Origin Story: Drilling for Air 

When a harmful chemical, called a pollutant, gets into the air, water, or land, it can end up in a plant and animal that are important to the food chain. The food chain shows how different living things in nature depend on one another for food. Now imagine predators will eat these plants and animals. Since the food they eat daily is contaminated, they will also absorb the pollutant. This continues all the way up the food chain, where apex or top predators might be eating high amounts of that pollutant too. This process is called bioaccumulation.

Ice cores are long cylinders of ice that are drilled from ice sheets and glaciers. Some ice does not melt, even in the summer, so the snow that falls on it buries snow from past years. That snow eventually turns into ice that has captured the chemicals that were in the air and on the snow when it formed, including pollutants. Ice cores can reveal atmospheric particles or aerosols (which are tiny invisible pieces of solids or liquids that float in the air and even in our atmosphere!) from thousands of years ago and tell us a lot about what the world used to be like.

What Is in Your Fridge? 

Refrigerators work by pulling heat away from the inside and absorbing it into a refrigerant. Refrigerant is a chemical that helps carry away the hot air leaving in the fridge nice cool air. For the most of its life, this special substance is contained in the tubes at the back of your fridge. But it can sometimes leak especially if a device is not disposed of properly. 

Chlorofluorocarbons (CFCs) are types of refrigerants that were used in air conditioners, fridges, and aerosol cans from the 1920s until the 1990s. These chemicals are damaging to our ozone layer. The ozone layer is incredibly important because it shields us from the harmful ultraviolet (UV) radiation that comes from the sun by absorbing most of the radiation and filtering it out, keeping us safe from getting severe sunburns and other health problems. Luckily, most of CFCs are not used anymore, thanks to the Montreal Protocol, an agreement to stop using this type of chemical, signed by many countries in 1989. CFCs were replaced by hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), these chemicals do not damage our ozone layer, but when both HCFCs and HFCs break down, they can release another harmful pollutant that has an environmental impact.

HCFCs and HFCs that have leaked into our air eventually break down into smaller chemicals like trifluoroacetic acid (TFA), which can fall to the ground as part of rain or snow. TFA takes a long time to break apart, often being absorbed by plants and animals that cannot break them down easily. This means that when TFA is in the environment, it stays for a long time and can be introduced into the food chain. We do not know every problem that might be caused by TFA, but it can be toxic to living things. We have even found TFA in humans!

A team of scientists  wanted to figure out the amount of TFA that has been introduced to the environment in the last few decades, and ice cores are the perfect record for figuring that out. When TFA is created, it mixes with rain and snow and falls to the ground. In most places, this spreads out as water, but in the Arctic, the snow piles on top of other snow, and on Mount Oxford and in the Devon Ice Cap, the snow does not melt. This gives us layers of packed snow that can be melted and checked for TFA.

The team found that the amount of TFA and other chemicals like it have increased since 1990. This is because in 1990, we started replacing ozone-damaging CFCs with HCFCs and HFCs . Saving the ozone layer was a big accomplishment, and now that we have realized that HCFCs and HFCs might be causing other types of damage, we are in need for better solutions to keep our food cold.

Finding so much TFA in the Arctic means that when we throw out refrigerators and air conditioners, leaking HCFCs and HFCs end up moving all over the world. Everything we do can affect the world near us and far from us. 

Try This at Home: Moving Currents 

When it is time to clean under the fridge, ask an adult to let you take a look at the back. Some will have coils attached to the back, which contain HCFCs or HFCs. Most of new fridges will have the coils covered, but they will have a fan that blows hot air away from the fridge; this is the heat that is removed from the inside!

Our atmosphere moves air between lots of spaces through convection currents that is a natural process of heat transfer. To understand how these currents work, try placing a coloured ice cube on top of warm water in a clean container and watch how the colour moves through the water. This shows that air containing pollutants does not stay in one place, these pollutants travel with the air as it moves and changes temperature.

Climate Action: Recycle Your Fridge

If your family is getting a new fridge or air conditioner, make sure to recycle the old one properly, so that harmful chemicals do not leak into our atmosphere.

Here are some other actions that are in your power to take.
•    Use a spritz bottle instead of an aerosol bottle.
•    Learn more about how the Montreal Protocol has been updated over time. 
•    Investigate other types of bioaccumulations affecting climate change, and what is being done to better control them.

Meet Our Local Science Hero: 

Dr. Alison Criscitiello is an ice core scientist, and high-altitude mountaineer. Criscitiello's research explores the history of sea ice in polar regions using ice core chemistry, which involves long months of living in a tent and drilling ice cores in places like Antarctica, Alaska, the Canadian High Arctic, and Greenland. She is the Director of the Canadian Ice Core Lab (CICL) at the University of Alberta, and an Adjunct Assistant Professor at the University of Calgary. Criscitiello holds a bachelor’s degree in Earth and Environmental Science from Wesleyan University, a master’s degree in Geophysics from Columbia University, and the first PhD in Glaciology ever conferred by Massachusetts Institute of Technology (MIT). 

When not busy shivering for science, Criscitiello seeks out the cold for fun, whether working as a climbing ranger in the national parks or guiding expeditions to the major peaks in the Andes, Alaska, and the Himalaya. In 2010, she led the first all-woman ascent of Lingsarmo (6955m) in the Indian Himalaya. She has been the recipient of three American Alpine Club (AAC) climbing awards including one for Borderski, her two-month winter ski traverse of Tajikistan's border in the eastern Pamirs with two other Canadian women. In 2016 she was awarded the Mugs Stump Award and John Lauchlan Award to attempt the first alpine ascent in the Indian Himalaya. Dr. Alison Criscitiello has been named a National Geographic Explorer, and a Fellow of the Explorers Club and the Royal Canadian Geographical Society. Criscitiello is founder and co-director of Girls on Ice Canada.

THIS ARTICLE IS COURTESY OF GENACTION.

Credit

This Science Spotlight was written based on Pickard, H.M., Criscitiello, A.S., Persaud, D., Spencer, C., Muir, D.C.G., Lehnherr, I., et al. 2020. “Ice Core Record of Persistent Short-Chain Fluorinated Alkyl Acids: Evidence of the Impact from Global Environmental Regulations” Geophysical Research Letters, 47, e2020GL087535. https://doi.org/10.1029/2020GL087535