Silver speciation in liver of marine mammals by synchrotron X-ray absorption fine structure and X-ray fluorescence spectroscopies

The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise (Phocoenoides dalli), and Baird's beaked whale (Berardius bairdii), whereas Ag(2)S was present in the livers of the striped dolphin (Stenella coeruleoalba) and pygmy killer whale (Feresa attenuata). XRF spectroscopy results revealed that the distribution patterns of Ag and Se in a thin section of the liver of the Franciscana dolphin were the same; this also implied that Ag was associated with Se in the liver. Thus, the interaction of Ag with Se or S may offer significant protection against the toxicity of Ag in marine mammals. The formation of either Ag(2)Se or Ag(2)S might depend on the Hg levels in the liver. Ag(2)Se was observed in liver samples with relatively high Ag/Hg ratio, whereas liver samples with low Ag/Hg ratio contained Ag(2)S.     

Contrasting population structures in two sympatric fishes in the Baltic Sea basin

Detailed multispecies studies on the patterns of genetic variability and differentiation in marine environments are still rare. Using mitochondrial and nuclear genetic markers, we compared genetic variability and population structuring of threespine (Gasterosteus aculeatus) and ninespine (Pungitius pungitius) sticklebacks from the same eleven marine and six freshwater locations within the Baltic Sea basin. Analyses of both marker types revealed a significantly lower degree of genetic structuring in both marine and freshwater populations of threespine than those ninespine sticklebacks. Isolation-by-distance (IBD) was detected across the marine populations in both species, suggesting spatially limited gene flow. However, the levels of genetic diversity and differentiation across the localities were uncorrelated between the two species in both marine and freshwater environments. Accordingly, estimates of effective population sizes were larger and migration rates were higher for three- than for ninespine sticklebacks. Hence, ninespine stickleback populations from the Baltic Sea basin appear to be subject to stronger genetic drift than sympatric threespine sticklebacks, and the proximate reason for this difference is likely to be found from autecological differences between the two species. In accordance with the earlier studies, genetic variability was higher and the degree of genetic differentiation was lower in marine than in freshwater populations in both species.     

Evaluating compost maturity with a newly proposed index based on a germination test using Komatsuna (Brassica rapa var. peruviridis) seeds

A new index for evaluating compost maturity was developed based on a germination test of Komatsuna seeds using water extract from compost. Several compost samples were collected from a kitchen-garbage composting plant to determine an index to evaluate compost maturity. Firstly, some extraction conditions for extracting compost ingredients with water were evaluated using the time course of total organic carbon concentration in water extract. The water temperature of 60?°C, periodic mixing, and extraction period >1 were selected. Secondly, applying these conditions, the germination test was performed using the water extract solutions at several dilution ratios. The relationship between the germination rate and the dilution ratio was expressed using a logistic regression curve. The dilution ratio to give a germination rate of 0.5, defined as DG₅₀, was calculated with the parameters of the curve. Compared with other maturity indices, DG₅₀ was the most effective. Moreover, it has a unique feature in that maturity is quantified even for the compost from which water extract results in a germination rate of 0. This feature can be used to compare the maturity of different kinds of composts and quantify the change in the levels of inhibitory substances in a composting process.     

Maternal exposure to high levels of dioxins in relation to birth weight in women affected by Yusho disease

Background

Studies on the association of maternal exposure to polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) with decreased birth weight in humans have produced conflicting results. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease.

Objective

The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on birth weight.

Methods

Blood samples, obtained from 101 Yusho women (190 births) who gave birth after exposure, were analyzed for congeners of seven PCDDs, ten PCDFs, and four non-ortho PCBs.

Results

Total PCDD TEQ (adjusted beta = − 161.9 g; 95% CI, −265.3 to − 58.6), total PCDF TEQ (adjusted beta = − 105.9 g; 95% CI, −179.5 to − 32.2), and total non-ortho PCBs (adjusted beta = − 178.4 g; 95% CI, −318.3 to − 38.5) levels were inversely associated with birth weight. Significant inverse associations with birth weight were also found for total PCDD TEQ, total PCDF TEQ, and total non-ortho PCB TEQ levels among male, but not female, infants. Significant inverse associations with birth weight were also found for nine congeners among all infants; the adjusted beta coefficients were largest for 1,2,3,6,7,8-HxCDD and smallest for 2,3,4,7,8-PeCDF.

Conclusion

In the setting of exposure to high levels of dioxins, maternal blood levels of PCDDs, PCDFs and PCBs are associated with lower birth weight in Yusho patients. The association exhibited gender-specific differences, as male infants are more susceptible than females to growth restriction induced by in utero dioxin exposures.     

Elution control of radioactive cesium in MSWI fly ash using water repellent treatment

Journal of Material Cycles and Waste Management - Radioactive cesium found in municipal solid waste incineration (MSWI) fly ash can be easily eluted through contact with environmentally sourced...     

Blood levels of PCDDs,PCDFs, and coplanar PCBs in Yusho mothers and their descendants: Association with fetal Yusho disease

Maternal exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) may result in adverse health effects in their children. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease. Yusho mothers delivered descendants with low birth weights and hyperpigmented skin and mucosa, which are characteristic of fetal Yusho disease (FYD). The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on the development of FYD. Blood samples, obtained from 64 Yusho mothers (117 descendants: 10 with FYD and 107 without FYD), were analyzed for congeners of seven PCDDs, 10 PCDFs, and four coplanar PCBs. We investigated the association between the maternal estimated blood levels of dioxins at delivery and the risk of fetal Yusho disease. We also studied the differences in dioxin blood levels in 24 mother–descendant pairs (5 with FYD and 19 without FYD). The estimated levels of total PCDD TEQ, total PCDF TEQ, total coplanar PCB TEQ, and total TEQ in the maternal blood at delivery were associated with significantly increased risk of FYD. The odds ratios, which present the risk of FYD for a 10-fold increase in blood dioxin, were largest for 1,2,3,6,7,8-HexaCDD (odds ratio = 28.6, 95% confidence interval = 1.67–489.9, p = 0.02). The levels of 1,2,3,6,7,8-HexaCDD in both the Yusho mothers and their descendants with FYD were higher than the levels in those without FYD. These findings suggest that 1,2,3,6,7,8-HexaCDD is the most important causative congener for the development of FYD.     

Germination test on Komatsuna (Brassica rapa var. peruviridis) seed using water extract from compost for evaluating compost maturity: evaluating criteria for germination and effects of cultivars on germination rate

Germination tests on the Komatsuna (Brassica rapa var. peruviridis) seed using water extract from compost has often been performed in Japan to evaluate compost maturity; however, most of the germination tests have been carried out without using any rationally defined experimental criteria to determine germination and to explain the influence of cultivars. Here, we performed a series of germination tests to examine the applicability of the experimental criteria for germination and the influence of cultivars on germination rate. Germination rate varied according to the criteria introduced in this paper, and two criteria, "seed size (3)" and "5?mm (2)", were selected for testing. In addition, two types of inhibitory influence, stop and slowness, were observed and compared with the criteria. The logistic regression curve of Logit, a function of germination rate to logarithmic value of the dilution ratio of the water extract was parameterized to compare the effects of the cultivars on germination rate. The statistical analysis of the parameters showed that dilution ratio greatly influenced germination rate, and the cultivar itself also influenced the rate. Consequently, the specific experimental criteria for germination and determining the influence of cultivars were proven to be indispensable for evaluating compost maturity using the germination test.     

A simple and convenient empirical survey method with a soil electrical conductivity meter for incineration residue-derived soil contamination

To facilitate field surveys for identifying areas of incineration residue-derived soil contamination, a simple and convenient method with a soil electrical conductivity meter was examined. First, the leaching test specified by Notification No. 13 of the Ministry of the Environment, 1973, was conducted on 506 samples of 11 types of wastes and compost, and the relationship between the concentrations of toxic elements [total Hg (T-Hg), Cd, Pb, Cr⁶⁺, and As] and values of electrical conductivity (EC) was examined. The results showed that bottom ash and fly ash were wastes with high EC values and that these wastes indicated higher levels of toxic elements. Second, an estimation method for the soil EC value of contaminated soil (ECc) was proposed based on the EC values of noncontaminated soil, and its usefulness was examined. The results of field surveys conducted at sites whose soils were suspected of contamination by dioxins and other pollutants derived from incineration residues showed that the contaminated spots and areas were identified by using ECc values. Moreover, comparison of the elemental contents of soils in terms of Cr, Ni, Zn, Na, K, Ca, Fe, Mn, and others, in addition to the above-mentioned toxic elements (excluding Cr⁶⁺), with those of the potential sources of pollution was verified to be effective for identifying the source of soil contamination.