This study was undertaken to provide reference values for relevant parameters of Chinese Reference Man. Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from autopsies of 68 healthy adult men living in four areas of China with different dietary patterns (Hebei, Shanxi, Sichuan, Jiangxi or Jiangsu provinces, including Shanghai City) who had just encountered sudden deaths. At the same time, whole blood samples were collected from 10 volunteers living in each of these areas. The concentrations of 60 elements in these samples were detected by using inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), neutron activation analysis (NAA), fluorometry (FL), graphite furnace atomic absorption spectrometry (GF-AAS) techniques and necessary quality control (QC) measures. Based on obtained concentrations and reference values of these organ or tissue weights for Chinese Reference Man, the elemental burdens in these organs or tissues were estimated. As a summary report of a series of research studies for Chinese Reference Man, which included three steps (from 1996 to 2006), the concentrations of 60 elements in 18 main organs or tissues were determined and their elemental burdens in the organs or tissues and whole body were estimated. Furthermore, the organ or tissue distributions of some important elements for radiation protection were discussed. These results may provide more reliable and better representative bases than before for establishing related reference values of Chinese Reference Man and revising current reference values of International Commission on Radiological Protection (ICRP) Reference Man. These basic data will also be very valuable for many other applications in radiation protection and other scientific fields.
Objective To assess whether a simple urine based estimate of relative daily nicotine intake could predict smoking related birthweight deficits more accurately than self‐reported cigarette consumption. Design Active smokers were identified by a simple qualitative colorimetric urine test procedure and their relative nicotine intakes assessed by determining the ratios of the urinary concentrations of nicotine plus its metabolites to creatinine using automated colorimetric methods. Setting A large teaching hospital. Participants Three thousand and thirty‐eight mothers from whom smoking histories had been elicited and who gave birth to live singleton babies after 28 weeks of gestation. Main outcome measures Birthweights (adjusted for maternal weight, maternal age, baby's sex, parity and length of gestation), maternal weight gains during pregnancy and placental weights. Results The adjusted birthweight deficits of babies born to proven active smokers averaged 226 g (95 % confidence interval 194 g to 258 g), but dose dependent effects were only apparent when nicotine intake was based on urinary nicotine metabolites/creatinine ratios. Among the smokers, adjusted birthweights fell linearly with increasing nicotine intakes but gave a predicted mean birthweight for nonsmokers that was 102 g (95 % CI 50 g to 154 g) lighter than that actually found (P < 0.0001). Maternal weight gains during pregnancy were substantially reduced in smokers and correlated more closely with urinary nicotine metabolite excretions than with reported daily cigarette consumptions. Placental weights were unaffected by smoking. Conclusions There was a closer dose‐effect relationship between birthweight deficits and urinary nicotine metabolites/creatinine ratios than with self‐reported daily cigarette consumptions. The influence of nicotine exposure on birthweight appears to be biphasic, with one mechanism operating at very low levels of tobacco smoke intake and the other causing seemingly linearly related effects over the whole range of nicotine intakes of active smokers. These findings support recent evidence that passive smoking can cause substantial birthweight deficits.
The objective of the present study was to evaluate the potential effect of environmental exposure to cadmium on pregnancy outcome and fetal growth. Normal pregnant women were selected from Da-ye city of Hubei province, a cadmium-polluted area, from November 2002 through January 2003. Whole blood of pregnant women, cord blood, and placenta were collected and cadmium levels were determined by inductively coupled plasma emission mass spectroscopy. Incidence rate of preterm labor (gestational age < or = 37 weeks) and neonatal asphyxia, neonatal birth height, and birth weight were compared between lower and higher cadmium exposure level groups. Whole blood cadmium of 44 mothers ranged from 0.80 to 25.20 microg/L. Cadmium concentration in maternal blood was significantly higher than that in cord blood (t = 11.44, P < 0.01). Placenta cadmium ranged from 0.084 to 3.97 microg/g dry weight. After adjustment for maternal age, history of gestation, abortion and lactation, Logistic regression analysis showed that there was no significant association between cadmium exposure levels and pregnancy outcome (premature labor or neonatal asphyxia). Multiple linear regression analysis showed that, cord blood cadmium level, but not maternal blood cadmium and placenta cadmium, was significantly negatively associated with neonatal birth height (t= -2.33, P < 0.05). Compared with lower cord blood cadmium level (< or = 0.40 microg/L), higher level of cord blood cadmium (>0.40 microg/L) was associated with 2.24cm decrease in neonatal birth height. There was no significant association between cadmium exposure and birth weight. It was concluded that environmental exposure to cadmium significantly lower neonatal birth height.
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