Fractional exhaled nitric oxide (FeNO) among elementary school children in Stockholm: Associations with asthma, allergies, and home and school environment.

Objective: Few studies have investigated links between fraction exhaled nitric oxide (FeNO), the home and the school environment. FeNO is a biomarker of T helper 2 (Th2) airway inflammation. We investigated associations between FeNO and airway symptoms, allergies, household and classroom exposure among pupils in ten primary schools in Stockholm (N = 415).

Effects of energy retrofits on the indoor microbiota in Northern European apartments.

While the urgent need for energy saving is triggering energy retrofit measures in buildings, there are still large gaps in our understanding of how these measures may impact indoor environmental quality, including particle, chemical, and microbial exposure, and ultimately human health. Here, we explore the effects of energy retrofits on the indoor microbiota characteristics of 193 apartments in 40 apartment buildings in two Northern European countries, Finland and Lithuania. Amplicon sequencing was used to characterise fungal and bacterial microbiota compositions in airborne, settled dust samples collected from apartments before and after energy retrofits, mostly targeting upgrades in insulation, heating and/or ventilation systems, and windows.

Cleaning products: Their chemistry, effects on indoor air quality, and implications for human health.

The use of cleaning and disinfecting products both at work and at home increased during the COVID-19 pandemic. Those products often include surfactants, acids/bases, carcinogens such as chloroform, and endocrine-disrupting chemicals, such as cyclosiloxanes, phthalates, and synthetic fragrances, which may cause harmful health effects among professional cleaners as well as among people exposed at home or in their workplaces. The aim of this study was to synthesize the effects of the commonly used chemical, surface cleaning and disinfecting products on indoor air quality, focusing on chemical and particulate matter pollutants, exposure, and human health in residential and public buildings.

Identification of environmental Actinobacteria in buildings by means of chemotaxonomy, 16S rRNA sequencing, and MALDI-TOF MS.

Unlabelled: Actinobacteria are abundant in soil and other environmental ecosystems and are also an important part of the human microbiota. Hence, they can also be detected in indoor environments and on building materials, where actinobacterial proliferation on damp materials can indicate moisture damage. The aim of this study was to evaluate the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of 28 environmental strains of Actinobacteria isolated from building materials and indoor and outdoor air samples, mainly collected in the context of moisture damage investigations in buildings in Finland.

Early-life environment and the risk of eczema at 2 years-Meta-analyses of six Finnish birth cohorts.

Background: Urban-related nature exposures are suggested to contribute to the rising prevalence of allergic diseases despite little supporting evidence. Our aim was to evaluate the impact of 12 land cover classes and two greenness indices around homes at birth on the development of doctor-diagnosed eczema by the age of 2 years, and the influence of birth season.

Methods: Data from 5085 children were obtained from six Finnish birth cohorts.

Association of indoor dust microbiota with cognitive function and behavior in preschool-aged children.

Background: Childhood cognitive development depends on neuroimmune interactions. Immunomodulation by early-life microbial exposure may influence neuropsychological function. In this study, we investigate the association between residential indoor microbiota and cognition and behavior among preschoolers.

Trajectories of cough without a cold in early childhood and associations with atopic diseases.

Background: Although children can frequently experience a cough that affects their quality of life, few epidemiological studies have explored cough without a cold during childhood.

Objectives: The objective of the study was to describe the latent class trajectories of cough from one to 10 years old and analyse their association with wheezing, atopy and allergic diseases.

Methods: Questions about cough, wheeze and allergic diseases were asked at 1, 1.

Determinants of bacterial and fungal microbiota in Finnish home dust: Impact of environmental biodiversity, pets, and occupants.

The indoors is where many humans spend most of their time, and are strongly exposed to indoor microbiota, which may have multifaceted effects on health. Therefore, a comprehensive understanding of the determinants of indoor microbiota is necessary. We collected dust samples from 295 homes of families with young children in the Helsinki region of Finland and analyzed the bacterial and fungal composition based on the 16S rRNA and ITS DNA sequences.

Continuous Rather Than Solely Early Farm Exposure Protects From Hay Fever Development.

Background: An important window of opportunity for early-life exposures has been proposed for the development of atopic eczema and asthma.

Objective: However, it is unknown whether hay fever with a peak incidence around late school age to adolescence is similarly determined very early in life.

Methods: In the Protection against Allergy-Study in Rural Environments (PASTURE) birth cohort potentially relevant exposures such as farm milk consumption and exposure to animal sheds were assessed at multiple time points from infancy to age 10.

Early-life residential exposure to moisture damage is associated with persistent wheezing in a Finnish birth cohort.

Background And Aims: Moisture damage increases the risk for respiratory disorders in childhood. Our aim was to determine whether early age residential exposure to inspector-observed moisture damage or mold is associated with different wheezing phenotypes later in childhood.

Methods: Building inspections were performed by civil engineers, in a standardized manner, in the children's homes-mostly single family and row houses (N = 344)-in the first year of life.

Indoor green can modify the indoor dust microbial communities.

Little is known about the potential role of indoor plants in shaping the indoor microbiota. Within the ENVIRONAGE birth cohort, we collected settled dust and performed 16S and ITS amplicon sequencing and qPCR measurements to characterize the indoor microbiota, including bacterial and fungal loads and Chao1 richness, Shannon, and Simpson diversity indices. For 155 households, we obtained information on the number of indoor plants.

Interplay between natural environment, human microbiota and immune system: A scoping review of interventions and future perspectives towards allergy prevention.

Background: Urbanization and biodiversity loss are linked to chronic disorders, in particular allergic diseases. The aim of this scoping review was to provide a synopsis of intervention studies specifically examining the influence of exposure to natural environments on human microbiota as well as immunological markers as suggested interlink between natural environment and the development of allergic diseases.

Methods: We searched PubMed (MEDLINE®) and all references cited in the included studies following the PRISMA statement guidelines.

Toxicological transcriptome of human airway constructs after exposure to indoor air particulate matter: In search of relevant pathways of moisture damage-associated health effects.

Background: Multiple health effects are associated with moisture damage in buildings. Studies explaining these associations and cell-level mechanisms behind the observed health effects are urgently called for.

Objectives: We focused on characterizing gene expression in human airway epithelium after exposure to indoor air particulate matter (PM) sampled from houses with and without moisture damage, alongside determination of general toxicological markers.

Toxicological and microbiological characterization of cow stable dust.

Exposure to farm environment has been shown to both protect from allergic diseases and increase the risk of respiratory syndromes. Mechanisms have been previously investigated by using farm dust extracts or specific components of dust. The use of authentic farm dust would better reflect the natural exposure.

Residential green space can shape the indoor microbial environment.

Background: The influence of outdoor green space on microbial communities indoors has scarcely been investigated. Here, we study the associations between nearby residential green space and residential indoor microbiota.

Methods: We collected settled dust from 176 living rooms of participants of the ENVIRONAGE birth cohort.

Microbial exposures in moisture-damaged schools and associations with respiratory symptoms in students: A multi-country environmental exposure study.

Moisture-damaged buildings are associated with respiratory symptoms and underlying diseases among building occupants, but the causative agent(s) remain a mystery. We first identified specific fungal and bacterial taxa in classrooms with moisture damage in Finnish and Dutch primary schools. We then investigated associations of the identified moisture damage indicators with respiratory symptoms in more than 2700 students.

Associations between dog keeping and indoor dust microbiota.

Living with dogs appears to protect against allergic diseases and airway infections, an effect possibly linked with immunomodulation by microbial exposures associated with dogs. The aim of this study was to characterize the influence of dog ownership on house dust microbiota composition. The bacterial and fungal microbiota was characterized with Illumina MiSeq sequencing from floor dust samples collected from homes in a Finnish rural-suburban (LUKAS2, N = 182) birth cohort, and the results were replicated in a German urban (LISA, N = 284) birth cohort.

Microbial diversity in homes and the risk of allergic rhinitis and inhalant atopy in two European birth cohorts.

Background: Microbial exposures in early childhood direct the development of the immune system and their diversity may influence the risk of allergy development. We aimed to determine whether the indoor microbial diversity at early-life is associated with the development of allergic rhinitis and inhalant atopy.

Methods: The study population included children within two birth cohorts: Finnish rural-suburban LUKAS (N = 312), and German urban LISA from Munich and Leipzig study centers (N = 248).

Particle Resuspension Dynamics in the Infant Near-Floor Microenvironment.

Carpet dust contains microbial and chemical material that can impact early childhood health. Infants may be exposed to greater quantities of resuspended dust, given their close proximity to floor surfaces. Chamber experiments with a robotic infant were integrated with a material balance model to provide new fundamental insights into the size-dependency of infant crawling-induced particle resuspension and exposure.

Practitioner-driven research for improving the outcomes of mold inspection and remediation.

This commentary is intended to provide a research roadmap for utilizing recent chemical and molecular-biological technological advances for addressing dampness and mold in buildings. The perspective is unique in that both the mold industry practitioners and academic researchers drive the questions. Research needs were derived from a 2018 international workshop attended by practitioners, researchers and governmental representatives, where challenges and opportunities in the mold remediation and restoration field were discussed focusing on the need to develop new tools that improve building diagnosis and clearance certification for mold inspectors and remediators.