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Health concerns about indoor air quality

Concerns started in the U.S. and Europe during the 1980s about the quality of ‘indoor’ air linked to reports of increased incidence of headaches, eye irritations and nausea in occupants. ‘Indoor air’ includes private houses and apartments, offices, salesrooms, public buildings (e.g. schools, hospitals etc) and transport means (e.g. cars, trains etc).

Many different factors may influence the quality of air, in particular physical conditions (e.g. temperature, humidity, air circulation), chemical factors (e.g. emissions, gasses, dust etc), biological factors (e.g. fungi, pollen, bacteria etc).

Psychological factors potentially play a role as well. Attention has focused on chemicals as possible causes though this should be regarded as one of many potential explanations. Actions at European Union and national level.

As part of a verification of the implementation of the 6th Environment Action Programme (EAP), the Commission’s Directorate General for Enterprise initiated work on this issue through standards of Construction Products.

The initiative regards the Construction Products Directive (CPD,89/106/CE), which objective is to ensure the free movement of all construction products within the EU by harmonising national laws with respect to the essential requirements applicable to these products in terms of health, safety and stability.

Many different factors may influence the quality of air, in particular physical conditions, chemical factors, biological factors

As the Directive applies to any products produced with a view to their incorporation in a permanent manner in construction works, it was necessary to identify each of these products. To that effect, the EC set up a database containing information about ‘dangerous substances’ in construction products as well as applicable national and EU legislation.

A preliminary list of ‘dangerous substances’, now called ‘regulated substances’, includes dioxin and furan, lead and its compounds, VCM, PCBs, chloroalkanes, 1,2-dichloroethane, hexachlorobenzene, hexachlorobutadiene and DEHP.

In 2004 the issue of indoor air quality was raised on the political agenda of the EU. One major driver has been the development of the EU Environment and Health Strategy (SCALE). Under Action 13 of the EU Action Plan (published June 2004) the EU Commission has to develop an initiative to reduce the health impact by indoor emissions.

Currently the EU Commission is discussing the consequences of various EU projects like INDEX (Critical appraisal of the setting and implementation of indoor exposure limits in the EU) on its strategy under the SCALE umbrella. In its Communication on this Action Plan the EU Parliament requested the drafting of a Green Book on indoor air quality and domestic pollution (February 2005). In addition certain member states have contacted the EU Commission to notify their specific legal approaches e.g. in the area of authorization of building products.

In 2005 Europe’s Scientific Committee for Health and Environmental Risks (SCHER) has been asked to provide support for future EU policies on indoor air pollution, in particular by identifying a risk assessment strategy.

This should take into account potentially vulnerable groups, such as children, pregnant women and the elderly. It should also take into account combined exposure and cumulative effects of specific air pollutants.

A mandate to the European Standardisation Committee (CEN) is being prepared in order to develop “horizontal assessment methods for harmonised approaches relating to dangerous substances under the Construction Products Directive. This will include measurement/test standards for assessing the emission performance of regulated dangerous substances from construction products, under normal conditions of use, into indoor air

The deadline for completion is currently February 2007. National and international bodies, in particular the European Collaborative Action (ECA) “Indoor Air Quality and its Impact on Man”, have already dealt with the assessment of VOC emissions from building products.

Experts thoroughly examined the specific knowledge available in Europe over a wide range of indoor issues. The results of their work have been published in reports, which contain sufficiently detailed information to be considered as ‘pre-normative’ documents.

One of them is Report No 18 “Evaluation of VOC Emissions from Building Products” (ECA, 1997).
The German Committee for Health-related Evaluation of Building Products, AgBB issued in 2000 a scheme for healthrelated evaluation of VOC emissions from building products used for applications indoors. It entails full-scale tests for product approval and small-scale tests for surveillance. France is coordinating its approach with Germany.

Many chemical substances are present within indoor air. There are as yet no limit or guideline values at EU level. The German AgBB document mentions the following threshold values, which are mandatory for some special flooring products:

• Measurement after 3 daysTVOC (total volatile organic compounds) ≤ 10 mg/m3
Sum of all carcinogens (EU Categories 1 and 2) ≤ 10 μg/m3
• Measurement after 28 days
TVOC (total volatile organic compounds) ≤ 1 mg/m
SVOC (semivolatile organic compounds) ≤ 0.1 m

Hypersensitivity to chemical substances:
Once hypersensitivity develops due to exposure to relatively high concentrations of chemical substances, or after repeated exposure to comparatively low concentrations of chemical substances for extended periods of time, a subsequent exposure to even trace amounts of the same chemical substances may trigger hypersensitivity.

Such a symptom is called hypersensitivity to chemical substances. The syndrome may also be observed with workers in chemical products manufacturing industries who are occupationally exposed to high concentrations. Accordingly, “hypersensitivity to chemical substances” is not the same as concerns about indoor air.

The syndrome may also be observed with workers in chemical products manufacturing industries who are occupationally exposed to high concentrations

Japanese study on indoor concentration of DEHP

The hygiene bureau of the Tokyo Metropolitan Government measured the indoor concentration of phthalates for the first time as a municipal government, in order to check the pollution level of indoor air. Both indoor air and outdoor air were measured in 46 residences (92 rooms) and 25 office buildings (50 rooms).

The 1999 report revealed that the indoor concentration of DEHP was 0.052~0.59 μg/m3 (average value: 0.22 μg/m3), and the outdoor concentration was between ND and~0.15μg/m3 (average value: 0.015 μg/m3)9).

Furthermore, the DEHP concentration in fiscal 2000 was reported to be 0.011~2.38 μg/m3 and more than 85% of DEHP was collected as particulates10). On the other hand, the report on the measurement of indoor phthalate ester concentration during the August- September 2001 period conducted by the Japanese Ministry of Environment for 71 detached houses and 21 apartments throughout Japan revealed that the indoor concentration of DEHP was 0.023~3.4 μg/m3 (outdoor concentration: 0.04~ 0.51 μg/m3)11).

The occurrence of persistent environmental contaminants room air samples from 59 apartments and 74 kindergartens in Berlin were tested in 2000 and 2001. These substances were also measured in household dust from 30 apartments. Among phthalates, DBP had the highest concentrations in room air, with median values of 1083 ng/m3 in apartments and 1188 ng/m3 in kindergartens.

With around 80% of all values, the main phthalate in house dust was diethylhexyl phthalate, with median values of 703 mg/kg (range: 31–1763 mg/kg). No statistically significant correlation could be found between air and dust concentration. The intakes corresponding to above phthalate concentrations represent only a small average proportion of the presently acceptable tolerable daily intake values (TDI)16, less than 1and 8% respectively.

TDI: Tolerable Daily Intake. An index for the quantity of chemical substances deemed harmless through lifetime intake considering impacts on human health. It is expressed in terms of intake per day per kg of body weight

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