Complete blood cell counts and blood chemistry in Yusho

Background:

Because of their lipophilic nature, polychlorinated biphenyls (PCBs) bioaccumulate in the food chain and their residues have been detected in foods. Consequently, they accumulate readily in the human body. Reports suggest that PCB blood levels remain constant or increase. Little, however, is known about the long-term hazardous effects of PCBs and dioxins on human health. Yusho is a type of food poisoning caused by PCBs and dioxins that contaminated rice bran oil. We analyzed blood samples of the Yusho patients from 1986 to 2002, and studied changes in blood cell counts, blood chemistry and tumor markers.

Participants and methods:

A population of 1041 patients was divided into patient and control groups based on the diagnostic criteria established for Yusho and participant's blood polychlorinated quarterphenyl (PCQ) levels. In total, 1666 blood and 1652 urine samples from 374 patients in the patient group (PCQ levels = 0.1 ppb), and 373 blood and 302 urine samples from 151 people in the control group (PCQ levels < 0.02 ppb) were analyzed. Blood levels of PCBs, PCQs, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined, and we analyzed their correlation with the data of complete blood cell counts, blood chemistry and urinalysis.

Results and conclusion:

Blood analyses, blood chemistry and urine values in Yusho patients were not significantly different from those in the control group 34 years after the Yusho incident. PCBs, PCQs or PCDFs may, however, affect hematogenesis, serum potassium, serum phosphorus, protein metabolism and creatine kinase metabolism because these parameters had slight but significant correlations with the levels of PCBs, PCQs or PCDFs. Exposure to PCBs and the related organochlorine compounds should be avoided.