BACKGROUND INFORMATIONMankind has made enough plastic to cover the Earth entirely with synthetic polymers. Since the year 1950, worldwide production and consumption of plastics have proceeded to increase (Lytle, 2017). Two million tonnes of plastic was first mass manufactured in 1950, a report found that this figure has risen to 8.3 billion tonnes of plastic generated last year. An analysis published in an article ‘Worldwatch Institute, January 2015’, reveals that humans have yielded an estimate of 299 millions tonnes of plastic since 2013, realising a 4% increase over the year 2012, thus establishing an upward trend over past years (Gorumelon, 2015). To be able to cover Earth in plastic is alarming to scientists; for it proves that human activities are now having a harmful impact on our environment. Plastic is described as a lightweight, flexible, durable and relatively inexpensive material. Even though it may durable, plastic is a very slow substance to degrade. By examining the classification of plastics according to their degradability and chemical properties of plastics into degradable and non-degradable polymers. Normally Non-biodegradable plastics are synthetic plastics are composed of a small monomer that has a very high molecular weight. Whereas degradable plastics are composed of starch and have less molecular weight. In this experiment, a Low-Density Polyethylene (LDPE) plastic will be used. LDPE is a flexible, inexpensive and relatively durable. LDPE is widely used for manufacturing various containers, disposable water bottles, tubing and most common in the use of producing plastic bags (Raymond) (Fig 1). With the amount of plastic bags produced, it can lead to high amount of littering. Singapore uses 3 billion tonnes of Low-Density Polyethylene (Reyes, 2013). With that large of amount of plastic being produced, there is a high probability that some LDPE have been littered onto the environment. Thus leading to plastic degradation in the environment of Singapore. With Singapore being on the equator, the temperature of land can increase a plastic degrading process. The difference in temperatures in soil and sand can affect the area of degradation of LDPE, in two environments that are likely to be polluted with plastic bags, soil and sand. HYPOTHESISIn this investigation, I expect that plastics exposed to higher temperatures in both soil and sand have a larger circumference/ area of degradation. Due to LDPE having a thinner and lighter material and chemicals in them, higher temperatures are able to degrade them. Therefore plastic shopping bags would have a bigger area/ circumference of degradation when being exposed to a greater temperature within two different areas of land, soil and sand, thus a decrease in its service life resulting in a degradation of plastic in both areas. This leads me to my research question.RESEARCH QUESTIONWhat is the effect of different temperatures on plastic degradation in soil and sand?PRIMARY RESEARCHVARIABLESExperimental VariableNamed VariableUnitsEquipment for measurements/ controlIndependent VariableTemperature of Soil and Sand °C(Degree celsius)Incubator: The incubator maintains optimal temperature- low to highDependent VariableDegradation of Low-Densitypolyethylene materials Area of degradation (centimeter)Calculating each degraded area through Microsoft Excel, the average number of degradation seen on Plastic. Controlled VariablesHow WhySoil and SandDuration in the IncubatorLow-Density Polyethylene BeakerCollected at Pasir Ris Park in SingaporeOver a period of weekUsing the same three materials, a Fair Price shopping bag, candy wrappers and plastic bottles. Enough soil and sand to degrade the plasticUsing the same located area of extracting soil and sand is due to the difference in ph levels in both areas. Thus causing an influence on the degradation A weeks time period is in the middle of the degradation process These materials are all composed of LDPE. If Composed by a different type of plastic, can affect my results.A beaker will be a container to observe the degradation. MATERIALSFair- Price Shopping bag x 1Plastic bottles x 2Candy wrapper x 650 ml Beaker x 18Soil x 500 gSand x 500 gIncubator x 3Refrigerator x 1Spoon x 2Thongs x 1Scissor x 1Cling wrap x 1Camera x 1Marker x 1METHODIn this experiment, I choose to explore with different types of Low- Density Polyethylene (refer to Figure 1 above). I have chosen to experiment with a shopping bag, candy wrappers and plastic bottles. As these are daily and most common materials that are littered. Firstly acquire all materials, in order to conduct the experiment. Prepare 18 beakers and the chosen LDPE objects. Each object has to be cut down into a diameter of 5cm. This is so that the plastic is able to fit into the beaker (But do not place it into the beaker just yet). Cut shopping bag to 5cm and prepare 6 cut-outs. Cut plastic bottles to 5cm and prepare 6 cut-outs. Cut candy wrapper to 5cm and prepare 6 cut-outs. Secondly, using a spoon place the soil into 9 of the beakers to reach a max height of 20 ml, then place each cut out into the 9 soil filled beakers. Later adding more soil on top of the plastic to reach the 50 ml mark. Then with a marker write down the different temperature on the side of the beakers 27°C, 35°C and 53°C. Using the Spoon, place the Sand into the beaker to reach a max height of 20 ml, then place the polyethene plastic into the beaker, later adding more sand on top of the plastic to reach the 50 ml mark.Lastly, once all beakers are filled with Low- Density Polyethene plastic, soil and sand to the mark of 50ml. Place all 18 beakers into their respective incubators with the temperature of 35°C, 53°C and 27°C in the refrigerator. this is done, as this investigation is finding the different temperature of soil and sand that affect the degradation of Shopping bags, Candy wrappers and Disposable water bottles. Finally, this experiment is held through a period of seven days and record results. SAFETY/ ETHICAL CONSIDERATIONIn this investigation it is important to be ethically considerate when placing the beakers into the incubator, do not drop the beakers into the incubator. This will damage the incubator and beakers. Leftover soil and sand can be recycled or can be placed back into the respective environments at Pasir Ris Park. There is no safety issue with this experiment.RESULTS TABLESTable 1 and 2 will depict the diameter of degradation of each Low-Density Polyethene material, fair Price supermarket shopping bag, Candy wrapper and plastic bottles. Each type of LDPE was placed into different temperature of soil and sand calculated at Singapore’s Pasir Ris Park. Table 1: Diameter of Degradation of three LDPE materials, in three different temperature of soil. Table 2: Diameter of Degradation of three LDPE materials, in three different temperature of sandThe tables below is a summarised table of the total degradation and standard deviation of each material in the different temperatures of both environments. Table 1: Total degradation and Standard Deviation of LDPE Materials in SoilTable 2: Total degradation and Standard Deviation of LDPE Materials in SandQUALITATIVE DATARecording the data shown in the tables above, my observations area that there is definitely more active degradation shown in the second table than the in Table 1. Another observation is that the higher the temperature the wider the area/diameter of degradation in these LDPE materials. It is evident that the first material to degrade are shopping bags. (this will be explained further in the analysis). These images were taken during the investigation.GRAPHSGraph 1: Diameter of Low Density Polyethene Degradation with Three Different Temperatures of soil found at Pasir Ris Park. Graph 2: Diameter of Low Density Polyethene Degradation with Three Different Temperatures of sand found at Pasir Ris Park coastal shores.ANALYSIS/ CONCLUSIONGraph 1 and 2, both may look similar at first, but with a close examination there is a trend and or relationship can be seen. The higher the temperature held within the land, the wider the diameter of degradation. As can be seen in both graphs the purple coloured bar indicating the temperature of 53oC, are either well above the 2 cm mark an is the highest bar compared to the other temperatures. Analysing the graphs even furthur, it is evident that there is a +/- 0.1 cm increase in the total standard deviation of LDPE encased within the sand, than within the soil. It may be due to the level of salinity in the sand, causing Low-Density Polyethylene to degrade faster than those stationed with soil. From the data and results we can conclude that the hypothesis was supported, as expected that LDPE plastics exposed to higher temperatures in both soil and sand have a larger diameter of degradation. Due to LDPE having a thinner and lighter material and chemicals in them, higher temperatures are able to degrade them. Therefore plastic shopping bags would have a larger area of degradation when being exposed to a greater temperature. Although the fluctuation of data shows that other uncontrolled factors may have had an effect on the degradation of polyethylene plastic. Examining the data more closely, we can see how the diameter of LDPE plastic bottles have decreased in degradation, even if placed in a hotter temperature within the sand, where there is likely a faster degradation rate. Even though this data was surprising that sand has a strange effect on the degrading process, the abundance of more polyethylene plastic being degraded at a higher temperature proves my hypothesis is valid.