If snow samples are collected from roadside, sidewalk, field, and backyard locations, then the roadside snow will have the highest level of contaminants due to vehicle traffic and human activity. Sidewalk snow is expected to have moderate contamination due to foot traffic and road salt, while field snow is expected to have lower contamination. The reference sample I will use is my backyard snow which is expected to be the least contaminated because it is farther from roads and frequent human activity.

In my research I found that snow can become contaminated by its surroundings because it can trap particles from the air as it falls and while it remains on the ground. These particles can include dust, pollutants, and debris of various sizes.Areas near roads are more likely to have contaminated snow due to vehicle traffic, which releases pollutants and causes debris to be disturbed. Road salt can also contribute to contamination near roads and sidewalks. In contrast, snow that falls in areas with less human activity, such as open fields, is generally expected to contain fewer contaminants. I also surveyed my classmates on whether or not they ate snow. In my survey I found that 13 people in my class eats snow still. Over 50 percent ( 24 people) of my classmates once ate snow, and in total, only 11 percent ( 5 people ) never ate snow before.

Manipulated variable: Where I take the snow from, and when I take the snow. Controlled variables: What I am collecting ( snow ). How much snow I am collecting. Responding variable: How dirty the snow is

I took samples from three spots around a field, three spots along the grassy side of a sidewalk, and three spots along the side of a road, and one spot from my backyard as a reference sample. I placed the samples into separate plastic bags and allowed them to melt. Once melted, I poured the samples through coffee filters. Next, I dipped pH strips into the liquids to check their acidity. Finally, I photographed the filtered water to compare turbidity. This procedure was repeated three times: once using undisturbed snow, once after snow had been stepped on, and once after additional foot traffic.

Across all three trials, the road snow always ended up being the dirtiest after filtering. In the first trial, when the snow was almost untouched, the field snow and the snow from the grassy side of the sidewalk looked very similar after filtering and had about the same amount of debris. The backyard snow surprised me a bit because it had slightly more dust and debris than both the field and sidewalk snow. All of the samples in this trial showed a pH of around 6, and once filtered, all of the water looked clear.

In the second trial, after the snow had been sitting for a few days, everything was noticeably dirtier. The field snow had more debris than before, but its pH stayed around 6. The sidewalk snow was much dirtier than in the first trial and had more debris than the field snow. The road snow was, once again, the dirtiest. Even though there was more debris overall, the filtered water samples were still mostly clear, and the pH stayed the same.

By the third trial, after waiting a few more days, all of the snow samples were very dirty. The field snow was dirtier than in the earlier trials but was still the cleanest compared to the sidewalk and road snow. The sidewalk snow had even more debris, and the road snow had the most by far. This time, the pH of all the samples increased slightly to about 7. After filtering, the water was no longer clear and appeared slightly murky.

Most of my observations matched my hypothesis. Overall, the field snow was usually the cleanest. This makes sense because it was farther away from roads, cars, and people, so it had fewer chances to collect debris. Since there was no road salt and very little foot traffic, the field snow stayed cleaner than the other locations.

The sidewalk snow was dirtier than the field snow but not as dirty as the road snow. This was expected because sidewalk snow is exposed to people walking on it and to nearby road salt. Even though it was not directly on the road, it still collected debris over time.

The road snow was the dirtiest in every trial. This makes sense because it is exposed to cars, road salt, and pollutants. All of these things likely caused the road snow to collect more debris than the other snow samples.

One result that surprised me was that the backyard snow was sometimes dirtier than the field snow. This may have happened because the snow was collected under a tree, where small pieces of debris could fall into it. Wind could have also blown dust or dirt into the backyard snow.

The pH values did not change very much between samples. At first it was about 6 then it increased to about 7. The increase maybe because of melting, or other substances mixing in to the snow as it aged. The little variation in pH values maybe because all the snow started as the same water in the atmosphere and already had a similar acidity when it fell. Also, most of the debris collected did not affect pH, and the pH strips only show larger changes, so small differences may not have been detected.

The purpose of this experiment was to compare how contaminated snow is in different locations, including the roadside, sidewalk, field, and backyard. The results partially supported my hypothesis. The roadside snow had the most contaminants in every trial, and the sidewalk snow had a moderate amount. The field snow usually had the least contamination and was the cleanest. In general, snow that had been on the ground longer tended to be dirtier.

The backyard snow was not always the cleanest, since it sometimes had more debris than the field snow. This suggests that things like nearby trees and wind may have affected the snow. The pH values stayed pretty similar for all samples and only changed slightly, from about 6 to 7.

I could have improved this experiment by collecting more samples from each location or by using better tools to measure contamination and pH. I could have done extra tests, like checking conductivity to see how salty the snow was or using a microscope to look at debris, to give more detailed results.

WHY THIS MATTERS:

- In my experiment\, the coffee filter is my "artificial lung." It shows what is trapped in the environment.But\, in your actual lungs: Your nose and throat have tiny hairs (cilia) and mucus that act exactly like that coffee filter. They try to catch the grit so it doesn't reach your lungs. That meant that up in our nostrils\, we accumulate all this grit and we don't even catch everything. So\, that meant we are breathing in part of whatever the snow decides to capture ( Car fumes\, etc) for whatever reason. HAZARDOUS!

-Lots of kids take snow as a free, refreshing snack from god. However, snow can be misleading, as shown in my experiment, making snow consumption a health warning.

Debris could have been spread through the wind, meaning my results could have been messed up and the snow could have been much cleaner. My acidity measurements were also likely messed up since I was using pH strips and pH strips aren't the most accurate. They detect the major idea, meaning 6 might've been 6.3 and 7 might've been 6.8. I could have improved it by using a pH meter instead of a pH strip.

Snow Pollution LINK: https://www.cityofflint.com/wp-content/uploads/2024/12/Snow-Pollution.pdf

National snow and ice da LINK:

https://nsidc.org/learn/parts-cryosphere/snow/quick-facts-about-snow#:~:text=The%20fresher%20the%20snow%2C%20the,pollutants%20into%20its%20intricate%20latticework

McGill University LINK: https://www.sciencedaily.com/releases/2017/04/170404160052.htm

YouTube BBC Earth Science Link: https://www.youtube.com/watch?v=5NCOnr3VSAY

I would like to thank my family for providing me with supplies I needed for the project ( pH stripes, filters...). Additional thanks to Mr. Z for project guidance and helping me reach the deadline.