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Numerous reports have elucidated different statistical approaches to identify temporal trends in atmospheric persistent organic pollutant (POP) time series. However, the correlation of industrial activity with concentrations of atmospheric POPs in Japan has not yet been determined. Herein, a panel data analysis of a 16-year monitoring program (2003–2018) conducted by the Japanese Ministry of Environment was used to investigate a range of POPs in the atmosphere above Japan. This work focuses on polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), and pentachlorobenzene (PeCBz) collected each year at 53 sites across Japan. The panel analysis revealed that PCB, PCN, and PBDE concentrations were influenced by a combination of factors including year, industrial activity (municipal and industrial waste incinerators, cement kilns, steel industry, and secondary zinc production), population, temperature, and atmospheric boundary layer. However, HCB and PeCBz were not significantly affected by these factors. Industrial activity showed stronger positive correlations with all homologues of PCBs, PCNs, and PBDEs as compared to those demonstrated by population. Significant decreasing trends were identified for the atmospheric ∑ P B D E s (half-life t1/2 = 9.4 years), ∑ P C N s (t1/2 = 8.9 years), and ∑ P C B s (t1/2 = 13.5 years) concentrations, while HCB and PeCBz showed slightly increasing or steady levels. As a statistical tool, panel data analysis can contribute to the assessment of spatial and temporal trends of POPs at a national scale, while elucidating different behavioral responses to numerous environmental variables.

In this study, the amount of prevented household waste in Kyoto city was quantified using three methods. Subsequently, the greenhouse gas (GHG) emission reduction by waste prevention was calculated in order to monitor the impact of waste prevention. The methods of quantification were "relative change from baseline year (a)," "absolute change from potential waste generation (b)," and "absolute amount of activities (c)." Method (a) was popular for measuring waste prevention, but method (b) was the original approach to determine the absolute amount of waste prevention by estimating the potential waste generation. Method (c) also provided the absolute value utilizing the information of activities. Methods (b) and (c) enable the evaluation of the waste prevention activities with a similar baseline for recycling. Methods (b) and (c) gave significantly higher GHG reductions than method (a) because of the difference in baseline between them. Therefore, setting a baseline is very important for evaluating waste prevention. In practice, when focusing on the monitoring of a specific policy or campaign, method (a) is an appropriate option. On the other hand, when comparing the total impact of waste prevention to that of recycling, methods (b) and (c) should be applied.

The purpose of this study was to quantify the life-cycle greenhouse gas (GHG) emissions reduction that could be achieved by replacement of fossil-derived materials with biodegradable, biomass-based materials for household plastic containers and packaging, considering a variety of their treatment options. The biomass-based materials were 100% polylactide or a combination of polybutylene succinate adipate and polylactide. A scenario analysis was conducted considering alternative recycling methods. Five scenarios were considered: two for existing fossil-derived materials (the current approach in Japan) and the three for biomass-based materials. Production and waste disposal of 1 m3 of plastic containers and packaging from households was defined as the functional unit. The results showed that replacement of fossil-derived materials with biomass-based materials could reduce life-cycle GHG emissions by 14–20%. Source separation and recycling should be promoted. When the separate collection ratio reached 100%, replacement with biomass-based materials could potentially reduce GHG emissions by 31.9%. Food containers are a priority for replacement, because they alone could reduce GHG emissions by 10%. A recycling system for biomass-based plastics must be carefully designed, considering aspects such as the transition period from fossil-derived plastics to biomass-based plastics.

In this study, we aim to determine the correlation between the height of the atmospheric boundary layer (ABL) and the concentrations of polybrominated diphenyl ether (PBDE) congeners, in an effort to improve comprehension of the atmospheric behavior of PBDEs. We used the PBDE data in air (n = 298), which were measured by the Japan Ministry of Environment (JMOE) at 50 sites across Japan during the period 2009-2012. The height of the ABL, which directly affects the PBDE concentrations in the near-surface air, was estimated by employing data retrieved from the Japanese global reanalysis (JRA-55) database, using the parcel and Richardson number method. The ABL has shown a strong inverse relationship with BDE-47 and BDE-99 (p0.01). In contrast, there was less correlation between BDE-209 and the ABL (p = 0.258). These differing behaviors could be explained by differences in particle size distribution of PBDEs, where BDE-47 and BDE-99 are associated with gas phases and fine particles and BDE-209 is associated with coarse particles. To our knowledge, this paper represents the first large-scale analysis of correlations between the ABL and the concentrations of PBDEs in the air.

A simplified life cycle assessment was conducted to estimate greenhouse gas (GHG) emissions and energy production from each component of biogenic waste treated in an open dumping site, and by composting, anaerobic digestion, and incineration employed with additional options. The impact of uncertainties and sensitivities of the parameters in the treatment methods were investigated. We conducted a sensitivity analysis to identify the most sensitive parameters, and we discussed the relationship between uncertainty and sensitivity. Our results revealed that the moisture content of food waste and the biomass-derived carbon and methane concentration of the landfill gas of biogenic waste subjected to open dumping are the most sensitive parameters across all the treatment methods. The net GHG emissions from food waste treated in an open dumping site ranged over ten times (0.30 − 3.67 Gg CO2 eq/Gg). In addition, by employing additional options for the open dumping site, including soil cover, a landfill gas collection system, shifting to a semi-aerobic condition, and energy conservation by using a gas engine, we found that the net GHG emissions could be reduced by 10, 27.9, 37.4 %, and up to 56.7 %, respectively. Shifting to a semi-aerobic system is the most effective method for reducing GHG emissions, followed by landfill gas collection.

国内都市部の一例として京都市を対象に，都市ごみ中のバイオマスである厨芥類および紙類の賦存量を推定した。厨芥類の発生量は22.2万ton-wet/年，紙類は22.3万ton-wet/年であり，ほぼ全量が焼却処理されている。これらを対象に利用システムの温室効果ガス (GHG) 削減効果およびエネルギー回収率を評価した結果，「バイオガス化 (高温乾式メタン発酵)＋ガスエンジン発電 (GE)」は既存の「直接燃焼＋蒸気発電」，「直接燃焼＋堆肥化」よりも有利であった。また，バイオガス発電時の廃熱を利用する超高温可溶化技術を組み込んだ可溶化システムでは，現状の乾式方式に対してエネルギー回収率およびGHG削減効果で27%の向上が見込まれた。さらに，バイオガスの燃料電池利用により，GE利用の最大1.7倍まで効果向上が期待された。国内温室効果ガスの削減に向けて都市ごみ中バイオマスの高度なエネルギー変換技術の普及が望まれる。

This study analyzed polyhalogenated compounds (PHCs) such as brominated flame retardants (BFRs) in indoor air and dust samples from two modern homes in Japan. Concentrations of polychlorinated biphenyls (PCBs) and 2,4,6-tribromophenol (2,4,6-TBP) in exhaust and indoor air of two houses were detected at 10(2)-10(3)pgm(-3) order, which were well above those in outdoor air. For dust samples, the detected polybrominated diphenyl ether (PBDE) and polybrominated dibenzo-p-dioxins/furan concentrations resembled values found in our past study. Interestingly, compared to PBDE concentrations, two orders of magnitude higher concentration (13000 ng g(-1)) was observed for hexabromocyclododecanes (HBCDs) in a dust sample from one house. Based on the calculation of air/dust partition ratio values (Kad), low Kad values (log Kad

Aimed to give a preliminary image of dioxin pollution in China, chemometric analysis was performed to determine background dioxin levels during the period 1994-2002 and potential emission sources. Using principal components analysis (PCA), the congener profiles of 71 sediment samples from rivers, lakes, and sea bays around China were compared with the congener profiles of various known or suspected industrial, residential, and municipal dioxin sources to determine whether the dioxin residues typically found in a broad range of potential environmental sources could explain the presence of these chemicals in China. It was found that the background dioxin levels of China were similar to those of lightly polluted samples from other countries during the period 1994-2002. Primary ferrous ore sintering and secondary lead and aluminum smelters were the major sources of dioxin emission in China. Chloranil and wastewater from chemical plants, sodium pentachlorophenate, and pulp bleaching were also important sources of dioxin emission. Open burning of e-waste as well as diesel-fueled and leaded gas-fueled vehicles were additional possible sources of dioxin. In contrast to other countries, in China, flue gases from incineration of municipal waste, hazardous waste, and medical waste might be minor sources of dioxin emission.

We used polybrominated diphenyl ether (PBDE) data in air at 38 sites across Japan (2009-2012), which were measured by the Japan Ministry of Environment (JMOE), to elucidate the time trend and seasonality of atmospheric PBDEs. In order to address few (7% for BDE-47) to many (63% for BDE-153 and 183) non-detect data, Tobit model, also called a censored regression model was used. The model revealed that the concentrations of PBDE congeners were influenced by a combination of year, temperature, rainfall rate, and population density. Greater declines were observed for BDE-47, -99, -153 and -183 (-21, -25, -17, -23%/year, p < 0.05) than for BDE-209 (-6%/year, p = 0.065). These trends were consistent with the estimated trends of penta-, octa- and deca-BDE contained in in-use products based on domestic demand for PBDEs in Japan and product lifespan. Seasonal patterns were opposite for light congeners (BDE-47 and -99), which increased with temperature, and heavy congeners (BDE-183, and -209), which decreased with temperature. Temperature-dependent emission (evaporation) for light congeners and temperature-independent emission (abrasion) for heavy congeners, coupled with seasonality of atmospheric boundary layer height, might explain these seasonal patterns. Human population density showed a positive correlation with all PBDE congener concentrations, whereas PBDEs showed negative correlation with rainfall rate.

バイオ資源・廃棄物等について, 各市町村の統計データを基に賦存量を推定し, 資源品目毎に1自治体あたりおよび1人あたり賦存量と人口規模との関係を整理した。農産系・林産系・畜産系バイオマスでは人口規模が小さいほど1人あたり量や累積賦存量 (一定の人口規模の自治体での総量) が多くなるのに対して, 廃棄物系バイオマスでは逆の傾向を示すことが明らかになった。また, 厨芥類を対象として, 燃料電池でのバイオガス利用を含む4つの処理シナリオを設定し, 人口規模小の地域 (農村部) および人口規模大の地域 (都市部) をモデルに温室効果ガスを評価項目としたケーススタディを行った。焼却や堆肥化と比較してメタン発酵によるバイオガス回収・発電利用はCO2排出量が少ないこと, 燃料電池はガスエンジンよりもCO2削減効果が大きいこと, 農村部と都市部の違いがシナリオの評価に影響することが示された。

Intake fractions (iFs) for emissions to air, water, and soil for 17 PCDDs/DFs and 12 Co-PCBs were calculated with a level III multimedia model and a food-chain exposure model in succession. The two integrated models were tested by comparing the predicted and measured concentrations in the environment and by comparing intakes through food. Measurement-based iFs were also calculated and compared with the model-based iFs. The air concentrations predicted by the fate model were close to the median of the observed concentrations, whereas the predicted soil and water concentrations were one-third to one-tenth the observed concentrations. This difference was large in case of PCDDs and Co-PCBs, which was explained by the past pollution such as commercial PCB products and PCDD impurities in chloronitrofen (CNP) and pentachlorophenol (PCP). For fish, the predicted and observed exposures agreed well each other. For meat and milk, the predicted exposures were about 10 times the observed exposures for PCDDs/DFs, whereas the predicted and observed values agreed well for Co-PCBs. When the model was modified to consider feeding of fish meal to livestock and geographic bias in feed-grass production, the predicted congener profile was comparable to the measured profile. The comparison also suggested that chickens should be modeled separately from other terrestrial livestock. The model-based iFs for air emission of OCDD and 2378-TCDD were 0.001% and 0.1%, respectively. The iFs of most Co-PCBs were higher than those of PCDDs/DFs. These iF differences suggest the importance of the fate factor in assessing emissions of the 29 congeners.

PCB廃棄物処理事業の費用効率性を既往対策 (廃棄物焼却炉ダイオキシン類対策事業) と比較した。比較には, 同一の環境運命・曝露モデルによって算出した摂取量削減量あたりのコストを用いた。対策コストは既報の値を用い, 摂取量削減量は既報の放出量削減量をモデルの入力として, 環境運命・曝露モデルによって推定した。評価期間は, 現世代にとっての費用効率性という視点から, 30年間とした。PCB処理事業による摂取量削減量の上限は, 大気放出削減時0.8g-TEQ, 水系放出削減時5.79-TEQ, 土壌放出削減時1.6g-TEQと推定され, 焼却炉対策事業での摂取量削減量は3.5～11g-TEQと推定された。また, 摂取量削減量あたりコストはPCB処理事業で0.27～1.9億円/mg-TEQ, 焼却炉対策で0.67～2.1億円/mg-TEQと同程度となった。PCB処理事業は焼却炉対策と同程度の費用効率性を有するといえる。

ヘキサクロロベンゼン (HCB) 排出量の推定と動的環境挙動モデルによるHCBの運命予測を組み合わせ, 底質中HCB濃度トレンドを推定した。HCB発生源として農薬 (PCP, PCNB, TCTP) 不純物, テトラクロロエチレン蒸留残渣焼却, 都市ごみ焼却を考慮した。この底質トレンド推定結果を琵琶湖北湖東岸と大阪湾西宮沖の底質コア濃度実測値と比較した。底質到達への時間遅れにより, HCB排出量トレンドとHCB底質濃度トレンドの差違を部分的に説明できた。琵琶湖と大阪湾の底質トレンドの違いは, 発生源と流入経路の違いを反映したものと思われる。

Television (TV) set components are highly flame resistant, with their added brominated compounds such as polybrominated diphenyl ethers (PBDEs). These compounds might be released indoors via dust, which presents a potential exposure pathway for humans in the home environment. In this study, we collected dust from inside TV sets and TV set component samples (parts of housing front cabinets, rear cabinets and circuit boards) of five sets used in Japan. We measured BFRs (i.e., PBDEs, tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs)) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/DFs). Analytical results of the TV components showed that the concentrations of PBDEs, TBBPA and PBDFs (48,000 microg/g, 19,000 microg/g and 9600 ng/g as mean values, respectively) were all highest in the rear cabinets. The SigmaPBDD concentrations (460 ng/g as a mean value) detected were highest in the circuit board samples. The respective SigmaPBDE and SigmaPBDF concentrations in the dust samples were 67-500 microg/g (mean 300 microg/g) and 180-650 ng/g (mean 410 ng/g). Such concentrations were 2-3 orders of magnitude higher than those previously reported for house dust samples, which suggests that the brominated compounds are transferred from TV components into dust. Comparison of congener patterns of the brominated compounds in the dust identified the components as the source of these BFRs.

The Chinese Government ratified the Stockholm Convention on Persistent Organic Pollutants (POPs) on 25 June 2004. As a party to the Convention, China is preparing its National Implementation Plan (NIP), which must be finished and submitted to the Conference of the Parties before November 11, 2006. The emission inventory and strategy for reducing unintentionally formed products is a very complex and difficult part of the NIP. In this paper, we analyzed the potential sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in China and calculated their possible emissions. We included municipal solid waste incineration, hazardous and medical waste incineration, pulp bleaching, sodium pentachlorophenate production and usage, illegal electrical and electronic waste ("e-waste") recycling, and ferrous and non-ferrous metal production, and prepared a preliminary analysis of dioxin emissions in China. The results show that ferrous metal production (104.2-6648.3g TEQ), non-ferrous metal production (2.6-3389.8 g TEQ), and sodium pentachlorophenate production and usage (120-368.0 g TEQ) should be major potential sources of dioxins and furans. Moreover, municipal solid waste and hazardous and medical waste incineration (35.5 g TEQ) should also be considered high priority sources owing to a rapidly increasing incineration ratio anticipated for the near future.