The number of cattle has increased rapidly according to the increase of the population and the meat's demand. From old time, cattle have eaten grass and crop wastes, offered beef, milk, hides, manure and fuel energy, and worked as beasts of burden. In modern days, overgrazing of cattle has caused range degradation and ranchers have converted much tropical forest to cattle pasture. Especially in the developed countries, livestock producers have adopted feed grain faming in feedlots. Much animal waste from large livestock facilities has polluted rivers and groundwater.We research into global environmental burdens on livestock farming. Moreover we study the extent of cattle's contribution to global emissions of greenhouse gases(GHG). For example there are emissions of methane from rumina and CO₂ from breath. Decrease of CO₂ absorption comes from rangeland degradation and deforestation. N₂O is discharged from fertilizer use on cropland for feed. In the total we estimate 25% in CO₂, 19% in methane and 18%(with uncertainty) in N₂O as contribution of anthropogenic GHG emissions, taking the above vegetative degradation into account. The required menthane's reduction rate to stabilize concentration is 10% to all anthropogenic emission because of short life in troposphere. Therefore we can conclude catte's contribution to methane emission is great. On the other hand, reduction rates of CO₂ and N₂O are required to be more than 60% and 7080% respectively. So we can not solve the problem of the global warming even if cattle farming is stopped in the world.

View full abstract

It is a distinctive feature for Aomori Prefecture that the forest and agricultural ecosystems which are carrying out CO₂ fixation through photosynthesis occupy 90 % of the land area. The scales of secondary and other extremely degree industries and human community which are releasing a large amount of CO₂ through consumption of materials and energy are highly limited. In this study, Aomori Prefecture was treated as a regional ecosystem. Plant biomass and net primary production on this regional ecosystem on carbon basis were calculated to be 27.6 × 10⁶ t and 4.2 × 10⁶ t?y^-1respectively. The biomass and the net primary production per area and per population on this regional ecosystem were estimated to be one of the most large values for the whole of Japan. The total amount of CO₂ released through soil respiration from the natural and agricultural ecosystems and through consumption of materials and energy for the industrial processes and human life was 8.2 × 106 t?y^-1. This amount correspnded to two times that of the net primary production. Seventy two percent of the total CO₂ emission from this regional ecosystem was due to the sum of consumption of various petroleum products for human life, industrial processes and production of electric power. The imported material, of which 89 % was various petroleum products, from other regional ecosystems to this regional one was estimated to be 13 times that of the exported material to other prefectures. Most of the exported material to other regional ecosystems comprised of marine, agricultural and wood items and their processed products.

View full abstract

In order to clarify mechanism of fluoride poisoning in silkworm, Bombyx mori, mulberry leaves sprayed with NaF solution were fed to 4th instar larva. After oral administration of NaF, numerous fine granules were observed on the surface of the midgut lumen, and in the cytoplasm of midgut cells using a scanning electron microscope and a transmission electron microscope, respectively. Elemental analysis of the granules using an energy dispersive X-ray microanalyzer(EDX)revealed that the granules consisted mainly of magnesium, phosphorus and oxygen. From these observations, it may be concluded that the formation of fine granules was likely due to the aggregation of magunesium phosphate in the midgut cells, resulting from the disturbance of magnesium and calcium metabolism and changes in the regulation of phosphate concentration induced by fluoride; granules were then discharged into the midgut lumen.

View full abstract

The disposal of waste plastics has emerged as a serious problem facing the global environment in recent years. In Japan, more than five millon tons of plastics are disposed of every year, and the recycle rate for waste plastics is below 30%. Recently, a number of sources have suggested that utilization as energy via incineration is one of the best ways to manage waste plastics. Several unsolved problems, however, remain in the system for the utilization as enegy, and the disposal of ashes after the incineration of waste plastics is another unsolved problem. In our research, the elution of toxic elements from ashes was investigated under the conditions of artificial environments, and the elution of Pb, Cd and Sb in toxic elements was strikingly observed. In view of the elution of toxic elements, it was inferred that ashes remaining after the incineration of waste plastics became safer for the environment through reduction of plastic additives containing Pb, Cd and Sb elements.

View full abstract

We found a large amount of antibiotic-resistant Staphylococcus aureus (S. aureus) in urban river water. The principal source of these organisms was untreated sewage. S. aureus in the environment can cause several infections. Especially when they have antibiotic resistance, it makes therapy difficult. Fifty eight S.aureus strains were isolated from river water and their resistance to eleven antibiotics was assessed. We found that the resistance was most common to penicillin and methicillin. About 60 % of these S.aureus strains were considered to have multiple antibiotic resistance.

View full abstract

In order to achieve "Sustainable Development", it is important for decisionmaking to analyze the processes used to develop environmental policies relating to economic development. There have been no comparative analysis of such processes in Japan and Korea. The authors clarified the similarities and differences between Japan and Korea. First, as the result of an examination of historical data, it was shown that despite the time-lag, they have gained the same experiences in similar steps. Then, the results from analysis of the economic indicators corresponded with those from the examination of historical data. It is of note that both countries have taken measures to lower sulfur in fuel and regulated the emission gases from motor vehicles in the same phases of economic development. However, the authors showed four points of difference between Japan and Korea. In particular, the environmental administration of Korea considers three environmental problems at the same time ; pollution regulation, improving quality of life and global environmental protection. This difference is important for discussing future environmental policy development in Korea.

View full abstract