4-52, a human-relevant PCB 52 metabolite (Shimada et al., 2016), was continuously released in vitro from implants containing 0 (sham), 1, 5, or 10% of 4-52 over 28 days. The percentage of 4-52 released is shown for both (A) daily and (B) cumulative release from the implants. These implants were incubated in PBS with 10% bovine calf serum at 37 °C. Data are expressed as mean ± standard deviation (n=3).