Environmental pollution by dioxins is a problem which has attracted much public concern in Japan, where various large-scale investigations of dioxins were started in the latter half of the 1990s. In the interest of preserving the environment and public health, the authors have been investigating dioxins in various media, such as emission sources, the atmosphere, water, aquatic organisms, soil, food and breast milk. In the present paper, we summarize the current state of dioxin pollution in the environment based on our experience.
The use of heavy metals for various materials and chemicals has contributed to affluent living by humankind. Some of these metals are both essential and toxic. In response to recent attention given to vanadium, zinc, lead and arsenic arising from the hopes and fears they pose for human health, this paper reviews their environmental impacts as well as their presence, usage and action in living bodies. In Osaka, vanadium in airborne particles has been related to anthropogenic combustion processes. Zinc, which is essential but toxic for some aquatic organisms, has been detected at higher levels in waters with inputs from sewage treatment plants than in others. Zinc is thought to be a traffic-related metal ascribed to high concentrations in road runoff and airborne particles adjacent to a highway. Lead has proved to be more traffic-related by isotopic analyses of road runoff, road sediments, road paints, vehicular wheel materials and airborne particles. Arsenic has been detected in Osaka surface waters at levels lower than the environmental quality standard, but is characteristically high in groundwater and soil leachate depending on geologic conditions.
Liquid chromatography coupled with mass spectrometry (LC/MS) has become an invaluable technique for trace analysis of pollutants in our lifestyles and environment. Use of this technique offers a faster, more convenient, and more sensitive way to analyze many pollutants. The present article introduces the principles of LC/MS and describes LC/MS analysis of pesticides in foods and of surface-active agents.
An approach to marine pollution is described using antifouling biocides as a example. Spatial and horizontal distribution of antifouling biocides and degradations of antifouling biocides in the aquatic environment are discussed in concrete terms. It was found that sediment acts as a reservoir for antifouling biocides and that booster biocides such as Irgarol 1051 and Diuron are not degraded easily in water. Further study is thus necessary to monitor these antifouling biocides in the aquatic environment and elucidate the toxicity of booster biocides for aquatic organisms.
Regarding environmental hygiene, as the pesticides in current use have high solubility in water, pesticides applied to paddy-field soil are detected in river water. Their residual potentials are low and the residual period in river water ranges from two weeks to one month. Regarding food hygiene, a number of pesticides in current use have been detected in vegetables and fruits. The number of cases in which pesticides are detected in vegetables and fruits at above the minimum residue level is very small.
Landfill leachate containing wastewater from a sea-based type solid waste disposal site is quite large relative to that from a land-based landfill site, because the amount of waste water to be treated corresponds to that of solid waste dumped into seawater. In order to perform wastewater treatment effectively, planned reclamation is required to adequately maintain the water quality of the pretreatment pond. In this report, the influence of leachate from waste reclamation on water quality and particularly on microbial activity in relation to nitrogen processing is examined, and intermittent reclamation is found to be effective for controlling water quality of the pretreatment pond.
The relation between wastes and a sustainable society was considered. The waste problem is a major social issue and has become an important task for resource and environmental, management as seen for instance in the shortage of landfill sites and the frequent occurrence of illegal disposal. The conversion to a recycling-oriented society has been presented as a radical solution to these problems. The meaning of recycling in a recycling-oriented society was examined and it was concluded that an approach based in the local community was important to the achievement of such a society. The role in such an approach played by local government research institutes is great.
An outline of odor measurement procedures and odor countermeasures is given. Basic aspects of the sense of smell are: (1) odor intensity, (2) odor character or quality, (3) hedonic tone, and (4) frequency. Odor concentration, which indicates number of dilutions until odorless, is usually used to quantify odor. Japan′s Offensive Odor Control Law provides for sensory testing and measurement of 22 odorous substances. The sensory test known as the Triangular Odor Bag Method is conducted by at least six panelists with normal smell function to measure concentration. The Law defines the Odor Index as ten times the common logarithm of odor concentration. There are two steps to prevent odor emission from industry. First, the cause of the odor is removed. Secondly, deodorant equipment is introduced. Duct work is also important.
As advances in local emission control are made, the relative importance of background air pollution levels increases. Ship emissions in Osaka Bay were found to affect inland air quality relating to NO2 levels in Osaka City, while strong emissions of NOx and NMHC in developing regions on the Asian continent increased O3 levels in background air pollution in Japan. Emissions from metropolitan areas, on the other hand, can affect not only local but also global air quality. Transboundary air pollution, which impacts other cities, prefectures, and countries, should be considered in relation to recent local air pollution problems. These local and regional interactions should be taken into account for the future of air pollution control.
Recently, the rapid change in the heat environment caused by the increase in energy consumption and the high-density of urban structures has become a serious problem of global scale. Although the global warming caused by greenhouse gases is becoming worse, the problem of local heat environments should also not be ignored, especially in urban areas. Air temperature rise is observed in the city in comparison with the urban fringe. This is called the “urban heat island” phenomenon because the plotting of isothermal lines results in an island shape. Because this phenomenon causes serious problems for human health, such as heat stress, countermeasures against the thermal pollution of urban heat islands are necessary. Various approaches to heat island countermeasures have been considered, including research into the space-time characteristics of energy consumption, the effect of greenspace and tree-planting on roof surfaces, and networks to monitor urban air temperature distribution.
In the cities of Japan, many green areas have recently been created not only as “green space for citizen′s amenity and relaxation” but also as “biotopes that harbor diverse birds, insects and wild plants”. However, the interactions between organisms in urban biotopes are fewer than and different from those in natural settings. Restoration and effective use of biotic interactions would help to qualitatively improve urban ecosystems. In this review, we illustrate a number of biotic interactions and propose methods for restoring or controlling them: (1) pollination and seed dispersal, (2) plant-herbivore-enemy interactions, (3) biological control of Microcystis using allelopathy, and (4) control of interactions between exotic and native organisms. In conclusion, (1) to restore biotic interactions in urban settings, an understanding of biotic interactions in the original ecosystems is required, (2) to prevent negative effects from alien species, the impact of alien on native species should be clarified using manipulative experiments as well as direct observation, (3) effective use of ecosystem services could be realized such as allelopathic control of Microcystis, biological control of insect pests and pollination of farming crops, and (4) the results and products of our studies on biotic interactions should be shared with local governments and park planners.
In June 2005, media coverage of the health effects of asbestos used at factories on nearby residents developed into an “asbestos panic” in Japan. Asbestos is a natural mineral fiber and is widely used as a material for industrial and construction purposes because of its significant tensile strength, heat resistance and thermal insulating properties. Japan′s Ministry of Health, Labor and Welfare has proposed a new regulation for the prevention of asbestos scattering due to building demolition. Here, we provide a brief overview of asbestos from the viewpoints of present and future problems.
Data on the indoor environment, especially in relation to the sick building syndrome (SBS), were collated. SBS problems have increased since the 1990s in Japan. A range of legislation has however been introduced and manufacturers of architectural and construction materials have made efforts to improve. As a result, the concentration of volatile organic compounds (VOC) in indoor air has recently shown a decreasing tendency. However, even if the concentration in indoor air falls below the guideline value set by the Ministry of Health, Labour and Welfare, the SBS problem may not be completely resolved. Attention also needs to be paid to other materials not subject to guideline values. Especial consideration needs to be given to people in high-risk groups sensitive to chemical exposure, such as patients with multiple chemical sensitivity, children, the elderly, and expectant mothers.
A review was undertaken of fungal contamination in indoor environments. Fungal contamination of house dust in carpets and tatami-mats during the summer seemed to have decreased compared to thirty years ago, unlike contamination in winter. Recently, excessively dry indoor environments have been found in the upper stories of condominiums. On the other hand, bathrooms are still the rooms most severely contaminated by fungi. Especially in bathrooms without windows, ventilation and dehumidifying equipment are essential for eliminating fungal contamination. Air-conditioners and washing machines as new sources of fungal contamination were discussed. Contaminated air-conditioners discharge fungal spores in their output and may promote fungal allergy in users. In the last ten years, manufacturers have attempted to improve the design to reduce fungal contamination. The interior of automatic-type washing machines can become contaminated by mold with dark hyphae. The concentration of mold and dirt was most severe in the upper part of the spine tube and seemed to parallel the quantity of surfactant adhering to the surface of the spine tube. Detergent is thought to promote fungal contamination in washing machines. Effective treatments are thus important for controlling fungal contamination in washing machines, including usage of nutrient-free detergent.
There are numerous kinds of household products in our homes, such as textiles, aerosol products, and acidic and alkaline detergents. These are made from many kinds of materials and treated with many kinds of chemicals to impart waterproof, repellent, anti-shrink, antimicrobial, and other properties. These materials and chemicals sometimes bring about health hazards such as contact dermatitis and inhalation accidents, in particular for children and householders. In the present paper, toxic compounds that bring about health hazards are reviewed.
Allergic contact dermatitis is an important and common health problem. It is known that the large number of chemicals used in household products, including biocides, dyes, rubber-accelerators, solvents, and UV-absorbers, have the inherent potential to cause skin sensitization. With cases of allergic contact dermatitis being reported constantly in many countries, the need for precise criteria is clear. In order to prevent the adverse health effects caused by exposure to skin-sensitizing chemicals, it is essential as a first step to identify sensitizing chemicals and quantitatively evaluate their potency. Such data have been obtained from animal experiments, especially with guinea pigs and mice. However, recent progress in computer technologies and mounting demands for priority to animal welfare have made it necessary to include other methods such as in silico prediction of quantitative structure-activity relationships and in vitro methods using cultured immunocytes. In the present article, recent methods of evaluating skin-sensitizing chemicals and of applying the data in the risk management process are reviewed.
As food apparatus, containers and packages are necessary in daily life, they must not contain harmful chemicals that could migrate to food. Investigations are necessary in this respect to confirm their safety. This review introduces recent problems and topics relating to the hygiene of food apparatus, containers and packages. The topics are as follows: di-2-ethylhexyl phthalate from polyvinyl chloride products, bisphenol A from polycarbonate and epoxy resin products, epoxidized soybean oil and semicarbazide from bottle cap sealing agents for infants, PFOA from fluoroplastics and the fluorine coatings, lactic acid from polylactide, and abietic acids from paper products.
The report “Healthy Japan 21” sets out Japanese public health targets for the year 2010. Under the item of “Nourishment/eating habits”, detailed numerical values are given for the whole human lifespan. For adult women, in particular, the pregnancy period is important, as poor nourishment and bad habits can sow the seeds of lifestyle-related disease. It is important to lay the foundations for healthy eating habits and dietary education activity early on. Now, the Dietary Education Law, enforced in 2005, has provided backing for such activity, and dietary education activities specific to each region are being developed. By teaching children the value of home cooking, it is important to nip lifestyle-related disease in the bud.
Some methods have been developed to analyze the relatedness of bacteria isolated from patients with enteric infections. Pulsed-field gel electrophoresis (PFGE) is a technique of molecular epidemiology and a powerful tool for determining differences in nucleotide sequences among bacterial genomes. Epidemiological investigations such as that described are becoming important due to the wide distribution of foods today.
There are many human infectious diseases derived from pathogenic viruses. In line with the infectious disease surveillance systems of Osaka City, the staff of our institute′s department of microbiology seek to isolate and identify human pathogenic viruses from patient specimens using a number of routine methods. In the present review, I describe methods of pathogenic virus identification using the standard virus neutralization test and the latest methods using virus genome gene analysis, together with Japanese law on infectious disease.
Pathogenic analysis of clinical samples to detect the causative agent is the most reliable method of confirming infection. Morphological examination using light microscopy is a convenient tool, but the information thus obtained is limited. In Japan, while morphological examination is still the gold standard in many parasitic infections, recent molecular studies have produced a wealth of new findings helpful in the diagnosis, treatment and prophylaxis of parasitic infections. Currently, genetic examination is applied in the diagnosis of various infectious diseases to obtain rapid and accurate results and also to understand their molecular epidemiology. It is expected that molecular methodologies will be necessary for the diagnosis of various parasitic infections. In the present paper, the author summarizes the significance and prospects of genetic examination in parasitic infections.