Implications of Air Pollution
Air pollution is one of the world’s biggest problem as it can have adverse effects on human health and the environment. Some examples of air pollutants(which are also present in haze) are given below:
Carbon monoxide (CO), sulfur dioxide (SO2), Sulfur Trioxide (SO3), Nitrogen oxide (NOx) and Ozone (O3).
Health effects:
Carbon monoxide (CO):
Formed when hydrocarbon fuels are burned in a place with not enough oxygen to produce Carbon Dioxide. CO is colourless, odourless and tasteless. In high concentration, it can cause CO poisoning, giving symptoms such as headache, vomiting, nausea, etc. This is due to its ability in displacing oxygen in our blood as it binds to haemoglobin 250 times better than oxygen to form carboxyhemoglobin, resulting in the decrease of oxygen supply to our body. A 50% of carboxyhemoglobin can cause coma, seizure and even death.[1]
sulfur dioxide (SO2):
Usually produced from the burning of fossil fuel e.g. Coal. It is a pungent toxic irritant and can cause temporary breathing difficulties when high concentration of SO2 is inhaled. [2]
Nitrogen oxide (NOx) and ozone (O3):
NOx such as Nitrogen monoxide (NO) and Nitrogen Dioxide (NO2) are produced at high temperature in the presence of O2 and N2. When NO (very toxic) is formed, it will quickly oxidize in air to form NO2. NO2 is a pungent irritant that can affect skin and cause burns. High concentration of gaseous NO2 have the ability to diffuse and dissolve in our lungs, causing some chemical reaction to occur which produces products that are reactive that can cause inflammation, reduced immune response and affect the heart.[3]
When NO2 is exposed to sunlight, it undergoes reaction to give NO and O atom. The O atom will then react with an oxygen molecule giving rise to ozone (O3) a secondary pollutant in our troposphere. O3 has a acrid smell and is capable of destroying living tissues. It can affect respiratory tissue causing chest pain, coughing, sneezing and pulmonary congestion.
Environmental effects:
Some of these air pollutants such as nitrogen oxides and sulfur oxides can combine with water droplets during rain which result in acidic rain. Acidic rain can cause damage to animals, crops and infrastuctures.
NO2 reacts with OH to form nitric acid which contributes to acid rain.
SO2 reacts with O2 to form Sulfur trioxide (SO3). SO3 can react with water to form sulfuric acid which can also contribute to acidic rain.
Acidic rain can cause the drop in pH of lakes and streams. The United States Environmental Protection Agency’s (EPA) website states: “Of the lakes and streams surveyed, acid rain caused acidity in 75% of the acidic lakes and about 50% of the acidic streams”. At pH lower than 5, most fish eggs will not hatch and lower pHs can kill adult fish, insects and birds in the ecosystem are also affected. [4]
Forests are also damaged as acid rain reduces the amount of nutrients in soil and releases aluminium making it difficult for trees to take up water. Leaves are also damaged by acid.
Solutions to for air pollution:
Since most of these pollutants are anthropogenic emission, there are things that we can do to reduce it:
- Use public transport
- Conserve energy e.g. switching off lights when not in use
- Using clean energy e.g solar, wind, etc.
- Using energy efficient devices
By doing these, we can reduce the amount of eletrcity generated and reduce the amount of coal being burned leading to a drop in amount of air pollutants like NO2 and SO2 being produced. [5]
Implication References:
[1] https://en.wikipedia.org/wiki/Carbon_monoxide
[2] https://en.wikipedia.org/wiki/Sulfur_dioxide
[3] https://en.wikipedia.org/wiki/Nitrogen_dioxide#Toxicity
[4] https://en.wikipedia.org/wiki/Acid_rain
[5] http://www.conserve-energy-future.com/current-environmental-issues.php