Effect+of+pollutants+on+plant+growth

Title: The Effect of Pollutants on Plant Growth Based on How Natural it is

Abstract: If we give germinated radish seeds different pollutants, then they will have lower growth rates based on how unnatural the pollutant is. We tested this hypothesis for ten days using 9 plants in pots. After ten days the plants that grew the least averagely are as follow: ibuprofen 5%, Gasoline 1%, ibuprofen 50%, Gasoline 5%, control 1, motor oil 1%, motor oil 5%, control 2. This follows the hypothesis as the least natural caused the least growth.

Purpose: We have chosen to test the effects of pollutants on plant growth according to how natural the pollutant is, because this is a fairly controversial issue. Recent studies have been done that suggest fake sugars, such as those that are put in diet drinks, are in fact bad for you and are believed to be able to cause cancer and/or diabetes. Also this lab could be a model for what we really need to worry about, in relevance to what we use for everyday life, and pollute into our ecosystems. Another reason we chose to do this lab is because it seemed like an interesting topic and a fun one to do an experiment on. Pollution plays a big part in society today, and any small school child could tell you that. The effects of pollution play a part in the growth and development of humans, animals, and yes, plants. “key sources that we tap for drinking water are being overdrawn or tainted with pollution.”(Water 2012) Water from rain, storm drains, and ditches flows directly to streams and bays with little or no treatment.” (Water 2012) This means it is easy to give water polluted with gas and motor oil to plants along the stream and if water is drawn from streams it can be given to polluted plants. Another item in the water which could affect plants are pharmaceuticals. “Further determinations found the influence of sewage treatment plants to be significant sources for the entry of pharmaceutical residuals to rivers, streams and surface waters.(Investigation 2012) This means that sewer treatment plants are not capable of pulling drugs like ibuprofen out of the water and are instead being put back into streams, the environment, and even drinking water. What we plan to do, to test this is germinate radish seeds to the same growth and then give them amounts of water diluted with oil, gasoline, and ibuprofen each. We chose radishes for 3 reasons. They (radishes) are easy to grow, and one of the fastest to harvest of all vegetables (Grow 2013). ...radishes are hearty plants....(Growing 2013). ..don’t require much care or nutrients.... (Growing 2013). Next we must observe how natural each pollutant is. Ibuprofen is the least natural, as it must be manufactured in a lab, or synthesized. Gasoline is the next least natural pollutant, as “It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. ” (Gasoline 2013) This means gasoline is still natural, but has some chemicals added to it. Next is motor oil. Motor oil is derived from crude oil and has synthesized chemicals in it also, but is less volatile, and more stable. Next is our most natural “pollutant”. That pollutant is water, our most sacred natural resource besides oxygen. All of these will be diluted in tap water, and given to the radishes. After 10 days of polluting, we will stop and tally up the growth and see if each pollutant causes the growth dwindling results that were expected. Based on this we can make the thesis that if we give germinated radish seeds different pollutants, they will have lower growth rates based on how unnatural the pollutant is.

Hypothesis: If we give germinated radish seeds different pollutants, then they will have lower growth rates based on how unnatural the pollutant is.

Materials: 90 Germinated radish seeds 9 cups Soil Sunlight Motor oil Liquid Ibuprofen 9 Plant pots 1 Dropper Tap water 1 Graduated cylinder 1 Plant Tray 3 Glass containers 1 plastic Tupperware 1 small scrub brush 1 ruler 1 bottle of dish soap

Procedure: First we will put equal amounts of soil in labeled plant pots. We will then plant 10 radish seeds about 1 centimeter into the soil. Next we will give them 10 milliliters of undiluted tap water for 3 days, until they are properly germinated. After they have reached an appropriate height, we will start giving the plants their appropriate pollutants. We will make a dilution of 9.9: .1 ml for the %1 dilutions of gasoline and motor oil. For the %5 dilutions we will mix 9.5: .5 ml of liquid ibuprofen, motor oil, and gasoline. For the 50% dilution of 100 mg of liquid ibuprofen, we will dilute a 5:5 ml dilution. To do this we will pour the dilutions in a graduated cylinder, shake, and pour the dilution onto the plants. We will then put them under UV lights or sunlight for about 8 hours per day. As they grow, we will measure their heights with a ruler and record it on a spreadsheet. After 10 days of recording heights, we will take the average growth and analyze it.

Data: Data table
Data graph

Analysis: As you can see in my graph, the results are conclusive. The pollutant which caused the plant to grow the least was the 10 mg of ibuprofen, or a 5% dilution. The fact that ibuprofen was the most inhibiting was not surprising, but the fact the smaller dilution caused the most lack of growth was surprising. However this is easily explainable. The high dilution percentages for gasoline and ibuprofen killed their plant very quickly, and basically preserved it in its pre pollutant state. Through their quick death they were still able to elongate somewhat, either do to small growth from the water, or just flooding of shriveled cells that then swelled. But the smaller dilutions slowly killed their plant, keeping it alive to stop it from growing and kill sections of it slowly, opposed to the high concentrations that killed it right away without picking away at it. Gasoline 5% came in a close second, only growing an average of .06 inches more than the ibuprofen. The fact that gasoline grew more was not surprising, as it is more natural. But the smaller dilution growing less is surprising, but most likely happened for the same reason as the ibuprofen 5%. Next was ibuprofen 100 mg or 50%. This result was not surprising as this plant was getting about half the water as others, and twice the synthesized chemical. This plant was shriveled and dying on the second day of testing, and slowly broke apart over the next 8 days. Next was gasoline %5, which had a growth rate only about .4 inches less than one of the controls. This plant died very quickly, though not as quickly as the ibuprofen dilutions. It still grew some amounts though as it had more time to do so. It only died within around 3 or 4 days of the start of the experiment. After those days, it sat relatively still, not growing or shrinking much. Next came the control 1 plant, which grew more than ibuprofen and gasoline, but less than the motor oil. This result is a bit of an outlier. This control had a few plants that grew later than the other plants in the pot. These plants were below 1.5 inches and caused the average to go down significantly. Next came the motor oil 1%. This result was also surprising, as it grew less than its 5% counterpart. This could possibly be because motor oil has chemicals that cause plant growth to increase, causing the plant getting more of these chemicals to grow more. Next came the motor oil 5% plant, which grew .26 inches more than its 1% counterpart. This could be because of beneficial chemical this plant got more of than the 1% plant. The plant that grew the most averagely was the control 2 plant. This is most likely because water is good for plants and plants need water to grow.

Conclusion: If we give germinated radish seeds different pollutants, then they will have lower growth rates based on how unnatural the pollutant is. After ten days of testing I can confirm this hypothesis to be true. I say this because the least natural substance grew the least averagely and each pollutant grew more according to how natural it was.

Limitations: One error that was encountered while performing this experiment, was the inconsistency of the heights of the germinated radish seeds at the start of the experiment. Because of this there were outliers which affected the average growth of each. To solve this pregerminated plants could be bought, that are already at the same height. Another problem encountered was the inconsistency of measurement. Using a ruler was difficult to fit in the small pots and could be hard to match up accurately with the ruler measurements. This could be fixed by buying a skinny and more compact ruler that is more maneuverable. Another problem encountered was the lack of a UV light to ensure consistent light on the plants. Instead I had to use sunlight. To fix this, a UV light could be bought and placed over the plant tray. My new hypothesis is that if radishes are given pollutants, then the plants getting the least natural and the smallest amount of pollutants will grow the least

Work Cited: "The Effects of Pollutants on Plant Structure." Small Business. N.p., n.d. Web. 14 Dec. 2012. "Google." Google. N.p., n.d. Web. 14 Dec. 2012.

"Growing Radishes (Raphanus Sativus)." Growing Radishes, from Seed to Harvest. N.p., n.d. Web. 16 Jan. 2013

"How to Grow Radishes, Growing Radish Seeds." How to Grow Radishes, Growing Radish Seeds. N.p., n.d. Web. 16 Jan. 2013

"Pollution Effects On Humans, Animals, Plants and The Environment." Pollution Effects â¢ Environmental Pollution. N.p., n.d. Web. 14 Dec. 2012. "Water." Pollution Facts, Effects of Pollution, Clean Act. N.p., n.d. Web. 29 Nov. 2012. . "Water Pollution Facts." Water Pollution Facts. N.p., n.d. Web. 27 Nov. 2012. <http://www.cityofbremerton.com/content/sw_waterpollutionfacts.html "Ibuprofen." //Wikipedia//. Wikimedia Foundation, 25 Mar. 2013. Web. 24 Mar. 2013. "Gasoline." //Wikipedia//. Wikimedia Foundation, 24 Mar. 2013. Web. 24 Mar. 2013. "Motor Oil." //Wikipedia//. Wikimedia Foundation, 20 Mar. 2013. Web. 24 Mar. 2013.