Influence of paint chips on lead concentration in the soil of public playgrounds in Tokyo

Lead concentration in the surface soils from 31 playgrounds in a ward in Tokyo was measured to examine if paint chips, peeled off from playing equipment installed in the playgrounds, contribute to elevated Pb concentration in the soil of public playgrounds. Lead concentration in the paint chips sampled from playgrounds ranged from 0.003 to 8.9%. Lead concentration in the surface soil ranged from 15.2 to 237 mg kg(-1) (average, 55.5 mg kg(-1)) and higher Pb concentration was found in the soil near painted playing equipment indicating that paint chips from playing equipment contributed to increase soil Pb level of playgrounds in Tokyo. The degree of peeling-off of paint on the surface of playing equipment in the public playground (peeling-off index: POI) positively correlated with Pb concentration in the soil (Spearman rank-correlation coefficient, r = 0.366, p = 0.043). The stronger correlation between Pb concentration and isotope ratios (207Pb/206Pb and Pb conc., r = 0.536, p = 0.002, 208Pb/206Pb and Pb conc. r = 0.600, p < 0.001) than that between Pb and POI indicated that gasoline Pb contributed more to the playground-to-playground variation in soil Pb concentration. It was concluded that both gasoline Pb of the past and paint chips contributed to increased Pb concentration in the surface soil of playgrounds in Tokyo, though the contribution of paint chips is smaller than gasoline Pb.     

Speciation of the radioactive nuclides in incinerator fly ash of municipal solid waste using sequential extractions

Journal of Material Cycles and Waste Management - The radioactive nuclides in the incinerator fly ashes from municipal solid waste sampled in June 2006 were analyzed with γ-ray spectrometry....     

Advantages and risks of using steel slag in preparing composts from raw organic waste

It had been reported that iron and manganese oxides in steel slag enhanced the production of humic acid (HA) from low-molecular-weight compounds, such as phenolic acids, amino acids, and saccharides. In the present study, this function of steel slag was applied to the composting of raw organic wastes (ROWs). The degree of humification of HAs is an important factor in evaluating compost quality. Thus, HAs were extracted from the prepared composts and the humification parameters were determined, in terms of elemental compositions, acidic functional group contents, molecular weights, spectroscopic parameters from UV–vis absorption and ¹³C NMR spectra. The timing for adding steel slag affected the degree of humification of HAs in the composts. The weight average molecular weight of a HA when slag was added initially (29 kDa) was significantly higher than when slag was added after elevating the temperature of the compost pile (17–18 kDa). These results show that ROWs are decomposed to low-molecular-weight compounds after the pile temperature is elevated and the presence of slag enhances the polycondensation of these compounds to produce HAs with a higher degree of humification. Because the slag used in the present study contained several-tens ng g^?1 to several μg g^?1 of toxic elements (B, Cu, Cr, and Zn), leaching tests for these elements from the prepared composts were carried out. Levels for leaching boron from composts prepared by adding slag (0.2–0.4 mg L^?1) were obviously higher than the corresponding levels without slag (0.05 mg L^?1).     

Dietary patterns and blood levels of PCDDs, PCDFs, and dioxin-like PCBs in 1656 Japanese individuals

The association between dietary patterns and blood dioxin levels has not been fully investigated. The present study population consisted of 755 men and 901 women (aged 15-73 years) living in 90 different areas of 30 prefectures of Japan. Dietary habits were assessed by inquiring about the consumption frequency of 28 foods, food groups and beverages. In addition, the blood levels of 29 polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), and dioxin-like polychlorinated biphenyl (DL-PCBs) congeners were determined by high-resolution gas chromatography/mass spectrometry. The median total toxicity equivalent (TEQ) in the blood, which was calculated on the basis of the toxicity equivalency factors of WHO (2005), was 16 pg TEQ g⁻¹ lipid. Principal component analysis identified five dietary patterns: Healthy diet (high intake of vegetables and fruits); Meat/High fat intake (high intake of meat, meat products, and eggs); Seafood and Alcohol (high intake of fish, shellfish, and alcoholic beverages); Miscellaneous; and Milk products and Alcohol intake (high intake of milk, Milk products, and alcoholic beverages). After adjusting for sex, age, body mass index, and smoking habits, the Seafood and Alcohol pattern scores were significantly related to higher blood levels of total TEQ and PCDDs/PCDFs/DL-PCBs, and the Milk products and Alcohol pattern scores were correlated with higher blood levels of DL-PCBs. More detailed analysis showed that the intake frequencies for alcoholic beverages and seafood were independently and positively associated with total TEQ and the TEQ of PCDFs and DL-PCBs. The association between alcoholic beverage intake and PCDDs was also significant. Analysis of dietary patterns may be useful for identifying the dietary characteristics of individuals with a high dioxin body burden.     

Land-use change and its socio-environmental impact in Eastern Ethiopia’s highland

The Alemaya district (Eastern Ethiopian highlands) is characterized by undulating physiographic features with arid, semi-arid, and humid climatic conditions. This study evaluated socio-environmental changes in land use and land cover during 1985–2011. Screen digitization on remotely sensed data (i.e., Landsat images from 1985 to 2011) was performed to produce 10 classes of land use and land cover. Then, final land-use maps were prepared using a geographic information system following field verification and accuracy assessment. The drying of water bodies, including the prominent lakes Alemaya, Adele, and Tinike, had been the most important environmental change observed. Degraded land, marsh, perennial cropland, and residential areas increased by 37, 438, 42, and 190 %, respectively, whereas grassland, plantation, shrubland, and temporal cropland decreased by 64, 11, 63, and 29 %, respectively. The increase in land degradation (+37 %), the other major observed problem, has made large areas unsuitable for agriculture and has reduced crop productivity. These land-use and land-cover changes have affected both the environment and the livelihoods of local residents; especially the issue related to land degradation requires urgent attention.     

Radiostrontium monitoring of bivalves from the Pacific coast of eastern Japan

In early April 2011, radiostrontium was accidentally released from the Fukushima Daiichi Nuclear Power Plant to the Pacific coast of eastern Japan. We developed a simple procedure to analyze radiostrontium levels in marine mussels (Septifer virgatus) and seawater using crown ether (Sr Resin; Eichrom). Then, we used our method to describe the spatial and temporal distribution of radiostrontium in mussels and seawater on the Pacific coast of eastern Japan from 2011 to 2013 and for 2015. Activity of ⁹⁰Sr in mussels and seawater decreased with distance from the Fukushima Daiichi Nuclear Power Plant and between 2011 and 2013 tended to be higher in areas south of the Fukushima Daiichi Nuclear Power Plant than to the north of it. Activity in mussels and seawater also tended to decrease from 2011 to 2013 and by 2015 had reached levels experienced prior to the Fukushima accident. Our results suggest that radiostrontium discharged from the Fukushima Daiichi Nuclear Power Plant was dispersed by coastal currents in a southerly direction along the Pacific coast of eastern Japan from 2011 to 2013, following which its activity decreased to background levels by 2015.     

Evaluating the fish safety level of river water and wastewater with a larval medaka assay

A larval medaka (Oryzias latipes) assay was proposed to evaluate the fish safety level of river waters and wastewaters. Organic toxicants were 10-100 times concentrated with adsorption cartridges from 4 l of river water or 1-10 times concentrated from 400 ml of wastewater. Toxicity of these concentrated solutions was determined by exposing 48-72 h post-hatch age larvae for 48 h. The method effectively revealed a variation of the median lethal concentration ratio (LCR50) from 13 to >100 in 125 river water samples, and from <1 to >10 in five typical wastewater samples. Ayase River, which takes water mostly from agricultural or household discharge, showed significantly (P<0.001) lower LCR50 than Sagami River that takes natural water as the source. Safety Levels in both Sagami River and Ayase River were influenced by the irrigation activity, LCR50 at some sites showing a seasonal-specific decrease in winter. Pollution from pulp and paper industries contributed to the low LCR50 in several tributaries of Ayase River. Required little manpower in sampling, pretreatment and testing, the proposed larval medaka assay was proved as an efficient tool for screening those high risk sites for priority management.     

Application of a Larval Medaka Assay to Evaluate the Fish Safety Level in Sagami River, Japan

Physico-chemical characteristics of some river and hand-dug well waters used for drinking and domestic purposes in the oil rich Niger Delta area of Nigeria were assessed using standard methods. The concentrations of the parameters in the river water samples ranged in the following order: pH (5.6–6.9), temperature (26.90–28.60°C), turbidity (23–63 NTU), electrical conductivity (52–184 μs/cm), DO (5.4–7.2 mg/l), BOD (21–57 mg/l), TDS (6.0–217 mg/l), PO₄ ³⁻ (0.19–1.72 mg/l), SO₄ ²⁻ (25–36.8 mg/l), NO₃ ⁻ (20.3–28 mg/l), Fe (6.07–15.71 mg/l), Zn (0.04–0.24 mg/l), Pb (0.01–0.17 mg/l), Ni (0.01–0.13 mg/l), Vn (0.01–0.20 mg/l) and Hg (0.001–0.002 mg/l). The concentrations of these parameters in the hand-dug well water ranged in the following order: pH (5.7–6.8) temperature (26–30°C), turbidity (134–171 NTU), electrical conductivity (160–340 μs/cm), DO (5.4–6.4 mg/l), BOD (13–34 mg/l), TDS (110–190 mg/l), PO₄ ³⁻ (0.84–1.84 mg/l), SO₄ ²⁻ (10.6–28.1 mg/l), NO₃ ⁻ (11.3–23 mg/l), Fe (13.17–16.31 mg/l), Ni (0.01–0.02 mg/l), Vn (0.01–0.04 mg/l) and Hg (0.001–0.004 mg/l). The concentrations of BOD, turbidity, NO₃ ⁻ and Fe in the water samples were above WHO and FMENV permissible limits for safe drinking water. The results suggest that the use of such waters for drinking and domestic purposes pose a serious threat to the health of the users and calls for the intervention of government agencies.     

Photochemical generation rates of hydroxyl radical in aqueous solutions containing Fe(III)-hydroxy complex

The rates of photochemical generation of hydroxyl radical at 313 nm in aqueous solutions containing ferric ion at acidic pH were measured by the competitive kinetic method using 2-chlorophenol as a test compound and 1-octanol as a radical scavenger. The quantum yield of hydroxyl radical generation calculated from the rates was about 0.02. From the results, it was suggested that this system could be used as a method of wastewater treatment.     

Aluminum position in Rb-feldspar as determined by X-ray photoelectron spectroscopy

Al/Si configurations in some natural and synthetic Rb-feldspars have been examined carefully by EMPA and XPS analyses. Our results indicate that a small amount of H₂O and excess Si and Al are incorporated in hydrothermally synthesized Rb-feldspar. The quantities of excess Al are 0.056 atoms per formula unit and are negatively correlated with those of the Rb, suggesting the presence of excess Al occupying non-tetrahedral sites in feldspar structures. This leads to incorporation of Al(Al₃Si)O₈ endmember into Rb-feldspars, estimated as one appropriate endmember indication for unusual chemistry of feldspars. In addition, Si2p, Al2p and O1s XPS signals of Rb-feldspars shift drastically toward the higher energy side than those of any natural feldspars. These provide conclusive evidence not only for existence of perceptible excess Si and Al, but also for Al at both extra-framework and tetrahedral sites in feldspar structures.