Paradoxical increases in serum levels of highly chlorinated PCBs in aged women in clear contrast to robust decreases in dietary intakes from 1980 to 2003 in Japan.
OBJECTIVE
Exposure to polychlorinated biphenyls (PCBs) is considered to have culminated between 1950 and 1970 in Japan, and exposure through diet, the major exposure route, has decreased significantly over the last 10 years. The primary goal of the present study was to investigate the long-term trends and congener profiles of serum and dietary levels of PCBs using historical samples.


METHODS
Using banked samples collected in 1980, 1995, and 2003 surveys, we determined the daily intakes and serum concentrations of 13 PCB congeners (#74, #99, #118, #138, #146, #153, #156, #163, #164, #170, #180, #182, and #187) in women.


RESULTS
The total daily PCB intake [ng/day, geometric mean (geometric standard deviation)] decreased significantly from 523 (2.5) in 1980 to 63 (3.2) in 2003. The serum total PCB level (ng/g lipid) in women <40 years of age decreased significantly from 185 (1.8) in 1980 to 68 (1.8) in 2003. In contrast, the level in women >50 years of age increased significantly from 125 (1.7) in 1980 to 242 (1.7) in 2003. Specifically, the serum concentrations of hexa (#138, #146, #153, #156, #163, and #164) and hepta (#170, #180, #182, and #187) congeners increased significantly. A comparison of the serum PCB levels of women born from 1940 to 1953 revealed that their serum total PCB level was significantly higher in the 2003 survey [242 (1.7), n = 9] than in the 1995 [128 (2.0), n = 17] surveys. This increase in the total PCB level was attributable to increases in the hepta congener groups.


CONCLUSIONS
Present results suggest a decreased rate of elimination of hepta congeners with aging in females, rather than a birth-generation phenomenon.
Koizumi
Akio
A
Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo, Kyoto, 606-8501, Japan, koizumi@pbh.med.kyoto-u.ac.jp.
Harada
Kouji H
KH
Eslami
Bita
B
Fujimine
Yoshinori
Y
Hachiya
Noriyuki
N
Hirosawa
Iwao
I
Inoue
Kayoko
K
Inoue
Sumiko
S
Koda
Shigeki
S
Kusaka
Yukinori
Y
Murata
Katsuyuki
K
Omae
Kazuyuki
K
Saito
Norimitsu
N
Shimbo
Shinichiro
S
Takenaka
Katsunobu
K
Takeshita
Tatsuya
T
Todoriki
Hidemi
H
Wada
Yasuhiko
Y
Watanabe
Takao
T
Ikeda
Masayuki
M