Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in blood and breast milk collected from pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0-23 (mean: 13, median: 14) and 2.7-20 (mean: 8.6, median: 8.5) pg TEQ g⁻¹ lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16-326 (mean: 107, median: 100) and 12-252 (mean: 73, median: 67) ng g⁻¹ lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.     

Remediation of cadmium-contaminated paddy soils by washing with calcium chloride: verification of on-site washing

We developed a new, three-step soil-wash method to remediate Cd-contaminated paddy fields. The method comprises (1) chemically washing the field soil with a CaCl2 solution; (2) washing the treated soil with water to eliminate residual Cd and CaCl2; and (3) on-site treatment of wastewater using a portable wastewater treatment system. Cd concentrations in the treated water were below Japan's environmental quality standard (0.01 mg Cd L-1), and the removal of Cd from the exchangeable fraction was 55% and from the acid-soluble fraction 15%. While soil fertility properties were affected by the soil washing, adverse effects were not crucial and could be corrected. The washing had no affect on rice growth, and reduced the average Cd concentration in rice grains by about two-thirds compared to a control plot. These results confirmed the effectiveness of the soil-wash method in remediating Cd-contaminated paddy fields.     

Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling

Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500 degrees C for 1h under nitrogen atmosphere. In order to evaluate the quality of char as fuel, proximate analysis and heating value were examined. The composition of raw waste had a significant influence on the quality of produced char. The higher the ratio of woody biomass in waste, the higher heating value of char produced. Moreover, an equation to estimate heating value of char was developed by using the weight fraction of fixed carbon and volatile matter in char. De-ashing and chlorine removal were performed to improve the quality of char. The pulverization and sieving method seems to be effective for separation of incombustibles such as metal rather than ash. Most char met a 0.5 wt% chlorine criterion for utilization as fuel in a shaft blast furnace after it was subjected to repeated water-washing. Carbonization could remove a considerable amount of organic matter from raw waste. In addition, the leaching of heavy metals such as chrome, cadmium, and lead appears to be significantly suppressed by carbonization regardless of the type of raw waste. From these results, carbonization could be considered as a pretreatment method for waste before landfilling, as well as for fuel recovery.     

Honeybee foragers adjust crop contents before leaving the hive

Upon leaving the hive, foragers carry a small amount of honey, which they subsequently consume to generate energy for flight. We investigated the relationship between waggle-phase duration and crop volume in foragers (both dancers and dance followers) leaving the hive. Our findings indicate that these variables were positively correlated in the two types of bee, suggesting that they were able to adjust the amount of food that they carry depending on the distance to a food source. We also found that dance followers left the hive with a larger amount of honey than dancers. We suggest two possible explanations: (1) dance followers have less information about the location of the food source than dancers, who have a better knowledge of the surrounding area; or (2) honeybees lack a precise calibration method for estimating energy needs from waggle-run duration. The effect of foraging experience was confirmed: bees decreased their honey load at departure with repeated trips to a sugar-syrup feeder. Honeybees showed a different pattern of change when the feeder provided soybean flour as a pollen substitute, possibly because honeybees use honey not only as an energy source but also as “glue” to form “balls” of pollen on their hind legs. Based on our observations that followers of sugar-syrup foragers carry a different amount of honey in their crop than followers of soybean-followers, we suggest that waggle dancers also convey information concerning food type.     

The impact of institutional factors on the performance of genuine savings

This study investigates institutional factors affecting the performance of genuine savings (GS), which are often used in assessing sustainable development, and adopts a model of autoregressive conditional heteroscedasticity in mean. We pay particular attention to the contribution of institutions to decrease the volatility level of the GS path. The estimation results show that there are two ways in which institutions affect GS performance. First, high quality of institutions enhances the GS level directly. Second, high quality of institutions enhances the GS level via stabilizing the volatility of the GS path. Considering both effects in their totality, institutional improvement plays an important role in realizing a sustainable development path.     

New biofidelic corridor and biofidelity test procedure for pedestrian legform impactors

The objectives of this research are to propose a new impact response corridor for the ISO legform impactor and to determine the biofidelity of the current legform impactor with rigid leg and thigh developed by the Transport Research Laboratory (TRL). The latest data obtained from Post Mortem Human Subject (PMHS) knee impact tests were analyzed in connection with the proposal, and biofidelity legform impact tests were conducted using the current rigid legform impactor. New normalized biofidelic corridors of impact force corresponding to adult male 50th percentile (AM50) are proposed. The impact test results indicate the current rigid legform impactor does not have sufficient human knee biofidelity. The present results suggest that human tolerance can not be used directly for the injury reference value of the legform impactor. A conversion method is needed to interpret the data measured by current legform impactors as the injury reference value.