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vol.46-1(2008/5/31)
| The perspectives of sick house syndrome |
| Sick house syndrome (SHS) is a concept distinctively Japanese and is derived from sick building syndrome (SBS) which generally indicates various health disturbances, including a poor physical condition induced by just living inside the problem buildings. However, in a narrow sense, it indicates the physical effects caused by inhalation exposure of volatile organic compounds, such as formaldehyde or toluene, diffused from materials used in construction and/or interior designing. The concept of SHS has not yet been established medically, but has been given various definitions by researchers. A total of 214 patients with suspected SHS or multiple chemical sensitivity (MCS) were independently classified using a new classification by clinical ecologists and general physicians according to disease pathogenesis from clinical records : type 1 (symptoms developed after showing chemical intoxication), type 2 (symptoms developed possibly due to chemical exposure), type 3 (symptoms developed not because of chemical exposure but rather because of psychological or mental factors), type 4 (symptoms developed due to allergies or other diseases). A 77.1% consensus was reached. The joint committee of two groups of invenstigation on SHS supported by the Ministry of Health Labour and Welfare recently proposed a narrow sense of definition of SHS and its criteria for diagnosis of SHS. The criteria may help avoiding confusion of clinical approach to SHS. Since the criteria include no objective finding nor specific laboratory finding, the studies on the pathogenesis of SHS and development of laboratory test should be continued. |
| Status and Change of Indoor Air Pollution by VOCs in Houses |
| This paper describes the present states and the changes of the indoor air pollutions by volatile organic compounds in Japanese houses, as revealed through measurements of concentrations and investigations on the actual conditions in the resudential environment by questionnaire survey covering a total of more than ten thousand newly built houses over six years (from 2000 to 2005). Especially the survey in 2000 revealed the serious situation exceeding the guideline values established by the Ministry of Health, Labor and Welfare of Japan. This rapidly led to the development a variety of countermeasures for IAQ, such as the amendment of the Building Standard Law. This study presents the changes in the state of IAQ on a nationwide basis in all the types of building structures, when the regulatory measures mentioned above were instituted, and discusses factors associated with these changes. |
| Long-Term Field Survey about IAQ and Occupants' Health of "Sick House" and Recovered Cases of Health Problems |
| In order to make clear the relationship between chemical substances concentrations and symptoms of sick building syndrome in residential house, an investigation of 30 sick houses in Japan has been done for 8 years. Chemical substance concentrations show a decrease as the building age increases. However, there are some houses where concentrations increased due to low air change rate, use of moth crystals for clothes and new furniture. Because there were cases where indoor air quality affects seriously on occupants' health, it is important to take necessary measures, such as increase of ventilation rates, not to use so many chemicals, or to use low chemical emission materials in order to avoid "SHS". |
| The Prediction Method and Countermeasure Technology to Indoor Air Pollution Caused by Volatile Organic Compounds |
| In order to prevent problems associated with sick building syndrome, it is important to minimize occupant exposure to indoor chemical substances as much as possible. One method is to predict indoor chemical substance concentration during the design stage of building, to realize buildings with low pollutant concentrations. We have already investigated the chemical substance emission rates on many emission sources and the removal performance on the countermeasure products against indoor air pollution. With this experimental experience, we have known the ideal building materials, furniture and the countermeasure technique or products to indoor air pollution. And we developed a house planning method and established a reliable concentration prediction technique for indoor chemical pollutants during the design stage to realize a healthy living environment. By using low-emission building materials and a room air cleaner, the reduction of formaldehyde and VOC concentrations were predicted. |
| Measuring Methods and Standardization for Chemical Emission |
| Trends and prospect are mentioned here for the sick house syndrome. Building Standard Law was enforced since 2003 and formaldehyde emitting materials was restricted to use for interior. F**** materials are occupied inside Japanese market. Mechanical ventilation system for 24 hours is also mandatory to install for the residential buildings. However, until 2002 no chemical substance is added to the guideline of chemical substances by the Ministry of Health Labor and Welfare. Japanese industrial standard (JIS) for sick house have been published and latest one was published during 2008. Building materials approved by the Minister was started. For VOC emission materials voluntary standard system is started from April 2008. Series of ISO 16000 have been also published. New work items for the sensonary evaluation and microbes are prepared. There is no excellent mean to measure emission of SVOC form building materials. Japanese method for emission measurement of SVOC, namely micro chamber method is used as a basic document for ISO. Bornehag et al. recently published risk of SVOC, especially for DEHP. On the other hand, VOC emission besides building products is also pointed out for the electric appliances. Indoor air concentration of automobile is also discussed in the ISO committee. |
| The World Metrology |
| Since disregarding the trend in metrology in the world will not produce good result, it is important to understand the activities of the international metrological organizations. As to the measurement standards, there are the General Conference on Weights and Measures (CGPM), the International Committee for Weights and Measures (CIPM) and the International Bureau of Weights and Measures (BIPM) as the organizations of the Metre Convention. The International Mutual Recognition Arrangement (CIPM MRA) has been drawn to establish the degree of equivalence of national measurement standards maintained by National Metrology Institutes. An international organization about accreditation system is the International Laboratory Accreditation Cooperation (ILAC). In order to gain the confidence of accreditation system, efforts to prove the reliability of the system have been continued by inspecting local accreditation organizations and accredited laboratories mutually (peer review). About legal metrology, the OIML (International Organization of Legal Metrology) treaty has been established. A mutual recognition system was introduced also into the legal measurement field. "OIML Certificate System" was inaugurated in 1991. Mutual Acceptance Arrangement (OIML MAA) was materialized in 2005 in which Declaration of Mutual Confidence (DoMC) are made for meters which apply OIML form acknowledgements. The regional coorperation associations are made of each field of measurement standards, accreditation, and legal metrology such as the Asia-Pacific Metrology Program (APMP), the Asia-Pacific Legal Metrology Forum (APLMF), and Asia-Pacific Laboratory Accreditation Cooeration (APLAC). Furthermore, BIPM, OIML, and ILAC have proposed "The World Metrology System" in the joint declaration, aiming at realization of the compatibility of measurement through the world. |
vol.46-2(2008/7/31)
| Issues and Activities on Social Acceptance of Nanotechnology |
| Nanotechnology is expected to bring great many benefits to society. On the other hand, there are concerns about its societal implications including risks. In activities for better social acceptance of nanotechnology, the most urgent issue is the health and environmental risk assessment and management of nanomaterials. What should be protected are workers, consumers and the environment. Among them workers are most likely to be exposed to nanomaterials, and most of the projects underway are focusing on their safety and health. Amount of data has not been enough yet for the risk assessment, and the establishment of the best practice for handling nanomaterials is also very important. The activities on the social acceptance of nanotechnology first began in the United States, and then continued in Europe and Japan. There are also institutions for international cooperation such as OECD and ISO. Currently in Japan, risk assessment research projects on the risk assessment of nanomaterials are vigorously being promoted. On the other hand, the core institution for communication among industry, government, academia and NGOs should be urgently established. |
| Present status of regulations and management of Nano-risk among countries |
| There is no country that regulates the manufactured nanomaterials and the products that use them because the risk of those to health and environment is currently still uncertain. The new chemical substances should be examined under "Chemical Substances Control Law" in Japan, "REACH" in Europe and "TSCA" in U.S.A., and the nanomaterials of the new chemical substance are naturally examined by these laws. On the other hand, as for the examining of the existing materials with nano size under these laws, it depends on recognizing them as "New materials" or not. This is an on-going discussion subject. However, several study reports have been published mentioning the potential risk of nano particles. From view point of risk management, some countries have studied and proposed the guidance for "Best practice" at research and manufacturing site of the nanoparticles. In this report, we introduce the proposals for Best practice and the trend of the discussion on regulation related to the nanomaterials in each country including Japan. |
| Safety Action for the Airborne Drug Exposure in the Pharmaceutical Industry --Setting of Control Banding-- |
| For the purpose of securing the safety against airborne drug powder dust exposure to the workers who manufacture the pharmaceutical drug substance and drug product, here we report the "Control Banding" that we originally introduced. We determined the criteria of the controlled concentration of the airborne drug powder dust in the workplace based on the hazard information in the various animal studies and clinical trials - OEB (Occupational Exposure Band) in the early stage of the drug development and OEL (Occupational Exposure Limits) in the late stage of the drug development. The exposure concentration of the airborne drug powder dust in the workplace should be measured when we manufacture the drug substance and the drug product. If it exceeds the level of the controlled concentration, corrective measures and environmental improvement should be executed. |
| Risk Assessment of Nanomaterials --Introduction of AIST's research activities and NEDO project-- |
| National Institute of Advanced Industrial Science and Technology (AIST) started a research project on risk assessment and risk management of nanomaterials using New Energy and Industrial Technology Development Organization (NEDO)'s fund in 2006. This is an unprecedented comprehensive project in which major nanotechnology-related research branches in AIST, such as the Nanomaterial Production Department, Metrology Department, Environmental Management Department, and Chemical Risk Management Department, conduct joint studies on the standardization and risk assessment of nanomaterials. In this project, many research resources have been invested on not only nanomaterials toxicity research but also the development of nanomaterials in the workplace and research laboratory, and the assessment of exposure due to products made of nanomaterials during the life cycle of products. The goal of this project is to present the proposal of how to manage the risks and benefits of nanomaterials. |
| Current researches on the work-environment measurements for nanoparticles |
| Recently, toxicological studies on health effects related to particle exposure suggest that nanoparticles (particles with diameter of <100 nm) may cause severe health effects after inhalation. Although the toxicological mechanisms for these effects have not yet been explained, measuring exposures against mass alone may be not sufficient. It is also necessary to consider exposures against surface area and number concentration. In this paper, we overview the current sampling and measurement techniques for exposure assessment to nanoparticles in the workplace. |
vol.46-3(2008/9/30)
| Technology Requirements of WECC (Wafer Environmental Contamination Control) in ITRS 2007 |
| ITRS (International Technology Roadmap for Semiconductors) is revised every two years and this year not only the table but also the text was revised. In WECC (Wafer Environmental Contamination Control), some requirements were revised. First, requirements of sulfur compounds were added to AMC. Second, temperature and humidity range were added to AMC. In addition to these, requirements of specialty gases and particles in DIW were changed. In this article, technology requirements of WECC in ITRS 2007 are summarized. |
| Effect of Molecular Contaminants on Semiconductor Processes |
| It is necessary to control SMC (surface molecular contaminants) around gate oxidation process and lithography environments. It was reported that organic compounds on silicon wafer surfaces causes the dielectric breakdown of gate oxide films. In this paoer, I report on the effect of various molecular contaminants on semiconductor processes and describe analytical methods and some problems. |
| Airborne molecular contamination control of semiconductor manufacturing equipments and AMHS environment |
| Now, 65-45 nm technology is applied to mass production, and such miniaturization is reaching a physical limit in a gate insulation film or Cu wiring. In order to stay on Moore's Law (scaling trend), we are pushing forward the development of new material, new process, and new device structure, which requires more advanced clean technology. Above all, control of molecular contamination in production environment air becomes increasingly important. For example, clean-dry-air purging was applied to prevent haze on lens surface of i-line exposure, and chemical filters were applied to eliminate ammonia which caused T-top defect of photoresist pattern in KrF lithography. Furthermore, acid and ortanic contaminants should be removed to prevent haze on reticle surface in ArF lithography. Clean technology in a large vacuum chamber of EUV exposure also grows into a subject in the next generation. In a back-end process, Cu corrosion caused by the manufacturing environment becomes important issue, since wafers in a multiplayer Cu/Low-K process are exposed in the environment longer than a front-end process. With the ITRS 2007, the year of introduction of 450mm wafer is assumed around 2012～20016 or 22nm generation from economical efficiency. Since the clean room and automatic material handling system (AMHS) also need to be modified, the argument of standardization in SEMI has started. |
| The Present Situation and the Subject of Contamination Measurement |
| The metal contamination on the wafer is recognized to make huge influence at yield. But the described values on roadmap at recent ITRS are kept constant for long term (～2022). The background of described metal contamination on the wafer as starting materials and surface preparation at FEP (Front End Process) is shown. Current discussion of wafer environmental metal contamination at WECC (Wafer Environmental Contamination Control) as sub-working group of YE (Yield Enhancement) in ITRS is also shown. Recent topics and development at TXRF (Total reflection X-Ray spectrometry) is discussed and some application data are shown. |
| Static Eliminating Characteristics of Soft X-ray Air Jet Ionizer with Control Grid |
| Soft X-ray air ionizers are the most useful devices for controlling electrostatic charges on LSI wafers in the manufacturing process because they are contamination-free. An air jet ionizer in which ions generated inside the pipe-shaped shield are transported to the charged wafer has been proposed. However, the ionizer lacks eliminating speed because positive and negative ions recombine with each other during the transport process. We tried to increase the eliminating speed by equipping the pipe-shaped shield with a control grid that absorbs ions with the same polarity charge as that on the wafer. The effects of operating conditions such as control grid position, applied voltage to control grid and airflow velocity, on the eliminating speed were investigated. The eliminating speed of the soft X-ray air jet ionizer with the control grid was strongly dependent on the operating conditions, showing 8 times higher speed than the conventional air ionizer, when operated under optimum conditions. |
| Deodorizing cooking exhausts from food processing factory & restaurants with ozone |
| In the past, smells coming from restaurants and the food processing factories were not regulated. It is because of the idea that these exhausts are good smells. The Offensive Odor Control Law of present Japan turns all smells into stinks if there was a complaint. Cooking odors with oil mist are not deodorized easily with ordinary deodorization machines. The food industry can't afford expensive deodorization machines because there are a lot of small businesses. The deodorization system that uses water mist and ozone is suitable for the deodorization of exhausts from kitchens at a low price. Water returns the evaporating oil to an original solid and the liquid and helps the separation of oil. The oxidation resolves remaining smells to ozone. The government provided Triangle Odor Bag Method for Odor Sensory Measurement for the evaluation of stench. Results of the effect on the deodorization by the evaluation were shown and many presented reports. |
| Dynamics of Bacteria in indoor Environment |
| The air-borne microorganism including bacteria often seen at indoor environment which aerosolized from various sources is called bio-aerosol. A variety of sources, including house-dust, food, plants, and occupants are found in indoor environment. And also air handling unit in building is important sources of bio-aerosol. From the former researches, it is clear that bio-aerosol such as droplets or droplet nuclei serves as one of infection routes. And now, it is worried about pandemic spreads of SARS (severe acute respiratory syndrome), H5N1 bird-flu via air-borne viral aerosol as a threat of new infection. In this lecture, it explains what kind of bacteria is further separated from indoor environment, what factors or parameters influence to the fate and transport of bio-aerosol in indoor air. Furthermore, it explains what kind of maintenance and management are required for the control of the contaminated environmental bacteria in air such as food factories and hospital facilities. |
| The actual condition of controls of PFOS inside and outside Japan |
| In recent years, the legal controls of PFOS (Perfluorooctane sulfonate) have been introduced in the world. The Swedish Chemicals Agency (KemI) proposed that PFOS and its related compounds would be listed in Annex A of the Stockholm Convention on Persistent Organic Pollutants (POPs). PFOS and its related compounds have been discussed about its worldwide prohibition of the production, export, import and usage at the POPRC (the Persistent Organic Pollutants Review Committee), a subsidiary body on the Stockholm Convention established for reviewing chemicals. In Japan, PFOS and its related compounds will be intended to be registered with Class I Specified Chemical Substances of "the Act on the Evaluation of Chemical Substances and Regulation of Their Manufacture, etc." at the earliest in the spring 2010. This report will summarize the basic information about PFOS and the actual condition of its controls under the POPRC. After that, it will examine the current control system in U.S., Canada, EU and Japan. |
vol.46-4(2008/11/30)
| Activities of ISO/TC142 "Cleaning equipment for air and other gases" |
| In the international standardization of air filters, there are two existing national standards accepted world-wide. They are similar but very much different in test dusts and measuring instruments, resulting in serious confusions among users as well as manufacturers. ISO/TC 142 tries to mitigate much of the confusion caused by a multiplicity of national standards. Recently, the voting of FDIS 21220 for testing methods of general ventilation filters was carried out and the results surprisingly came out to "disapprove". The voting results might imply the denial of international standardization as a compromise of EN and ASHRAE standards. Since the perspectives of TC 142 on making other standards were to modify the ISO 21220 (if approved) to adjust the usage and application of various types of filters, we are now forced to restructure the whole attitude towards making international standard. Japan, as a leader of making international standards on air filters, is now asked to fulfill important and major role in TC 142. |
| WG3 (General ventilation filters) --Contents, the point at issue and tendency in future for ISO/FDIS21220 |
| ISO/FDIS21220 was voted in this September, but it was disapproved unfortunately. This paper gives the outline of FDIS21220 and the main point at issue. Furthermore, a round robin test with JIS-11 test powder in progress for ISO/21220 in future by Japanese proposal in introduced. |
| ISO/TC 142/WG 4 HEPA and ULPA Filters Performance Testing and Classification of High Efficiency Filter and Filter Media for Removing Particles in Air |
| The first meeting of ISO/TC 142/WG 4 was held on May 6th, 2006 in Phoenix AZ and continued efforts are being made to reach the 2011 goal of establishing an ISO Standard for HEPA and ULPA filter test methods. Through many arguments and efforts, the first CD was established on May 16th, 2008 and was approved as the base document of the DIS on August 15th, 2008. The first CD is chiefly derived from EN 1822 with extensive changes applied to meet the requests of non EU P members. This CD proposes MPPS-based (Most Penetrating Particle Size) efficiency test methods using CPCs (Condensation Particle Counter), DMAs (Differential Mobility Analyzer) and OPCs (Optical Particle Counter). This report summarizes the CD's proposals and introduces potential topics for debate among WG members. |
| Gas-phase Cleaning Equipment for general ventilation |
| A work process to make drafts started in ISO WG8 to evaluate performance of gas-phase cleaning equipment for general ventilation. Both draft of media for removal such as active carbon and device of full-scale is planned. The following items are chiefly discussed: Cleaning air, both of kind and concentration of challenge gases, test condition such as flow rate and temperature/humidity of air, and gas monitors. The opinion of parties concerned in Japan of this draft will be consolidated. |
vol.46-5(2009/1/31)
| Sterilization case with ozone in clean room for sterile medicine manufacturing |
| Up to now, formaldehyde has been used for sterilization in a clean room of the pharmaceutical company. Recently, from the residual element and the doubt of carcinogenic, alternative sterilizer is searched. Ozone and the hydrogen peroxide vapor are predominant alternative sterilizer. These two kinds of sterilizers destroy and sterilize the cell of the bacterium by the oxidation power. However, sometimes strong oxidation power destroy the composition material and the production machine of a clean room. Ozone can be made from oxygen and easily by a high-pressure electrical discharge on the site. It is easy to do the feedback control of the density of ozone because the density of ozone can be measured easy and consinuously. The complete automatic operation driving is also easy. The three element of the ozone sterilization are a density of ozone, humidity, and elapsed time. These can be easily measured. Therefore, it is easy to do the validation. To decide the sterilization condition, the basic data of sterilization of the environmental bacillus and the spore bacillus is shown. The outline of the fumigation system that had already practical to use in the pharmaceutival company is explained. |
| Particle reduction in semiconductor manufacturing equipment |
| Particles generation in actual plasma etching process has been studied using a laser light scattering method. The particle generation mechanisms involve the re-suspension of particles off the chamber inner wall. We therefore studied each of the factors that influenced the re-suspension of particles in the vacuum chamber. It is found out that particles are not only suspended by the shockwave or gas viscous force generated when the valve opens or when the gas is introduced into the chamber, but also are suspended due to electromagnetic stress caused by wafer chucking voltage or plasma discharge. |
| Degradation of Cultural Properties Conserving in atmosphere and its Analysis |
| Degradation of cultural properties conserving in the atmosphere is caused by various factors such as temperature, humidity and light. A type of degradation is different of materials formed cultural properties, and researching a material is controlling a degradation of cultural properties for the first step. At a conservation science, material analyses show degradation modes. Effective methods for a conservation of cultural properties are raised. |
| The detection of fungal allergens in air pollution |
| The fungal detection of low volume sampler (3L/min) with 3 kinds of particle sizes, PM10, PM2.5-10 and PM2.5 was investigated at indoor environments. Fungi were remarkably isolated from PM2.5-10. It is same results as the theoretical value because the cell size of most fungi is ranged from 3 to 10 micron meter in diameter. On the other hand, the fungal detection by PM10 or PM2.5 was generally shown a low CFU. The fungi in indoor environments were predominantly isolated to identify as Cladosporium spp., and then Penicillium spp.. As the fundamental examination to detect both active and inactive fungal cells in air pollution, the double fluorescent technique using propidium iodide and fluorescent diacetate was carried out among 7 fungal species. Each fungus was generally reacted the fluorescent activity. From the available results, it must be continued the developed study of the fungal detection in indoor environments. |
vol.46-6(2009/3/31)
| Methods for Determining Asbestos in Building Materials (Revised JIS Methods) |
| JIS A 1481 (2006) "Determination of Asbestos in Building Material Products" was revised as JIS A 1481 (2008) in response to the revision of the Ordinance on Prevention of Health Impairment due to Asbestos, which now employs a stricter regulatory level of 0.1wt% instead of conventional 1wt% as the asbestos content of asbestos-containing products. The revised JIS methods specify the methods for determining asbestos in building material products (methods for preparing primary test samples, methods for qualitative analysis of primary test samples, methods for determining asbestos presence, methods for preparing secondary and tertiary test samples to be used for determination, and X-ray diffraction quantitative analysis method by basic standard absorption correction method). |
| Sampling Methods for Analysis of Asbestos |
| Asbestos had been used for various applications owing to its excellent properties; but the import, production and use of any products containing more than 0.1 wt% of asbestos have been prohibited in Japan since September 2006, in view of its health risks. Addressing Japan's current asbestos problem requires accurately confirming whether parts of buildings and structures contain asbestos whenever buildings or structures are dismantled or repaired, and appropriate measures must be taken as required. Taking such measures requires identifying how much asbestos dust these activities will generate, and confirming whether imported products and natural minerals contain more than 0.1 wt% of asbestos. The present paper describes sampling methods for analyzing whether or not asbestos is present, and methods for sampling asbestos suspended in air. Meanwhile, sampling methods for analyzing whether or not a material contains asbestos include the methods proposed by ISO (International Organization for Standardization) and American and European nations; and these methods are considered to be the most suitable methods for the nations involved. However, sampling Japan must consider the differences in asbestos-containing products (raw materials, asbestos content, density, etc.) between American and European nations and Japan. On the other hand, regarding the measurement of asbestos dust's concentration in air, no large difference is evident, although there is a difference in purpose. |
| Analysis of the samples related to asbestos by electron microscopy |
| Although asbestos is the outstanding precious material, human beings were mistaken in the use. Human beings have enjoyed the big merit from asbestos in their life for a long time, but asbestos induced serious damage in human beings. Recently asbestos measurement has been changed from airborne asbestos to asbestos in bulk materials, such as building materials, soil, etc. This paoer focused on the asbestos measuring method by electron microscopy, and reviewed the public methods of airborne asbestos and asbestos in a bulk material in and outside the country. To asbestos measurement in the general atmosphere, electron microscopic method is indispensable. In Japan, scanning electron microscopy is to be adopted for an asbestos monitoring manual of the Ministry of Environment. Moreover, in the asbestos analysis in the bulk material with which needs is growing in recent years, the electron microscopic methods are used as an important way and the position and importance were summarized. At present, electron microscopic method is not used popularly in Japan for asbestos analysis in the air and a buld material, it is expected that the needs of electron microscopic measurement will increase in the near future. |
| Analytical Methods of Asbestos and Their Related Materials by X-ray Diffractometry and Thermal Analysis |
| The products which exceed asbestos content 0.1 wt% contain in building-materials and/ or natural mineral resources were forbidden since inport, manufacture, and use from September, 2006. Qualitative and quantitative and analysis of the asbestos mineral components are required with high precision and quickly. When determining quantity of mixtures of approximate chemical compositions and/ or similar crystal structures, the quantitative analysis is sometimes difficult with an X-ray diffraction method. If the heat behavior of each composing material has been already known, it would be able to analyze their contents precisely by combining thermal analysis techniques. |
| Analysis of asbestos by dispersion staining method using a dispersion staining phase-contrast microscopy, and accuracy control analysts |
| The analysis methods specified in JIS A 1481-2008 and JIS K 3850-2006 include the dispersion staining method using a dispersion staining phase-contrast microscopy as a method for identifying asbestos fibers among the fibrous particles existing in an analysis sample. It is especially an important analysis method for deciding whether or not asbestos is contained in the building material concerned or the like in the preliminary investigation based on paragraph 2, article 3 of the Ordinance on Prevention of Health Impairment due to Asbestos. The present paper explains the dispersion staining method using a dispersion staining Phase-contrast microscopy and describes the present situation on the cross-check of asbestos analysts performed in the Accuracy Control Center of Japan Association for Working Environment Measurement, for securing the analysis accuracy of the method. |
| Fundamentals and practice of the method for the identification of asbestos in bulk building materials by polarized light microscopy |
| Becauce the fibrous nature of asbestos is considered to be related to its risks, microscopy is the principal equipment for asbestos analysis in foreign countries. Routine analysis of asbestos in bulk building materials is performed by Polarized Light Microscopy (PLM), because the identification of the individual types of asbestos in bulk materials as well as the identification of all other fibrous components of those materials by PLM is considered to be rapid, cost-effective and certain. Fundamentals and practice of PLM method is briefly described in this article. |
| Portable Air Cleaner |
| It is well known that a portable air cleaner is effective in removal of indoor air pollution substances. In recent years, consumers' concerns on indoor air quality are increasing. The selling number of the annual portable air cleaners in Japan is going up to 1,500,000 sets. However, although there are various types of portable air cleaners are marketed now, it is doubted whether all of those have the performance as manufacturer's display. This paper shows the essence of the purification performance of a portable air cleaner, after describing the test method, valuation method of the purification performance of a portable air cleaner, and purification performance. |
| The dynamics and control of indoor environmental fungi |
| The environmental fungi are distributed in indoor. Several kinds of fungi are normally attached on indoor materials and widely drifted in air. Generally, the fungi are originated from soil as saprophytic microbes. They are scattered in air, and then the fungi adhere or contaminate in plants, animals, human beings and some materials. The fungal problems in indoor environment are shown as human health hazards such as fungal allergen, toxic dust and infectious microbes. On the contrary, they are known as the harmful ones such as biodeterioration, discoloration, decay, putrifaction, damage and so on. In indoor environments, the fungi remark in dust and air because it has detrimental problems. In this review, it explains on the ecological point of environmental fungi, the biological characteristics, hazardous problems of environment and human beings and control points. |
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