Elaine Fuertes1, Marie Standl2, Iana Markevych3, Wolfgang Bischof4, Joachim Heinrich3. 1. ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Spain; Universitat Pompeu Fabra (UPF), Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain. Electronic address: elaine.fuertes@isglobal.org. 2. Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany. 3. Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany; Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Munich, Germany. 4. University Hospital Jena, Institute of Occupational, Social and Environmental Medicine, Department of Indoor Climatology, Jena, Germany.
Abstract
BACKGROUND: Pet ownership is consistently associated with higher indoor endotoxin concentrations, but may also be related to the amount of greenspace around the home. This study examined whether the association between pet ownership and higher indoor endotoxin concentrations is confounded or modified by residential greenspace. METHODS: Information on pet ownership was collected at the time of recruitment of the German LISA birth cohort. Endotoxin levels were measured in settled house dust sampled from mothers' mattresses (N=1197) and living room floors (N=390). Greenspace around the home was assessed as the mean Normalized Difference Vegetation Index in 100m, 500m and 1000m buffers around the home, and as the distance to the nearest urban and natural green space. Linear regression models assessed cross-sectional associations between pet ownership and log-transformed endotoxin levels, adjusted for known predictors of endotoxin levels. Confounding by greenspace was assessed by additionally adjusting the models for each greenspace variable. Effect modification was assessed by including interaction terms between pet ownership and each greenspace variable, and by model stratification. RESULTS: Dog and cat ownership were associated with higher endotoxin levels in mothers' mattresses, whereas only dog ownership was associated with endotoxin levels in the floor samples. All associations were highly robust to further adjustment for greenspace, and there was little evidence to suggest any effect modification (interaction terms had p-values >0.05). CONCLUSIONS: Residential greenspace did not confound or modify the association between pet ownership and indoor endotoxin levels. Studies should continue investigating whether pets influence the indoor environment only by their presence, or also by acting as transmission vectors of the outdoors.
BACKGROUND: Pet ownership is consistently associated with higher indoor endotoxin concentrations, but may also be related to the amount of greenspace around the home. This study examined whether the association between pet ownership and higher indoor endotoxin concentrations is confounded or modified by residential greenspace. METHODS: Information on pet ownership was collected at the time of recruitment of the German LISA birth cohort. Endotoxin levels were measured in settled house dust sampled from mothers' mattresses (N=1197) and living room floors (N=390). Greenspace around the home was assessed as the mean Normalized Difference Vegetation Index in 100m, 500m and 1000m buffers around the home, and as the distance to the nearest urban and natural green space. Linear regression models assessed cross-sectional associations between pet ownership and log-transformed endotoxin levels, adjusted for known predictors of endotoxin levels. Confounding by greenspace was assessed by additionally adjusting the models for each greenspace variable. Effect modification was assessed by including interaction terms between pet ownership and each greenspace variable, and by model stratification. RESULTS:Dog and cat ownership were associated with higher endotoxin levels in mothers' mattresses, whereas only dog ownership was associated with endotoxin levels in the floor samples. All associations were highly robust to further adjustment for greenspace, and there was little evidence to suggest any effect modification (interaction terms had p-values >0.05). CONCLUSIONS: Residential greenspace did not confound or modify the association between pet ownership and indoor endotoxin levels. Studies should continue investigating whether pets influence the indoor environment only by their presence, or also by acting as transmission vectors of the outdoors.
Authors: Jenni M Mäki; Pirkka V Kirjavainen; Martin Täubel; Eija Piippo-Savolainen; Katri Backman; Anne Hyvärinen; Pauli Tuoresmäki; Balamuralikrishna Jayaprakash; Joachim Heinrich; Gunda Herberth; Marie Standl; Juha Pekkanen; Anne M Karvonen Journal: Sci Rep Date: 2021-03-05 Impact factor: 4.379