When the U.S. dropped the atomic bomb on Nagasaki, Michael Koerner’s mother, Kimiko, was an eleven-year-old girl living in Sasebo, a mere forty miles away from the epicenter of the detonation. She grew into womanhood on that irradiated land, and married her American sweetheart—a civil servant with the Department of Defense—after a nine-year courtship. They relocated to the U.S. base in Okinawa, where Koerner was born, and then to Arizona. In 1976, at the age of forty-three, Kimiko received a diagnosis: as a likely result of the nuclear radiation, she had a tumor growing on top of her pituitary gland, causing high spikes of adrenaline to pump through her body in moments of distress. That summer, the family returned from vacation to a home that had been robbed. Koerner was thirteen, with his Japanese mother’s slight wrists; his younger brother was six. The two beach-tired boys followed their parents into the house to inspect the damage. Suddenly, they heard screams, and when they entered the kitchen they saw their mother swinging a ten-inch meat cleaver above her petite body, yelling that she was going to kill the neighbor’s kids. When their father tried to calm her down, she picked him up and threw him against the refrigerator.

In his photo series “My DNA,” currently on view at the Catherine Edelman Gallery, in Chicago, Koerner, a professor of chemistry at the University of Illinois at Urbana-Champaign, confronts the long legacy of the atomic bomb in his family. Kimiko’s diagnosis was the beginning of a string of medical crises. Koerner’s brother, Richard, died of pneumonia in 2002, at the age of thirty-two. Richard couldn’t fight the infection because he didn’t have a spleen–it was removed years earlier as part of his treatment for Non-Hodgkin’s Lymphoma. Around the time of his funeral, Koerner learned, from a cousin, that he had been the eldest not of two boys but of five: three brothers had been lost to crib death, stillbirth, or miscarriage. His mother would die, from complications due to Cushing’s disease, in 2008. “I used to say, ‘Family, what family?’ ” Koerner told me on a recent afternoon. “All of mine are dead.” In “My DNA,” he used collodion tintype, a laborious method of photography that was in vogue during the eighteen-fifties. His process, which involves sloshing, slapping, flinging, and blowing chemicals through a straw, yields abstract works that tackle the subject of atomic radiation through transformation, dilution, and chance—in short, the fraught process of inheritance. “See those fractal patterns, these bursts?” he asked me, pointing at at work titled “Fingerprints #6187.” “They’re mutations.”