Some inventions use simple solutions to solve big problems. When middle school student Tina Jin learned that billions of people around the world do not have access to clean drinking water, she was inspired to help.

“When I was watching the news after dinner, I was shocked to see children drinking dirty murky brown water,” Jin told the Society for Science, a nonprofit organization that promotes scientific research. “While I was picking which type of water to drink, some people couldn’t even have clean water.”

Drinking contaminated and unfiltered water means risking water-borne illnesses like diarrhea or cholera. However, many people don’t have filtration systems that can clean contaminated water.

This led Jin to wonder, is there a common natural material that could also act as a water filter? That’s when she thought about using animal bones.

Jin says she got the idea while eating with her family. The beef bones in her meal reminded her of a type of human-made filter material called polymer membranes. Since meat is a part of many diets around the world, animal bones are an accessible material nearly everywhere. This inspired her to study the ability of beef bones to filter dirty water.

The bones Jin saw in her meal are called trabecular bones. The inside of a trabecular bone has many small holes, making it look like a sponge. These bones can be found in humans and animals in the spine, at the base of the skull, and at the ends of leg bones like the femur. Jin decided to test whether the trabecular bones could trap impurities when water flows through them.

To make the filter, Jin cleaned trabecular beef bones and sliced them into cross sections. She then tested the bone slices’ ability to filter “dirty” water by pouring black tea, rose tea, water with microplastics, and stream water through the slices. Jin recorded which pore sizes from the bones filtered the water best. Her results showed that the smaller the pore sizes on the bone, the better it was at cleaning water.

A water company in Jin’s hometown of San Jose, California, tested her results and confirmed that her bone-filtered water was drinkable and safe.

“I created this whole method, using 100 percent natural, easily accessible materials and household supplies so that anyone from any part of the world can filter their own dirty water into clean water,” said Jin.