OBJECTIVEExposure 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.

METHODSUsing 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.

RESULTSThe 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.

CONCLUSIONPresent results suggest a decreased rate of elimination of hepta congeners with aging in females, rather than a birth-generation phenomenon.

Acupuncture to Gaohuang carries a risk of causing pneumothorax because it reaches the lungs at deep portion. This study was designed to consider a safe depth for acupuncture to Gaohuang.
1) We inserted a needle to Gaohuang on both sides of a cadaver to examine the location of the needle tip and measure the distance from the body surface of the left Gaohuang to the pleura. The tip was located at the fifth intercostal region on both sides, and the distance was 44 mm with a rib thickness of 10 mm. 2) Using 104 students, we inserted a needle to the left Gaohuang until the tip reached the rib, and measured the distance between the bodysurface and rib. The minimal distance was 14 mm. 3) We inserted a needle to Gaohuang on both sides of two males and took CT-radiographs to examine the location of the needle tip and measure the distance from the body surface of Gaohuang to the pleura. In a man of standard body size, the needle reached the rib on the left and the intercostal region on the right. The thickness of the left rib was 10.9 mm, and the distance from body surface to pleura was 33.6 mm on the left and 28.4 mm on the right. In a man of thin body size, the needle reached the rib on both sides, with the rib thickness was 9.8 mm on the left and 8.8 mm on the right. The distance from body surface to pleura was 29.4 mm on the left and 31.8 mm on the right. The above results showed that needle insertion within 19 mm (the minimal value of the measured distance between the body surface and rib + the half thickness of the rib) is safe.