Brame, Joel EWarbrick, IsaacHeke, DeborahLiddicoat, CraigBreed, Martin F2024-11-122024-11-122024-03-28Environmental Research, ISSN: 0013-9351 (Print); 1096-0953 (Online), Elsevier, 252(Pt 1), 118814-. doi: 10.1016/j.envres.2024.1188140013-93511096-0953http://hdl.handle.net/10292/18289Indigenous health interventions have emerged in New Zealand aimed at increasing people's interactions with and exposure to macro and microbial diversity. Urban greenspaces provide opportunities for people to gain such exposures. However, the dynamics and pathways of microbial transfer from natural environments onto a person remain poorly understood. Here, we analysed bacterial 16S rRNA amplicons in air samples (n = 7) and pre- and post-exposure nasal samples (n = 238) from 35 participants who had 30-min exposures in an outdoor park. The participants were organised into two groups: over eight days each group had two outdoor park exposures and two indoor office exposures, with a cross-over study design and washout days between exposure days. We investigated the effects of participant group, location (outdoor park vs. indoor office), and exposures (pre vs. post) on the nasal bacterial community composition and three key suspected health-associated bacterial indicators (alpha diversity, generic diversity of Gammaproteobacteria, and read abundances of butyrate-producing bacteria). The participants had distinct nasal bacterial communities, but these communities did not display notable shifts in composition following exposures. The community composition and key health bacterial indicators were stable throughout the trial period, with no clear or consistent effects of group, location, or exposure. We conclude that 30-min exposure periods to urban greenspaces are unlikely to create notable changes in the nasal microbiome of visitors, which contrasts with previous research. Our results suggest that longer exposures or activities that involves closer interaction with microbial rich ecological components (e.g., soil) are required for greenspace exposures to result in noteworthy changes in the nasal microbiome./© 2024 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).http://creativecommons.org/licenses/by/4.0/AerobiomeMicrobial ecologyMicrobiomeNasal microbiomeUrban greenspacesAerobiomeMicrobial ecologyMicrobiomeNasal microbiomeUrban greenspaces3107 Microbiology31 Biological SciencesClinical Trials and Supportive ActivitiesHealth Effects of Indoor Air PollutionClinical ResearchPreventionSocial Determinants of HealthMicrobiome2.2 Factors relating to the physical environment03 Chemical Sciences05 Environmental Sciences06 Biological SciencesToxicology31 Biological sciences34 Chemical sciences41 Environmental sciencesAdultFemaleHumansMaleMiddle AgedYoung AdultAir MicrobiologyAir PollutantsBacteriaCohort StudiesCross-Over StudiesEnvironmental ExposureMaori PeopleMicrobiotaNew ZealandNoseParks, RecreationalRNA, Ribosomal, 16SNoseHumansBacteriaRNA, Ribosomal, 16SAir PollutantsCohort StudiesCross-Over StudiesAir MicrobiologyEnvironmental ExposureAdultMiddle AgedNew ZealandFemaleMaleYoung AdultMicrobiotaParks, RecreationalMaori PeopleAdultFemaleHumansMaleMiddle AgedYoung AdultAir MicrobiologyAir PollutantsBacteriaCohort StudiesCross-Over StudiesEnvironmental ExposureMaori PeopleMicrobiotaNew ZealandNoseParks, RecreationalRNA, Ribosomal, 16SJournal ArticleOpenAccess10.1016/j.envres.2024.118814