Species, production, and regional differences in the sum of total PCBs and total PBDEs in serum samples collected across California. Caprine and ovine serum have a greater amount of PCBs (A) and PBDEs (B) compared to bovine serum (n = 145 bovine, n = 17 caprine, n = 10 ovine). Dairy producing cattle have greater amounts of PCBs (C) and PBDEs (D) compared to beef cattle (n = 44 beef, n = 61 dairy). There are no regional differences in the total PCBs (E) and total PBDEs (F) (n = 36 northern, n = 41 bay area, n = 46 central). Plots are showing the 5th–95th percentile. *Significant differences with p values set at p < 0.05, **p < 0.01, and ***p < 0.001.