For the past 250 years, people have mined coal industrially in Pennsylvania, USA. By 1830, the city of Pittsburgh was using more than 400 tons of the fossil fuel every day. Burning all that coal has contributed to climate change. Additionally, unremediated mines—especially those that operated before Congress passed regulations in 1977—have leaked environmentally harmful mine drainage. But that might not be the end of their legacy.

In research presented last week at GSA Connects 2025 in San Antonio, Texas, USA, Dr. Dorothy Vesper, a geochemist at West Virginia University, found that those abandoned mines pose another risk: continuous CO2 emissions from water that leaks out even decades or centuries after mining stops. 

A research team has developed pioneering technology that enables human kidney organoids to be produced on a scalable basis. These organoids can then be combined with pig kidneys outside the body and transplanted back into the same animal in a viable manner.

The experiment, led by the Institute for Bioengineering of Catalonia (IBEC), is in the preclinical phase. It confirms the safety and viability of the procedure, paving the way for future trials involving humans.

In the long term, this approach could help to extend the useful life of organs intended for transplantation and provide an alternative therapy for patients with chronic kidney disease.