Hospitals, notorious for producing waste, could reduce health care costs by switching to environmentally friendly practices -- with no threat to patient safety, according to Johns Hopkins researchers.

Health care facilities are second only to the food industry in generating waste in the U.S., producing more than 6,600 tons per day and more than 4 billion pounds annually. Operating rooms and labor-and-delivery suites together, the researchers say, account for nearly 70 percent of hospital waste.

Reporting in the February issue of the Archives of Surgery, the Johns Hopkins team said hospital operating rooms notoriously open sterilized equipment that is never used, install energy-sucking overhead lights and fill red bags that are labeled as medical waste with harmless trash that could be more cheaply disposed.

"There are many strategies that don't add risk to patients but allow hospitals to cut waste and reduce their carbon footprints,"says study leader Martin A. Makary, M.D., M.P.H., an associate professor of surgery at the Johns Hopkins University School of Medicine. "If we're going to get serious as a country about being environmentally conscious, we need to look at our biggest institutions. When an individual decides to recycle or dispose of waste differently, it has an impact. But when a hospital decides as an organization to go green, the impact is massive."

Makary and his team reviewed 43 previously published studies about hospitals’ environmental practices, then asked a panel of experts to come up with practical strategies to reduce waste in surgical units.

The panel's top five strategies were reducing and segregating operating room waste, reprocessing single-use medical devices, making environmentally conscious purchasing choices, managing energy consumption and managing pharmacy waste.

In surgical suites, for example, two kinds of disposal bags are used to separate waste: red bags for infectious and pathologic waste and clear bags for noninfectious waste. Makary says that as much as 90 percent of what ends up in red bags does not meet the criteria for red-bag waste, which costs far more to process. "Although hazardous and regulated medical waste (equivalent to infectious waste) makes up only 24 percent of medical waste, it accounts for 86 percent of costs," the study team concluded.

Makary says the volume of medical waste could be decreased by more than 30 percent solely by proper waste separation.

Makary says many discussions of green initiatives -- such as recycling single-use medical equipment -- have been framed as a choice between what is best for the environment and what is best for patients, with patients the obvious priority. But the team's research, he says, shows there are ways to be green without compromising patient safety.

One medical center, the authors note, instituted a system of making clear plastic bags more readily available during surgical preparation and then replacing them with red bags just before the patient was wheeled into the operating room, when most red-bag waste is generated. The center also began washing and reusing all of its surgical scrubs and jackets. These two changes made up the lion's share of a 50 percent reduction in medical waste volume over seven years, and Makary says patient safety was not compromised.

The Johns Hopkins team says wider adoption of the practice of recycling medical equipment is a potentially big saver of health care dollars and landfill space. Such equipment includes laparoscopic ports and durable cutting tools typically tossed out after a single use, Makary says. With proper sterilization, recalibration and testing, previous experience has shown that reprocessing equipment is safe, he adds. Often in surgery, items are taken out of their sterile packaging - sometimes in duplicate - in order to be quickly available should they be needed over the course of an operation. That practice needs to be reconsidered, he says.

"The overall carbon footprint of the hospital has not been a priority in the past," Makary says. "But we live in a much more cost-conscious medical climate now and there is a lot that hospitals can do to go green."

Gabriel A. Brat, M.D., M.P.H., of Johns Hopkins also participated in the study.