23
positive associations between how green an environment is and physical activity
rates (Kaczynski and Henderson 2007 in Coutts and Hahn 2015). Similar positive
associations are also found between ‘blue’ spaces and physical activity rates
(Grellier et al. 2017; White et al. 2014) (see also Hunter et al. Chap. 17, this volume). Encouragement of physical activity is particularly important in the context of
increases in non-communicable diseases (NCDs) related to inactivity, such as Type
2 diabetes (Cook et al. Chap. 11, this volume).
The other important, and increasingly well recognised, pathway explaining why
physiological responses might be seen at rest in ‘natural’ spaces is due to the regulating functions of green and blue spaces through moderating noise, air quality and
temperatures. In other words, some health benefits are due to the influence that
green and blue spaces have on removing or reducing environmental stressors, especially in busy, densely populated urban centres (Hartig et al. 2014; Coutts and Hahn
2015; Markevych et al. 2017). Indeed, this also makes physical activity undertaken
in urban green spaces potentially more healthy since it could otherwise lead to
increased exposure to harmful levels of air pollutants with acute or chronic effects
on the respiratory and cardiovascular systems (Mölter and Lindley 2015). However,
the ‘absence of stressors’ argument does not explain all associations, such as have
been found in studies where physiological responses are seen in response to visual
cues with no direct contact, something that points to psychological and sociocultural factors (Clark et al. 2014). Due to the interwoven biophysical, psychological and socio-cultural elements underpinning connections between nature and
health some conceptualisations are based on grouped biopsychosocial pathways,
specifically pathways that positively influence health through reducing the potential
for harm (reducing environmental stresses), restoring capacities (improving recovery functions) and building capacities (reducing individual susceptibility to harm)
(Hartig et al. 2014; Markevych et al. 2017) (see also Marselle et al. Chap. 9, this
volume).
The role of reduced exposure to environmental noise is one particularly interesting example given that reductions in noise exposure have been given relatively little
emphasis in earlier models, e.g. Hartig et al. (2014), compared to those developed
more recently, e.g. Markevych et al. (2017) and van den Bosch and Sang (2017).
Explanatory mechanisms have also been proposed to link noise stress with impacts
on cardiovascular, respiratory, immune response and metabolic health through
stress-response models (Recio et al. 2016). Similar processes may apply to some of
the other common environmental stressors, in addition to the better known, but still
imperfectly understood connections. For example, new research is finding a wider
range of connections between air pollution and human health than ever before, not
just through morbidity and mortality from cardiovascular and respiratory diseases
but also through neurodevelopmental disorders and birth defects (Landrigan et al.
2018). It should be remembered that environmental stresses also affect other animals and have been linked to biodiversity loss. Although an issue that is particularly
acute in urban areas, anthropogenic sources have been found to elevate noise levels
2 Biodiversity, Physical Health and Climate Change: A Synthesis of Recent Evidence
positive associations between how green an environment is and physical activity
rates (Kaczynski and Henderson 2007 in Coutts and Hahn 2015). Similar positive
associations are also found between ‘blue’ spaces and physical activity rates
(Grellier et al. 2017; White et al. 2014) (see also Hunter et al. Chap. 17, this volume). Encouragement of physical activity is particularly important in the context of
increases in non-communicable diseases (NCDs) related to inactivity, such as Type
2 diabetes (Cook et al. Chap. 11, this volume).
The other important, and increasingly well recognised, pathway explaining why
physiological responses might be seen at rest in ‘natural’ spaces is due to the regulating functions of green and blue spaces through moderating noise, air quality and
temperatures. In other words, some health benefits are due to the influence that
green and blue spaces have on removing or reducing environmental stressors, especially in busy, densely populated urban centres (Hartig et al. 2014; Coutts and Hahn
2015; Markevych et al. 2017). Indeed, this also makes physical activity undertaken
in urban green spaces potentially more healthy since it could otherwise lead to
increased exposure to harmful levels of air pollutants with acute or chronic effects
on the respiratory and cardiovascular systems (Mölter and Lindley 2015). However,
the ‘absence of stressors’ argument does not explain all associations, such as have
been found in studies where physiological responses are seen in response to visual
cues with no direct contact, something that points to psychological and sociocultural factors (Clark et al. 2014). Due to the interwoven biophysical, psychological and socio-cultural elements underpinning connections between nature and
health some conceptualisations are based on grouped biopsychosocial pathways,
specifically pathways that positively influence health through reducing the potential
for harm (reducing environmental stresses), restoring capacities (improving recovery functions) and building capacities (reducing individual susceptibility to harm)
(Hartig et al. 2014; Markevych et al. 2017) (see also Marselle et al. Chap. 9, this
volume).
The role of reduced exposure to environmental noise is one particularly interesting example given that reductions in noise exposure have been given relatively little
emphasis in earlier models, e.g. Hartig et al. (2014), compared to those developed
more recently, e.g. Markevych et al. (2017) and van den Bosch and Sang (2017).
Explanatory mechanisms have also been proposed to link noise stress with impacts
on cardiovascular, respiratory, immune response and metabolic health through
stress-response models (Recio et al. 2016). Similar processes may apply to some of
the other common environmental stressors, in addition to the better known, but still
imperfectly understood connections. For example, new research is finding a wider
range of connections between air pollution and human health than ever before, not
just through morbidity and mortality from cardiovascular and respiratory diseases
but also through neurodevelopmental disorders and birth defects (Landrigan et al.
2018). It should be remembered that environmental stresses also affect other animals and have been linked to biodiversity loss. Although an issue that is particularly
acute in urban areas, anthropogenic sources have been found to elevate noise levels
2 Biodiversity, Physical Health and Climate Change: A Synthesis of Recent Evidence