Wayne State University Department of Pharmacology Ph.D. candidate Samantha Heldman presented her research on the link between broken liquid crystal display panels (LCDs) and obesity at the 2024 Graduate Research Symposium in February and placed first in the Three-Minute Thesis Competition (3MT). In total, eight graduate students summarized their research in three minutes or less, speaking to a standing-room-only crowd.

As someone who originally set out to be a high school biology teacher, it was a lot of fun to go back to my roots and transform complicated science into something accessible and engaging,” Heldman said.

She will move on to compete in the regional Midwestern Association of Graduate Schools 3MT, April 3-5, 2024.

A member of the Kassotis Lab in the Department of Pharmacology and the Institute of Environmental Health Sciences (IEHS), Heldman’s research is timely. 40 million tons of electronic waste are generated globally every year. The statistical hub The World Counts quantifies on their website: “That’s like throwing away 800 laptops every second.”

Is it any wonder? Screens break all the time. Our phones fall out of our pockets. The movers are too rough with our TVs. The kids chuck their iPads across the room. All it takes is a trip to the store and a swipe of the credit card to get a shiny replacement, but the waste remains.

Many of our devices use LCD panels that leave chemical pollutants called liquid crystal monomers (LCMs) behind when they break. Recent studies have found these emerging toxins in household dust, on users’ skin, even in human blood and breast milk.

“These studies are sounding the alarm on LCM exposure but there’s been little risk assessment done to determine if they are potentially hazardous to our health,” said Heldman.

It was a 2019 study led by a Chinese research team that had discovered LCMs in diverse indoor locations such as residential homes, places of business, and electronic repair centers that put the issue on the Kassotis Lab’s radar.

“Then more work started coming out that focused on measuring exposure levels in the environment—in, near, and far from LCD panel and LCM manufacturing hubs and waste recycling plants—and trying to better understand how LCMs move through, accumulate in, and breakdown in the environment, food, and in animals,” Heldman said. “Many of these exposure assessments are being done in China, which is a major hub for LCD panel and LCM manufacturing as well as globally produced electronic waste.”

Most of that waste is not safely disposed of, she said, with a majority being sent to landfills or incinerators, where they release toxins like LCMs into the environment.

Keep swimming

As consumer demand for the latest and greatest in tech increases, so does that for the chemical compounds that comprise them. It’s turned into a retroactive footrace to determine what long-term exposure means for our health.

Back in 2019 when the study that piqued Heldman’s interest was published, about 350 LCMs were predicted to be in circulation worldwide. That number has now more than tripled, she said.

For her study, Heldman was able to get her hands on 10 different LCMs. In 2021, she exposed human stem cells to individual LCMs and LCM mixtures and found that they were starting to fill up with fat. This suggests that LCM exposure might contribute to the development of fat in cells and tissues where it doesn’t typically develop in excess, which could negatively affect their ability to function normally.

Since experiments with cells can’t fully capture the complexity of how a chemical interacts with the whole body, Heldman followed up on these findings with animal experiments.

“I exposed zebrafish when they were young to these liquid crystal monomers and then raised them to about 30 days old. At this age, they are still mostly transparent, which allows me to easily see how much more fat LCM-exposed fish may have in their bodies.”

She found LCM mixtures were significantly obesogenic, or fat-inducing in the zebrafish as well, but at much lower concentrations than in the human stem cells.

The next steps in her research are to find out why.

“That’s science. Each incremental step is one move closer to the whole story and the bigger picture.”

Trial by research

Heldman is currently conducting a pilot study with the Center for Urban Responses to Environmental Stressors (CURES) funded by One Health Initiative, a collaboration of IEHS and the College of Engineering. The study will allow WSU researchers to connect with community residents and collect dust samples from their homes to test for LCMs.

“It’s a small-scale pilot study to determine the risk to residential populations, but it’d be the first of its kind in the U.S.,” she said.

“There are two angles to this research: hazard and risk assessment. The hazard is that the LCM chemicals are potentially toxic, but we then need to figure out at what concentration of these chemicals does it become a risk for our health?”

She hopes her research will contribute to the increasing demand to hold manufacturers and distributors accountable and inform stricter electronic waste regulation. That customers are made aware of how to properly dispose of their devices either through recycling or buyback programs to mitigate electronic waste.

“LCMs are just one piece of a larger mosaic of chemical pollutants we are exposed to every day. At this stage, the best thing you can do as a consumer is reduce your exposure” by damp dusting in frequently used rooms at home using a wet sponge or cloth often. Dry dusting can mobilize these contaminants into the air and increase exposure. Have a cracked screen? Recycle the device, or get the screen fixed.

By Kristy Case

Faculty spotlight

• Christopher Kassotis