A decade ago, the desert town of Fallon, Nevada made national headlines when 16 cases of acute lymphoblastic leukemia emerged in children over a short period of time. Health officials declared it the most significant childhood cancer cluster on national record and launched an investigation unprecedented in cost and scope. They never found the cause. Epidemiology is a notoriously difficult science: Out of 400 state and federal investigations of cancer clusters since 1990, only three revealed a culprit. The odds have led many scientists to dismiss clusters as coincidence. But there are other explanations: Could it be that our tools of inquiry are not a match for the complex mysteries we’re trying to solve? And even if they were, disease clusters are often so small that studies have high margins of error, offering no conclusive causal links, when, really, links could exist. “By the time you see a relationship between environmental exposure and a health concern,” says Rachel Morello-Frosch, a professor of public health at the University of California-Berkeley, “you’re basically doing a body count.” “Fallon’s Deadly Legacy” is about the limits of epidemiology and what happens after science fails to explain a traumatic event. The story follows April Brune, whose eleven-year-old son recently died of brain cancer, as she tries to uncover the cause of his illness, believing it is related to the leukemia cluster. Brune makes some startling discoveries–a leaky jet fuel pipeline running beneath her son’s school, a heavy-metal processing facility near to her house–but is discouraged by a shortage of answers and stymied by her community’s collective silence. In the end, the answer is likely a combination of factors: “the culmination of a long chain of unfortunate events — a ’causal pathway’ (as one researcher put it) — each link representing a genetic mutation provoked by toxic exposure, infection, or another challenge to the immune system.” “Saying there’s one particular cause,” the researcher explains, “is a difficult thing to do.”
