Summary
Overview
Are your students passionate about the environment? Do they like to explore new ideas for more eco-friendly products? This lesson will give your students a chance to grow a product out of mycelium composite, a material that recently gained traction as an eco-friendly alternative for many plastics and foams. Students will analyze the impact of this product on the environment at every step of its life cycle, from raw material to the end of its life, and compare it to a plastic or cardboard alternative. Will it come out on top in overall eco-friendliness? Try it out and see!
Learning Objectives
- Understand what a life cycle assessment is, and why it is important.
- Question claims on environmental impact of a product in light of a life cycle assessment.
- Understand that the environmental impact of a product is complex.
NGSS Alignment
This lesson helps students prepare for these Next Generation Science Standards Performance Expectations:- HS-ESS3-4. Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.
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Science & Engineering Practices
Analyzing and Interpreting Data.
Analyze data using computational models in order to make valid and reliable scientific claims.
Using Mathematics and Computational Thinking. Use mathematical and/or computational representations of phenomena or design solutions to support explanations. Constructing Explanations and Designing. Design or refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations. Engaging in Argument from Evidence. Evaluate competing design solutions to a real-world problem based on scientific ideas and principles, empirical evidence, and logical arguments regarding relevant factors (e.g., economic, societal, environmental, ethical considerations). |
Disciplinary Core Ideas
ESS3.A: Natural Resources.
All forms of energy production and other resource extraction have associated economic, social, environmental, and geopolitical costs and risks as well as benefits. New technologies and social regulations can change the balance of these factors.
ESS3.C: Human Impacts on Earth Systems. Scientists and engineers can make major contributions by developing technologies that produce less pollution and waste and that preclude ecosystem degradation. ETS1.B: Developing Possible Solutions. When evaluating solutions, it is important to take into account a range of constraints, including cost, safety, reliability, and aesthetics, and to consider social, cultural, and environmental impacts. |
Crosscutting Concepts
Influence of Science, Engineering, and Technology on Society and the Natural World.
Engineers continuously modify these technological systems by applying scientific knowledge and engineering design practices to increase benefits while decreasing costs and risks.
Analysis of costs and benefits is a critical aspect of decisions about technology. |
Materials
For Growing Mycelium Products:
For each student:
- Disposable gloves, three pairs
Per group of 4–5 students:
- Mycelium growing material, like the Grow-It-Yourself Mushroom® material sold by Grow.bio
- Spray bottle
- 70% isopropyl alcohol
- Flour, people with gluten allergies can use maltodextrin as a substitute
- Water
- Measuring spoon
- Measuring cup
- Large bowl
- Clips or tape
- Growing containers to mold the product. The type of container will depend on the product the students choose to make. Please read the information on growing containers below for more detail.
To share with the class:
- Scissors
- Plastic wrap
- Kitchen scale
- Wire cooling rack
- Optional: Oven or fan
- A place away from direct sunlight, where the growing products can stay undisturbed for 4–6 days
For the Life Cycle Assessments:
- Access to the internet to perform research
- At least two colors of pens or pencils
Note on Growing Containers:
Mycelium composite can be molded into any form you would like: a box, an egg shape, etc. The growing containers will serve as molds for the product. Students can make their own growing containers or use existing containers. A good growing container has the following qualities:
- It is made from non-porous material, like plastic or metal or glass, or covered with a non-porous material like tape or plastic wrap.
- It can hold moisture inside. It is okay to cover a side with plastic wrap to hold moisture inside.
- It has holes to allow air exchange. It is okay to have the holes only on one side; for example, in the plastic wrap that covers the top.
- It allows easy removal of the product once it is ready and grown into one piece. It could consist of two or more parts sticking together, or have a side covered with plastic wrap, or a lid that allows you to remove the product in one piece.
- To make removal easier, we suggest that you create a product with sides that slant outward by 2 degrees or more.
Food containers, flower pots, baking pans, and silicon molds are good options for a mold. A few options are shown in the figure. If you can, have at least one group of students choose a transparent growing container so students can see the mushroom roots grow.
Background Information for Teachers
This section contains a quick review for teachers of the science and concepts covered in this lesson.More than half of all plastic ever manufactured was created in the last 20 years (data from ourworldindata)! The same source claims that global plastic waste amounted to 275 million tons in 2010 alone, more than the amount of plastic produced that same year. Of all this plastic waste, only 16% was recycled in 2010, 22% was incinerated, and 62% was left as pure waste in landfills, or found its way to oceans, etc. It can easily take over 100 years until most plastics begin to degrade in a landfill. We are facing an ecological problem.
The packaging sector is by far the largest contributor to all the plastic waste. In this project, students will explore if mycelium composite material—a compostable material obtained from organic waste and mushroom roots—can serve as a viable eco-friendly packaging alternative. Students will grow a mycelium composite product, evaluate its effectiveness as packaging material, and then explore its overall ecological impact. As comparison, students will also analyze the impact of a similar product made from a different material. In the process, students will gain an appreciation for the complexity of ecological questions and start to understand why ecological challenges rarely have a simple answer.
Mushrooms are part of the kingdom of fungi. The larger part of the fungus is the root system, the mycelium. It is a network of strong bonds, that, when grown in molds around biological waste like wood chips, can create strong, lightweight, biodegradable products. These characteristics make it a viable candidate for packaging material. Figure 1 shows a packaging mold grown from mycelium and hemp by Science Buddies staff. It has been designed to hold two fragile bottles.
Figure 1. An example of mycelium composite packaging material.
One might think that due to its biodegradable characteristics, mycelium composite material can reduce the trash problem and thus is eco-friendlier; however, only a wider perspective like the one seen in a life cycle assessment (LCA) can reveal its overall impact. An LCA is a systematic study of the environmental impacts of a product or service throughout its entire lifespan, from the extraction of raw materials to the end of its life. The life cycle of a product is usually broken down into five steps, as shown in Figure 2. The cycle starting at the extraction of raw materials and ending in disposal is often referred to as cradle-to-grave. When the disposal stage is exchanged for recycling processes, the loop is closed (Figure 3). This is referred to as the cradle-to-cradle, closed-loop recycling, or circular economy.
Figure 2. Main steps in the life cycle of a product that is not recyclable, also referred to as the cradle-to-grave cycle.
Figure 3. Main steps in the life cycle of a product that is recyclable. This is also referred to as the cradle-to-cradle cycle.
A life cycle assessment can be broken down into four steps. First, one defines the scope of the assessment. An LCA usually provides the groundwork of a sustainability decision or claim, and the goal largely sets the scope. The scope includes the unit of the study, how deep the study needs to go, and what will and will not be included. For example, if the goal is to create an environmental product declaration, the unit of the study will be the product, the study could follow a cradle-to-grave concept and analyze the impact categories required for the declaration. Once the scope is set, one takes the inventory of everything that flows in and out of the system (e.g., materials, water, different types of energy, gases, etc.). The impact of each of these flows is evaluated in a third step. The last step is the interpretation of the results. This includes listing the limitations of the study and the assumptions made during the study.
Students will make a partial LCA of mycelium composite and an alternative material. The goal is to get a more realistic view of the impact of mycelium composite compared to that of an alternative material. Because they are studying a packaging material, students are not asked to include the retail and use stage of the product. During their assessment, they may—but do not have to—include adjustments for recycling, or byproducts. More details on how these can be included are given in the explore section.
An LCA evaluates the impact across many categories like global warming potential, ecotoxicity potential, human toxicity potential, acidification potential of land and water, eutrophication potential, non-renewable energy (or fossil fuel) indicator, depletion potential for non-fossil resources, ozone depletion potential, freshwater depletion, solid waste, etc. Students will only evaluate two parameters of their choice.
Measurements within the LCA are usually expressed in equivalents. An example is CO2-equivalent for global warming potential. The use of equivalents allows us to capture the impact of several different components in one indicator. For example, if the production of 1 ton of a product releases 250 kg of nitrous oxide, and 1,000 kg of CO2. Because nitrous oxide is 298 times more potent in creating global warming compared to CO2, its contribution gets multiplied by 298 when the total is expressed in CO2-equivalents. For the example, this stage will contribute (250 times 298 kg + 1,000 kg) or 75,500 kg of CO2-equivalents.
No LCA is ever perfect, it is always a snapshot in time, based on the information available and plausible assumptions. It can, however, give valuable information of the environmentally taxing points along the life cycle of a product, allows comparison of the full impact of several products, and can quantify the ecological impact of a change in the life cycle of a product.
As students perform their own assessments, they will gain an appreciation for the complexity of ecological claims.
