396
17.2.4 Greening Interventions
There was strong evidence to support the greening of vacant lots (4/4 studies showed
a significant intervention effect) and greening of urban streets (4/4 studies demonstrated a significant intervention effect), for environmental, physiological, psychological and improved social environment outcomes (see Table 17.3).
A decade-long study using a difference-in-difference design in the USA (Branas
et al. 2011) showed that greening of vacant urban lots (>725,000 m
2
) resulted in
reductions in gun assaults (p < 0.001), vandalism (p < 0.001) and residents reporting
less stress and more exercise (p < 0.01). In an RCT, Garvin et al. (2013) demonstrated a decrease in the number of total crimes and gun assaults, and increased
safety around greened vacant lots compared with control lots (p > 0.05). Anderson
et al. (2014) demonstrated significant biodiversity outcomes for a range of greening
interventions in three deprived urban areas in South Africa. In a US-based study,
South et al. (2015) found that heart rate lowered significantly in local residents
living near greened compared to non-greened vacant lots (n = 2 clusters of vacant
lots) (p < 0.001).
Four (out of four) studies showed significant impacts on health and environmental factors for interventions involving greening of urban streets. Ward Thompson
et al. (2014) found evidence to support the provision of so-called ‘DIY streets’ in
urban areas in the UK. Streets were made safer and more attractive (e.g. planting
trees/plants), and traffic calming measures were added at nine different sites.
Longitudinal data showed that participants perceived they were significantly more
active post-intervention (p = 0.04) than the comparison group, and there were significant improvements in perceptions of the environment. Joo and Kwon (2015)
found that illegal dumping of household garbage occurred at 55.4% of greened sites
(n = 74) compared to 91.9% of sites without greenery (n = 74) in South Korea.
Strohbach et al. (2013) showed a significant increase in bird species in a study
investigating 12 community-driven greening projects involving tree plantings carried out in deprived areas compared to random urban sites without greening
(p = 0.049). Adverse outcomes from greening interventions were also reported by
Jin et al. (2014), who demonstrated that increased street tree canopy was positively
associated with PM 2.5 (particulate matter with aerodynamic diameters of 2.5 mm or
less) concentrations owing to reduced air circulation.
17.2.5 Green Infrastructure Interventions
There was promising evidence to support the provision of rain gardens (3/4 studies
showed a significant positive effect) and strong evidence to support the provision of
roof gardens (3/3 studies showed a significant positive effect) for managing the
adverse impact of storm water. One study (1/1 study) demonstrated significant cooling effects for a roof garden in a suburban area (see Table 17.4).
R. F. Hunter et al.
17.2.4 Greening Interventions
There was strong evidence to support the greening of vacant lots (4/4 studies showed
a significant intervention effect) and greening of urban streets (4/4 studies demonstrated a significant intervention effect), for environmental, physiological, psychological and improved social environment outcomes (see Table 17.3).
A decade-long study using a difference-in-difference design in the USA (Branas
et al. 2011) showed that greening of vacant urban lots (>725,000 m
2
) resulted in
reductions in gun assaults (p < 0.001), vandalism (p < 0.001) and residents reporting
less stress and more exercise (p < 0.01). In an RCT, Garvin et al. (2013) demonstrated a decrease in the number of total crimes and gun assaults, and increased
safety around greened vacant lots compared with control lots (p > 0.05). Anderson
et al. (2014) demonstrated significant biodiversity outcomes for a range of greening
interventions in three deprived urban areas in South Africa. In a US-based study,
South et al. (2015) found that heart rate lowered significantly in local residents
living near greened compared to non-greened vacant lots (n = 2 clusters of vacant
lots) (p < 0.001).
Four (out of four) studies showed significant impacts on health and environmental factors for interventions involving greening of urban streets. Ward Thompson
et al. (2014) found evidence to support the provision of so-called ‘DIY streets’ in
urban areas in the UK. Streets were made safer and more attractive (e.g. planting
trees/plants), and traffic calming measures were added at nine different sites.
Longitudinal data showed that participants perceived they were significantly more
active post-intervention (p = 0.04) than the comparison group, and there were significant improvements in perceptions of the environment. Joo and Kwon (2015)
found that illegal dumping of household garbage occurred at 55.4% of greened sites
(n = 74) compared to 91.9% of sites without greenery (n = 74) in South Korea.
Strohbach et al. (2013) showed a significant increase in bird species in a study
investigating 12 community-driven greening projects involving tree plantings carried out in deprived areas compared to random urban sites without greening
(p = 0.049). Adverse outcomes from greening interventions were also reported by
Jin et al. (2014), who demonstrated that increased street tree canopy was positively
associated with PM 2.5 (particulate matter with aerodynamic diameters of 2.5 mm or
less) concentrations owing to reduced air circulation.
17.2.5 Green Infrastructure Interventions
There was promising evidence to support the provision of rain gardens (3/4 studies
showed a significant positive effect) and strong evidence to support the provision of
roof gardens (3/3 studies showed a significant positive effect) for managing the
adverse impact of storm water. One study (1/1 study) demonstrated significant cooling effects for a roof garden in a suburban area (see Table 17.4).
R. F. Hunter et al.