Q2. What are the future works mentioned in the paper "Residential green spaces and mortality: a systematic review" ?
In this sense, further studies are needed. But further studies are needed to confirm the results of the current meta-analysis in different locations with different climate, urban and socio-economic characteristics and also to understand the impacts of such exposure increases in each area of study. However, studies included in the 23 present review and that did adjust for air pollution still found beneficial effects of green spaces ( see Supplemental material, Table A for further information on the variables included in the models ).
Q3. What is the way to explain the reduced mortality associated with green spaces?
For instance, if physical activity is the mechanism explaining the reduced mortality associated to green spaces then possibly large green spaces are needed.
Q4. What are the main reasons for the increase in mortality in urban areas?
Certain environmental factors in urban settings, such as air pollution, noise and extreme high temperatures have been associated with increased mortality (Selander et al.
Q5. What is the effect of natural outdoor environments on the health of adults?
studies have observed that people living near or having access to natural outdoor environments are more likely to be physically active and have better mental health and therefore to be healthier (Shanahan et al.
Q6. How did the authors calculate the effect estimate for each unit increase of the exposure?
in those studies where the effect estimate was calculated for each unit increase of the exposure, the authors calculated the exposure value that corresponded to a 10% of increment with respect to the median of the exposure and calculated the new effect estimate.
Q7. How many studies were included in the systematic review?
The authors also evaluated the influence of each study by conducting sensitivity analyses excluding studies one by one from the main meta-analysis and fitting the meta-analyses for the12 rest of studies.
Q8. What are the mechanisms that explain the beneficial effects of green spaces?
These mechanisms include: a) intrinsic qualities of natural outdoor environments that enhance health or well-being (restoration theory) and that have an effect through simple viewing or observing natural outdoor spaces (Shanahan et al. 2015; Wolf and Robbins 2015), b) the healthy environment associated with green spaces (increasing biodiversity which influences immune response and less temperature, air pollutants and noise have been observed in greener areas) (Gidlöf-Gunnarsson and Öhrström 2007; Selander et al.
Q9. What is the effect of green spaces on mortality?
Evidence from their review supports the hypothesis that living in areas with higher amounts of green spaces reduces mortality, particularly CVD mortality.
Q10. What was the common approach used to evaluate exposure to green spaces?
Evaluation of exposure to green spaces was quite heterogeneous between studies, although in all of them exposure was based on a single point in time measurement (and not the average of measurements of several years, for instance); the most used approach was the calculation of the percentage of green space based on land-cover maps (Mitchell and Popham 2008; Richardson and Mitchell 2010; Richardson et al.