Superior Health Council INDOOR AIR QUALITY IN BELGIUM SEPTEMBER 2017 SHC № 8794 COPYRIGHT Federal Public Service Health, Food Chain Safety and Environment Superior Health Council Place Victor Horta 40 bte 10 B-1060 Bruxelles Tel.: 02/524 97 97 E-mail: [email protected] All rights reserved. Please cite this document as follows: Superior Health Council. Indoor air quality in Belgium. Brussels: SHC; 2017. Report 8794. Public advisory reports as well as booklets may be consulted in full on the Superior Health Council website: www.css-hgr.be This publication cannot be sold. ADVISORY REPORT OF THE SUPERIOR HEALTH COUNCIL No. 8794 Indoor air quality in Belgium In this scientific policy advisory report the Superior Health Council of Belgium reviews national data on indoor air quality in residences and public buildings and its potential impact on the health of building occupants. The Superior Health Council recognizes the need for national, harmonized data on indoor air quality and formulates general as well as specific recommendations for research, for policy and the implementation hereof. This version was validated by the Board on 6 September 20171 EXECUTIVE SUMMARY Indoor air contains a variety of contaminants, typically in a wider range than encountered outdoors and at higher concentrations for some pollutants. In our region, people spend on average 85 % of the day indoors. Because the indoor air quality (IAQ) can affect the overall personal exposure (EU ENVIE study, 2009) of building occupants, it is an important environmental determinant of an individual’s health. The potential health impact of a poor IAQ and its context have been acknowledged since several decennia (Nederlandse Gezondheidsraad, publicatie nr. 1984/01), highlighting environmental tobacco smoke (ETS) as a major indoor air pollutant and assigning the building envelope and its ventilation as potential determinants of IAQ. Current global trends and evolutions in sustainability, leading to an increased use of new, more sustainable or recycled building materials as well as to increasingly energy efficient, airtight and insulated buildings with controlled mechanical ventilation, are indeed likely to cause a considerable impact on the quality of the indoor environment in the near future (Crump et al., 2010). This evolution also tends to lead to an increasing responsibility of building occupants in creating a healthy indoor air, in terms of use and maintenance of ventilation systems but also in terms of behaviour and product use indoors. Therefore there is a need for targeted educational, preventive and remedial initiatives that respect the social context of this field, in order to guarantee a healthy indoor air for Belgian citizens. It was reported that ambient air is responsible for 2/3 of the total burden of disease (BoD) from indoor air exposures in Europe (Jantunen et al., 2011). The other 1/3 of the BoD related to indoor air exposures is caused by heating and combustion equipment (cooking and heating with solid fuels), water systems, and water leaks. Condensation and underlying soil as source of radon are other important sources for the IAQ associated BoD. 1 The Council reserves the right to make minor typographical amendments to this document at any time. On the other hand, amendments that alter its content are automatically included in an erratum. In this case, a new version of the advisory report is issued. Superior Health Council − 1 − www.shc-belgium.be This critical review on the IAQ of Belgian households and public buildings includes scientific and grey literature published from 2005 until 2015. The current national understanding on indoor chemical agents, microbiological indoor pollution as well as radon, was inventoried and evaluated, and resulted in the identification of national knowledge gaps and needs for further research. The review is divided into 3 main sections: Chemical indoor air priority pollutants (PART A), Indoor microbial pollutants (PART B) and Radon in indoor air (PART C). Subsections of each section critically evaluate the current national state-of-the-art (in terms of indoor concentrations and exposures), identified indoor sources, selected health effects and risk assessments, available legislation, and quantified health benefits resulting from policies, prevention or remediation, followed by the formulation of conclusions, recommendations and research needs. The indoor environments considered in this review are homes and public buildings e.g. schools, day care centres, offices, excluding interiors of transport vehicles and professional (occupational) exposures indoors. The contaminants considered are chemical agents present in indoor air, microbial pollutants and radon, excluding physical parameters of indoor environments (e.g. temperature, humidity, electromagnetic fields). The indoor chemical sources addressed are product emissions (of building materials, furnishing, household and consumer products), excluding human activity controlled measures (e.g. passive smoking, impact of HVAC installations and air cleaning devices). Because of the exhaustive scientific evidence on the significant impact of ETS on indoor exposure and health, as well as the past and current European, federal as well as regional legislative preventive measures, sensibilisation campaigns and recommendations concerning indoor smoking, this issue is not included in this review. Nevertheless, the authors underline the major impact of indoor smoking on IAQ and human health. Since 2005, a wide variety of chemicals was assessed in at least 788 Belgian indoor sites, mostly health complaint-free residences, schools and nurseries. Based on this work, a considerable knowledge is available on the indoor occurrence of chemicals, characterised by well-established sampling and analysis methods and by known toxicological impacts (such as BTEX (benzene, toluene, ethylbenzene, and xylenes), formaldehyde, acetaldehyde, trichloroethylene, tetrachloroethylene, pinene, limonene and also particulate matter (PM), CO, CO2 and radon). However, considerably less is known about the indoor occurrence of chemical agents with less well established sampling and analysis methods. A traditional health impact evaluation of NO2, PM, volatile organic compounds (VOC), total volatile organic compounds (TVOC) and formaldehyde in this review, indicates that 95 % of the studied Belgian indoor sites can be classified as of “limited health concern caused by IAQ”, but also that 5 % of the studied sites is of high concern. Exceedances of health based reference values and high TVOC concentration levels are found to most likely occur in health complaint buildings. Benzene and benzo(a)pyrene are identified as causing the largest impact on the cancer incidence in the studied indoor sites. It is important to note that this conclusion is based on a traditional substance-by-substance evaluation of a few compounds and on a selection of available health based reference values. In order to achieve a reduced health risk of indoor exposure, a dedicated source control is needed. However the limited public availability of emission data still hampers an accurate assessment of the impact of material emissions on IAQ and on the associated health risk. The presence of animals, plants and human beings inside the building is an important source of allergens. Outdoor air is also an important source of natural airborne fungal spores which can be introduced inside buildings and accumulate in settled dust. Bacteria from outdoors and specific contaminations in the surrounding of the dwellings, produced by human activities, can be introduced indoors and accumulate in settled dust. Taking into account dust resuspension in the air, the accumulation phenomenon of settled dust may be a significant source of harmful effects all year long. In our areas, visible fungal developments due to moisture excess are frequent and often considered as the major microbiological contamination in the habitat. Humidity also seems to be an important factor in mites or in cockroach infestation. In Belgium, there are public local structures which carry out interventions on site. Superior Health Council − 2 − www.shc-belgium.be The outcomes of these interventions help the doctors in their diagnosis. Coordinated actions may contribute to a better comprehension of pathologies with an environmental etiology. For biological indoor pollution, it is not possible to define health-based standards on the acceptable number of microorganisms in the indoor environment, but some threshold values are calculated based on existing databases and are used by the different laboratories. These values are linked to the specific sampling and analysis methodology used by each laboratory and permit to detect microbial anomalies in environments. Considering the important contribution of radon to the exposure of the Belgian population and the well-established link with an increased risk of lung cancer, the long-term objective for Belgium is to reduce the average exposure of the population to radon. For the southern part of the country, this can be achieved by radon prevention in new buildings and measurements and mitigation in existing buildings. In order to avoid an additional increase of the radon exposure, the radioactivity of building materials has to be kept under scrutiny, and radon has to be considered in the development of low- energy building (appropriate ventilation rates, avoid direct contact with soil-air, etc). For the northern areas of Belgium, this will