Differences in the responses of three plasma selenium-containing proteins in relation to methylmercury-exposure through consumption of fish/whales.

Putative protective effects of selenium (Se) against methylmercury (MeHg) toxicity have been examined but no conclusion has been reached. We recently reported the lack of serious neurological symptoms in a Japanese fish-eating population with high intakes of MeHg and suggested a potential protective role for Se. Here, relationships between levels of Hg and Se in the blood and plasma samples, with a quantitative evaluation of Se-containing proteins, obtained from this population were examined.

Effects of in utero exposure to polychlorinated biphenyls, methylmercury, and polyunsaturated fatty acids on birth size.

The adverse effects of in utero exposure to polychlorinated biphenyls (PCBs) or methylmercury (MeHg), and the beneficial effects of nutrients from maternal fish intake might have opposing influences on fetal growth. In this study, we assessed the effects of in utero exposure to PCBs and MeHg on birth size in the Japanese population, which is known to have a high frequency of fish consumption. The concentrations of PCBs and polyunsaturated fatty acids in maternal blood, and the total mercury in hair (as a biomarker of MeHg exposure) were measured during pregnancy and at delivery.

Demographic, behavioral, dietary, and socioeconomic characteristics related to persistent organic pollutants and mercury levels in pregnant women in Japan.

Persistent organic pollutants and mercury are known environmental chemicals that have been found to be ubiquitous in not only the environment but also in humans, including women of reproductive age. The purpose of this study was to evaluate the association between personal lifestyle characteristics and environmental chemical levels during the perinatal period in the general Japanese population. This study targeted 322 pregnant women enrolled in the Hokkaido Study on Environment and Children's Health.

Methylmercury exposure and neurological outcomes in Taiji residents accustomed to consuming whale meat.

Methylmercury (MeHg) is a major environmental neurotoxicant that causes damage to the central nervous system. In Japan, industrial emission of MeHg has resulted in MeHg intoxication in Minamata and Niigata, the so-called Minamata disease. Humans are exposed to MeHg derived from natural sources, primarily fish and fish predators.

Methylmercury monitoring study in Karakuwacho peninsula area in Japan.

Methylmercury (MeHg) is a worldwide concern owing to its adverse health effects. To explore MeHg exposure burdens and the potential contributing factors in different subpopulations in a peninsula area (Karakuwacho) in Japan, a cross-sectional survey was performed. This study included 189 individuals from 102 families.

Effect of methylmercury administration on choroid plexus function in rats.

Methylmercury (MeHg) is a well-known environmental neurotoxin. The choroid plexus (CP), the main component of the blood-cerebrospinal fluid (CSF) barrier (BCSFB), protects the brain from xenobiotics, similar to the blood-brain barrier. Because CP is considered a critical target site of MeHg-induced neurotoxic damage, functional alterations in CP may be caused in relation to the extent of MeHg-induced brain injury.

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.

Accumulation of inorganic mercury in hair of rats exposed to methylmercury or mercuric chloride.

The concentration of methylmercury (MeHg) in human hair is an excellent marker for its exposure, since a portion of MeHg is taken up from the blood circulation to the hair protein in a dose-dependent manner. However, a small portion of the mercury in human hair is found in the inorganic form, though the mechanism of its occurrence is not well established. Here, we examined the hair uptake of inorganic mercury in the rat.

Historical and geographical aspects of the increasing perfluorooctanoate and perfluorooctane sulfonate contamination in human serum in Japan.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have recently received attention due to their widespread contamination in the environment, as well as in wildlife and humans. We measured the PFOS and PFOA concentrations in historically recorded human serum samples at an age range between 20 and 59 years collected in Kyoto, 20 persons per each time point (n=100), and also the PFOS and PFOA concentrations in human serum samples at an age range between 20 and 59 years from 10 locations throughout Japan (n=200). The historical samples collected from 1983 to 1999 demonstrated that the PFOA concentrations in males and females from Kyoto have increased 4.

Large-scale evaluation of the current level of polybrominated diphenyl ethers (PBDEs) in breast milk from 13 regions of Japan.

Polybrominated diphenyl ethers (PBDEs) were measured in 2004 in 105 breast milk samples collected from 13 regions of Japan (Hokkaido, Akita, Miyagi, Tokyo, Gifu, Fukui, Kyoto, Hyogo, Wakayama, Shimane, Yamaguchi, Kochi and Okinawa). Six congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154) were determined by gas chromatography /mass spectrometry (GC/MS). Total PBDE levels ranged from 0.

Assessment of human exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in Japan using archived samples from the early 1980s and mid-1990s.

Persistent organic pollutants have been linked to various adverse effects on human health. We conducted a retrospective exposure assessment for 11polychlorinated biphenyl (PCB) congeners and 4 polybrominated diphenyl ether (PBDE) congeners. We analyzed paired samples of blood and food duplicate portions collected in the 1980s (1980 survey, N=40) and the mid-1990s (1995 survey, N=40) from females (five participants from each of eight sites per survey) living throughout Japan, from Hokkaido to Okinawa.

Free water 3H concentrations in serum samples collected during 1969-1992 in Akita, Japan.

The measurements for human and environmental samples from the 1960's and 1970's are important to understand the long-term transfer of 3H from the environment to the human body. The authors have previously reported 3H concentrations in diet samples collected in Akita Prefecture during 1969-1988. Serum samples from persons living in Akita Prefecture during 1969-1992 were recently obtained.

Current hair mercury levels in Japanese: survey in five districts.

To understand the current Japanese hair mercury levels, we planned a survey of hair mercury among the general populations of different regions in Japan. The present paper, as the first report of the survey, summarized the results obtained in five districts, Minamata, Kumamoto, Tottori, Wakayama and Chiba. Hair samples were collected at beauty salons, barbershops and primary schools in each district with questionnaires on age, sex, amount and species of fish usually consumed, hair-dyed and artificial hair waving "permanent wave.