International data suggest that exposure to nature is beneficial for mental health and well-being. The restrictions related to the COVID-19 pandemic have created a setting that allows us to investigate the importance of greenness exposure on mental health during a period of increased isolation and worry. Based on 2060 responses from an online survey in Stockholm County, Sweden, we investigated: (1) whether the COVID-19 pandemic changed peoples’ lifestyle and nature-related habits, and (2) if peoples’ mental health differed depending on their exposure to greenness. Neighborhood greenness levels were quantified by using the average normalized difference vegetation index (NDVI) within 50 m, 100 m, 300 m, and 500 m buffers surrounding the participant’s place of residence. We found that the number of individuals that reported that they visited natural areas “often” was significantly higher during the pandemic than before the pandemic. Higher levels of greenness surrounding one’s location of residence were in general associated with higher mental health/well-being and vitality scores, and less symptoms of depression, anxiety, and perceived and cognitive stress, after adjustments for demographic variables and walkability. In conclusion, the results from the present study provided support to the suggestion that contact with nature may be important for mental health in extreme circumstances.

BackgroundChronic bronchitis is associated with substantial morbidity among elderly adults, but little is known about its prevalence and risk factors in young adults. Our aim was to assess the prevalence and early life risk factors for chronic bronchitis in young adults.MethodsQuestionnaire data and clinical measures from the 24-year follow-up of the Swedish BAMSE cohort were used. We assessed chronic bronchitis (CB) as the combination of cough and mucus production in the morning during winter. Environmental and clinical data from birth and onwards were used for analyses of risk factors.ResultsAt the 24-year follow-up, 75% (n=3064) participants completed the questionnaire and 2030 performed spirometry. The overall prevalence of CB was 5.5% (n=158) with similar estimates in males and females. Forty-nine percent of CB cases experienced more than 3 self-reported respiratory infections in the last year compared to 18% in non-CB subjects (p<0.001), and 37% of cases were current smokers (versus 19%). Statistically significant lower post-FEV1/FVC were observed in CB compared to non-CB subjects (mean z-score −0.06 versus 0.13, p=0.027). Daily smoking (adjusted Odds Ratio, aOR=3.85, p<0.001), air pollution exposure (black carbon during ages 1–4 years old, aOR=1.71 per 1 μg·m3 increase, p=0.009) and exclusive breast-feeding during four months or more (aOR=0.66, p=0.044) were associated with CB.ConclusionChronic bronchitis in young adults is associated with recurrent respiratory infections. Besides smoking, our results support role of early life exposures, such as air pollution and exclusive breast-feeding, for respiratory health later in life.

Background Young adults are now considered major spreaders of COVID-19 disease. Although most young individuals suffer from mild to moderate disease, there are concerns of long-term adverse health effects. The impact of COVID-19 disease and to which extent population-level immunity against SARS-CoV-2 exist in young adults remain unclear. Objective To conduct a population-based study on humoral and cellular immunity to SARS-CoV-2 and explore COVID-19 disease characteristics in young adults. Methods We invited participants from the Swedish BAMSE birth cohort (age 24-27 years) to take part in a COVID-19 follow-up. From 980 participants (October 2020-June 2021), we here present data on SARS-CoV-2 RBD-specific IgM, IgA and IgG titres measured by ELISA and on symptoms and epidemiological factors associated with seropositivity. Further, SARS-CoV-2-specific memory B- and T-cell responses were detected for a subpopulation (n=108) by ELISpot and Fluorospot. Results 28.4% of subjects were seropositive of which 18.4% were IgM single positive. One in seven seropositive subjects were asymptomatic. Seropositivity associated with use of public transport, but not with sex, asthma, rhinitis, IgE-sensitization, smoking or BMI. In a subset of representative samples, 20.7% and 35.0% had detectable SARS-CoV-2 specific B- and T-cell responses, respectively. B- and T-cell memory responses were clearly associated with seropositivity, but T-cell responses were also detected in 17.2% of seronegative subjects. Conclusion Assessment of IgM and T-cell responses may improve population-based estimations of SARS-CoV-2 infection. The pronounced surge of both symptomatic and asymptomatic infections among young adults should imply a continuation of the large-scale vaccination campaign.