|1 Challenges and the Present Condition of Countermeasures against Indoor Air Chemicals|
|Hiroshi Hirose||Department of Engineering, Hiyoshi Corporation|
The research group on health effects of indoor air quality defines Sick Building Syndrome (SHS), a disorder which is caused by indoor air in residential housing, as a nonspecific disorder which shows subjective symptoms; skin and membrane irritation such as the skin, eyes, nose, and throat and indefinite complaints such as headaches, general malaise, and dizziness. There is no diagnostic criterion for SHS. However, SHS is an authorized disorder that is listed as one of the injuries and diseases in the “Guideline Described concerning Invoice for Payment for Medical Treatment” in March, 2003. There exists Chemical Sensitivity (CS), which is confused with SHS. CS had been confused with SHS because housing triggers CS as well as SHS in many cases. However, it actually differs. SHS develops from a higher exposure concentration than CS. When a person leaves the affected place, the symptoms are abated. The measures against SHS in our country aim at reduction of chemical substance concentrations centered on formaldehyde in indoor air.
1. Progress and the present condition of countermeasures against sick building
"Development promotion enterprise for a comfortable life style" had been advanced by the Ministry of Health and Welfare (the former ministry) since 1985 because it was important to secure the health of the living environment. Consequently, the approach arranged basic information concerning countermeasures against sick building and a foundation for a relatively prompt response was established. The diagnostic criteria for CS were shown in 1996 and the guidelines (health guideline values) for formaldehyde were set the following year. Subsequently, the guidelines for 12 substances were established between 2000 and 2002 after several years and the subsidy system for cleanroom construction aimed at the maintenance of medical service providers was also founded. The measuring method, which is suitable for setting up the required guidelines to promote evaluation of the current status of pollution, understanding and countermeasures against causative agents, was shown. The concrete condition describes that a sampling must be conducted when residents’ health risks become the highest. A simplified measuring method can be used for the purposes of screening. Today, the measuring method concerning carbonyl compounds including formaldehyde and volatile organic compounds (VOC) is standardized and is included in the JIS (Japanese Industrial Standards).
The standards with relation to the measurement of chemical emission strength from building materials were also established. A small chamber method was employed as a standard. Since the measured value using this method indicates emission strength (μg/m2・hr) at 28 degrees Celsius and 50% relative humidity, indoor concentrations of carbonyl compounds including formaldehyde and volatile organic compounds (VOC) can in principle be estimated from the measured results.
JAS (Japan Agricultural Standards) of building materials with respect to formaldehyde emission was also established. The JAS divides building materials that emit formaldehyde into 4 categories and their use is controlled by the Building Standards Law (Revised, in 2003).
The scope of the guidelines can be applied to every space, such as general buildings, vehicles and underground shopping areas. It is the characteristics of the guidelines. The status of achievement of indoor air quality is influenced by how to use the guidelines. The possible application of the guidelines under the current system is desired. The outline of the related legal system on the countermeasures against Sick Building is shown in Table 1.
The standards for school environmental health are applied to educational facilities from nursery school to university. The Ministry of Education, Culture, Sports, Science and Technology sent the chiefs of the local governments a notification which reflects the spirit of the report by the investigative commission in relation to sick building problems as well as promoted awareness. However, there are differences in the responses between the education boards of the local governments.
Progress in the approaches of related organizations concerning countermeasures against sick building is helpful in predicting trends for future countermeasures.
After the measures against sick building began to be paid attention as a social problem, they were implemented with exceptional speed. The biggest milestone that promoted implementation was that a Liberal Democratic Party lawmaker in projects formed a aimed at curbing sick building syndrome in April, 2000. Based on their requests, the liaison committees of 5 former ministries and agencies (The Ministry of Health and Welfare, the Ministry of International Trade and Industry, the Ministry of Construction, the Ministry of Agriculture and Forestry and the Ministry of Labor) began to take action. If the legislative body functions, so does the administration. We must not forget that the activities of CS patients’ organizations and a NPO chemical sensitivity support center also made the legislative body work.
The guidelines for 13 chemical substances are currently established. Risk assessment evaluates influence on humans based on the data which is influenced by animals. It is generalized by procedure to determine standards. This method is scientific and correct. However, the bad point of this procedure is that high costs and long duration are required, so that countermeasures can be delayed. The appearance of an assessment method focused on damage prevention is expected. With respect to TVOC (Total Volatile Organic Compounds), provisional health guideline values established from another viewpoint, not based on health effect assessment, is suggested. For instance, such a method could also be managed subject to social agreement.
As far as measurement, it is important to set sampling conditions suitable for the purposes of use of indoor space, for example 30 cm – 50 cm above a floor in a nursery school, 10 cm above a floor in an afternoon nap room.
With regard to legal systems, it is necessary to impose management of air quality on the facility manager of a nursery school. An immediate response is desired because it is a facility that infants, who are the most susceptible, utilize.
There is also a report that persons with CS symptoms account for approximately 0.7% of the population. Because future increases are expected, together with maintenance of medical service providers, provisions for their temporary shelter must be hastily secured.
CS is not only a mere indoor air pollution problem, but is also a type of modern disease including problems concerning the use of chemical substances in connection with substance pollutants caused by chemical substances in the external environment as well as food, clothing and shelter. Furthermore, changes in the countermeasures, which need a certain number of outlines about peoples’ senses of living, environment and philosophy of life, would be demanded. It is expected that the government will examine measures of a long-range plan with respect to the use of chemical substances that can make national consensus-building possible.
Measures against indoor air pollution and health for children
1 Challenges and the Present Condition of Countermeasures against Indoor Air Chemicals
2 Children’s Environmental Health and Countermeasures against Indoor Air Chemicals
3 Measurement and Evaluation for the Determination of Indoor Air Chemicals
4 Building Materials and Furniture and Reduction Countermeasures against Indoor Air Chemical
5 Daily Life of a Patient with Multiple Chemical Sensitivity