Exposure assessment and childhood asthma physics to provide temporally resolved predic- tions across large spatial areas (~ 1 × 1 km and larger grids) (Byun and Schere 2006). Local- scale air dispersion models (e.g., AERMOD) use emissions data to estimate local concen- trations with smaller-scale spatial variability (Cimorelli et al. 2005). Unlike the regional- scale models, these do not incorporate detailed atmospheric chemical reactions, and meteoro- logical information (e.g., wind direction and speed) is rarely available for all the locations of interest. Combining grid-based regional-scale Table 1. Summary of exposure assessment in some previous birth cohort studies of asthma and allergies in children that did not focus exclusively on air pollution. Cohort (references) Year(s) Type Exposures Sample type Sample location Timing of measurement CaPPS (Canadian 1995 C, I, HR HDM, cat (µg/g dust) Dust Bedroom floor (child, parent), Before birth, 2 weeks, Asthma Primary mattress (child, parent), living 4 months, 8 months, Prevention Study) room floor, furniture 12 months, 18 months, (Canada) (Becker et al. 2 years, 7 years 1999, 2004; Carlsten Dog (µg/g dust) Dust 1 year, 2 years, 7 years et al. 2009) ETS (ng/mg creatinine) Biomarker Urine (cotinine) 2 weeks ETS (ng/mg creatinine) Biomarker Breast milk (cotinine) 4 weeks Outdoor air pollution (NO, NO2, LUR model Home address 1 year, 7 years PM2.5, black carbon – µg /m3) BAMSE (Sweden) 1994–1996 C Air change rate (changes Measurement, passive All rooms First winter season after (Almqvist et al. 2003; per hour) tracer gas birth Emenius et al. 2003, Temperature (°F and °C) Measurement Living room and bedroom (child) 2004; Wickman et al. RH (g/kg) Measurement Living room and bedroom (child) 2002) Indoor NO2 (µg/m3) Air, passive sampler Living room, outside living room window Cat, dog (µg/m3 dust) Dust, vacuum Mattress (parent) 2 months Outdoor NO2 (µg/m3 dust) Dispersion model using Home address(es) First year of life emission data MAS (Multicentre 1990 C, HR HDM, cat (ng/g dust) Dust, vacuum Living room, bedroom (child, 6 months, 18 months, Allergy Study) parent) 3 years, 4 years, 5 years, (Germany) (Lau et al. 7 years 2000, 2005; Nickel HDM, cat (ng/g dust) Dust, vacuum Mattress 5 years, 10 years et al. 2002) Endotoxin (EU/mg dust) Dust Mattress 10 years PIAMA (Prevention 1996–1997 C, I, HR HDM (ng/m2), cat (mU/m2), dog Dust, vacuum Mattress (child, parent), living 3 months, 4 years, and Incidence of (dog ng/m2) room floor 6 years, 8 years Asthma and Mite LPS (U/mg), EPS (U/mg), Dust, vacuum Mattress (child), living room floor 3 months Allergy) (Netherlands) β-glucans (g/mg dust) (Brunekreef et al. ETS (µg/m3) Air (nicotine) Home 2-week samples, 2000; Gehring et al. 1997–1998 2009; van Strien et al. Outdoor air pollution [PM2.5 LUR model Address at birth Long-term average 2000, 2002) (µg/m3), NO2 (µg/m3), soot (10–5 m–1)] MAAS (Manchester 1995–1997 C, I HDM (ng/m2 and µg/g dust) Dust, vacuum Bed (child, parent), bedroom floor Week 10 of pregnancy, Asthma and Allergy (child, parent), living room floor, birth, 6 months, 1 year Study) (United furniture Kingdom) (Custovic et al. 2000) Boston, MA (USA) 1994–1996 C, HR HDM (µg/g), cat (µg/g), Dust, vacuum Bedroom floor (child), bed (child, 2–3 months (Chew et al. 1998; cockroach (µg/g) parent), kitchen floor, chair/sofa Gold et al. 1999) Temperature (°C) and RH Measurement Bedroom floor (child) 2–3 months (absolute g/kg, relative %) British (United 1990–1991 C, I HDM (µg/g dust) Dust, vacuum Bedroom (child), living room floor, Birth, 3 months, 6 months, Kingdom) (Arshad furniture 9 months et al. 1992) PREVASC (Prevention 1997–2002 C, I HDM, cat, dog (ng/g dust and Dust, vacuum Mattress (child, parent), LR floor 3–5 months, 7–9 months, of Asthma in Children) ng/m2) 4 years (Netherlands) RH (NR) Measurement Bedroom (child, parent) Months 3–5 and 7–8 of (Kuiper et al. 2005; ETS (NR) Biomarker Exhaled carbon monoxide pregnancy, 4 weeks, Schonberger et al. 7–9 months, 1 year, 2005a, 2005b) 2 years, 4 years Krakow (Poland) 2000–2003 C ETS (ng/mL) Biomarker Cord blood (cotinine) At birth (Jedrychowski et al. 2009) Detroit, MI (USA) 1987–1989 C ETS (ng cotinine/mg creatinine) Biomarker Urine (cotinine) Every 2 months after birth (Ownby et al. 2002; for 2 years Peterson et al. 1997, HDM (µg/g dust), cat (mU/g dust) Dust, vacuum Beside bed (child) 2 years 1999) HDM (µg/g dust), cat (mU/g dust) Air Bedroom (child) 2 years Oslo (Norway) (Magnus 1992–1993 C, CC NO2 (µg/m3) Air, passive sampler Breathing zone (child); area: During first 2 years of et al. 1998; Nafstad bedroom (child), kitchen wall, living life, after meeting case/ et al. 1998) room, child care, outside of house control definition HDM (count per bed) Dust, vacuum Mattress (child) RH (g/kg) Measurement Living room Air change rate (changes per Measurement, passive Whole home hour) tracer gas Abbreviations: C, cohort; CC, case control; EPS, extracellular polysaccharides (specifically from genera Penicillium and Aspergillus in PIAMA cohort); ETS, environmental tobacco smoke; HDM, house dust mites; HR, high risk; I, intervention; LPS, lipopolysaccharide; NR, not reported; RH, relative humidity. Environmental Health Perspectives • volume 119 | number 5 | May 2011 593