Air & Water Pollution — Set 1
Environment · वायु और जल प्रदूषण · Questions 1–10 of 70
Which gas is primarily responsible for the greenhouse effect leading to global warming?
Correct Answer: A. Carbon dioxide
Carbon dioxide traps heat in the atmosphere, creating a warming effect on the planet. It is primarily released through the burning of fossil fuels and deforestation activities. This process is generally recognized as the leading cause of climate change.
What is the primary indicator used to measure the level of organic pollution in a water body?
Correct Answer: C. Biochemical Oxygen Demand (BOD)
BOD measures the amount of oxygen consumed by bacteria while decomposing organic matter under aerobic conditions. A high BOD value indicates that the water is heavily contaminated with organic waste. It is a fundamental parameter for assessing the health of aquatic ecosystems.
Which pollutant is the main cause of 'Minamata disease' in humans?
Correct Answer: D. Mercury
Minamata disease is a neurological syndrome caused by severe mercury poisoning. It first occurred in Japan due to the release of methylmercury into industrial wastewater. This toxic metal accumulates in fish, which then enters the human food chain.
What is the phenomenon called when excessive nutrients in water bodies lead to overgrowth of algae?
Correct Answer: A. Eutrophication
Eutrophication is caused by the runoff of fertilizers and detergents containing phosphorus and nitrogen. This nutrient enrichment triggers rapid algal blooms that deplete dissolved oxygen in the water. It often results in the death of fish and other aquatic organisms.
Which layer of the atmosphere contains the ozone layer that protects Earth from ultraviolet rays?
Correct Answer: C. Stratosphere
The stratosphere houses the ozone layer, which filters out harmful UV radiation from the sun. Human activities like the use of chlorofluorocarbons (CFCs) can lead to the depletion of this protective shield. Damage to this layer is generally linked to increased risks of skin cancer and cataracts.
Which of the following is considered a primary air pollutant?
Correct Answer: D. Sulfur dioxide
Primary pollutants are substances directly emitted into the air from a source like a factory or vehicle. Sulfur dioxide is produced by the combustion of coal and petroleum products. Secondary pollutants, like smog, are formed when primary pollutants react in the atmosphere.
What does the 'Air Quality Index' (AQI) primarily represent?
Correct Answer: A. Concentration of air pollutants
The AQI is a numerical scale used by government agencies to communicate the daily health risk of air pollution. It focuses on major pollutants like PM2.5, PM10, and nitrogen dioxide. A higher index value indicates poor air quality and potential health hazards.
Which heavy metal pollution is the main cause of 'Itai-Itai disease'?
Correct Answer: C. Cadmium
Itai-Itai disease is caused by chronic cadmium poisoning, often from contaminated water or soil. It leads to severe bone pain and softening of the bones, along with kidney damage. The disease was first documented in Japan's Toyama Prefecture in the mid-20th century.
Which gas is known as the 'Silent Killer' because it is colorless, odorless, and highly toxic?
Correct Answer: D. Carbon monoxide
Carbon monoxide is produced by the incomplete combustion of fuels like charcoal, gas, or wood. It is dangerous because it binds to hemoglobin in the blood, preventing oxygen delivery to body tissues. Proper ventilation is essential when using combustion heaters or engines indoors.
Which chemicals are the major contributors to the formation of 'Acid Rain'?
Correct Answer: A. Sulfur dioxide and Nitrogen oxides
Sulfur dioxide and nitrogen oxides react with water vapor in the atmosphere to form sulfuric and nitric acids. These acids fall to the ground as rain, snow, or fog, damaging forests and aquatic life. Acid rain is also known to corrode historical monuments and buildings.