Short-term exposure sequences and anxiety symptoms: a time series clustering of smartphone-based mobility trajectories.

BACKGROUND: Short-term environmental exposures, including green space, air pollution, and noise, have been suggested to affect health. However, the evidence is limited to aggregated exposure estimates which do not allow the capture of daily spatiotemporal exposure sequences. We aimed to (1) determine individuals' sequential exposure patterns along their daily mobility paths and (2) examine whether and to what extent these exposure patterns were associated with anxiety symptoms. METHODS: We cross-sectionally tracked 141 participants aged 18-65 using their global positioning system (GPS) enabled smartphones for up to 7 days in the Netherlands. We estimated their location-dependent exposures for green space, fine particulate matter, and noise along their moving trajectories at 10-min intervals. The resulting time-resolved exposure sequences were then partitioned using multivariate time series clustering with dynamic time warping as the similarity measure. Respondents' anxiety symptoms were assessed with the Generalized Anxiety Disorders-7 questionnaire. We fitted linear regressions to assess the associations between sequential exposure patterns and anxiety symptoms. RESULTS: We found four distinctive daily sequential exposure patterns across the participants. Exposure patterns differed in terms of exposure levels and daily variations. Regression results revealed that participants with a "moderately health-threatening" exposure pattern were significantly associated with fewer anxiety symptoms than participants with a "strongly health-threatening" exposure pattern. CONCLUSIONS: Our findings support that environmental exposures' daily sequence and short-term magnitudes may be associated with mental health. We urge more time-resolved mobility-based assessments in future analyses of environmental health effects in daily life.

Daily space-time activities, multiple environmental exposures, and anxiety symptoms: A cross-sectional mobile phone-based sensing study.

BACKGROUND: Few mobility-based studies have investigated the associations between multiple environmental exposures, including social exposures, and mental health. OBJECTIVE: To assess how exposure to green space, blue space, noise, air pollution, and crowdedness along people's daily mobility paths are associated with anxiety symptoms. METHODS: 358 participants were cross-sectionally tracked with Global Positioning System (GPS)-enabled mobile phones. Anxiety symptoms were measured at baseline using the Generalized Anxiety Disorder-7 (GAD-7) questionnaire. Green space, blue space, noise, and air pollution were assessed based on concentric buffers of 50 m and 100 m around each GPS point. Crowdedness was measured by the number of nearby Bluetooth-enabled devices detected along the mobility paths. Multiple linear regressions with full covariate adjustment were fitted to examine anxiety-environmental exposures associations. Random forest models were applied to explore possible nonlinear associations and exposure interactions. RESULTS: Regression results showed null linear associations between GAD-7 scores and environmental exposures. Random forest models indicated that GAD-7-environment associations varied nonlinearly with exposure levels. We found a negative association between green space and GAD-7 scores only for participants with moderate green space exposure. We observed a positive association between GAD-7 scores and noise levels above 60 dB and air pollution concentrations above 17.2 µg m-3. Crowdedness was positively associated with GAD-7 scores, but exposure-response functions flattened out with pronounced crowdedness of >7.5. Blue space tended to be positively associated with GAD-7 scores. Random forest models ranked environmental exposures as more important to explain GAD-7 scores than linear models. CONCLUSIONS: Our findings indicate possible nonlinear associations between mobility-based environmental exposures and anxiety symptoms. More studies are needed to obtain an in-depth understanding of underlying anxiety-environment mechanisms during daily life.

Transportation noise exposure and anxiety: A systematic review and meta-analysis.

BACKGROUND: Exposure to transportation noise is hypothesized to contribute to anxiety, but consistent associations have not been established. OBJECTIVE: To provide a comprehensive synthesis of the literature by examining associations between traffic-related noise (i.e., road traffic noise, railway noise, aircraft noise and mixed traffic noise) and anxiety. METHODS: We systematically searched Web of Science, Scopus, Embase, PubMed, and PsycINFO for English-language observational studies published up to February 2020 reporting on the traffic noise-anxiety association. We appraised the risk of bias using an assessment tool and the quality of evidence following established guidelines. A random-effects meta-analysis was performed for pooled and separated traffic-related noise sources. RESULTS: Of the 3575 studies identified, 11 fulfilled the inclusion criteria and 9 studies were appropriate for meta-analysis. For the pooled overall effect size between transport noise and anxiety, we found 9% higher odds of anxiety associated with a 10 dB(A) increase in day-evening-night noise level (Lden), with moderate heterogeneity (OR = 1.09, 95% CI: [0.97; 1.23], I2 = 70%). The association was more likely to be significant with more severe anxiety (OR = 1.08, 95% CI: [1.01; 1.15], I2 = 48%). Sub-group analysis revealed that the effects of different noise sources on anxiety were inconsistent and insignificant. The quality of evidence was rated as very low to low. CONCLUSIONS: Our findings support the hypothesis of an association between traffic noise and more severe anxiety. More high-quality studies are needed to confirm associations between different noise types and anxiety, as well as to better understand underlying mechanisms.