Levels and profiles of organohalogenated contaminants in human blood from Egypt

- PBDEs, PCBs and OCPs were determined in 67 human blood samples from Egypt.
- No significant differences between colorectal cancer patients and control group.
- ΣDDT and ΣOCPs increased significantly with age and BMI.
- PBDEs and PCBs in serum of Egyptians are among the lowest worldwide.

Concentrations of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and some organochlorine pesticides (OCPs) were determined in serum of Egyptian colorectal cancer patients (n = 35) and compared to a healthy control group (n = 32). p,p′-DDE (the major metabolite of DDT) was the most frequently detected contaminant with the highest concentration (median = 131 ng/g lw) in all studied serum samples. BDE-209 was the least frequently detected contaminant with a median concentration <0.3 ng/g lw. The contamination profile in patients and controls was almost identical with p,p′-DDE showing the highest median contribution (77%) and oxychlordane the lowest (1%). The low p,p′-DDT/p,p′-DDE ratio (3.7%) in serum implies bioaccumulation and past exposure to DDT (c.f. recent and ongoing intake). Statistical analysis revealed no significant differences (P > 0.05) between the levels of target contaminants in serum of patients and the control group. Gender, age and body mass index (BMI) were investigated as potential factors influencing serum contaminant levels. ΣDDT, hexachlorobenzene and pentachlorophenol concentrations showed significant positive associations with age and/or BMI of the participants. Comparison with other countries revealed concentrations of PBDEs and PCBs in Egyptian serum among the lowest reported worldwide.