(A) Acid rain is a type of rain that is acidic in nature, typically with a pH level of less than 5.6. It is caused by emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) from burning fossil fuels, such as coal and oil. These emissions react with water vapor in the atmosphere to form sulfuric acid and nitric acid, which then fall back to the ground as acid rain. Acid rain can be prevented by reducing emissions of SO2 and NOx, using cleaner energy sources, and using catalytic converters in cars to reduce emissions.
(B) Water pollution refers to the contamination of water bodies such as rivers, lakes, oceans, and groundwater by various pollutants, including chemicals, microorganisms, and waste products. Causes of water pollution include industrial and agricultural activities, urbanization, and natural disasters. Water pollution can be measured through various methods such as testing for pH, dissolved oxygen, turbidity, and the presence of specific contaminants such as heavy metals or bacteria. According to the World Health Organization, countries with the highest levels of water pollution include India, Bangladesh, and China, while countries with the lowest levels include Finland, Canada, and New Zealand.
(C) Smog is a type of air pollution that occurs when a mixture of smoke and fog or haze forms in the atmosphere. It is caused by emissions from vehicles, industry, and other sources, which react with sunlight to form ground-level ozone and other pollutants. Smog can cause respiratory problems, eye irritation, and other health issues. It can be reduced by reducing emissions from vehicles and industry, using cleaner energy sources, and promoting public transportation.
(D) Tsunamis are large ocean waves caused by sudden movements of the earth’s crust, such as earthquakes, volcanic eruptions, or landslides. They can also be caused by meteor impacts or nuclear explosions. Tsunamis can travel long distances across the ocean and can cause significant damage and loss of life. A tidal wave, on the other hand, is a large wave caused by the gravitational pull of the moon and the sun. It is not the same as a tsunami, which is caused by a geological event. The worst tsunami ever recorded was the 2004 Indian Ocean tsunami, which killed over 230,000 people in 14 countries.