Committee on Sick House
Syndrome: Indoor Air Pollution
Progress Report No.
4
- Summary on the discussions
at the 8th and 9th meetings -
22 January 2002
1.
Guideline values of individual
Volatile Organic Compounds (VOCs)
Scientific discussions leading to the establishment of guideline values for indoor air concentration of acetaldehyde and fenobucarb are summarized. The guideline values of all the chemicals determined so far at this committee are also tabled. The objectives and anticipated effects of providing the guideline values together with the criteria for selecting chemicals are described as well.
1.1 Outline of guideline values for
indoor air concentrations
It is possible that all indoor air chemicals will have some impact on human health. Therefore, public health assessment has been made for the establishment of guideline concerning individual indoor chemicals in order to reduce unnecessary human exposure to them.
The guideline values for indoor air concentration mean that, given the current available scientific knowledge, no adverse health effects would be caused in humans with the lifetime exposure of the chemical at the level of no more than the value. The intention is that the lower a measured value is than the guideline value, the more desirable, not that it is acceptable if a measured value is not more than the guideline value.
Lots of residents are reported to experience allergic, toxic and multiple adverse health effects due to indoor air pollution by chemicals. The term ‘Sick House Syndrome’ is used to describe the conditions in which their complaints vary considerably and where the cause of the symptoms and the mechanism of action are still not completely known.
Therefore, further research and investigations are needed to demonstrate that the symptoms were caused by the exposure of any chemical that gained the guideline value. However, even before it is demonstrated, it is recommended that building materials, design and construction, housing and ways of living should be improved so as to meet the guideline. It is considered that the establishment and proper application of the guideline values will be effective to promote the improvement of residential environment and eventually, to prevent many people from health hazards due to indoor air pollution.
The guideline values may be revised in the future, as necessary, depending on further available knowledge and/or progress in international assessment works based on scientific knowledge.
All indoor environments should be subject to application of the guideline unless there are particular chemical sources.
All stakeholders including general public, constructors and related industry, and building management should have a correct understanding for the guideline values: they never indicate that, under any circumstances, a chemical subject to the guideline be harmful to human health. Scientific discussions leading to the establishment of guideline values should contribute to how chemicals will be used so safely and properly as not to cause health hazards and how chemicals will provide a maximum performance of the efficacy.
The selection of chemicals subject to the development of the guideline value follows the six criteria, which were described in the Progress Report No.1, June 2000, under the subheading “Priorities for setting up guideline values”. Works on individual chemicals without still included in the guideline will be put forward consistently in accordance with these criteria.
As for a chemical with multiple exposure sources, it is important to consider the feasibility of total exposure assessment taking account of all the exposure sources in the environment. The establishment of the guideline value for the exposure to the chemical from indoor air will surely contribute to the promotion of efforts to mitigate the total exposure of the chemical.
1.2 Guideline values for indoor air
concentration of individual chemicals
The guideline values for indoor air concentration of these chemicals have been provided based mainly on chronic toxicity via a long-term exposure, except that of formaldehyde has been given as a 30-minute average value based on toxicity via a short-term exposure. However, the advisable value of Total Volatile Organic Compounds (TVOC) has been gained not based on toxicological information, but as low as reasonably achievable from the results of investigations on indoor VOC concentration in our country. Therefore, the TVOC advisable value is used as an indicator for indoor air quality, independently of individual VOC guideline values.
The details of the assessment on chemicals newly added to the guideline are given separately, available only in Japanese.
VOCs* |
Toxicity endpoint |
Guideline value for indoor air concentration** |
Acetaldehyde 1),
2) |
Effects on nasal olfactory epithelium in rats exposed by
inhalation |
48
μg/m3 (0.03 ppm) |
Fenobucarb 3),
5) |
Effects on choline esterase, etc. in rat orally exposed |
33
μg/m3 (3.8 ppb) |
VOCs* |
Toxicity endpoint |
Guideline value for indoor air concentration** |
Formaldehyde |
Nose, throat irritation in humans exposed by
inhalation |
100 μg/m3 (0.08 ppm) |
Toluene
1), 2) |
Effects on central nervous system (CNS) behavior functions and
development and reproduction in humans exposed by inhalation |
260 μg/m3 (0.07 ppm) |
Xylene
1), 2) |
Altered development of central nervous system in offspring
whose mother rat exposed by inhalation during its pregnancy
period |
870 μg/m3 (0.20 ppm) |
p-Dichlorobenzene
1),
2) |
Liver/kidney effects in beagles dogs orally exposed |
240 μg/m3 (0.04 ppm) |
Ethylbenzene
1), 2), 3) |
Liver/kidney effects in mice and rats exposed by
inhalation |
3800 μg/m3 (0.88 ppm) |
Styrene 1),
2) |
Brain/kidney effects in rats exposed by inhalation |
220 μg/m3 (0.05 ppm) |
Chlorpyrifos 4), 5) |
Altered development of CNS and morphological effects on brain
in offspring whose mother rat orally exposed |
1
μg/m3 (0.07 ppb) For children: 0.1 μg/m3 (0.007 ppb) |
Di-n-butyl
phthalate
1), 3), 5) |
Abnormal genitals in offspring whose mother rat orally
exposed |
220 μg/m3 (0.02 ppm) |
Tetradecane 2), 6) |
Effects on liver in rat orally exposed to C8-C16 hydrocarbon mixture |
330 μg/m3 (0.04 ppm) |
Di-(2-ethylhexyl)
phthalate
3), 5) |
Histopathological effects on testicle in rat orally exposed |
120 μg/m3 (7.6 ppb) |
Diazinon 4), 5) |
Effects on blood plasma and erythrocyte choline esterase in rat exposed by inhalation |
0.29 μg/m3 (0.02 ppb) |
Total Volatile
Organic Compounds
(TVOC)
1), 3) |
Gained as low as reasonably achievable from investigations on indoor air in our country. |
Advisable value: 400 μg/m3 |
Table 3. Chemical for
further investigations
VOCs* |
Toxicity endpoint |
Interim guideline value for indoor air
concentration** |
Nonanal
2), 6) |
Toxicological effects in rat orally exposed to C8-C12 hydrocarbon mixture |
41
μg/m3 (7.0 ppb) (Interim value because of data gap) |
*
Numbers indicate the following criteria used for selection: 1) chemicals for
which guidelines have been given by foreign governments or international
organizations; 2) chemicals for which investigations demonstrated that the
indoor air concentration has been found high because of apparent indoor chemical
emission sources; 3) Chemicals for which public comments have particularly
claimed; 4) Chemicals for which foreign governments have provided a new
regulation and the like; 5) Chemicals to be selected so as to comprehend indoor
chemical sources; and 6) Chemicals to be selected so as to comprehend chemical
structural categories.
**
At 25 degree Celsius
2. Sampling and analytical
methods
About acetaldehyde, the revised sampling and analytical methods of indoor air chemicals, which are provided in the Progress Report No.3, 24 July 2001, should be followed.
About fenobucarb, refer to the interim sampling and analytical methods of chlorpyrifos in the Progress Report No.3.
The details of the sampling and analytical methods of these chemicals are given separately, available only in Japanese.
3. Revision to Manual for Analysis of
Indoor Air Chemicals and Guide for Preparation of Manual for
Consulting
Information on the two chemicals
newly included in the guideline was added to the Manual for Analysis of Indoor Air Chemicals
and the Guide for Preparation of Manual for Consulting, which had been published
in the Progress Report No.3, 24 July 2001, respectively. The details of the addition
are given separately, available only in Japanese.
Both the Manual and the Guide will
be revised every year to include information on chemicals newly added to the
guideline and scientific knowledge newly made available.
Appendix
Member of the
Committee on Sick House Syndrome: Indoor Air Pollution
Dr
Shunichi ARAKI
Dr
Masanori ANDO
Dr
Kouichi IKEDA
Dr
Satoshi ISHIKAWA
Dr
Iwao UCHIYAMA
Dr
Haruhiko SAKURAI
Dr
Shin-ichi TANABE
Dr
Yoshiteru TSUCHIYA
Dr
Yuzo HAYASHI (Chairperson)
Dr
Masao HIROSE
Secretariat for the
Committee
Mr.
Toru YAMAMOTO
Mr.
Jun YOSHIDA
Mr. Hideyuki HIRANO