Gas-tastic Adventures: Cooking Up Health Discoveries with Biogas vs. Natural Gas

Full Disclaimer: ChatGPT gave us the title – we aren’t that creative!

Welcome to the Benka-Coker Lab!!

Meet the Lab:

Dr. Benka-Coker: Welcome to our “lab”! I am a faculty member in the Health Science department and I’m also a Gettysburg alum! I have a Masters of Public Health degree in Global Health and a PhD in Environmental Health. My research focuses on quantifying the exposures from air pollution, primarily focusing on the harmful emissions of cookstoves in the global setting (my most recent field project was in Northern Ghana). I also research the health effects of air pollution exposures and work with governmental policymakers to advocate for cleaner-burning fuel alternatives that would improve human health.

Emily Lyons: Hello! I’m a rising junior and a health sciences major with neuroscience and education minors. On campus, I’m a member of the climbing club and the community service organization APO, and I work as an outdoor facilitator at the Garthwait Leadership Center. This summer, I’m working in Dr. Benka-Coker’s lab with Bramley!

Bramley Hawkins: Hi! I’m also a rising junior, with environmental science and biology majors and a data science minor. On campus, I’m a member of our Women’s Swim Team, I teach swim lessons to kids in the community through our Center for Public Service, and I work as a tour guide for our Admissions Office. This summer, I’m working in Dr. Benka-Coker’s lab with Emily!

What’ve we been working on?

This summer, we’re studying the effects of burning biogas for stovetop fuel on indoor air quality compared to natural gas, with the hypothesis that the biogas will release fewer nitric oxides and other pollutants that are harmful to human health into the air. Our work is a collaboration with Dickinson College and Matt Steiman (pictured below), the Energy and Livestock Manager at the Dickinson College Farm in Carlisle.

The first step of our project relies on the production of biogas! Farmer Matt has been a long-time advocate of biogas and a “waste to energy” model and his work is an essential part of our project this summer. (Take a listen to this April 2024 podcast interview with him and the new grant for the midscale biodigester on the Dickinson College Farm).  Matt takes agricultural waste generated on the Dickinson Farm and local restaurants, including leftover crops, food waste, and cow manure, and pours it into an anaerobic digester. The bacteria in the digester break the material down, separating it into a bottom layer of sludge sediment that can be used as a fertilizer on future crops, and a top layer of biogas (diagram and the Dickinson College Farm Biogas Digester pictured below)! That’s the cool part- absolutely everything gets used. If the digester weren’t in use, this waste would’ve broken down outside, releasing methane into the open air. Instead, CO2, a significantly less potent greenhouse gas, is released by burning the biogas in stoves. By using the digester, all of that CO2 and methane gets captured and repurposed instead!

Once all the biogas is made and ready for use, our task is to see what happens when we burn it. We’ve got some fantastic participants for that purpose; a couple of households with access to biogas, and the apprentices on the Dickinson College Farm. In our experimental setup, we will measure pollutants in the air under two conditions; biogas and natural gas. Our participants will first cook only with biogas for 72 hours, and then they will cook using natural gas for 72 hours. There will be a “washout” period in between the two experimental conditions.

Bramley cooking popcorn on a biogas stove, assisted by Matt and an apprentice.

In order to evaluate the pollution under both conditions, we will be using many different pieces of equipment that measure air pollution; the Home Health Box (NO2, gravimetric and continuous PM 2.5, VOC, CO2 inside the kitchen, pictured below), a temperature probe (to monitor stove use), the Ogawa Sensor (gravimetric NO2), the URAD monitor (ambient NO2, PM 2.5, CO2, VOC), and the PurpleAir Monitor (ambient PM2.5).  These different particles are all produced from combustion. PM2.5 is ultra-fine particulate matter, less than 2.5 microns, which is small enough to enter the bloodstream after inhalation. VOC, volatile organic compounds, are chemicals found in everyday life that, when breathed in, can be harmful to health. NO2 is a compound that can irritate the respiratory system and it also contributes to the production of ozone. CO2 is a greenhouse gas that contributes to global warming.   If you’re interested in learning more about what’s in our air and how it affects our health, check out the EPA’s introduction to indoor air quality! The monitors that collect gravimetric data are continuously pulling air into the machine, leaving matter on the filters placed inside. We will pre- and post-weigh the filters to see how much matter accumulated. Lots of our time has gone towards learning how to set up and use these monitors. 

Benefits to the Environment

Biogas as a cooking fuel has a variety of applications. From an energy standpoint, biogas is a renewable resource, with digesters fed by manure, household scraps, and agricultural byproducts. The decomposition of these waste products would release methane, however, by using them as the feedstock for the digester, the biogas that is produced, when burned, releases CO2, which is a much less potent greenhouse gas than methane. The plants uptake the CO2 released by the combustion of biogas, and because organic material is the feedstock for the biogas digesters, biogas can be considered a carbon-neutral source. Biogas as a form of energy is great for our environment! Additionally, the byproducts of the digestion process can be used as fertilizer in the fields. And, when using fibrous manure as a feedstock, the byproducts can be dried out and turned into straw bedding for the cows to use. It is a very sustainable process.

Benefits for Human Health

Once the biogas is produced, it can either run a generator to produce electricity, or it can be used as is for activities like cooking and heating. This has global implications. In rural or impoverished areas, gas and electricity can be expensive, or not available. Because biogas digesters are relatively cheap and can be made with Big Blue Barrels and PVC pipes, it is a good solution for these hard-to-reach areas. Communities in rural areas of low and middle-income countries often rely on firewood or charcoal for their cooking and heating needs, both of which don’t burn cleanly, releasing harmful volatile organic compounds (VOCs), CO2, NOx, and particulate matter (PM) into the air. This poor air quality causes health issues such as increased rates of asthma, and heart and respiratory diseases.  If you’re interested in learning more about the health impacts of global air pollution, check the information on State of Global Air. By switching to biogas, we can save our planet and the people who live on it cost-effectively and sustainably!

The friends we’ve made this summer (so far)

Mochi: our fantastic friend and an invaluable lab team member. He lives at one of our participants’ houses and has welcomed us with open arms (and mouth- sometimes he leaves his tongue sticking out).

The fish at the Huntsdale State Fish Hatchery: We had a free hour in the middle of one of our days out at the farm and had a lovely time feeding the fish

Baxter, Bear, and Sam: a trio of Golden retrievers who live near campus with a colleague who advocates for cleaner energy!

The cows at the Dickinson College farm: Our partners in biogas production! Their digestive systems are truly paving the way for our project to run, and we are eternally grateful for their contributions

The sheep at Dickinson College Farm: they are just cute and fluffy!

Sugar and Spice: Professor Benka-Coker is in the process of adopting two kittens😻

The whole lab, including our partners from Dickinson College! Here we are in front of one of the participant’s houses

Thanks for reading!! Come visit us at the poster session to see what we find!!

I don’t care about spots on my apples, Leave me the birds and bees (and butterflies!), Please!

Listen to Counting Crows’ Big Yellow Taxi as you read our blog!

Hi guys! Welcome to the Ferster Lab, where my people get to study the diversity of the butterflies in Gettysburg, PA! It’s a pretty awesome lab, where lots of butterflies are spotted, plants are counted, and flowers are planted. Keep reading to see some beautiful pictures of butterflies!

Ferster Lab in one of our sites, Sherfy Garden. From left to right, Bramley, Dr. Ferster, Gabe.

But before we get to that, I want to introduce you to the Butterfly Band, the four of us who make up the Ferster lab. First off, there is me, Christopher Robin, but I often go by Chrissy. Dr. Ferster is my human. I love to wander around the greenhouse, but my most favorite activity is chewing on the garden clippers. My labmates often have to take them away from me, which is so unfair because they get to use them and I don’t. Sometimes I get a little scared of the gardening equipment and I have to be left behind on the survey days because I might scare away the butterflies.

Chrissy resting after a hard day of work!

Next, we have Dr. Ferster, our fearless leader. An ant lover at heart, she expanded to also study butterflies about 20 years ago, supposedly. I’m only 2, so this is all just what I have been told. When not thinking about butterflies, Dr. Ferster can be found snuggling with her favorite dog (me!), browsing the aisles of the local nursery (Ashcombes!), or baking her students yummy treats such as sourdough (Bramley’s favorite) and carrot cake (Gabe’s favorite). 

That brings us to Gabe, the botanist of the group. Gabe is a rising senior who loves all things plants. A Biology and Environmental Studies double major, Gabe likes to spend his free time climbing and trying out new recipes! His favorite meal he cooked this summer was vegetarian tacos.

Lastly, there is Bramley, the designated butterfly counter in the group. A rising sophomore Environmental Studies major with Biology and Data Science minors, Bramley can often be found swimming in the pool or testing out the local creameries. Contrary to popular opinion, she thinks Half Pint Creamery is superior to Mr. G’s. Her favorite flavor is the lemon blueberry swirl from Half Pint.

So what are my humans actually doing? Well, they are studying how flowering plant diversity affects the diversity and abundance of butterfly species. Flowering plant diversity is closely tied to butterfly diversity and abundance. Basically, this means they are looking at the plants present in Gettysburg that butterflies use as larval hosts, nectar sources, and refugia to hide in during their life stages.

Nectar plant and butterfly diversity study:

Once a week, on days meeting specific conditions (>75 F, <50% cloud cover, <10mph wind speed), the lab goes out to 6 sites around the Gettysburg area. Bramley walks through the sites first, looking low for the small skippers who sit in the grass and high for the swallowtails swooping through the air, as well as everywhere in between. She records each species in her notebook and also (tries) to take a picture of each in order to get verification for the field identification. They move fast, though! These pictures are then uploaded to the citizen science database, iNaturalist.com. Gabe and Dr. Ferster follow behind Bramley to identify the flowering plants. There are set paths that the lab follows through the field sites each week in order to maintain consistency. The flowering plants are then compared to the species of butterflies that have been spotted to compare how the diversity of flowering plants affects the diversity of the butterflies that they see each week in six different sites. 

They are comparing the diversity of this year to the three previous years that this lab has been collecting data. Due to the cold spring that we’ve had, they were seeing fewer flowering plants and butterflies than they typically would have seen at this time. In order to accurately compare the data they standardize our diversity data using growing degree days. Originally used for predicting corn harvest times, degree days are a measure of heat accumulation. They use the cumulative degree days in order to compare one year to the other. 

Over the last three years, we have found low diversity and abundance across all of our sites. The main butterflies we have observed have been grass-eating skippers and long-distance migratory butterflies. We are now trying to figure out why. We are counting the nectar plants and looking at larval host plant density to determine if a lack of resources is causing the decline in diversity and abundance.

Larval Host Plants:

We have also recently added a new part to the project. Fritillary butterflies are now rare. In the four years that this lab has been studying butterflies, only five fritillaries have ever been seen. I have never seen one as I get left at home, but everyone else has seen one. Part of the problem may be that the habitat is not suitable for fritillaries. Fritillaries need violets for caterpillars, nectar plants for adult food, and bunch grasses to use as protection for overwintering and summer diapause. They believe that one of these plant resources may be the limiting factor explaining the fritillary decline. To determine violet density they are taking a 2m x 2m PVC pipe square and dropping it on coordinates randomly generated by GIS in the New Jersey Brigade and Wheatfield field sites. Within that plot, they will count the number of violets and estimate the bunchgrass cover in order to determine if fritillaries in the Gettysburg National Military Park have declined due to a lack of these resources.

Great Spangled Fritillary spotted at the New Jersey Brigade field site in the Gettysburg National Military Park on June 19, 2023.

Because fritillaries only use violets (Viola spp.) as larval host plants, they might be more vulnerable to changing plant populations than other butterflies. Other species, such as the black swallowtail, eat a variety of plants within the same family (Apiaceae). Because they eat a wider variety of plants, including some non-native weeds and garden plants, black swallowtails might be more resistant to changes in plant diversity. My humans search plants for black swallowtail caterpillars weekly to see if they can determine a host preference.

Black Swallowtail Caterpillar on Bronze Fennel in the Sherfy Garden.

We also have our very own pollinator garden! Located behind the observatory, this is a place where they are wondering, “If they build it, will they (the butterflies) come?” They spend a lot of time maintaining this garden and looking for native butterfly plants to plant! We have numerous types of milkweed, Zizia auria, blue vervain, and so much more! At the moment, we have built a garden on campus, but the butterflies have not yet come en mass. This is likely due to the cold spring, so hopefully in the next few weeks, they will start coming! Also in our pollinator garden, they are conducting a feeding survey for black swallowtail and monarch caterpillars. We have dill, parsley, native Zizia, and green and bronze fennel all located near each other in the garden for black swallowtails. And an assortment of milkweeds for monarchs. Some of these plants are native, and others are not native, but the black swallowtail caterpillar will still munch on them, so they are trying to see which is the preferred food type when all are available. 

Our Pollinator Garden is located behind the Observatory. Come visit!

You can help us collect data! If you see a butterfly in Gettysburg you can upload photos to iNaturalist.com. Happy butterfly-ing!