Refinery workers face 2.4x elevated leukemia risk from chronic benzene exposure

A study of 2,264 Swedish oil refinery workers found 10 cases of leukemia among refinery operators -- a standardized incidence ratio of 2.4 (95% CI: 1.18-4.51), meaning they developed leukemia at 2.4 times the expected rate. All leukemia cases occurred exclusively among workers who directly operated refinery equipment, not office or support staff. Italian refinery worker studies found a similar pattern: four deaths from acute myeloid leukemia, all after 20+ years of latency, with risk doubling for the longest-duration workers. In the U.S., 13 refineries released benzene above EPA action levels in 2020 alone. The people who suffer are the roughly 40,000 U.S. refinery workers -- welders, pipefitters, unit operators -- who face chronic low-level benzene exposure during turnarounds, tank cleaning, and routine maintenance. Why does it hurt? Benzene-induced leukemia has a 20+ year latency period, so workers are diagnosed long after exposure, making it nearly impossible to prove causation for workers' compensation claims. Why does this persist? Refineries are permitted to release benzene up to certain thresholds. Fenceline monitoring only began in 2018. Short-term exposure during turnarounds can spike far above annual averages but goes unrecorded in cumulative exposure assessments.