Recently, my young son was hospitalized for several days, and I couldn’t help but notice the massive amount of goods that were thrown away during the course of his care—disposable smocks, one-use saline syringes, etc. The trash can in our room was emptied three or four times daily! Just how much trash do hospitals produce?

Firm, up-to-date numbers on hospital waste are hard to come by, but the short answer seems to be: A lot. One widely cited statistic holds that the nation’s hospitals generate 6,600 tons of waste daily, but that figure comes from a survey that’s more than 20 years old. Two million tons a year (or about 5,500 tons a day) is another estimate that pops up frequently. But that number dates back to at least the late 1990s, and the Lantern couldn’t track down its original source.

To ballpark a more recent figure, the Lantern turned to Practice Greenhealth, a network for eco-friendly health care institutions. In a 2010 survey, 114 of the group’s member hospitals reported generating an average of 33.8 pounds of waste per day, per staffed bed. According to the American Hospital Association, there are 951,045 staffed hospital beds in the country. That works out to about 5.9 million tons of garbage annually—perhaps even more, considering that the hospitals surveyed already recycle or otherwise divert at least 10 percent of their waste. (By comparison, Americans produced 250 million tons of municipal solid waste—what we typically call “garbage”—in 2008.)

The discrepancy between this estimate and the older figures may reflect an actual increase in waste generation, says Cecilia DeLoach Lynn, director of sustainability education at Practice Greenhealth. But the difference could also be due to the fact that hospitals have begun to track their waste more closely in recent years.

Since the late 1990s, when the EPA and the American Hospital Association set a series of pollution prevention goals (PDF) for the industry, hospitals have taken a variety of measures to send less trash to the landfill. Basic recycling efforts are an obvious but potentially significant way to reduce waste without affecting the quality of patient care. Paper and cardboard might account for a full half of a hospital’s solid waste, according to one older estimate.

Other hospitals are experimenting with reprocessing and reusing disposable devices and composting their food waste. Operating rooms have become a special focus of waste minimization efforts: Anecdotal reports from the 1990s suggest that 20 to 30 percent of a hospital’s waste comes from ORs, despite the fact that they take up a relatively tiny amount of floor space.

Hospitals don’t just produce a lot of garbage; they produce fantastically complicated garbage. Besides all the paper, linens, and food waste they generate, they also churn out unused and expired pills, infectious waste (such as blood-soaked bandages and tissues from surgery), hazardous lab chemicals, electronics, and a host of other materials that need to be carefully separated and treated in order to minimize their impact on the planet.

Trash is only one aspect of a hospital’s environmental footprint—they’re also major users of energy. In 2003, health care facilities (which includes not only hospitals but also outpatient clinics and medical offices) gulped down 9 percent of all the energy consumed onsite by the country’s commercial buildings, making them the fourth-largest consumers in the category. On a per-square-foot basis, health care facilities use twice as much energy as the average office building—and hospitals use even more (PDF).

It’s not surprising that hospitals require so much juice: After all, they operate 24 hours a day, seven days a week, and house some very energy-hungry equipment, like MRI machines. Hospitals also cycle air in and out of the building very frequently, tohelp prevent infection. In a typical American hospital, about a fifth of the electricity is used for ventilation, second only to lighting. Still, the EPA estimates that hospitals (like all commercial buildings) can cut their energy use by as much as 30 percent, on average, with improved maintenance and the installation of more efficient equipment.

In terms of emissions, what does that all add up to? In 2007, hospitals generated about 215 million metric tons of carbon-dioxide equivalent, according to a study published in the Journal of the American Medical Association last year. That’s about 3 percent of total U.S. greenhouse gas emissions. (The figure includes the production of all goods that flow through hospitals, not only the emissions generated by onsite operations.) In total, the health care sector contributed 8 percent of the country’s greenhouse gas emissions.

That’s a number that should give the medical industry pause. After all, doctors have a particular reason to worry about climate change, which the World Health Organization has noted “will inevitably affect the basic requirements for maintaining health: clean air and water, sufficient food and adequate shelter.” And air pollution from the health care sector’s own electricity usage increases cases of asthma, respiratory illnesses, and emergency department visits to the tune of $600 million a year (PDF), according to a discussion draft paper published by the WHO and the organization Health Care Without Harm. To fulfill the Hippocratic Oath to “do no harm,” hospitals need to keep the planet healthy along with their patients.

Is there an environmental quandary that’s been keeping you up at night? Send it to ask.the.lantern@gmail.com, and check this space every Tuesday.

Like Slate on Facebook. Follow us on Twitter.