Evidence

Air pollution exposure is linked to higher cardiovascular, diabetes and dementia risk; personal-scale habits that reduce exposure are not covered by the research reviewed here.

Living near green space is associated with lower mortality, consistently and dose-responsively, and with lower cardiometabolic risk.

Reviews report green space associated with lower depression and anxiety (Liu 2023; Patwary 2022) and better mental health (Bryer 2024); Gascon 2015 finds limited evidence that the link is causal, and Noordzij 2021 finds no significant association in four ageing cohorts.

Residential and chronic noise are associated with higher cardiovascular and dementia risk.

Green space is not uniformly good for everyone.

Walkable neighbourhoods are associated with lower obesity, type 2 diabetes and hypertension (Chandrabose 2018), which reports the evidence on whether physical activity explains this as inconclusive.

Spending time in natural environments is associated with lower stress and better mood versus built settings.

A short period outdoors in daylight early in the day: Duffy 1996 concludes that light is the primary synchronizer of the human circadian pacemaker, and van Maanen 2016 that light therapy is effective for sleep problems.

Short, regular time outdoors: Barton 2010 reports that green exercise improved mood and self-esteem, with large benefits from short durations and diminishing returns.

Bright natural light by day and dim, warm light in the evening: Xu 2022 reports light at night associated with more sleep problems, and Lu 2023 concludes that nocturnal light inhibits night-shift workers' melatonin secretion.

Regular unhurried time in forests, parks, or trails, including slow, sensory 'forest bathing' walks; Siah 2023 suggests forest bathing can reduce symptoms of depression and anxiety.