Background understanding of the environment

Air Pollution is the contamination of the atmosphere due to the introduction of chemicals, particulate matter or biological materials into the environment. The release of these toxic substances will cause harm to the environment or health problems to humans. Air pollution is responsible for significant annual losses of food and fiber crops, ornamental plants and trees. Other living organisms will also be affected by air pollution. Smoke is a type of air pollutant and can lower the quality of the air we breathe.

What is smoke?

“Smoke is a complex mixture of different gases and particles. Burning wood, fuel, plastics, and other synthetic materials produce smoke with a variety of chemicals. Regardless of what specific chemicals make up the smoke, it can cause health effects.”

Smoke emissions will cause relatively negative severe health problems on humans when they inhale the smoky air in the surroundings. These health problems include cough, shortness of breath, hoarseness, headache, and acute mental status changes. The emission of smoke will also cause negative effects on the local environmental parameters. For example smoke produced is absorbed by plants because it lingers in the air. The symptoms of air pollution damage to plants include: “ (1) collapse of leaf tissue with the development of necrotic patterns, (2) yellowing or other color changes, and (3) alterations in growth or premature loss of foliage.”

In Singapore, the sources of air pollution include “stationary sources such as power stations, oil refineries and industries; mobile sources such as motor vehicles; and others such as open burning of waste materials and transboundary air pollution”. These sources produces smoke to the environment. Singapore through decades of planning and cultivation, has earned the name of a Garden City. Singapore is a lush green city that is nestled in an environment of trees, flowers and parks. If smoke produced from the sources stated above not only affect humans but the plants as well, there will be a reduction in the growth of plants. Hence, this is the cause of our research on how the amount of smoke the plants are exposed to can affect their growth.

Another reason why we became interested in this experiment was because one of our group members grew placed her pots of plants on her balcony which was very near to the roadside. She never did expect that her plants would actually suffer from the effects of air pollution (smoke produced by vehicles travelling on the road). In general, there were colour changes and stunted growth in her plants. Hence, we decided to come up with this experiment to measure how the amount of smoke exposed to the plants will affect the plants. It is hoped that through the experiment, a better understanding of how the plants are affected by the amount of smoke it is exposed to will be gained.

Vehicle producing smoke

The 4 pots of plants being used in the experiment

Research Question

What is the relationship between the amount of smoke given out by the burning of papers each plant was exposed to and the number of leaves that will change in colour for each plant?

Materials

1) Four similar small-sized pots of the same species of plant

 ·         Volume of one pot: 300cm³

 ·         Height of one pot: 12cm

Pot A

Pot B

Pot C

Pot D



2) 25ml of tap water given to each pot per day (Total volume of tap water given to plants per day: 100ml for four pots)

 
3) One container filled with 25ml of water to water each pot of plant

4) One transparent tank with no holes (volume of tank: 20cmx13cmx13cm = 3380cm³) to cover each pot of plant when the plant is exposed to smoke

5) One lighted 7-cm wax candle needed per day to burn the papers

6) One small dish (to place the burning paper)

7) Six pieces of rough paper per day (Total number of paper used for experiment: forty-two of paper)

8) 800cm³ of soil (200cm³ of soil per pot of plant)

Procedure

Step 1:  Place four pots of plants (Pot A, Pot B, Pot C and Pot D) alongside each other outdoors (balcony) to ensure that they will receive the same amount of sunlight. Each pot will be placed 20cm away from each other.

Description of the location/ environment: The balcony where the 4 pots of plants are placed is an open area (no form of shelter) which allows sunlight to easily reach the plants. It is also a windy area as gentle breezes occasionally passes through the balcony.

Step 2:  Fill a container with 25ml of tap water to water the plants. Each pot of plant will be watered with 25ml of tap water every day (7 days).

Step 3: Three  pots of plants, (Pot B, C and D)  will be exposed to smoke produced by the burning of 1, 2, and 3 pieces of rough paper respectively while the plant in Pot A will act as a control. Plant in Pot A which is the control will not be exposed to any smoke produced by the burning of rough paper. Every piece of rough paper is torn into small pieces and placed in a small dish. A 7cm lighted candle will then be used to light up the small pieces of rough paper(s) which will be placed on the small dish. In order to create a smoky environment for plants in Pot B, C and D, the burning paper will be positioned next to each of the three pots of plants. During this process, a transparent tank (with no holes) will be used to cover up each pot of plant. The three pots will be exposed to smoke produced by the burning paper for 5 minutes per day. After 5 minutes, the burning paper will be extinguished and removed. The tank will then be removed from the pot of plant.

The variables of our experiment are as follows:

·         Independent Variable : Amount of smoke produced by the burning paper exposed to each pot of plant (Pot B, C and D. Plant in Pot A used as a control)

·         Dependent Variable   : The number of leaves for each pot of plant that will change in colour due to the amount of smoke that it was exposed to

·         Control Variable        :  (1) Type of plant used

                                            (2) Type of soil used

                                            (3) Amount of soil given to each pot of plant

                                            (4) Size and shape of pots and plants

                                            (5) The number of leaves for each pot of plants

                                            (6) Amount of tap water given to each pot of plant

                                (7) Environmental conditions (Eg amount of sunlight each pot of plant received)

Step 4: Repeat Step 3 for 1 week (7 days) concurrently with Step 2.

Step 5: Results of the number of green and brown leaves of the four pot of plants (Pot A, Pot B, Pot C and Pot D) will be recorded every day on an observation table to see how the amount of smoke each pot of plant was exposed to affected the number of leaves that changed in colour. The data collection process will be done at the balcony where the 4 pots of plants are placed. The counting of the number of leaves that changed in colour and the number of green leaves left per pot of plant will be done manually. The experiment and the data collection process will be done every night. The recoding process of each pot of plant (Pot B, C and D) being exposed to smoke will be done every 2 days. Hence there will be a total of 3 recording process for each pot of plant. The recording process will be done on (Day 1, 3 and 5).

Data Presentation and Analysis

Record of Data

Day	Pot A		Pot B		Pot C		Pot D
1	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0
2	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 22	Number of Leaves that changed in colour: 1 (Tips of 1 leaf turn a light brown)	Number of Green Leaves: 21	Number of Leaves that changed in colour: 2 (Tips of 1 leaf turn a light brown. The edges of the other leaf turned brown)
3	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 22	Number of Leaves that changed in colour: 1 (Tips of 1 leaf turn a light brown)	Number of Green Leaves: 20	Number of Leaves that changed in colour:  3 (Tips of  2 leaves turn a light brown and the edges of the other leaf turned brown)	Number of Green Leaves: 18	Number of Leaves that changed in colour: 5 (Tips of  2 leaves turn a light brown,  the edges 2 other leaf turned brown and half of the last leaf turned brown in colour and starts to curl up
4	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 21	Number of Leaves that changed in colour: 2 (Tips of 1 leaf turn a light brown while the edges of the other leaf turned brown)	Number of Green Leaves: 18	Number of Leaves that changed in colour: 5 (Tips of  2 leaves turn a light brown, the edges of  2 other leaves turned brown and the last leaf turned 1/3 brown and the edges starts to curl  up)	Number of Green Leaves: 15	Number of Leaves that changed in colour: 8 (Tips of  3 leaves turn a light brown,  the edges  of 3 other leaf turned brown, 1 leaf turned 1/4  brown and the majority of the  last leaf turned brown  (only the ends of the leaf were not brown) in colour and the edges curled up
5	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 19	Number of Leaves that changed in colour: 4 (Tips of 2 leaf turned a light brown, edges of the 2 other leaf turned brown)	Number of Green Leaves: 17	Number of Leaves that changed in colour: 6 (Tips of 1 leaf turn a light brown, the edges of  3 other leaves turned brown, 2 of the leaves start turning 1/4 brown and and the last leaf turned mostly brown and the edges curled up)	Number of Green Leaves: 13	Number of Leaves that changed in colour: 10 (Tips of  3 leaves turned a light brown,  the edges  of 4 other leaf turned brown,  2  leaves turned 1/3  brown and starts to curl up and the entire last leaf turned brown  in colour and the edges curled up
6	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 17	Number of Leaves that changed in colour: 6 (Tips of 2 leaf turned a light brown, edges of the 2 other leaves turned brown and 2 other leaves turned about 1/4 brown and the  edges start curling up	Number of Green Leaves: 16	Number of Leaves that changed in colour: 7 (Tips of  1 leaves turned a light brown, the edges of  2 other leaves turned brown, 3 leaves are about 1/2  brown and and the last 1 leaf turned mostly brown and the edges curled up)	Number of Green Leaves: 11	Number of Leaves that changed in colour: 12 (Tips of  1 leaves turned a light brown,  the edges  of 1 other leaf turned brown,  3 leaves turned 1/4  brown, 3 leaves turned 1/3 brown  and starts to curl up and the entire last 4 leaves turned brown  in colour and the edges curled up
7	Number of Green Leaves: 23	Number of Leaves that changed in colour: 0	Number of Green Leaves: 15	Number of Leaves that changed in colour: 8 (Tips of 3 leaf turned a light brown, edges of the 2 other leaves turned brown , 1 leaf turned about ¼ brown and 2 other leaves turned about 1/2  brown and the  edges curled up	Number of Green Leaves: 13	Number of Leaves that changed in colour: 10 (Tips of  3 leaves turned a light brown, the edges of  3 other leaves turned brown, 2 leaves are about 1/2  brown and 2 of the leaves turned mostly brown and the edges curled up)	Number of Green Leaves: 10	Number of Leaves that changed in colour: 13 (Tips of  2  leaves turned a light brown,  the edges  of  3 other leaf turned brown, 3 leaves turned 2/3 brown  and starts to curl up and the entire last 5 leaves turned brown  in colour and the edges curled up

Analysis of Data

From the table, we can see that Pot A has the most number of green leaves left, Pot B has the second most number of green leaves left, Pot C has the second least number of green leaves left, and Pot D has the least number of green leaves left. Thus we can see that the more the amount of smoke a plant is exposed to, the more the number of leaves turned brown and therefore, it can be concluded that smoke causes leaves to be subjected to colour change.

Discussion

This experiment has shown that smoke causes a colour change in leaves of plants. As the leaves start turning brown, it shows that the plant is dying. The smoke produced by the burning of paper may not have the same effect on plants as the smoke produced by other sources of pollution, thus the results may not be accurate for plants growing in different areas. The outcome of the experiment which was that the green leaves turned brown might have been due to the age of the plant as we could not determine the age of the plant we bought.

 From this experiment, we can see that air pollution has negative effects on the environment as it harms the plants which help to control the balance between carbon dioxide and oxygen in the environment which will then in turn affect the food web.

To better our experiment, we can increase the number of plants exposed to the smoke to ensure better accuracy. This experiment can also be carried out on different species of plants to determine whether smoke will affect other species of plants.

From our experiment, we can see that air pollution is a serious and ongoing problem and we should do our best to lessen the release of smoke into the environment. We can change our habits to help our environment, for example, taking the bus instead of car to school or work.

Personal Reflections (by Guo Lilian)

This SIA has been challenging and each of us had to sacrifice a fair amount of time and money to buy the materials needed. However, I am glad that I had a chance to learn something new, and at the same time, I managed to bond with my group mates. I had to learn how to manage my time as well, due to the many other assignments that were due.

Done by: Guo Lilian (12) Class: 201

Personal Reflections (by Olivia Ng)

I feel that doing this Science project was a wonderful experience for me. I learnt and gained a lot of things through this project. I learnt how smoke affected the plants but my biggest takeaway from this project was learning the power of teamwork. Teamwork allowed my groupmates and I to work towards a common goal and finished this Science project together. For me, this journey was definitely not a smooth one. My groupmates and I faced challenges and obstacles along the way. Our biggest obstacle occured at the start of our experiment. When we first we tried lighting up round candles to create smoke, we realised that the smoke produced was very little and the little amount of smoke was not going to affect the plants alot.  We bought many different candles to try out but we still failed to find something that produed a lot of smoke. Finally, after much discussion and  research, my groupmates and I found out that burning paper could create the amount of smoke we desired. I was really glad that my groupmates and I did not give up when we first failed in finding a source that produced alot of smoke but insead we perservered to the end and managed to overcome our obstacles. I would like to thank my groupmates for everything that they have done and also I would like to thank the school for giving me this chance to work on the project.

Done by: Olivia Ng Wei Jin (21) Class: 201

Personal Reflections (by Rachel Chua)

         Through this project, I learnt about how pollution affects the environment and thus I have decided to change my habits to help the environment. For example, instead of usually taking a bus even though it was quite a short distance, I would now walk there. I have also learnt about teamwork as my group cooperated and thus we managed to finish our work quickly. I enjoyed this project and I hope to able to do more projects of this type in the future.

       

Done by: Rachel Chua Jia Ying (23) Class: 201