surface?
a) Coal is a naturally forming rock.
b) Coal formed from remains of plants.
c) Coal is mined from Earth and burnt.
d) None of the above
Answer: c) Coal is mined from Earth and burnt.
32. Protecting resources and using them wisely is called:
a) Pollution
b) Irrigation
c) Conservation
d) Crop rotation
Answer: c) Conservation
33. Burning garbage is not good because:
a) It releases toxins
b) Increases CO₂ and black carbon
c) Produces haze
d) All of the above
Answer: d) All of the above
34. Fossil fuels are:
a) Non-renewable
b) Renewable
c) Preserved
d) Unlimited
Answer: a) Non-renewable
35. Decomposition of plants and animals forms:
a) Solar energy
b) Fossil fuels
c) Permafrost
d) Geothermal energy
Answer: b) Fossil fuels
36. Problems caused by mining:
a) Erosion
b) Mudslides
c) Loss of habitat
d) All of the above
Answer: d) All of the above
37. A cut-off meander lake is known as:
a) Oxbow lake
b) Delta
c) Canal
d) Basin
Answer: a) Oxbow lake
38. The ancient southern landmass containing India was called:
a) Tethys
b) Angara Land
c) Gondwana
d) Laurasia
Answer: c) Gondwana
39. Highest mountain on Earth:
a) Mt Abu
b) Mt Everest
c) Mt Kilimanjaro
d) Mt K2
Answer: b) Mt Everest
40. Burning natural gas instead of coal reduces:
a) Mercury
b) CO₂
c) Nitrogen oxides
d) All of the above
Answer: d) All of the above
41. Which statement is true for natural gas?
a) Produces less air pollution
b) Lower greenhouse emissions
c) Costs less today
d) All of the above
Answer: d) All of the above
42. Bird declared state bird of Delhi in 2012:
a) House Sparrow
b) Peacock
c) Duck
d) Crow
Answer: a) House Sparrow
43. Biodiversity hotspot along western coast of India:
a) Himalayas
b) Eastern Ghats
c) Western Ghats
d) Nilgiris
Answer: c) Western Ghats
44. River flowing through MP, Maharashtra, and Gujarat:
a) Godavari
b) Krishna
c) Mahi
d) Narmada
Answer: d) Narmada
45. Which is NOT an official UN language?
a) Spanish
b) French
c) Chinese
d) German
Answer: d) German
46. Kenyan activist who founded Green Belt Movement:
a) Wangari Muta Maathai
b) Ellen Johnson-Sirleaf
c) Laure Olga Gondjout
d) Oprah Winfrey
Answer: a) Wangari Muta Maathai
47. The third type of coral reef (besides barrier and fringing) is:
a) Atolls
b) Polyps
c) Biotic reef
d) Bioherm
Answer: a) Atolls
48. Which is true about African vs Asian elephants?
a) Asian elephants are smaller
b) Asian: 4 toes hind, 5 fore; African: 3 hind, 5 fore
c) Only some Asian males have tusks; all African elephants have tusks
d) All of the above
Answer: d) All of the above
49. Species sharing 98.3% DNA with humans:
a) Lemurs
b) Lorises
c) Langurs
d) Gorillas
Answer: d) Gorillas
50. Most energy-efficient light bulb:
a) Incandescent
b) CFL
c) Halogen
d) LED
Answer: d) LED
LEVEL 2 ( CLASSES 6,7 AND 8) QNO 51 TO 100.
51. Deficiency of Vitamin B-12 causes:
a) Anaemia
b) Night blindness
c) Beri Beri
d) Biotin
Answer: a) Anaemia
52. Which of the following is a primary nutrient for plants?
a) Sulphur
b) Cobalt
c) Sodium
d) Potassium
Answer: d) Potassium
53. Which animal in Antarctica is endangered due to climate change?
a) Penguins
b) Whales
c) Seals
d) Southern Fulmar
Answer: a) Penguins
54. Most minerals in Earth’s crust are found in which layer?
a) Crust
b) Mantle
c) Inner crust
d) Core
Answer: a) Crust
55. Winds during cyclones are known as:
a) Seasonal winds
b) Permanent winds
c) Local winds
d) None of the above
Answer: c) Local winds
56. Warm air rising over oceans during cyclones creates an area of:
a) Low air pressure
b) High air pressure
c) Neutral air pressure
d) Same air pressure
Answer: a) Low air pressure
57. Which of the following is an active volcano?
a) Kilauea (Hawaii)
b) Mt. Vesuvius (Italy)
c) Krakatoa (Indonesia)
d) Mt. St. Helens (USA)
Answer: a) Kilauea (Hawaii)
58. Plastic crusts found on rocks in Madeira are called:
a) Plasticrusts
b) Plastic hills
c) Plastic spill
d) Plastic waves
Answer: a) Plasticrusts
59. Oldest dump in India (326 acres) is:
a) Deonar dumpsite
b) Ghazipur dumpsite
c) Dhapa dumpsite
d) Okhla dumpsite
Answer: a) Deonar dumpsite
60. E-waste is generated from:
a) Discarded electrical/electronic devices
b) Solid domestic waste
c) Chemical fertilizers
d) None of the above
Answer: a) Discarded electrical/electronic devices
61. Types of industrial waste include:
a) Electronics, metals, paints, ash, radioactive wastes
b) Leaves, flowers
c) Used bandages, syringes
d) None of the above
Answer: a) Electronics, metals, paints, ash, radioactive wastes
62. Main cause of global increase in e-waste:
a) Increasing market penetration
b) Replacement market
c) High obsolescence rate
d) All of the above
Answer: d) All of the above
63. Which products can be composted?
a) Food scraps
b) Paper
c) Yard trimmings
d) All of the above
Answer: d) All of the above
64. Photovoltaic cells convert which energy into electricity?
a) Light
b) Sound
c) Wind
d) Nuclear
Answer: a) Light
65. Units on electricity bill represent:
a) Current
b) Energy consumed
c) Voltage
d) Frequency
Answer: b) Energy consumed
66. The 5-star rating on appliances is called:
a) BIS
b) ISI
c) Power
d) Star labeling
Answer: d) Star labeling
67. High coliform count in drinking water indicates contamination by:
a) Human wastes
b) Phosphorus
c) Industrial effluents
d) Hydrocarbon
Answer: a) Human wastes
68. Which dam is built across the Mahanadi River?
a) Hirakud Dam
b) Deras Dam
c) Indiravati Dam
d) Mandira Dam
Answer: a) Hirakud Dam
69. Greywater should NOT be used for:
a) Watering lawns
b) Mopping floors
c) Washing cars
d) Washing edible vegetables and fruits
Answer: d) Washing edible vegetables and fruits
70. Fuse wire is made of:
a) Plastic (low melting point)
b) Metal (low melting point)
c) Plastic (high melting point)
d) Metal (high melting point)
Answer: b) Metal with low melting point
71. Energy Conservation Act (2001) was amended in:
a) 2002
b) 2005
c) 2010
d) 2017
Answer: d) 2017
72. Producers in an ecosystem are:
a) Green plants
b) Herbivores
c) Carnivores
d) None of the above
Answer: a) Green plants
73. Objective of a biosphere reserve:
a) Conserve biodiversity
b) Promote ecological research
c) Provide education & training
d) All of the above
Answer: d) All of the above
74. RDB stands for:
a) Red Data Book
b) Red Diversity Book
c) Red Depictions Book
d) Red Demarcations Book
Answer: a) Red Data Book
75. Species diversity means:
a) Variety of species in an area
b) Variation in genes
c) Variation in habitats
d) None of the above
Answer: a) Variety of species in an area
76. Human blood is a specialized:
a) Organelle
b) Tissue
c) Organic compound
d) Inorganic compound
Answer: b) Tissue
77. Vitamin needed for formation of rhodopsin (night vision):
a) Vitamin A
b) Vitamin C
c) Vitamin D
d) B complex
Answer: a) Vitamin A
78. Oxygen accounts for what % of human body mass?
a) 65%
b) 18%
c) 10%
d) 3%
Answer: a) 65%
79. Which of the following is NOT an airborne disease?
a) Meningitis
b) Chicken pox
c) Tuberculosis
d) AIDS
Answer: d) AIDS
80. Biomolecule made of C, H, O in 2:1 ratio (energy food):
a) Carbohydrate
b) Protein
c) Amino acid
d) None of the above
Answer: a) Carbohydrate
81. Colour of WBCs:
a) Yellow
b) Colourless
c) Red
d) Blue
Answer: b) Colourless
82. Adding salt to water increases boiling point?
a) Increase
b) Decrease
c) Remains same
d) None of the above
Answer: a) Increase
83. Giant clouds of gas and dust forming new stars are called:
a) Asteroids
b) Comets
c) Planets
d) Nebulae
Answer: d) Nebulae
84. Washing soda is:
a) Sodium carbonate
b) Calcium bicarbonate
c) Sodium bicarbonate
d) Calcium carbonate
Answer: a) Sodium carbonate
85. Study of trees is called:
a) Dendrology
b) Dermatology
c) Hematology
d) Pedology
Answer: a) Dendrology
86. Ethology (animal behaviour) studies:
a) Perception, learning, memory
b) Instinctive triggers
c) Evolution of behaviour
d) All of the above
Answer: d) All of the above
87. Global warming may turn storms into:
a) Cyclones
b) Earthquakes
c) Tsunami
d) None of the above
Answer: a) Cyclones
88. Name the cyclone that hit Bay of Bengal in May 2019:
a) Cyclone Fani
b) Cyclone Phailin
c) Cyclone Bhola
d) Cyclone Jal
Answer: a) Cyclone Fani
89. Greatest environmental threat of Greenland ice melting:
a) Ozone-layer depletion
b) Global warming
c) Greenhouse effect
d) Acid rain
Answer: b) Global warming
90. Most abundant greenhouse gas:
a) Carbon dioxide
b) Methane
c) Ozone
d) Water vapour
Answer: d) Water vapour
91. Process through which trees take CO₂ and release O₂:
a) Photosynthesis
b) Oxidation
c) Radiation
d) None
Answer: a) Photosynthesis
92. Theme of World Cities Day 2018:
a) Innovative Governance, Open Cities
b) Building Sustainable and Resilient Cities
c) Designed to live together
d) Inclusive Cities, Shared Development
Answer: b) Building Sustainable and Resilient Cities
93. Nuclear waste is isolated because:
a) Recycled for nuclear weapons
b) Must decay to safe levels
c) Reduce cost
d) None
Answer: b) Must decay to safe levels
94. City Beautiful Movement was conceptualized by:
a) George Edgar Merrick
b) Daniel Burnham
c) Frederick Law Olmsted Jr.
d) Cass Gilbert
Answer: b) Daniel Burnham
95. Bricks, iron rods, sand, grit, lumber are examples of:
a) Construction and demolition waste
b) Industrial waste
c) Commercial waste
d) Agricultural waste
Answer: a) Construction and demolition waste
96. What is an aftershock redesignated as if it becomes larger than the main shock?
a) Before shock
b) Foreshock
c) Earlier shock
d) Antecedent shock
Answer: b) Foreshock
97. Which UN agency promotes sustainable energy use and climate-neutral cities?
a) World Health Organisation
b) United Nations Human Settlements Programme
c) UNICEF
d) None of the above
Answer: b) United Nations Human Settlements Programme (UN-Habitat)
98. Reykjavik’s district heating system primarily uses what energy?
a) Solar
b) Hydro
c) Geothermal
d) Nuclear
Answer: c) Geothermal
99. Which city uses deep-lake water cooling from Lake Ontario?
a) Toronto
b) London
c) Frankfurt
d) Tokyo
Answer: a) Toronto
100. In which country is the Kola Superdeep Borehole located?
a) Russia
b) Germany
c) The USA
d) China
Answer: a) Russia
LEVEL 3 (CLASSES 9 AND 10) QNO 101-150
101. Lantana, Parthenium, and Eichhornia are known as:
a) Invasive alien species
b) Endangered species
c) Parasitic species
d) Rare species
Answer: a) Invasive alien species
102. Which of the following are biodiversity hotspots in India?
a) Himalaya
b) Indo-Burma
c) Sundaland
d) All of the above
Answer: d) All of the above
103. Which types of forests are found in India?
a) Moist tropical forests
b) Dry tropical forests
c) Montane temperate forests
d) All of the above
Answer: d) All of the above
104. Where can mangroves be found in India?
a) West Bengal
b) Gujarat
c) Andaman & Nicobar Islands
d) All of the above
Answer: d) All of the above
105. NARSS 2017–18 under Swachh Bharat Mission was conducted by:
a) Asian Development Bank
b) World Bank
c) UNICEF
d) WHO
Answer: b) World Bank
106. COP24 (2018 UN Climate Conference) was held in:
a) Germany
b) Philippines
c) Poland
d) Fuji
Answer: c) Poland
107. Theme of International Day of the Girl Child 2018:
a) With Her: A Skilled Girl Force
b) Empower Girls Emergency Response
c) Progress = Goals Progress
d) None of the above
Answer: a) With Her: A Skilled Girl Force
108. Father of Golden Revolution in India:
a) Nirpakh Tutej
b) Indira Gandhi
c) Dr. Arun Krishnan
d) M. S. Swaminathan
Answer: a) Nirpakh Tutej
109. First Indian to lead Global Solar Council (GSC):
a) Kirit Ranjan
b) Mayur A Seth
c) Naveen Kumar
d) Pranav R. Mehta
Answer: d) Pranav R. Mehta
110. Venue of ‘Women of India Organic Festival 2019’:
a) New Delhi
b) Bhopal
c) Chandigarh
d) Lucknow
Answer: c) Chandigarh
111. Uri Dam is constructed on which river?
a) Jhelum
b) Chenab
c) Beas
d) Sutlej
Answer: a) Jhelum
112. Ozone-layer depletion is caused by:
a) Global warming
b) Chlorofluorocarbons (CFCs)
c) Halons
d) All of the above
Answer: d) All of the above
113. Pearl of the Middle East (only Middle Eastern country without a desert):
a) Qatar
b) Syria
c) Lebanon
d) Israel
Answer: c) Lebanon
114. 21st-century French tax on technology giants (Google, Apple, Facebook, Amazon):
a) GST
b) GAFA
c) Environmental tax
d) GATT
Answer: b) GAFA
115. International coalition of solar-rich countries (between Tropics):
a) IRENA
b) REEEP
c) IEA
d) International Solar Alliance (ISA)
Answer: d) International Solar Alliance (ISA)
116. ______ cycling is key for ecosystem nutrient movement:
a) Nitrogen
b) Calcium
c) Potassium
d) Manganese
Answer: a) Nitrogen
117. Vehicle releasing maximum carbon emissions:
a) Petrol car without a catalyst
b) Petrol car with a catalyst
c) Electric car
d) Hybrid car
Answer: a) Petrol car without a catalyst
118. Device that removes particulates & bacteria from air:
a) Air cleanser
b) Air quality enhancer
c) Air purifier
d) Pure air device
Answer: c) Air purifier
119. AQI 301–500 (hazardous) is represented by:
a) Yellow
b) Red
c) Purple
d) Maroon
Answer: d) Maroon
120. First ever cloned animal:
a) Dolly
b) Crap
c) Tetra
d) Tetra
Answer: a) Dolly
121. Country with largest area covered by landfills:
a) China
b) India
c) The USA
d) Mexico
Answer: c) The USA
122. First mammal (rodent) extinct due to climate change:
a) Pocket gopher
b) Kit fox
c) Pinyon mouse
d) Bramble Cay mosaic-tailed rat
Answer: d) Bramble Cay mosaic-tailed rat
123. Disease causing deadly brain inflammation:
a) Encephalitis
b) Dysentery
c) Typhoid
d) Jaundice
Answer: a) Encephalitis
124. Rally for Rivers was launched by:
a) Guru Nityananda
b) Sadhguru Jaggi Vasudeva
c) Swami Ramdas
d) Gurnarnay Chidvilasananda
Answer: b) Sadhguru Jaggi Vasudeva
125. Giardiasis affects which organ?
a) Stomach
b) Kidney
c) Small intestine
d) Large intestine
Answer: c) Small intestine
126. POP stands for:
a) Persistent Organic Pollutants
b) Persistent Organic Pesticides
c) Permanent Organic Pollutants
d) None
Answer: a) Persistent Organic Pollutants
127. Process of using materials/waste to make new products:
a) Reuse
b) Reduce
c) Recycle
d) Refuse
Answer: c) Recycle
128. Correct statement:
a) Composting is a form of recycling
b) Composting generates lots of waste
c) Composting is very expensive
d) Composting creates toxic waste
Answer: a) Composting is a form of recycling
129. Microbes active at 50°C–80°C are:
a) Psychrophiles
b) Mesophiles
c) Thermophiles
d) Hypophiles
Answer: c) Thermophiles
130. Process using microbes to clean contaminated soil:
a) Bioremediation
b) Fragmentation
c) Inoculation
d) Gasification
Answer: a) Bioremediation
131. Controlled burning of waste producing syngas, charcoal, liquid fuel:
a) Incineration
b) Pyrolysis
c) Gasification
d) Bioremediation
Answer: b) Pyrolysis
132. Residue left after coal combustion:
a) Mud
b) Fly ash
c) Coke
d) None
Answer: b) Fly ash
133. AQI stands for:
a) Air Quality Index
b) Air Quantifying Index
c) Atmospheric Quality Index
d) Air Humidity Index
Answer: a) Air Quality Index
134. Cold Start Emissions refer to:
a) Lesser emissions on cold days
b) More emissions on cold days
c) Emissions only on cold days
d) None
Answer: b) More emissions on cold days
135. Soil erosion can be prevented by:
a) Deforestation
b) Afforestation
c) Overgrazing
d) Use of fertilizers
Answer: b) Afforestation
136. Benzene vapours cause which cancer?
a) Leukaemia
b) COPD
c) Brain cancer
d) DCIS
Answer: a) Leukaemia
137. Components necessary for photosynthesis:
a) Water, air, sunlight
b) Humus, water, sunlight, air
c) Water, CO₂, humus
d) Water, CO₂, sunlight, chlorophyll
Answer: d) Water, CO₂, sunlight, chlorophyll
138. Source of geothermal energy:
a) Heat from sun
b) Heat from inside Earth
c) Heat from fission
d) Natural gas
Answer: b) Heat from inside Earth
139. First airport in the world powered entirely by solar energy:
a) JFK Airport (USA)
b) Al Maktoum Airport (UAE)
c) Heathrow Airport (UK)
d) Cochin International Airport (India)
Answer: d) Cochin International Airport
140. Not a renewable source of energy:
a) Tidal energy
b) Solar energy
c) Wind energy
d) Fossil fuels
Answer: d) Fossil fuels
141. Dry area on the leeward side of mountains is called:
a) Weathering
b) Rainwater harvesting
c) Rain shadow
d) Silhouette
Answer: c) Rain shadow
142. Technology developed by CSIR-IITR (2018) for cheap water purification:
a) Ooneer
b) Water Filtering by Nanotechnology
c) Photocatalytic Water Purification Technology
d) Lifestraw
Answer: c) Photocatalytic Water Purification Technology
143. Flow of water from high tide to low tide:
a) Flood tides
b) Ebb tides
c) Neap tides
d) None
Answer: b) Ebb tides
144. Deliberate replenishment of groundwater:
a) Artificial recharge
b) Aquifer reinjection
c) All of the above
d) None
Answer: a) Artificial recharge
145. Equipment where magnets & coils produce electricity:
a) Generator
b) Transformer
c) Turbine
d) Reactor
Answer: a) Generator
146. Chemical name for natural gas:
a) Helium
b) Methane
c) Nitrogen
d) Freon
Answer: b) Methane
147. Place where a river meets a lake or ocean:
a) Estuary
b) Confluence
c) Ford
d) Escarp
Answer: a) Estuary
148. Only continent without glaciers:
a) Africa
b) Australia
c) South America
d) None
Answer: b) Australia
149. Theme for World Environment Day 2019:
a) Beat plastic pollution
b) Connecting people to nature
c) Air pollution
d) Go wild for life
Answer: c) Air pollution
150. Accidental discharge of oil into water bodies is called:
a) Water pollution
b) Oil leak
c) Oil spill
d) Tanker leak
Answer: c) Oil spill