Milanzi EB, Koppelman GH, Smit HA, et al. - Given that there is a lack of clarity with regard to the relevance of timing of exposure in the links of secondhand tobacco smoke (SHS), pets, and dampness or mould exposure with lung function, researchers determined the relevance of timing of these exposures for lung function in adolescence. From the Dutch Prevention and Incidence of Asthma and Mite Allergy cohort, they analyzed data from participants with spirometric measurements at ages 12 and 16 years (n = 552). By means of repeated parental questionnaires, they collected data on residential exposure to SHS, pets, and dampness or mould. In adolescence, decreased lung function growth and lower attained lung function could be seen as a result of SHS exposure during childhood. While there may not be an adverse influence of pet exposure in late childhood on lung function, a slowing down of FVC growth in adolescence may be caused by early childhood pet exposure.