WS 9.1 (Pg 98-99)
2 (a) Industries, forest fires, vehicles
– Industries release large amounts of dust, soot and poisonous gases such as sulphur dioxide and nitrogen oxide.
– Vehicles release smoke and harmful gases such as carbon monoxide and nitrogen oxides
– Forest fires produce dust and smoke
– When we are exposed to dust and smoke for a long time, we can develop respiratory problems such as bronchitis and asthma.
– Breathing in sulphur dioxide and nitrogen oxides over time can increase the risk of developing lung and heart diseases, and even cancer.
– Breathing in carbon monoxide is poisonous and can result in death.
– Flights have to be stopped or delayed. Thus, countries will lose important source of revenue from airport operations.
– Tourists may postpone or cancel their trips to the country thus affecting the tourism industry negatively.
– Harmful gases like these will combine with water vapour in the atmosphere to form acid rain. When acid rain falls over the rivers, the streams and lakes will have lower PH levels. Aluminum that is released into the soil eventually ends up in lakes and streams which will increase the acidity level. This will kill the fishes.
– Acid rain that seeps into the ground can dissolve nutrients that trees need to be healthy, such as magnesium and calcium. This causes aluminum to be released into the soil and makes it difficult for trees to take up water. It makes it easier for infections, insects, and cold weather to damage trees and forests.
WS 9.2 (Pg 102-103)
When untreated sewage is released into rivers or lakes, these water bodies get polluted because sewage contains human waste, detergents and chemicals which can be harmful if consumed.
Sewage that is treated may still contain non-biodegradable substances such as detergents. These substances remain in the water and cause water pollution.
A: People may use polluted water from the river or other water bodies for cooking and drinking.
B: People may consume contaminated seafood which comes from a polluted river or the sea.
C: People may come into contact with polluted water when they bathe or swim in the river or sea.
– When we consume contaminated seafood from polluted water, the poisons that accumulate in the bodies of fish and shellfish and passed on to us. This will make us ill.
– When we drink contaminated water, we may suffer from Cholera or Typhoid.
– The oil prevents oxygen from reaching fish in the sea, thus killing them. This will reduce the supply of fresh fish and threaten fishermen’s livelihood.