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It is suggested that Japanese children may ingest similar doses per body weight of methylmercury to their mothers. If maternal hair mercury was used as a proxy for mercury exposure at birth, no significant dose-effect associations with the BAEP latencies were observed in Japanese children with exposure levels below 6.9 mug/g of hair mercury, but only when higher-level exposures from Madeiran children were included. The BMDL was lower for the merged data than for Madeiran children alone.

Objectives: Exposure misclassification is a major obstacle to obtain accurate dose-response relationships. In order to solve this problem, the impact of hair treatment on total mercury in hair was assessed in Japanese women.Methods: A cross-sectional study was carried out among 327 women at age 24-49 years to determine hair mercury levels and estimate daily mercury intakes from seafood by using a food frequency questionnaire.Results: Hair mercury levels in the women and daily mercury intake ranged from 0.11 to 6.86 (median 1.63) μg/g and from 0.77 to 144.9 (median 15.0) μg/day, respectively. The hair mercury was positively correlated with the daily mercury intake (p<0.001). When the women were divided into two subgroups based on artificial hair-waving, hair coloring/dyeing, residence (non-fishing and fishing areas), and working status, a significant difference in the hair mercury level was observed between the women with and without artificial hair-waving only (p<0.001). The multiple regression analysis showed that the log-transformed hair mercury level was significantly related to the log-transformed daily mercury intake (standardized regression coefficient βs=0.307) and artificial hair-waving (βs=−0.276); but not to hair coloring/dyeing, residence, working status or age. Permanent hair treatment was estimated to reduce total mercury in hair by approximately 30%, after adjusting for daily mercury intake and other possible factors.Conclusions: These findings suggest that hair mercury is not the best biomarker of methylmercury exposure when a study population includes women with artificial hair-waving.

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The present study is aimed to clarify the degree of leanness desired by contemporary young Japanese women using questionnaires and to use allometry to define the body weight boundary between the excessively lean and the others for a given height. Questionnaires on ideal body shape were distributed to female college students living in Akita and the suburbs of Tokyo. Data for 578 respondents, aged 18 to 21 years-old, were analyzed. The questionnaire asked the subjects to report their current and ideal body shape and to make a qualitative self-assessment of their weight. On average, the perceived ideal weight was 5.2 kg lower than the current weight. The results also revealed that young women have a tendency to misunderstand their body shape and to regard themselves as heavier than they really were. Meanwhile, we defined leanness as a state of insufficient lean body mass (LBM, kg) in relation to height (Ht, cm). Allometric equation of LBM on Ht and the standard error of estimate (SEE) were calculated as LBMϭ3.87ϫ10 Ϫ3 ϫHt 1.826 and 1.09, respectively. The LBM boundary between the excessively lean and the others was determined using these values according to a statistical procedure comparing normal and abnormal values. The corresponding total body weight was estimated from the boundary LBM in the literature. Subsequently the body weight boundary for each height was tabulated in order to make young women reconsider weight control. The subjects were asked to assess the body weight boundary for their own height. The boundary values were found to be consistent with the sense of the subjects.

An association between ambient air pollution and reduced cardiac autonomic function assessed by heart rate variability (HRV) mainly in elderly persons has been suggested by a number of epidemiological studies, but the link between the HRV and pulmonary function in humans remains unknown although such air pollution should primarily affect pulmonary function. To clarify this link, pulmonary ventilation parameters such as oxygen uptake (V 4O 2 ) and carbon dioxide output (V 4 CO 2 ), as well as the HRV with spectral analysis (high-and low-frequency components of HRV, i.e., CCV HF and CCV LF , reflecting cardiac parasympathetic and sympathetic activities, respectively), were measured in 66 healthy women aged 19-20 years after an overnight fast of 12 h. Significant correlations were found between the CCV HF of HRV and both the end-tidal carbon dioxide concentration (FETCO 2 ) and gas exchange ratio (V 4 CO 2 /V 4 O 2 ) in the subjects (partial correlation coefficients r = 0.354 and 0.320, respectively), whereas there was no significant connection between the FETCO 2 and the V 4 CO 2 /V 4 O 2 . Similarly, the CCV LF correlated significantly with the resting tidal volume of lung (r = 0.364). These findings suggest that resting pulmonary ventilation function interacts with cardiac autonomic function assessed by the HRV, at least in healthy young adults, which may be useful for explaining the pathophysiology concerning the short-term effect of air pollution such as fine particulate matter on cardiovascular function.

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