Ultrafine particle concentrations and exposures in six elementary school classrooms in northern California

Mullen, Nasim A.; Bhangar, Seema; Hering, Susanne V.; Kreisberg, N. M.; Nazaroff, William W.

doi:10.1111/j.1600-0668.2010.00690.x

Cited by 87 publications

(98 citation statements)

References 31 publications

(41 reference statements)

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“…In contrast, studies on UFP in 39 primary schools in Spain Rivas et al, 2014), 7 primary schools in Greece (Diapouli et al, 2007), and 2 primary schools in Italy (Buonanno et al, 2013b) reported 1.2-to 3.5-fold higher values of UFP. Similarly, studies from other non-European countries such as in California (Mullen et al, 2011), Australia (Morawska et al, 2009), and South Korea (Kim et al, 2011) noted considerably higher levels of UFP than the findings obtained in the cur-rent investigation. These differences may be associated with seasonal influences, meteorological conditions, or specific characteristics of the environment where schools are located, such as level of development, urbanization, and traffic (World Health Organization [WHO] 2006).…”

Section: Discussionsupporting

confidence: 49%

Exposure of Children to Ultrafine Particles in Primary Schools in Portugal

Rufo¹,

Madureira²,

Paciência³

et al. 2015

Journal of Toxicology and Environmental Health, Part A

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Section: Discussionsupporting

confidence: 49%

Exposure of Children to Ultrafine Particles in Primary Schools in Portugal

Rufo¹,

Madureira²,

Paciência³

et al. 2015

Journal of Toxicology and Environmental Health, Part A

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“…Different levels of urbanization and development of the area surrounding schools, meteorological conditions, or seasonal influences might account for some of these differences (Morawska et al, 2009). It is also necessary to indicate that the majority of the existing studies on UFP in educational settings focused on assessments in classrooms (Clausen et al, 2012;Fromme et al, 2007;Guo et al, 2010;Mullen et al, 2011;Norbäck et al, 2011;Weichenthal et al, 2008). Zhang and Zhu (2012) also reported the information on UFP in other school microenvironments: gymnasium, canteen, and libraries.…”

Section: Discussionmentioning

confidence: 99%

Children’s Indoor Exposures to (Ultra)Fine Particles in an Urban Area: Comparison Between School and Home Environments

Slezáková

Texeira

Morais

et al. 2015

Journal of Toxicology and Environmental Health, Part A

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Due to their detrimental effects on human health, scientific interest in ultrafine particles (UFP), has been increasing but available information is far from comprehensive. Children, who represent one of the most susceptible subpopulation, spend the majority of time in schools and homes. Thus, the aim of this study is to (1) assess indoor levels of particle number concentrations (PNC) in ultrafine and fine (20-1000 nm) range at school and home environments and (2) compare indoor respective dose rates for 3-to 5-yr-old children. Indoor particle number concentrations in range of 20-1000 nm were consecutively measured dur-ing 56 d at two preschools (S1 and S2) and three homes (H1-H3) situated in Porto, Portugal. At both preschools different indoor microenvironments, such as classrooms and canteens, were evaluated. The results showed that total mean indoor PNC as determined for all indoor microenvironments were significantly higher at S1 than S2. At homes, indoor levels of PNC with means ranging between 1.09 × 10 4 and 1.24 × 10 4 particles/cm 3 were 10-70% lower than total indoor means of preschools (1.32 × 10 4 to 1.84 × 10 4 particles/cm 3 ). Nevertheless, estimated dose rates of particles were 1.3-to 2.1-fold higher at homes than preschools, mainly due to longer period of time spent at home. Daily activity patterns of 3-to 5-yr-old children significantly influenced overall dose rates of particles. Therefore, future studies focusing on health effects of airborne pollutants always need to account for children's exposures in different microenvironments such as homes, schools, and transportation modes in order to obtain an accurate representation of children overall exposure.

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“…1). Most of the source emission rate estimation methods (Mitra et al, 2002;Wallace et al, 2004;Mullen et al, 2011) use the concept of mass balance between generation and ventilation removal of the monitored number/mass concentration-size spectrum data. Quite often, this procedure may not be adequate for strong sources such as that due to combustion unless the joint effect of coagulation and ventilation is properly addressed.…”

Section: Methodsmentioning

confidence: 99%

Effective Coagulation Coefficient Approach for Estimating Particle Number Emission Rates for Strong Emission Sources

Anand

Bathula

Mayya

2016

Aerosol Air Qual. Res.

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Particle number emission rate is one of the important parameters that characterizes the emission source and it is an essential input to the aerosol dynamics models. Estimation of this quantity at the source is rather complicated due to the combined action of ventilation and coagulation on the depletion of particle number concentrations. Techniques to estimate number emission rate are still at preliminary stage and hence there is a definite need to develop a methodology for this purpose. In the present study, an effective coagulation coefficient (K eff ) approach is provided to correct for coagulation losses encountered during experiments for the determination of number emission rate. K eff is expressed as a function of single parameter (β) namely the ratio of the prescribed ventilation rate and measured number concentration in the experiments. The utility of the approach is demonstrated by applying it to few practical cases reported in the literature. The results are further discussed.

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Ultrafine particle concentrations and exposures in six elementary school classrooms in northern California

Cited by 87 publications

References 31 publications

Exposure of Children to Ultrafine Particles in Primary Schools in Portugal

Exposure of Children to Ultrafine Particles in Primary Schools in Portugal

Children’s Indoor Exposures to (Ultra)Fine Particles in an Urban Area: Comparison Between School and Home Environments

Effective Coagulation Coefficient Approach for Estimating Particle Number Emission Rates for Strong Emission Sources

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