Pollutants are substances or agents that contaminate the environment and can cause harm to living organisms and ecosystems.
1. Air pollutants.
a) Tropospheric pollution.
b) Stratospheric pollution.
2. Water pollutants.
3. Soil pollutants.
4. Thermal pollutants.
5. Radioactive pollutants.
6. Noise pollutants.
7. Light pollutants.
There are two types of pollutants:
That are directly emitted into the atmosphere as a result of human activities or natural processes (SO2, SO3, CO, NH3, Hydrocarbon etc.)
Which are formed by the primary pollutants (H2SO4, H2CO3, HCl, Ozone etc.)
Pollutant | Sources | Environmental Risks | Human Health Risks |
Carbon Monoxide (CO) | Incomplete combustion of fossil fuels, vehicle emissions | Contributes to global warming and reduces air quality | Headache, brain damage and affects the cardiovascular system. |
Nitrogen Oxides (NOx) | Combustion of fossil fuels, industrial processes | Contributes to smog and acid rain, harms ecosystems | Respiratory irritant, leads to respiratory problems. |
Sulfur Dioxide (SO2) | Burning of fossil fuels, industrial activities | Causes acid rain, damages vegetation and water bodies | Irritates respiratory system, lung diseases (Bronchitis, emphysema & lung cancer). |
Ozone (O3) | Formed by reactions of NOx and volatile organic compounds (VOCs) in sunlight | Damages crops and forests, reduces photosynthesis | Respiratory irritant, causes breathing difficulties. |
Particulate Matter (PM) | Combustion processes, industrial emissions | Reduces visibility, contributes to haze and acid rain. | Respiratory and cardiovascular problems. |
Lead (Pb) | Exhaust fumes from motor vehicles. | Contaminates soil and water, harms wildlife | Affects the nervous system, developmental issues. |
Greenhouse Effect: | Global Warming |
1. Earth has a special “blanket” of gases around it called the greenhouse effect. | Global warming means the Earth is getting warmer. |
2. This blanket keeps the planet warm by trapping some of the sun’s heat. | It’s happening because people are doing things that add too many greenhouse gases to the air. |
3. It’s like when you wear a cozy jacket in cold weather to stay warm. | These gases act like too many blankets and make our planet hotter. |
4. Greenhouse gases are like the threads in the blanket. They include carbon dioxide and methane. | As it gets hotter, ice at the North and South Poles melts and makes the sea rise. |
5. Without this blanket, Earth would be freezing, so the greenhouse effect is good, but too much of it can make our planet too warm. | This can cause problems like floods, big storms, and changes in weather, which is not good for plants, animals, and people. |