Equitable access to urban green spaces (UGS) is important for public health, yet spatial assessments often focus only on equal availability and accessibility. Health benefits, however, arise when supply is aligned with population-specific needs, calling for a shift toward equity-based assessments that explicitly link supply and demand. To address this, we introduce the Urban Green Equity Index (UGEI), a multidimensional framework designed to evaluate UGS equity based on health-relevant supply and demand factors. The UGEI integrates multiple aspects of supply - quantity, entrance-based accessibility, and ecological and structural quality of diverse UGS types - with demand indicators reflecting socio-economic and environmental conditions that shape health-related needs. Applied to Flanders, Belgium, the UGEI moves beyond city-scale, park-only assessments by combining regional coverage with fine-grained resolution (20 x 20 m for supply; 100 x 100 m for demand). Using both a composite index and a bivariate choropleth map, we show its ability to reveal spatial mismatches across scales, from broad regional inequities to neighborhood-level disparities. To illustrate its policy relevance, we further test the UGEI against the Belgian Index of Multiple Deprivation. Regression analyses reveal significant associations between green inequity and multiple forms of disadvantage, including health deprivation, consistent with the notion that benefits arise where provision meets socially embedded needs. This application underscores the UGEI's value as a transferable, evidence-based tool to detect underserved areas across diverse contexts and policy goals, link environmental and health inequities, and guide targeted interventions for maximum impact.

Green space offers numerous benefits for health and well-being, yet socioeconomic disparities continue to shape who has access to these benefits. The 3+30+300 guideline aims to reduce this inequity by promoting visible, available, and accessible green for all residents. This study assesses these components of green exposure across Flanders, Belgium, one of the most densely populated and highly urbanized regions in Western Europe, and examines how they intersect with multiple dimensions of socioeconomic deprivation, namely sensitivity and adaptive capacity. Using 264,622 building-level sample points, we quantified tree visibility from street-view imagery, tree canopy cover, and network distance to accessible green space. Median values of 5.0 (urban) and 6.0 (rural) visible trees, 16.1% (urban) and 12.4% (rural) canopy cover, and distances of 367 (urban) and 548 (rural) meters to accessible green were observed. Deprived neighborhoods, particularly those characterized by housing and health deprivation, showed the highest sensitivity to lack of green spaces, while areas with more elderly and higher-income residents had consistently greater exposure. These results suggest that green exposure and socioeconomic susceptibility intersect and reinforce one another, producing compounded distributive injustice. The findings highlight the need for equity-oriented interpretation and implementation of the 3+30+300 guideline and call for targeted greening strategies that address structural environmental and health inequalities.

BACKGROUND:Residential greenness has been associated with health, but exposure to visible, functional, and accessible green may be associated with different health outcomes. SOURCES OF DATA:We searched Web of Science, PubMed, Scopus, and Embase for quantitative studies evaluating health in relation to specific green space exposures. AREAS OF AGREEMENT:There is evidence for associations between visible, functional, and accessible green space exposures and health, but most evidence is derived from observational studies. AREAS OF CONTROVERSY:High heterogeneity was found across studies with the possibility of publication bias. Some studies suggest stronger associations in low socioeconomic status and urban neighborhoods, but the evidence is inconclusive. GROWING POINTS:Quantitative and clinical evidence for health impacts of interventions focusing on improving visible, functional, and accessible green space exposure is limited and therefore causal relationships can usually not be inferred. AREAS TIMELY FOR DEVELOPING RESEARCH:Further research should include randomized controlled trials and consider different green space types, private green, spatial configuration, street network distances, and quality and use.

BACKGROUND:Climate changes are increasing the frequency of concurrent extremes in temperature, air pollution, and aeroallergens, yet evidence on their joint and synergistic health impacts remains limited. We aimed to quantify the independent, joint, and interactive short-term effects of temperature, air pollutants, and airborne pollen on allergic rhinitis and asthma using long-term general practitioner (GP) data. METHODS:We conducted a population-based time-series study using 20 years of GP data. Daily maximum temperature, PM2.5, ozone, and pollen concentrations were linked to allergic rhinitis and asthma outcomes. We estimated cumulative relative risks (RR) over lag 0-14 days using distributed lag non-linear models, comparing high (95th percentile) versus median exposure levels. We evaluated effect modification through stratified analyses and quantified additive interaction for joint exposures at extreme levels (90th and 95th percentile) using relative excess risk due to interaction (RERI) and attributable proportion (AP). FINDINGS:Pollen exposure was strongly associated with allergic rhinitis (RR=2.54, 95% CI: 2.40-2.69) and with asthma (RR=1.49, 95% CI: 1.38-1.61). In joint-effects analyses, co-exposure to extreme heat and high pollen concentrations was associated with an increased risk of allergic rhinitis (RR= 2.07, 95% CI: 1.77-2.41), with clear evidence of synergistic interaction on the additive scale (RERI=0.48, 95% CI: 0.32-0.64, AP=0.23, 95% CI: 0.17-0.30). Similarly, co-exposure to high pollen and ozone was associated with elevated allergic rhinitis risk (RR = 2.03, 95% CI: 1.76-2.34), with positive additive interaction (RERI = 0.40, 95% CI: 0.25-0.54; AP = 0.20, 95% CI: 0.13-0.26). The same exposure combinations, heat-pollen and pollen-ozone, also exhibited positive synergistic interactions for asthma. CONCLUSION:Our findings identify pollen as a central driver of climate-sensitive allergic morbidity, with heat and ozone acting as key amplifiers through synergistic interactions. Our findings highlight the need for integrated early-warning systems, and risk assessments that account for joint environmental exposures.

Green spaces have a beneficial effect on health, but the perspective from a primary care setting, such as general practice, is often missing. This cross-sectional study investigated the association between residential green space, traffic exposure, and anxiety and depression in a primary care setting, which is often the first point of contact for mental health problems.We conducted this study in the urbanized region of Flanders, Belgium, based on consultations registered in the Intego general practice database from 2014 to 2023. Exposures were visible green, residential green space cover in different buffers (150m, 500m and 1500m), access to green space and traffic exposure. The outcomes were diagnoses of depression and anxiety, and prescriptions for antidepressants and benzodiazepines. Models were adjusted for gender, age, socioeconomic status and living in a city and included a random intercept for the level of the practice clinic, to account for spatial clustering of subjects.We identified 180,569 unique patients in the study period of which 16,659 (9.2%) had a diagnosis of depression or anxiety. Overall, increased residential total and taller green cover within 150m was associated with fewer diagnoses of depression or anxiety (total green: adjusted OR 0.95; 95%CI [0.93,0.98] and taller green: OR 0.97; [0.95,0.99]). Increased visible green was associated with decreased rates of diagnosis of depression and anxiety and psychoactive medication prescriptions (diagnoses: OR 0.89 [0.86,0.91], prescriptions: OR 0.92 [0.91,0.94]). There were no associations with green space accessibility. Associations remained robust when adjusting for air pollution.In conclusion, we found protective effects of visible green and green space cover on mental health consultation outcomes in general practice. These results are important as a basis for non-pharmacological, preventive mental health care interventions, and as a call for urban policy to prioritize green in urban areas.

The compound occurrence of extreme heat and the COVID-19 pandemic may have increased mortality risk beyond the impact of each factor alone. However, the interaction between these two risk factors and their combined effect on mortality has not been adequately quantified. We conducted a time-stratified case-crossover analysis of daily all-cause mortality, minimum temperature, and COVID-19 case counts in Flanders over the period 2018–2021. We applied a distributed lag nonlinear model (DLNM) with a conditional quasi-Poisson regression to estimate the cumulative effects (lag 0–14 days) of extreme heat. The relative risk (RR) was quantified at the 99th percentile (P99) of minimum temperature compared to 50th percentile (P50). To assess effect modification, we used a binary interaction approach (pre-COVID-19 and during COVID-19) and a linear interaction approach. We used a 15-day moving average of daily confirmed cases and centered it at three reference points representing 25th, 75th and 95th percentiles of the distribution, corresponding to low, mild and high intensity levels, respectively. We observed that during the COVID-19 pandemic, the risk of mortality associated with extreme heat was significantly elevated (RR = 1.55; 95

Madagascar, a globally recognised biodiversity hotspot, faces escalating biodiversity loss and zoonotic disease risks. Weak response systems and fragmented governance further exacerbate these threats. This study identifies key conservation and health actors and analyses their connections to understand decision-making and information flow. The findings emphasise the need to integrate One Health into conservation strategies to address interconnected public health and biodiversity challenges. Following the Laumann-Marsden-Prensky framework, a social network analysis (SNA) survey was conducted between March 14 and June 24, 2022. The study involved 30 senior leaders (>= 5 years experience) in biodiversity conservation and health in Madagascar. Key network metrics, indegree, outdegree, and eigenvector centrality, identified influential actors, while network density and centralisation assessed structural cohesion. Participants listed collaborators in conservation and health projects and funding sources. The strength of One Health integration and interaction was quantified. Among 287 identified actors, 54.4 % are international entities. SNA shows that foreign organisations dominate collaboration and funding networks in conservation and public health governance, while local government bodies have limited involvement. Only a few stakeholders have effectively integrated the One Health approach into their conservation and health governance practices. These findings highlight a reliance on international actors, primarily due to funding access, with limited local participation. While international support provides crucial resources, greater national and local leadership is essential for the sustainable implementation of One Health. This study provides insights to enhance local involvement in conservation governance.

Green spaces help to adapt urban environments to warming and other global change challenges. At school, green playgrounds help to incorporate natural elements into the daily lives of children, potentially improving wellbeing and academic performance. This study analyzed relationships between green space within and around the school, the landscape context, and well-being and sustained attention in 526 fifth-grade children (10-11 years old) in 37 Belgian schools, using a matched case-control design. By design, school level greenness did not vary with school level socioeconomic status. Attention was measured with the d2 sustained-attention test and well-being with the KIDSCREEN-27 questionnaire. Results of generalized multilevel models fitted within a Bayesian framework showed that attention was higher in schools located in more urbanized environments and that attention primarily increased with socioeconomic status. In models that accounted for partial missing data, attention was higher and attention waning lower in schools with green playgrounds, but only in low naturalness landscapes, and these associations were most prominent in high SES schools. Overall, our study suggests that green space within the school may partially compensate limited exposure to green space in highly urbanized environments, with beneficial effects on attention and well-being. Greening existing school playgrounds is expected to benefit child development in urbanized environments while simultaneously improving urban green space cover, with health benefits that extend beyond the school boundaries.

BACKGROUND:Residential exposure to trees has been associated with reduced mortality risks. We hypothesise that in addition to tree canopy cover, tree canopy configuration also plays a role in exposure-mortality relationships. As there is limited evidence on this hypothesis, especially longitudinal evidence, we performed a nationwide study to investigate the residential tree canopy configuration-mortality associations in the Swiss population. METHODS:In this longitudinal study, the tree canopy cover and configuration metrics within 500 m of individuals' residences were quantified using high-resolution tree canopy data (1 × 1 m) from 2010 to 2019. We developed single-exposure and multi-exposure time-varying Cox regression models to estimate the associations between the different exposure metrics and natural-cause and cause-specific mortality in Swiss adults (aged from 20 years to 90 years). Mortality and census data were taken from the Swiss National Cohort (SNC). We estimated the hazard ratios (HRs) and corresponding 95% CIs per IQR increase in the metrics adjusting for personal sociodemographic and contextual covariates. We also explored the effect modification by tree canopy cover, PM10, air temperature, urbanisation level, age, sex, and area-based local socioeconomic position. FINDINGS:Our analyses included 6 215 073 individuals from the SNC between 2010 and 2019. In the fully adjusted single-exposure models, we observed protective associations between natural-cause mortality risk and tree canopy cover (IQR 12·4%, HR 0·979 [95% CI 0·975-0·983]) and configuration metrics describing the aggregation (6·3%, 0·831 [0·823-0·840]), and connectedness (2·9%, 0·946 [0·938-0·953]); and detrimental associations with two metrics describing the fragmentation (211 patches per 100 ha, 1·073 [1·066-1·080]) and shape complexity (1·9, 1·094 [1·089-1·100]) of patches. The associations were generally preserved with other common causes of death. According to the multi-exposure models, the HR (95% CI) for the combination of one IQR decrease in aggregation and one IQR increase in fragmentation and shape complexity was 1·366 (1·343-1·390). Analyses on modification effects suggested a stronger association in people living in areas with a higher level of tree canopy cover, PM10 concentration, air temperature, and urbanisation level. INTERPRETATION:Aggregated, connected, and less fragmented forested greenspaces might offer stronger health benefits than isolated, fragmented ones, but are difficult to implement in cities. Our study provided valuable insights into optimising forested greenspaces and highlighted future directions for the planning and management of urban forests towards healthy and green cities. FUNDING:National Research Foundation, Prime Minister's Office, Singapore under its Campus for Research Excellence and Technological Enterprise programme and ETH Zurich.

The impact of heat on a vulnerable population, particularly those with pre-existing chronic diseases, is a growing public health concern. However, the risks for those with specific conditions and their variation across geographic, demographic, and socioeconomic (SES) status remain underexplored. This study aimed to investigate the association of extreme heat with morbidity and mortality among individuals with pre-existing chronic diseases in Flanders, Belgium. We analysed 14 years (2005–2019) of general practitioners (GPs) data from Flanders, northern Belgium, assessing both morbidity and mortality. Morbidity was defined as GP-recorded general and heat-related illnesses among individuals with pre-existing chronic diseases, while mortality included overall mortality and mortality among people with pre-existing chronic diseases. A space-time-stratified case-crossover design was employed, with a distributed lag non-linear model (DLNM) applied in quasi-Poisson regression. Various subgroup analyses were conducted to identify the most at-risk population. We quantified the relative risk (RR) at the 99th percentile of the daily minimum temperature relative to the minimum morbidity/mortality temperature (MMT). We found a strong association of heat with morbidity and mortality. A substantially increased risk of morbidity was observed among individuals with pre-existing heart failure (RR = 2.79 [95

BACKGROUND:The prevalence of allergy to aeroallergens is rising, driven by both environmental and lifestyle changes. However, the role of ubiquitous nitrogen enrichment in exacerbating pollen allergy remains unclear. This study aimed to investigate the impact of nitrogen on pollen allergenicity by connecting the resulting ecological changes with allergic outcomes. METHODS:We conducted a cross-sectional paired comparison study, examining differences between nitrogen-enriched (fertilised) and non-enriched common semi-natural grasslands in Belgium. Pollen from paired grasslands (n=50, enriched [n=25] vs non-enriched [n=25]) based on their common geography, were sampled following a standardised protocol. We analysed grassland pollen abundance, quantified pollen species composition via DNA sequencing, and assessed pollen allergenicity using basophil activation testing and specific IgE measurements in a cross-sectional sample of adults who were allergic to grass pollen (n=20). Basophil activation test outcome measures included area under the dose-response curve, maximal reactivity (CD63max), and effective concentration eliciting 50% basophil activation. FINDINGS:Nitrogen-enriched grasslands produced significantly more pollen, with a 6·2-fold increase compared with their unfertilised counterparts (3·6 mg/m2vs 0·6 mg/m2). When normalised to protein content, pollen from these enriched grasslands showed increased allergenic potential, with 5·1 times higher basophil activation test sensitivity and a 1·3-fold increase in specific IgE titres compared with their unfertilised counterparts (geometric mean fertilised 3·63 kUA/L vs unfertilised 2·81 kUA/L). INTERPRETATION:Nitrogen enrichment substantially increased pollen abundance and allergenicity, indicating a heightened allergy burden in nitrogen-rich environments. These findings underscore the need for policies addressing nitrogen pollution to mitigate its public health impacts. FUNDING:Belgian Science Policy Office.

BackgroundBirch pollen-food allergy syndrome is triggered by cross-reactive allergens in plant-based foods. Environmental factors such as nitrogen fertilization may influence food allergenicity, but this has not been studied before.MethodsWe compared and optimized protein extraction protocols for birch-homologue foods, including apple, carrot, and soybean. Various extraction buffers and mixing methods were tested for consistency and protein yield. We applied this to a pilot study assessing potential changes in the allergenic potential of plant-based foods due to altered nitrogen availability. A greenhouse experiment was conducted in which soybean plants were subjected to different nitrogen fertilization treatments. Allergenicity was evaluated using ex vivo basophil activation testing in five individuals with birch pollen-food allergy syndrome.ResultsNo major differences were observed between the tested extraction protocols, and key allergens were detectable in all food sources. In the pilot experiment, fertilized soybeans showed visible changes in size, a smaller shape, a different protein profile, and lower basophil reactivity compared to unfertilized soybeans.ConclusionOur findings support the feasibility of standardized extraction methods. Varying nitrogen fertilization in soybeans resulted in altered physical, proteomic, and allergenic characteristics in this pilot study. Our results highlight the need for further research on environmental influences on food allergy.

The ocean has an important impact on human health. Observational studies suggest that ocean-related stimuli can improve human health, but there is limited research investigating the underlying mechanistic and epidemiological principles. Research on the interactions between the ocean and human health remains fragmented, leading to a patchy understanding of these complex connections. To structure and advance research on interactions between the ocean and human health, a transdisciplinary framework is proposed comprising of four key components: (a) ocean stimuli originating from the hydrosphere, atmosphere, lithosphere, biosphere and anthroposphere, (b) time, location, and behavior dependent human interaction with these stimuli, (c) individual sensing and processing of ocean stimuli, and (d) health outcomes at individual and population level. In addition to the introduction of this framework that builds on and integrates previous theories, we discuss how its application can promote the protection of marine environments, thereby indirectly safeguarding the mechanisms that underlie ocean-human health connections. The proposed framework makes explicit a transdisciplinary approach of OHH research and contextualizes future studies.

Introduction: Global temperature rise has become a major health concern. Most previous studies on the impact of heat on morbidity have used hospital data. Objective: This study aimed to quantify the association between ambient temperature and a variety of potentially heat-related medical conditions and symptoms using general practitioner (GP) data, in Flanders, Belgium. Methods: We used eight years (2012-2019) of aggregated data of daily GP visits during the Belgian summer period (May-September). A distributed lag nonlinear model (DLNM) with time-stratified conditional quasi-Poisson regression was used to account for the non-linear and delayed effect of temperature indicators (minimum, mean and maximum). We controlled for potential confounders such as particulate matter, humidity, and ozone. Results: The overall (lag0-14) association between heat and most of the outcomes was J-shaped, with an increased risk of disease observed at higher temperatures. The associations were more pronounced using the minimum temperatures indicator. Comparing the 99th (20 degrees C) to the minimum morbidity temperature (MMT) of the minimum temperature distribution during summer, the relative risk (RR) was significantly higher for heat-related general symptoms (RR = 1.30 [95 % CI: 1.07, 1.57]), otitis externa (RR = 4.87 [95 % CI:2.98, 7.98]), general heart problems (RR = 2.43 [95 % CI: 1.33, 4.42]), venous problems (RR = 2.48 [95 % CI:1.55, 3.96]), respiratory complaints (RR = 1.97 [95 % CI: 1.25, 3.09]), skin problems (RR = 3.26 [95 % CI: 2.51, 4.25]), and urinary infections (RR = 1.37 [95 % CI: 1.11, 1.69]). However, we did not find evidence for heat-related increases in gastrointestinal problems, cerebrovascular events, cardiovascular events, arrhythmia, mental health problems, upper respiratory problems and lower respiratory problems. An increased risk of allergy was observed when the minimum temperature reached 17.8 degrees C (RR = 1.50 [95 % CI: 1.23, 1.83]). Acute effects of heat were observed (largest effects at the first few lags). Summary: Our findings indicated that the occurrence of certain symptoms and illnesses during summer season is associated to high temperature or environmental exposures that are augmented by elevated temperatures. Overall, unlike hospitalization data, GP visits data provide broader population coverage, revealing a more accurate representation of heat-health association.

Global warming and urbanization have exacerbated urban heat island issues in cities, affecting the liveability and long-term health and well-being of its citizens. This study explores how landscape composition and configuration regulate diurnal air temperature variations and the cooling potential of urban green spaces. Using a spatially -dense citizen science weather station network in Leuven (Belgium), mean night temperature, mean day temperature, and diurnal temperature range were recorded during summer heat periods of 2022. Urban land cover data were collected at two buffer scales (50m and 250m) and analysed using composition (relative cover) and configuration metrics (aggregation and shape indices). Multiple linear (mixed) models were used to investigate associations between the composition and configuration of various land covers and air temperature at different temporal and spatial scales. Results reveal dynamic effects of urban landscape on air temperature. A 10% increase in tree cover mitigated daytime warming by 0.11 degrees C, likely through shading and evapotranspiration. Aggregated trees further improved daytime cooling by 0.42 degrees C. A 10% increase in grasses and shrubs offered significant night-time cooling up to 0.47 degrees C, probably due to high albedo and ventilation potential. Additionally, increasing the aggregation of grasses and shrubs by 10% enhanced nocturnal cooling by 1.62 degrees C, while increasing the shape complexity of trees promotes night-time cooling by 0.44 degrees C. This study further highlights the need for context -specific strategies. Conserving green locations as urban forests, while designing enclosed grey locations as urban savannas, characterized by interconnected grasses and shrubs interspersed with standalone trees, could mitigate urban heat stress and enhance urban resilience.

Urbanization and global warming have led to the emergence of urban heat islands, profoundly impacting the liveability and long-term well-being of people living in cities. This study investigates the impact of urban green space composition and configuration on stress and sleep quality in Leuven, Belgium, during the summers of 2021 and 2022.Utilizing three validated stress questionnaires (PSS, PSQI, and HSSI), we assessed mental health, sleep quality and heat stress during 4 heat and 4 control events for 785 respondents. Concurrently, we recorded risk and vulnerability factors related to physical sensitivity, socio-economic sensitivity and personal living space for each respondent. Urban land cover data at 50m and 250m buffer scales were analysed using composition and configuration metrics. Structural equation models were employed to investigate the impact of urban green space on stress and sleep quality during both heat and non-heat control events. Models were adjusted for risk and vulnerability factors, and effectively dealt with spatial autocorrelation inherent in our data.During control events, mental health, sleep quality and heat stress were predominantly associated with risk and vulnerability factors. High physical sensitivity, elevated socio-economic sensitivity and suboptimal personal living spaces were associated with higher physiological stress, poor sleep quality, and higher heat stress. Conversely, during heat events, stress indicators were predominantly associated with the surrounding green space, while associations with risk and vulnerability factors were limited. Augmenting high green relative cover may mitigate heat stress, while increasing low green cover may alleviate both heat stress and enhance sleep quality. Stratified analyses for socio-economic status and distinct urban-rural regions revealed notable differences among subgroups.In conclusion, this study emphasizes the importance of incorporating both low and high green spaces to mitigate heat stress and improve sleep quality and therefore, human health, during heat events.

Introduction: Previous studies on prenatal green space exposure and early respiratory health show inconsistent results. This may reflect stage-specific in utero effects and pollen influence. We examine associations of surrounding greenness and pollen exposure during pregnancy (overall and by trimester) with preschool wheezing, and assess potential mediation by pollen. Methods: We used data from the PIPO birth cohort (n = 860). Wheezing was reported biannually between 18 and 48 months of age. Residential greenness was measured with Normalized Difference Vegetation Index (NDVI) in 100 and 250 m buffer. Cumulative grass and birch pollen was estimated using modelled airborne pollen counts and categorized per trimester into no, low and high. All exposures were assessed for the overall pregnancy and per trimester. We used Generalized Estimated Equations to obtain odds ratios (OR) and 95% confidence intervals (CI). To assess mediation by pollen we used a data duplication algorithm with a generalized estimation approach. Results: Approximately 10% of participants wheezed. During pregnancy, greenness (OR = 1.07, CI: 1.05-1.08) and grass pollen exposure (OR = 1.09, CI: 1.03-1.15) increased the odds of wheezing, while birch pollen decreased it (OR = 0.86, CI:0.87-1.00). Per trimester, more greenness during the 2nd trimester increased the odds (OR = 1.21, CI: 1.16-1.26), whereas third-trimester greenness decreased it (OR = 0.87, CI: 0.84-0.91). Grass pollen exposure in the 1st and 3rd trimesters increased the odds of wheezing (OR = 1.23, CI: 1.12-1.34 and OR = 1.13, CI: 1.00-1.27, respectively), while birch pollen exposure in the 1st and 2nd trimesters decreased the odds (OR = 0.88, CI: 0.77-1.00 and OR = 0.83, CI: 0.73-0.95, respectively). No significant associations were found for greenness in the 1st trimester, grass pollen in the 2nd trimester, and birch pollen in the 1st and 3rd trimester. Mediation analysis showed large uncertainty. Discussion: Surrounding greenness and pollen exposure during pregnancy may impact the likelihood of preschool wheezing differently depending on the timing of exposure and the pollen type.

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