|Measures against indoor air pollution and health for children|
|Hiroshi Hirose||Department of Engineering, Hiyoshi Corporation|
Not only is housing a safe shelter that protects people from foreign invasion, the severe cold, wind and weather, but housing is the place where family members can relax. Health, safety, relief, and comfort are key factors that are indispensable for a spatial environment – housing. In an era when a house was made of trees and earth, it was believed that housing was the place which cured illness and recovered physical strength, and maintained and improved health. This belief has not changed, even after products made from compound chemicals and new building materials appeared. Recently, this conviction has been unsettled because sick building syndrome (SHS), which is damage to health caused by indoor air, has become a late social problem.
SHS can be caused by chemicals dispersed into air during new construction or reconstruction and by microorganisms, such as ticks and fungi. Especially, the influence of indoor air contaminated by chemicals, such as formaldehyde and toluene derived from adhesive agents dispersed from building materials, wall-coverings and house furnishings, has drawn attention. The diagnostic criteria for SHS have not been established yet. However, some definitions are suggested. Although there are differences between the definitions, it is assumed that the rate of SHS is several percent or more. In 2003 the revised building standards law, which established the usage regulation of formaldehyde emitting building materials used for new residential housing, installation of 24-hour ventilation equipment and a ban on the use of Chlorpyrifos, began to be enforced. Afterwards, the formaldehyde concentration in new residential housing dramatically decreased. Consequently, the measures against SHS surely advanced. However, there are some reports on recent increases in concentrations caused by non-regulated substances used as alternative products. There is concern over the health effects. The concentrations of indoor air chemicals depend on the emission strength of chemicals from building materials and house furnishings, reduction measures against concentrations due to room ventilation, room temperature, the physical and chemical properties of chemicals and spatial distribution variance as well. Concentration measurement of chemicals is conducted based on the standard methods of measurement indicated by the Ministry of Health, Labour and Welfare. However, collection conditions are the most important factors that affect measurements. Health effects are linked to intake and length of exposure and the sensitivity of those who are exposed to air polluted by these chemicals. Thus, the evaluation of heath effects caused by indoor air chemicals must correspond to use of facilities, rooms and users. Especially, when a person is afflicted with chemical sensitivity (CS), which is now a social problem, a poor physical condition is developed by reacting to a concentration of less than one digit rather than a concentration that develops sick building syndrome. Thus the Guidelines for
Among health guideline values, Chlorpyrifos has established another guideline for the weak, like children. Since a child needs a larger respiratory volume per body weight than an adult, the rate of chemical substance inhalation is relatively large. A child is susceptible to chemicals because the immune and metabolism systems have not developed appropriately yet. Additionally, special attention must be paid to indoor air quality control in institutions which a child utilizes, such as nursery school, kindergarten, and Children's center, because the exposure space to chemicals is not similar to an adult’s.
In this special series, I, Hiroshi Hirose, first arranged the present condition and challenge by analyzing the process of previous measures against sick building. In order to protect the health of children from chemical substances, Mr. Iwao Uchiyama explained the measurements based on the pattern of a child's behavior and physical features and the points which should be considered at nursery schools and schools. Mr. Kiyoshi Imamura introduces the samples of the measurement methods and its accuracy for indoor air chemicals to form the basis of accurate diagnosis and measures for improvement of the environment. Mr. Kiyoomi Fujita viewed the reduction measures against indoor air chemicals from the viewpoint of measures against building materials and house furnishings, which are important source fields. Also, Ms. Chie Yamauchi reported about a trigger in the development of her CS, the progression of her CS, and daily life from the point of view of a patient with CS.
I hope this special series will pave the way to consider the indoor air pollution caused by chemical substances, health problems, and how to use chemical substances. It can be said CS is the indoor version of pollution-related diseases. Although it is a negative element of chemical substance civilization in the 20th century, I am sure that this problem is conquerable by developing a cooperated approach between various fields at the present time.