Heavy Metal Pollution of Landfills at Teshima Island in Seto Inland Sea, Japan - Before and after the cover soil treatment on the hazardous waste -

The illegal dumping of industrial waste was exposed at November in 1990. Industrial waste, including shredder-dust, slag, sludge, and the incinerated ash were carried into the Teshima island from 1978. The western part of this island in the Seto Inland Sea, Japan had been used as the illegal landfills for more than 10 years and the accumulated waste was estimated to be about 500,000 tons. The realities of heavy metal pollution for the soil, leachate, marine products, crab, and sea weeds were investigated at around the time of the cover soil treatment on the hazardous industrial waste of the landfill during 1991-1993. Afew reports of analytical results have been reported for chemical components of waste materials, plants, and marine products in Japan. It is characteristic that the concentration of Cu, Fe, Zn, Ni in soil with slag and the incinerated ash were very high, such as 8.3%, 1.5%, 0.9%, 0.1%, respectively

硫化カドミウムの高濃度添加時における小麦の生育とカドミウム集積濃度に対する炭酸カルシウムの影響

In Japan, wheat is usually cultivated from December to June as a second crop in the same field as rice. In Cd-polluted areas, the fields are affected by both wastewater and the emissions from the chimneys of zinc refineries or plating factories. The application of inhibition agents, such as slaked lime, calcium silicate or fused magnesium are applied to inhibit the absorption of these metals by plants. Many reports have been made on the decrease of metal absorption through the application of some form of calcium, phosphate or silicate. Also, it has been reported that wheat is more sensitive to CdS than to CdO. However, almost all experiments were performed at less than 500 ppm Cd in soil, and these experiments have not been made at a concentration close to the level critical for wheat plants. There have been few reports on the effects of calcium cabonate on metal tolerance or metal uptake at the a level critical wheat. The typical example of using calcium carbonate was investigated by Maeda, and the application of phosphate by Koshino, and by Muramoto et al. The effects of calcium carbonate on the metal content of wheat to the critical levels were examined.植物に対する有害金属の生育限界濃度域での実験は極めて少ない。ここでは、小麦の硫化カドミウム（CdS）に対する生育限界濃度と小麦穀粒中カドミウム含有量に及ぼす炭酸カルシウム添加栽培の影響を調べた。その結果、硫化カドミウムに対する小麦の生育限界濃度は1,500ppmであり、その時の小麦穀粒中のカドミウム含有量は123.2μg/g（乾燥物中）であることが判明した。すなわち溶解度の低いカドミウムの化学形においても、穀粒中への集積が生じる結果が表示された。また、炭酸カルシウムの同時添加により、無添加に対して1,500ppm区では穀粒中のカドミウム含有量は57％減少し、小麦の生育限界濃度5,000ppmに拡大された。茎葉長、茎葉重、穀粒重等の各生育項目において炭酸カルシウムの添加効果が見られ、特にカドミウム濃度500-5,000ppmの間では炭酸カルシウム添加によるカドミウム毒性の抑制現象が有意に認められた。このことは高濃度カドミウム汚地域における炭酸カルシウムによる植物保護の一策としての有効性を示唆したと考えられる

Water Quality of L. Taihu in China and the Possibility of Water cleaning by Plant floating culture system -L. Wuli and L. Meiliang-

The water quality of L.Wuli and L.Mei1iang of L. Taihu in China, and the possibility of water cleaning by plants floating culture system were examined. The eutriphication of lake water are strongly affected by both domestic and industrial wastewater because of the about 90% of wastewater without any treatments. Eutrophication has increased in most of the Chinese lake by high anthropogenic input of nutrients with the rapid progress human activity after the 1980s. For almost elements of water of L.Wuli were more polluted compared with those of L.Meiliang. The relation of nitrogen concentration of water was NH(3-)N > NO(3-)N> N0(2-)N in L. Wuli, and NO(3-)N > NH(3-)N > NO(2-)N in L.Meiliang, respectively. From the results of water quality analysis, the nutrient concentrations were increased, but not polluted by some heavy metals and slightly increased by surfactants, anionic surface active agents. It seemed to be able to clean the lake water by plant floating culture methods with using many kinds of plants by the data of another experiments in phytotron and in natural field

The Characteristics of Trace Metal Distribution of Artificial and Natural-Origin Suspended Particulate Matter (SPM) by grain size

Air pollution caused by suspended particulate matter (SPM) has increased remarkedly in industrial areas, and this has become an emergency issue in the global environment. Atomospheric SPM influences the local ecosystem including various plants and animals. It is necessary to examine the distribution characteristics of such trace metals in fine particulates (especially those with a diameter (φ) of less than 2.1μm). The Environment Agency of the Japanese goverment will complete analysis of the a concentration of suspended particulate matter less than 2.4μm by the end of 1999, and will be examining the relationship between the concentration of suspended particulate matter (0.1-9.0μm) with consideration given to the particle size throughout two years. It became clear that the metals of artificial origin such as Pb, V, Cd, Ni, Cr, existed in fine particulates (0.1 or more 2.0μm). By contrast, the metals of natural origin, such as Ti, Mn, Mg, Sr, mainly existed in coarse Area in Japan.浮遊粒子状物質（0.1～9.0μm）中の酸溶解性金属について、各金属の粒径別濃度分布を検討した。ことに人為起減金属と考えられるPb、Cd、Ni,Crは微小粒子（0～2.0μｍ）部分に存在する事が判明した。これに対し天然起源の金属であるTi、Mn、Mg、Sr等は粗大粒子（2.1～9.0μｍ）に多く存在した。すなわち微小部分に存在する人に由来の金属は酸性雨などによる溶解性が大きいと考えられる。そのために人に由来の金属は動植物のみならず人体への影響も引き起こし易い状況にあることが推察された。また本調査地点の倉敷市は立地的には水島工業地帯の北東に位置していること、西風、南西風が卓越した地点であることから、工業地帯の煙突からの放出物質ならびに自動車排気ガス等の汚染の影響を受けやすいことが判明した。発生源同定、発生源対策等の観点からも、今後において浮遊粒子状物質を含むエアロゾルの粒径別の化学組成の研究、特に微小粒子領域における詳細な研究が望まれる。現在の日本の大気汚染防止法は直径100分の1mm以下の浮遊粒子状物質について基準を設けているが、もっと小さい2.5μｍに焦点を当てた基準等の検討も必要であろう。浮遊粒子状物質には、ほこりやちり等の天然由来のものに含まれるのに対して、2.5μｍ以下は排ガス等の人為的な発生源が中心であり、肺の組織の深部まで到達して沈着しやすく健康への影響も大きいことからも、今後より詳細な研究と汚染防止対策が切望される