International Journal of Hygiene and Environmental Health
An assessment of indoor air concentrations and health risks of volatile organic compounds in three primary schools
Introduction
Primary schools accommodate children aged 7–14 for about 5–8 h daily, which make them the second most time-spent indoor environment after homes. This implies the importance of the schools in terms of the time component of exposure. The other component, the contaminant concentrations, is also important because volatile organic compounds (VOCs) are ubiquitous in the environment since there are many sources (e.g., traffic and industrial emissions as outdoor sources, building and furnishing materials, arts and crafts materials, cleaning agents, and personal care products as indoor sources) (Sexton et al., 2007, Shendell et al., 2004). There are also other factors that influence indoor air quality: schools are commonly associated with high population density, poor ventilation, lack of maintenance, and unsatisfactory cleaning (Daisey et al., 2003, Smedje et al., 1997). School children are more sensitive to environmental pollutants than adults, because of their higher breathing rate relative to their body size, and continuing growth (Faustman et al., 2000), which translate into higher health-risk levels. Moreover, according to critical reviews, there are studies relating poor indoor environmental quality in schools to the performance of students (Mendell and Heath, 2005), and poor ventilation to health symptoms (Daisey et al., 2003). Some of the VOCs are associated with variety of serious health effects (Sax et al., 2006, Shendell et al., 2004) and symptoms such as asthma and allergic reactions.
Allergic symptoms and diseases are common among children. It has been estimated that there were 6.8 million children with asthma (ALA, 2007) in the US, which was the principal cause of school absenteeism accounting for 20% of lost school days in elementary and high schools (Bayer et al., 2000). Demir et al. (2004) reported the prevalence of asthma in 1992, 1997, and 2002 at a primary school in Ankara, Turkey, as 8.3%, 9.8%, and 6.4%, respectively. In Edirne, Turkey, prevalence of asthma among primary school children was estimated as 5.6%, however 34% of the children experienced an allergy problem at some time in their life (Selcuk et al., 1997). Ones et al. (2005) reported that the prevalence of childhood asthma in Turkey varies between 3.8% and 12.9%. Meanwhile, a recent large-scale survey (more than 25,000 children in 14 cities in Turkey) showed that median prevalence values for asthma, wheezing, allergic rhinitis, and eczema were estimated as 13.4%, 12.6%, 17.3%, and 4.6%, respectively (Kurt et al., 2007).
Formaldehyde, the leading aldehyde in terms of both detection frequency and concentration levels, is considered separately since aldehydes require different sampling and analysis procedures than other VOCs. Norback et al. (1990) studied VOC and formaldehyde concentrations in six classrooms in Sweden. It was reported that, the concentration of formaldehyde was below the detection limit (<10 μg/m3) and the mean indoor Total VOC (TVOC) concentrations ranged from 70 to 180 μg/m3. VOCs were investigated in randomly selected 38 public schools (96 classrooms) by Smedje et al. (1997). Formaldehyde was below the detection limit of 5 μg/m3, the mean sum of 14 identified VOCs was 35 μg/m3, and the highest concentrations were of limonene, n-decane, toluene, and xylene. Lee et al. (2002) measured VOCs in 10 schools with air-conditioned classrooms located in urban, industrial, and residential areas in Hong Kong. Average indoor formaldehyde concentrations did not exceed the standard (100 μg/m3). The most abundant and frequently found VOCs were benzene, toluene, ethybenzene, p/m-xylene, and o-xylene with the mean values of 3.13, 17.7, 4.20, 3.30, and 1.66 μg/m3, respectively. According to a review (Daisey et al., 2003), the average TVOC concentrations ranged from 100 to 1600 μg/m3 in different European and US schools while the mean formaldehyde concentrations in the schools ranged from 10 to 430 μg/m3. The highest median VOC concentrations measured in Minnesota, USA, schools were reported as 4.6, 2.9, and 2.3 μg/m3 for d-limonene, toluene, and m,p-xylene, respectively (Adgate et al., 2004), where winter term concentrations were higher than those measured in spring term. A year long sampling was performed in three primary schools in Western Australia (Zhang et al., 2006). Ten compounds were identified (benzene, toluene, chlorobenzene, m,p-xylene, o-xylene, ethylbenzene, styrene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, and 1,4-dichlorobenzene) at low concentrations (TVOC < 100 μg/m3) of which the highest was measured in a visual art classroom. Godwin and Batterman (2007) conducted a study in 64 classrooms in a suburban school district not under the effect of ambient pollution sources in Michigan, USA. The most prevalent VOCs were benzene, ethylbenezene, toluene, xylene, and limonene but the concentrations were low with the mean TVOC level of 58 μg/m3. In general, the literature reported higher indoor, winter, and kindergarten VOC concentrations compared to outdoor, summer, and classrooms, respectively.
Although VOC concentration levels for schools in Turkey (Kocaeli) were reported before (Pekey and Arslanbaş, 2008), the focus was on the homes and offices. This is the first study that focuses on the school indoor air in Turkey, and assesses associated health risks. The aims of the study were to (1) measure VOC concentrations, including formaldehyde, in primary school classrooms, kindergartens, and outdoor playgrounds in fall, winter, and spring terms at three public schools, two located in the urban and one located in suburban İzmir, Turkey, and (2) conduct an assessment to estimate associated human health risks, and to classify the VOCs accordingly.
Section snippets
Site description and sampling
İzmir, the third most populated province in Turkey with a population of approximately four million, is located on the Aegean Sea shore, where the majority of the population (∼70%) resides in the metropolitan area. Three public schools, hereinafter School-1, School-2, and School-3, were selected based on their accessibility, availability, and willingness to participate, as well as their different geographic characteristics and building structure properties. Schools-1 and -2 are in the urban area
Concentrations
Indoor and outdoor VOC concentrations, including formaldehyde, were measured at three primary schools in three seasons (winter, spring, and fall) in İzmir, Turkey. The following sections present results and discussions on indoor concentrations measured in the classrooms and the kindergartens, and outdoor concentrations measured on the playgrounds.
Conclusions
Higher VOC concentrations were measured indoors than outdoors. Seasonal and spatial variations of the most abundant species were not significant, pointing at dominant indoor sources, whereas the effect of outdoor sources cannot be disregarded. Pollutant profiles differed between the kindergartens and the classrooms, and concentrations measured in the kindergartens were higher. Benzene, toluene, and formaldehyde were the most abundant compounds. Naphthalene and dichlorobenzene were the other
Acknowledgments
This study was supported by a research grant (105Y263) from the Scientific and Technical Research Council of Turkey (TUBITAK). GC–MS and HPLC analyses were performed at Environmental Research Center, İzmir Institute of Technology. We thank Dr. M. Odabasi for his help during method development for TD–GC–MS analysis.
References (42)
- et al.
Source characterization of BTEX in indoor microenvironments in Hong Kong
Atmos. Environ.
(2003) - et al.
Formaldehyde measurements in libraries: comparison between Infrared Diode Laser Spectroscopy and a DNPH-derivatization method
Atmos. Environ.
(2006) - et al.
Occurrence, oral exposure and risk assessment of VOCs in drinking water for İzmir
Water Res.
(2006) Indoor air and human exposure assessment – needs and approaches
Exp. Toxicol. Pathol.
(2005)- et al.
Inter-Comparison of air pollutant concentrations in different indoor environments in Hong Kong
Atmos. Environ.
(2002) - et al.
Volatile organic compounds in the air of Izmir, Turkey
Atmos. Environ.
(2001) - et al.
Air quality and well-being perception in subjects attending university libraries in Modena (Italy)
Sci. Total Environ.
(2002) - et al.
Indoor air quality investigation according to age of the school buildings in Korea
J. Environ. Manage.
(2009) - et al.
Outdoor, indoor, and personal exposure to VOCs in children
Environ. Health Perspect.
(2004) Diseases – Asthma & Children Fact Sheet
(2007)
Causes of Indoor Air Quality Problems in Schools: Summary of Scientific Research, A Report to Department of Energy
Indoor air quality, ventilation and health symptoms in schools: an analysis of existing information
Indoor Air
Asthma and allergic diseases in schoolchildren: third cross-sectional survey in the same primary school in Ankara, Turkey
Pediatr. Allergy Immunol.
Mechanisms underlying children's susceptibility to environmental toxicants
Environ. Health Perspect.
Toluene–Benzene concentration ratio as a tool for characterizing the distance from Vehicular Emission Sources
Environ. Sci. Technol.
Indoor air quality in Michigan schools
Indoor Air
Classification of Measured Indoor Volatile Organic Compounds based on Noncencer Health and Comfort Considerations
Formaldehyde and aromatic volatile organic hydrocarbons in the indoor air of Egyptian office buildings
Indoor Built Environ.
Prevalence and risk factors of allergies in Turkey: results of a multicentric cross-sectional study in children
Pediatr. Allergy Immunol.
Do indoor pollutants and thermal conditions in schools influence student performance? A critical review of the literature
Indoor Air
Cited by (176)
Field demonstration for the solvent-based sampling method to perform compound-specific isotope analysis on gas-phase VOC
2024, Journal of Contaminant HydrologyUnlocking the secrets: Volatile Organic Compounds (VOCs) and their devastating effects on lung cancer
2024, Pathology Research and PracticeThe underappreciated role of fugitive VOCs in ozone formation and health risk assessment emitted from seven typical industries in China
2024, Journal of Environmental Sciences (China)Volatile organic compounds in school environments of Hawassa city, Ethiopia and assessment of possible human health risks
2023, Atmospheric Pollution ResearchEvaluating the impact of air purifiers and window operation upon indoor air quality - UK nurseries during Covid-19
2023, Building and Environment
- 1
Abant İzzet Baysal University, Department of Environmental Engineering, Gölköy 14280 Bolu, Turkey.