The MERMAID study: indoor and outdoor average pollutant concentrations in 10 low‐energy school buildings in France

Abstract

Indoor air quality was characterized in 10 recently built energy-efficient French schools during two periods of 4.5 days. Carbon dioxide time-resolved measurements during occupancy clearly highlight the key role of the ventilation rate (scheduled or occupancy indexed), especially in this type of building, which was tightly sealed and equipped with a dual-flow ventilation system to provide air refreshment. Volatile organic compounds (VOCs) and inorganic gases (ozone and NO2 ) were measured indoors and outdoors by passive techniques during the occupied and the unoccupied periods. Over 150 VOC species were identified. Among them, 27 species were selected for quantification, based on their occurrence. High concentrations were found for acetone, 2-butanone, formaldehyde, toluene, and hexaldehyde. However, these concentrations are lower than those previously observed in conventional school buildings. The indoor/outdoor and unoccupied/occupied ratios are informative regarding emission sources. Except for benzene, ozone, and NO2 , all the pollutants in these buildings have an indoor source. Occupancy is associated with increased levels of acetone, 2-butanone, pentanal, butyl acetate, and alkanes.

Near Real-Time Monitoring of Formaldehyde in a Low-Energy School Building

“…The other aldehydes concentrations inside the classroom were measured using the reference ISO 16000-3 method based on DNPH derivatization from 24 February to 7 March 2015 (see Figure 4). Except formaldehyde, acetaldehyde was the main aldehyde detected, as was previously observed by previous studies in indoor air [4,11,39]. Its concentrations ranged between 2 and 5 µg m −3 , whereas the concentrations of the remaining aldehydes, i.e., hexanal, propanal, and benzaldehyde were lower than 1 µg m −3 .…”

“…Most of the studies required passive sampling on the DNPH tubes [3,4,[40][41][42] over a period of several days to a week, except Jarnstrom et al (2006) [43], who used active sampling using a 0.005 M sulfuric solution at 2-4 L/min, followed by a derivatization with acetyl-acetone and quantification by a spectrometric method. Our study appears to be the first one to report continuous formaldehyde monitoring in a low-energy building.…”

Epigenome-Wide Meta-Analysis of Methylation in Children Related to Prenatal NO 2 Air Pollution Exposure

“…Indoor exposure and time–activity patterns may introduce some bias, although this will most likely be nondifferential and thus would generally tend to attenuate the associations. Furthermore, several measurement studies conducted in different areas have demonstrated that indoor and outdoor NO 2 levels are strongly correlated ( R 2 = 0.7–0.9), pointing to indoor NO 2 concentrations being largely affected by outdoor sources (El-Hougeiri and El Fadel 2004; Verriele et al 2015; Wichmann et al 2010). …”

Investigation of A Potted Plant (Hedera helix) with Photo-Regulation to Remove Volatile Formaldehyde for Improving Indoor Air Quality

“…Besides, using effective means to reduce indoor air pollution and improve air quality are important issues for building occupants and users in nonventilated places, like hospitals and laboratories (Brown et al, 2015;Lucas et al, 2016;Verriele et al, 2016;Bradman et al, 2017). Indoor air handling systems with HEPA filters control the ambient environmental conditions, including the temperature, humidity, air flow and air cleaning (Russell et al, 2014).…”