Indoor and outdoor pollen concentrations in private and public spaces during the Betula pollen season

Abstract

Although the number of studies of pollen concentrations inside and outside buildings is increasing, little is known about the efficiency of penetration of pollen from outdoor to indoor air, and further. We studied indoor and outdoor pollen concentrations in the town of Lappeenranta and in the municipality of Rautjärvi in SE Finland from May 3-23, 2004, i.e. throughout the Betula pollen season, and assessed the risk of exposure to pollen grains. Pollen concentrations were measured inside and outside a block of flats, a detached house, and the regional central hospital, using rotorod-type samplers; in the town of Joutseno data were compared with Burkard counts. Outdoor concentrations of Betula pollen grains ranged between low and abundant (0-855 grains m À3 ). The corresponding indoor concentrations near the main front doors varied from low to moderate (0-17 grains m À3 ) in the central hospital and were low (<10 grains m À3 ) in both residential buildings. Indoor concentrations further from the main front door were low (<10 grains m À3 ) at all study sites. The concentrations of Betula pollen decreased substantially from outdoors to indoors, and further toward the centre of the building, probably indicating relatively poor penetrating properties of the pollen grains and/or the short-lived presence of pollen grains in indoor air. The concentrations of Betula pollen inside the buildings during the peak flowering period were mostly at a level barely inducing reactions even in the most sensitive persons.

Intrusion of airborne pollen through open windows and doors

“…The highest pollen amounts are usually found near ventilation windows and holes and in lobbies (Kiyosawa and Yoshizawa 2001;Hugg and Rantio-Lehtimäki 2007;Takahashi et al 2008). The airflow through the opening and the sampling height also had a significant effect on the ratio.…”

“…Outdoor concentrations have mainly been less than 100 grains/m 3 , but the sampling strategy, periods, and probably also the locations inside the houses were different (O'Rourke and Lebowitz 1984; Stock Lee et al 2006). In the same region in Southeast Finland, in the hospital entrance hall and in two homes, indoor concentrations were much lower (means 1.1-3.4 grains/m 3 ) but outdoor concentrations during the sampling periods were also much lower (7-96 grains/ m 3 ) (Hugg and Rantio-Lehtimäki 2007).…”

“…For example, during the peak flowering period for Betula, pollen concentrations indoors remained mostly at a level barely inducing reactions even in the most sensitive persons (Hugg and Rantio-Lehtimäki 2007). Measurements inside buildings have usually revealed concentrations 2-6% of the corresponding outdoor concentrations (Spiegelman et al 1963;Yankova 1991;Cariñanos et al 2004;Lee et al 2006;Hugg and Rantio-Lehtimäki 2007;Ishibashi et al 2008) but the average values have occasionally been as high as 30-53% (Stock and Morandi 1988;Sterling and Lewis 1998).…”

Forensic value of pollen from ornamental indoor plants

“…Most studies concerning indoor pollen focus on pollen from an allergological point of view (Enomoto et al 2004;Hugg & Rantio-Lehtimäki 2007). Many of them report that pollen can be found at indoor locations and that wind-pollinated taxa are predominant (Yankova 1991;Tormo-Molina et al 2009).…”

Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease

“…Knox et al, 1997; Motta et al, 2006; Després et al, 2012). Hence, building a quantitative model to link airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is needed to assess the health impacts on AAD and develop corresponding preventive actions (Hugg and Rantio-Lehtimäki, 2007; Efstathiou et al, 2011). Simulating the spatial-temporal variation of pollen occurrence is the central task toward this goal.…”