The last time I went to Bagram Air Field was August 2010. (I hope it’s the last time I ever go there.)  It was a dusty mess, full of construction. And it absolutely stunk — an acrid, bitter smell that wafted from a distance beyond my line of sight. It took maybe three or four days before Bagram’s air left so much residue in my lungs that I was hacking up nasty, discolored phlegm; coughing constantly; sleeping miserably; and sometimes getting nauseous.

I was on Bagram a month. The soldiers I was there to report on served year-long tours, and the airmen I was there to report on served (if I’m not misremembering) seven or eight month tours. Most of them were not there for the first time. They joked to me about “Bagram Lung.” And they explained its origins: a “burn pit” on the far side from where they worked, which incinerated broken furniture, endless sheaves of paper, and human waste. The shit I was breathing in was actually shit. And “burn pits” have been standard practice for in-a-jiff sanitation in Iraq and Afghanistan for decades.

In other words, millions of soldiers, sailors, airmen, Marines and coast guardsmen have served near these pits for decades. They know anecdotally what it does to their health. But they don’t know what it does to their long-term health, because the U.S. military says it lacks sufficient data to draw any conclusions.

Or, at least, that’s what it says publicly. Here’s what it says privately.

For years, U.S. government agencies have told the public, veterans and Congress that they couldn’t draw any connections between the so-called “burn pits” disposing of trash at the military’s biggest bases and veterans’ respiratory or cardiopulmonary problems. But a 2011 Army memo obtained by Danger Room flat-out stated that the burn pit at one of Afghanistan’s largest bases poses “long-term adverse health conditions” to troops breathing the air there.

The unclassified memo (.jpg), dated April 15, 2011, stated that high concentrations of dust and burned waste present at Bagram Airfield for most of the war are likely to impact veterans’ health for the rest of their lives. “The long term health risk” from breathing in Bagram’s particulate-rich air include “reduced lung function or exacerbated chronic bronchitis, chronic obstructive pulmonary disease (COPD), asthma, atherosclerosis, or other cardiopulmonary diseases.” Service members may not necessarily “acquire adverse long term pulmonary or heart conditions,” but “the risk for such is increased.”

The cause of the health hazards are given the anodyne names Particulate Matter 10 and Particulate Matter 2.5, a reference to the size in micrometers of the particles’ diameter. Service personnel deployed to Bagram know them by more colloquial names: dust, trash and even feces — all of which are incinerated in “a burn pit” on the base, the memo says, as has been standard practice in Iraq and Afghanistan for a decade.

Please read the whole thing while I’m on a sub for the next couple days.

There are real policy implications at stake here. After you leave the military, the clock starts ticking: the Department of Veterans Affairs will treat you for any ailment for five years. Afterward, veterans must show that their ailments are related to their service. So if the military denies in public that the burn pits are a long-term health risk, but concedes it privately, then the government put millions of this generation’s veterans at risk and will shaft them when the risks manifest.

And now to do something safer, like going on a submarine.