Table 1 Summary justification for the environmental factors selected for our wish-list, including examples of typical effect sizes.

Outdoor ambient air pollutants

Elevated risks of respiratory disease (RD), cardiovascular disease (CVD) and total mortality consistently associated with air pollutants, at concentrations frequently experienced in urban settings [11–16]. Evidence of health effects strongest for particulate matter (PM₁₀) and ozone (O₃), but also substantial for carbon monoxide (CO), sulphur dioxide (SO₂) and nitrogen dioxide (NO₂).

Meta-analysis all-cause mortality RR for 10 μg.m^-3 increase in pollutant [17]:

PM₁₀ = 1.006 (1.004 to 1.008) (33 studies)

O₃ = 1.003 (1.001 to 1.004) (15 studies)

Meta-analysis % excess mortality for stated increase [11]:

CO = 1.7 (1.2 to 2.2) for 1.1 ppm increase (22 effect estimates)

SO₂ = 0.9 (0.7 to 1.2) for 9.4 ppb increase (46 effect estimates)

NO₂ = 2.8 (2.1 to 3.5) for 24.0 ppb increase (32 effect estimates)

Climate

Increased risks of CVD, RD and total mortality with both elevated and reduced temperatures found in many studies. [18–20]. Small but persistent elevations in risk are seen with each incremental deviation away from the UK's comfort temperature of 20°C [20], hence the entire population are exposed.

RD mortality:

Cold: Six European country study, 2.46% (1.81 to 3.12) increase per 1°C drop below 18°C [21]

Heat: The Netherlands, 10.4% (0.0 to 20.8) increase per 1°C increase above 16.5°C [22]

London, 5.44% (1.92 to 9.09) increase per 1°C increase above 23°C [23]

Solar ultraviolet (UV) radiation

UV radiation is the main risk factor for skin cancer [24, 25], but a consistent protective effect of UV (via vitamin D production) has been found against a number of more prevalent cancers [25–27]. All studies on prostate, breast and ovarian cancer that were systematically reviewed by van der Rhee et al. [26] showed a significant inverse relationship between sunlight and mortality/incidence. Most of the UK population experience some vitamin D deficiency in winter because of inadequate exposure to solar UV [28].

Skin cancer: summary OR (29 studies) for maximally exposed subjects (non-occupational exposure) = 1.71 (1.54 to 1.90) [24]

Mortality OR for high vs. low sunlight exposure [29]:

Prostate cancer 0.90 (0.87 to 0.93) (97,873 cases)

Breast cancer 0.74 (0.72 to 0.76) (130,261 cases)

Ovarian cancer 0.84 (0.81 to 0.88) (39,002 cases)

Colon cancer 0.73 (0.71 to 0.74) (153,511 cases)

Industrial facilities

There is evidence that residence within 4 km of waste management sites or within 1.6 km of metal production/processing plants increases some cancer risks [e.g., [30–32]]. Evidence was inconsistent for refineries and combustion installations, and weak or non-existent for other facilities, therefore we included only waste management and metal production/processing sites. Analysis using a geographical information system (GIS) revealed that 21% of the UK population resided within the relevant effect buffers reported for these sites.

Within approx. 1.6 km of metal works:

HR all-cause mortality for boys resident ≥ 10 yr = 1.52 (significantly elevated) [33]

RR lung cancer mortality (vs. > 6 km) = 5.0 (1.4 to 17.8) [32]

Cancer incidence RR within approx. 4 km of waste site (vs. low exposure):

Non-Hodgkin's lymphoma = 2.3 (1.4 to 3.8) [34]

Stomach cancer = 1.27 (1.04 to 1.55) [30]

Green space

There is evidence that more natural environments have a beneficial effect on people's self-perceived health, blood pressure, levels of overweight and obesity and total mortality risks [35–42]. Population exposure to green space varies markedly across the UK and there is no indication of a minimum threshold for health.

IRR for high vs. low green space exposure [39]:

All-cause mortality 0.94 (0.93 to 0.96)

Circulatory disease mortality 0.96 (0.93 to 0.99)

Drinking water quality

Disinfection By-Products (DBPs) have been consistently associated with a small elevated risk of bladder cancer, the fourth most common cancer in the UK [43, 44]. Most of the UK population is exposed to disinfected drinking water.

Meta-analysis OR for cancer incidence (vs. low exposure):

Bladder cancer = 1.1 (1.0 to 1.2) for intermediate exposure and 1.4 (1.2 to 1.7) for long-term exposure (>40 years) (8 studies) [44]

All cancer = 1.15 (1.09 to 1.20) for high exposure (12 studies) [43]

Noise

Strong associations found with ischaemic heart disease and hypertension, both of which increase mortality risk [45].

Meta-analysis RR for 5 dB(A) increase in noise [45]:

Hypertension with occupational noise = 1.14 (1.01 to 1.29)

Hypertension with air traffic noise = 1.26 (1.14 to 1.39)

Ischaemic heart disease with road traffic noise = 1.09 (1.05 to 1.13)