Search

Abstract: In this paper, we determined the concentrations of antimony species (antimonite (Sb(III)), antimonate (Sb(V)) and dissolved inorganic antimony (DISb)) and arsenic, in Bohai Bay seawaters, as well as the relationships of the analytes with environmental factors such as seawater characteristics (e.g., suspended particulate material (SPM), salinity and total organic carbon (TOC)), heavy metals, nutrients and phytoplankton species, and evaluated the sources of arsenic and antimony. Dissolved arsenic and antimony concentrations in the surface waters were ranging spatially from 1.03 to 1.26ng/ml and 0.386 to 1.075ng/ml, with mean values of 1.18 and 0.562ng/ml, respectively. Sb(V) as the prominent chemical species constituted about 89%. Regarding arsenic concentrations in the surface waters, there was a tendency for a small variation. However, antimony species concentrations were much variable than arsenic. The highest arsenic and antimony concentrations were found near the Haihe Estuary. These distribution patterns were controlled mainly by environmental factors, biological activities and sources. In this region, DISb and Sb(V) negatively correlated with salinity. Besides, arsenic and antimony correlated well with the nutrients, chlorophyll a and phytoplankton, implying that arsenic and antimony had been involved in biological cycling. In addition, according to our estimate, about 333.5×108 mg/year of arsenic and 454.2×108 mg/year of antimony reached Bohai Bay via rivers. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether there is an association between diameter of bacille Calmette-Guérin (BCG) scars and effect of purified protein derivative (PPD) reaction and to determine whether vitamin A (VA) combined vitamin D (VD) supplementation influences the immune response to BCG revaccinated in Chinese infants., Methods: A cross-section and 3-month community-randomised trial was conducted. A total of 5 629 infants at 3, 6 and 12 months of age in Junan County of China were examined for BCG scar formation. Then, 597 revaccinated infants were randomly assigned to supplementation (n=307) and control (n=290) groups. The supplementation group were daily assigned to 1 500 IU VA and 500 IU VD for 3 months. Then all infants were subjected to skin test with PPD., Results: The diameter of BCG scars was positively correlated with diameter of skin indurations of PPD (r=0.17, P<0.05) in the 5 629 infants. The rate of positive response to PPD was higher in the supplementation group than in the control group (96.1% versus 89.7%, P<0.05, prevalence ratio 1.07, 95% CI 1.02-1.12). The prevalence ratio of PPD response for the supplementation group compared with that for the control group was 1.07 (95% CI 1.01-1.13) for the males and 1.08 (95% CI 1.00-1.17) for the females. For the supplementation group, the males got larger tuberculin induration than the females [(0.73±0.21) cm versus (0.67±0.20) cm, P<0.05) after intervention., Conclusions: The diameter of BCG scars was effectively correlated with PPD response, which indicates BCG scar formation may be an useful tool to evaluate the effect of tuberculosis prevention. VA combined VD supplementation may play an immuno-regulatory role in BCG revaccination. This may contribute to the prevention of childhood tuberculosis., (Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

The contents of Cu, Pb, Zn, Cr, As and Hg in surface sediment from 14 sampling sites in the Huanghe estuary during July-August, 2011 were measured to investigate environmental geochemical characteristics of heavy metals related to multiple factors. The distribution, relationship with fine fraction and TOC, and sediment quality assessment concerning heavy metals were analyzed. The results showed that average concentrations of Cu, Pb, Zn, Cr, As and Hg in the Huanghe estuary were (16.5 +/- 2.7), (16.0 +/- 3.4), (21.0 +/- 3.3), (17.4 +/- 3.1), (6.5 +/- 1.2), (0.0444 +/- 0.0307) mg x kg(-1), respectively, which were lower than those in other typical areas along the coast of China. The distribution of metals displayed higher profiles in south than that in north of the Huanghe estuary, with a trend of increase seaward, especially for stations in southwest of the Laizhou bay. The insignificant correlation among metals indicated the complex sources of heavy metals in flood season. Pearson correlation was also conducted between metal contents and percentage of fine particulates and TOC, which was also insignificant, suggesting heavy metal concentration and distribution in the study region were also controlled by other factors except grain size and TOC. There was a good correlation between clay fraction and TOC (r = 0.724, P < 0.05), indicating TOC tends to accumulate in clay. Compared with variety of background values and an internationally used consensus-based sediment quality guidelines (CBSQGs) for saltwater ecosystem, heavy metals in surface sediments from the Huanghe estuary implied a low probability of toxic effect, despite a sharp contamination trend pertaining to Hg and Pb since 1980s.

The geochemical characteristics of nitrogen forms in different grain size sediments of Jiaozhou Bay were investigated employing the sequential extraction technique. Results showed that the transferable nitrogen in Jiaozhou Bay sediments can be divided into four forms, ion exchangeable form (IEF-N), weak acid extractable form (WAEF-N), strong alkaline extractable form (SAEF-N) and strong oxidant extractable form (SOEF-N). The percentages of nitrogen forms for transferable nitrogen in different grain size sediments were different. Generally, for all grain size sediments, the SOEF-N was the primary form accounted for 35.38%, 44.38% and 58.69% of transferable nitrogen for fine, medium and coarse sediments. And for medium and coarse grain size sediment, SAEF-N was the dominant inorganic nitrogen accounted for 26.31% and 25.85%, respectively. And for fine-grained sediments, IEF-N was the primary inorganic nitrogen accounted for 27.67% of transferable nitrogen. The correlation analysis showed that generally, nitrogen was positive correlated with fine and medium grain size but negative correlated with coarse sediments. In addition, nitrogen in different grain size sediments had also positive correlations with phytoplankton abundance, chlorophyll-a and NO3- concentrations of overlying water. The results showed that sediments had great influences on element concentrations of overlying water, and on the other side, it also illustrated that sedimentary nitrogen was an excellent indicator of hypereutrophication and had essential environmental significance.

The geochemical characteristics of phosphorus forms in different grain size sediments, the influencing factors as well as the bioavailability of phosphorus in Jiaozhou Bay were investigated employing the sequential extraction method. The results showed that inorganic phosphorus was the dominant form of total phosphorus and organic phosphorus was only the minor part. The detrital carbonate-bound phosphorus was the largest part of total phosphorus. The grain size, organic carbon, temperature, pH and etc. are the main controlling factors of phosphorus in sediments. Except for Ca-P, most of other phosphorus forms contents increased as the grain size decreased. The bioavailability research showed that the bioavailable phosphorus was mainly the exchangeable phosphorus, phosphorus bound to Al and Fe and organic phosphorus. Moreover, the potential bioavailable phosphorus proportion in total phosphorus increased as the grain size decreased. The bioavailable phosphorus in different grain size sediments has positive correlationship with phytoplankton abundance and phosphate in overlying water.

Phosphorus is a key biogenic element and plays an essential role in global biogeochemical cycles. The geochemical characteristics of phosphorus as well as the controlling factors and the environmental marker function in Jiaozhou Bay sediments were presented. The different forms of sedimentary phosphorus were studied in three sediment cores, which are forms of inorganic phosphorus, exchangeable phosphorus, phosphorus bound to Al-Fe, and calcium, occluded phosphorus as well as total phosphorus and organic phosphorus, respectively. The vertical profiles of various forms of phosphorus in response to 210Pb chronological studies of sediment cores were investigated in order to reveal sedimentary environment changes. The results showed that inorganic phosphorus was the dominant form of total phosphorus and organic phosphorus was only the minor part. The detrital carbonate-bound phosphorus was the largest part of total phosphorus. The concentrations and burial fluxes of phosphorus were controlled by source and environmental factors including pH, salinity, temperature and grain size of sediments etc. Moreover, the analysis of OC/OP ratios suggested that the terrestrial inputs were the dominant source of Jiaozhou Bay sediments. The sedimentation fluxes of phosphorus increased in the past two decades, as a result, the pollution was still serious from the 1980 to 2000. But the state has greatly improved since 2000. The Fe-P, Al-P and Oc-P have close relationships with the degree of pollution and may act as good indicators for environment pollution in Jiaozhou Bay.