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), later replaced by the Construction Products Regulation 305/2011, which  ensure the free movementof all construction products within the EU by harmonising national laws with respect to the essential requirements applicable to these products.

One of essential requirements, or “basic requirements” as they are now called in the CPR, addresses “Hygiene, health and the environment“, and states ”
The construction works must be designed and built in such a way that they will, throughout their life cycle, not be a threat to the hygiene or health and safety of workers, occupants or neighbours, nor have an exceedingly high impact, over their entire life cycle, on the environmental quality or on the climate during their construction, use and demolition, in particular as a result of any of the following:
(…) (b) the emissions of dangerous substances, volatile organic compounds (VOC), greenhouse gases or dangerous particles into indoor or outdoor air;  

To that effect, the European Commission 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.

The issue of indoor air quality was raised on the EU political agenda in 2004.One major driver was 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. 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).

A key step was the Opinion of the Commission’s Scientific Committee on Health and Environmental Risks (SCHER) on risk assessment of Indoor Air Quality (IAQ) published in 2007. The main conclusion of the Opinion was that there is a need for significant further research to be undertaken. It recommended health risk assessments of all pollutants to be undertaken according to the rules that govern risk assessment of chemicals, It stressed that more exposure data are required. It also recommended the development of health based guideline values for key pollutants and other practical guidance to help risk management

To implement health-related aspects of the CPD/CPR, DG Enterprise issued in 2005 a Mandate M/366 to CEN. Based on this mandate, a CEN/TC 351 is working on harmonised methods for the assessment of emissions from construction products into indoor 

Completion of the work related to indoor air is expected in 2013. 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 several reports,

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 limits accepted by the German AgBB scheme are :

  • Measurement after 3 days TVOC (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 mg/m3

Germany (170 substances) and France (10 substances) have compulsory labelling schemes for some construction products, with reference to IAQ.”

PVC products have been tested. Results of tests according to the AgBB methodology showed that the results were below the accepted limit in all criteria.

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.

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