The scenario was posed that if there was a zombie outbreak: What would we do as scientists to get to the bottom of the mystery? Is it the air, water, or something in the soil that could be causing odd sightings. Beyond the theme of zombies lies connections of environmental issues that have real effects on people that makes it almost seem like a real apocalypse.
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Authors: S. North, A. Arpero, and T. Knighton
Mentor: Hua
Our Interest
Our Interest
We began this project by looking at the basics of soil, water, and air quality testing, such as understanding the chemistry behind how each works and EPA standards. We even got a visit from the Master Naturalists to help explain some concepts. From there, we decided which one of the three media we wanted to focus on. We chose to look into water quality after learning about microplastics in the ocean, especially when we found out they are most likely also in bottled water. We were intrigued to research and experiment in depth about the topic of microplastics because of how prominent the subject matter is in our society but how there does not seem to be a lot of awareness on this topic, at least among our peers.
When finding out that heat and sunlight causes plastics to break down, we wondered if leaving our bottles in cars or even sitting in the sun at the park could cause microplastics to leech into the water. When we were informed about this topic, we were immediately drawn to it and became curious to expand on the topic more. We took inspiration from the different brands of water bottles around the room. We wondered if certain brands contained more or less microplastics as they are sold at different prices, sometimes sold at prices only able to be afforded by some.
We outlined our project and conducted our own research to explore our hypotheses to learn more about the health effects of microplastics, who they impact, and find out the direct source of this issue. Research still points that some aspects of microplastics, such as certain health effects and how they can be detected, are still blurry among scientists.
National Geographic clip about microplastics.
The Importance
The Importance
We chose to focus on how sunlight can impact the water in a plastic water bottle, which is important because plastic is everywhere! We have already acknowledged the existence of microplastics in our oceans, and other bodies of water. It has become such a common habit to use bottled water that we don’t ever stop to realize if it can be harmful not only to us humans, but to all life on Earth. This is why we decided to experiment with how and what natural factors can impact the quality of bottled water.
We figured that it is important to expand our knowledge and awareness of sustainability concerning water and plastic.
Sustainability means that all of our natural resources that the Earth provides us with, are connected to humanity both geologically and economically.
The fact that this subject extends to so many interrelated concerns about our environment, quality of life, and economy emphasizes the importance of the need to spread this awareness. We conducted this experiment with the hope that this information and awareness will reach and impact society’s perception of sustainability and quality of water. Taking into consideration pricing of bottled water limits certain populations to bottled water that may have better or worse water quality, we thought it would be important to try and connect the dots.
The pH scale is a measures how acidic or basic a solution is.Credit: Science News for Students
*Spoiler alert* The fact that some of the bottle of water tested at or below 4.5 for their pH should be a major concern for a variety of reasons. Drinking low pH water over extensive periods of time can lead to a variety of health issues including vomiting, tooth corrosion, and lowered calcium retention. While drinking one bottle of low pH water will not seriously harm you, the effects still need to be taken into consideration and educated on. On the other hand, drinking alkaline water, water with a pH above 7, also has effects on your health including decreasing free calcium in your body, lowering your natural stomach acidity, and muscle twitching. In addition, many brands attempt to market themselves based on their pH like Fiji, and if you are paying extra for pH 7.7 water, you would hope the water was in fact at that pH. We found that Fiji was almost a half point lower than what was advertised which raises concern about the validity of their advertisements and branding.
Our Process and Procedures
Our Process and Procedures
From our research, we realized that experiments to test for microplastics are EXPENSIVE! Still set on learning more about microplastics, we tried to find workarounds to detect microplastics. Knowing sunlight can break down plastics, there were different chemical reactions we saw that could happen which creates new chemical products and can affect water quality. Some reactions we found are shown in the Figure 1 (Gewert, Plassmann, & Macleod, 2015).
Figure 1. These are some chemical reactions plastic can go through under sunlight.
Looking at the breakdown of new chemical products, we discussed how certain chemicals could affect water quality. According to Gewert et al., the, “Degradation of plastic polymers can lead to low molecular weight polymer fragments, like monomers and oligomers, and formation of new end groups, especially carboxylic acids.” Budgeting time, cost, and feasibility, we decided to explore pH in bottled water, analyzing if there were measurable changes in pH after leaving bottled water outside for 3 weeks. Although it is not an absolute indicator for microplastics, we wanted to see if pH would fluctuate as we exposed the bottles to sunlight and the elements as pH is an important test for water quality.
We refreshed our memory about pH! It is such an important indicator for water quality. Watch this video for more information on what it is.
Looking at the breakdown of new chemical products, we discussed how certain chemicals could affect water quality. According to Gewert et al., the, “Degradation of plastic polymers can lead to low molecular weight polymer fragments, like monomers and oligomers, and formation of new end groups, especially carboxylic acids.” With this logic, there may be changes to pH. Budgeting time, cost, and feasibility, we decided to explore pH in bottled water-and if there were measurable changes in pH after leaving bottled water outside for 3 weeks. Although it is not an absolute indicator for microplastics, we wanted to see if pH would fluctuate as we exposed the bottles to sunlight and the elements.
We tested five brands of bottled water including Dasani, Ozarka, Evian, Nestle, and Fiji for pH changes over the course of three weeks, totaling 15 bottles of water used for the experiment. Water bottles were left outside on the balcony of our school and had direct exposure to sunlight and weather conditions. pH measurements were taken on three separate occasions: For week 0 (no outdoor exposure), For week 1 (after 7 seven days of outdoor exposure), and For week 3 (after 21 days of outdoor exposure). Local weather data for the days we conducted the experiment (October 14-November 4) are in the Appendix of the blog.
Initially, we labelled each brand of bottle (week 0, week 1, and week 3), and we identified water brand, time, and temperature as our independent variables. Then, we proceeded to calibrate the pH meter using the powders and room temperature distilled water according to the manufacturer’s instructions. After calibrating the pH meters, we tested the pH for all the bottled water brands to collect a baseline pH for the week 0 bottles, and discovered Dasani and Ozarka had shockingly low pHs while Fiji was almost 0.5 below its advertised pH of 7.7.
To test the pH of water, we obtained three separate readings of the pH by placing the meter into the water until the reading stabilized. After taking all three readings, we averaged the three readings to find out what the pH was for each brand to represent the “week” reading after exposure or non-exposure. We repeated these steps for weeks one and three as well. We left the week one and week three bottles outside in direct sunlight until it was time to test them. Some possible discrepancies in our result may be due to cold weather and rain showers that happened during our experiment’s timeframe. We realize that this and other factors such as UV index, could also cause fluctuations in pH of the bottled water as many factors are included in the elements. This poses the opportunity to continue and refine the experiment more given more resources, time for experimentation and design for experiments.
pH recorded for each brand of bottled water over a 3 week period. The averages of temperatures for the week before measuring the week 1's pH was a high of 79.1° F and low of 51.2° F. The averages of the temperatures for the two week period before measuring week 3's pH was a high of 75.6° F and low of 48.2° F.
Our data
Our data
Fiji’s pH started at 7.15, increased to 7.27 when we measured during week 1, and decreased to 7.25 at the end of week 3. Evian’s pH was originally 7.06, and it increased to 7.17 during week 1. However, unlike the other brands, Evian’s pH continued to rise during week 3 to 7.40. Nestle’s pH started at 6.79, rose to 6.93 during week 1, and fell to 6.60 during week 3. Dasani’s pH was originally 4.61, and it rose to 5.40 during week 1 before decreasing to 5.35. Ozarka started at a pH of 4.52, and rose to 4.71 before falling to 4.61 at the conclusion of week 3.
From week 0 to week 1, the pH of all five water brands showed an increase with Dasani having the largest jump from 4.61 to 5.4, a 0.71 point increase; meanwhile, Evian had the lowest increase, only jumping from 7.06 to 7.17. With the exception of Evian, all of the other brands demonstrated a decrease in pH from week 1 to week 3 with Nestle having the largest dip from 6.93 to 6.6, below its original pH value from week 0.
What did we learn?
What did we learn?
We found a difference in the pH for most of the brands of water over time. Our initial idea was to find out how many microplastics are in bottled water and we learned about that through our experiment. When we measured pH in the bottled water, we found out some interesting results. Some of the brands had a pH lower than 7 which was concerning, Because it was lower than what the companies said they were. The result of which bottled water had the best water quality was ambiguous. The weather and too many other elements could affected the pH of the water and the amount of microplastics in the water. Exposure to the elements affected the pH levels, either increasing or decreasing it. We used this as a potential indicator to associate with microplastics. We conducted secondary research of experiments and chemical reactions that could create microplastics from plastic products. We learned that through our experiment everything is so interconnected. Looking at the problem with microplastics in water we discover that this issue is entangled with other factors such as people and profit. It is difficult to pinpoint the exact variables that may be causing environmental issues. We learned about how different environmental problems affect certain communities more. It is a challenge to try to fight this issue of microplastics in bottled water because there isn’t a direct source and we brings a discussion on which parties’ responsibility is it to handle this issue. There is so much more to learn.
Resources
Resources
Gewert, B., Plassmann, M. M., & Macleod, M. (2015). Pathways for degradation of plastic polymers floating in the marine environment. Environmental Science: Processes & Impacts, 17(9), 1513–1521. doi: 10.1039/c5em00207a
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