Table 1.
Summary of epidemiological evidence used to determine risk–outcome relationships for unsafe water, air pollution, radon, and lead in the Global Burden of Disease Study (GBD) 2017 (adapted from Stanaway et al. 2018).
| Risk factor | Outcome | Study type | ||
|---|---|---|---|---|
| RCTs (n) | Prospective observational studies (n) | Case–control studies (n) | ||
| Unsafe water, sanitation, and handwashing | ||||
| Unsafe water source – chlorination or solar (point of use treatment) | Diarrheal diseases | 25 | 6 | |
| Unsafe water source – piped | Diarrheal diseases | 1 | 9 | |
| Unsafe water source – filter | Diarrheal diseases | 11 | 2 | |
| Unsafe water source – improved water | Diarrheal diseases | 0 | 5 | |
| Unsafe sanitation – piped | Diarrheal diseases | 0 | 7 | |
| Unsafe sanitation – improved sanitation | Diarrheal diseases | 1 | 11 | |
| No access to handwashing facility | Diarrheal diseases | 19 | 0 | |
| No access to handwashing facility | Lower respiratory infections | 8 | 11 | |
| Air pollution: Particulate matter pollution | ||||
| Ambient particulate matter pollution | Lower respiratory infections | 0 | 17 | |
| Ambient particulate matter pollution | Tracheal, bronchus, and lung cancer | 0 | 30 | |
| Ambient particulate matter pollution | Ischemic heart disease | 0 | 16 | |
| Ambient particulate matter pollution | Ischemic stroke | 0 | 30 | |
| Ambient particulate matter pollution | Intracerebral hemorrhage | 0 | 30 | |
| Ambient particulate matter pollution | Subarachnoid hemorrhage | 0 | 30 | |
| Ambient particulate matter pollution | Chronic obstructive pulmonary disease | 0 | 12 | |
| Ambient particulate matter pollution | Diabetes mellitus type 2 | 0 | 8 | |
| Household air pollution from solid fuels | Lower respiratory infections | 2 | 8 | 17 |
| Household air pollution from solid fuels | Tracheal, bronchus, and lung cancer | 0 | 0 | 28 |
| Household air pollution from solid fuels | Ischemic heart disease | 0 | 2 | 2 |
| Household air pollution from solid fuels | Ischemic stroke | 0 | 1 | |
| Household air pollution from solid fuels | Intracerebral hemorrhage | 0 | 1 | |
| Household air pollution from solid fuels | Subarachnoid hemorrhage | 0 | 1 | |
| Household air pollution from solid fuels | Chronic obstructive pulmonary disease | 0 | 0 | 11 |
| Household air pollution from solid fuels | Diabetes mellitus type 2 | 0 | 1 | |
| Household air pollution from solid fuels | Cataract | 0 | 0 | 8 |
| Ambient ozone pollution | Chronic obstructive pulmonary disease | 0 | 3 | |
| Other environmental risks | ||||
| Residential radon | Tracheal, bronchus, and lung cancer | 0 | 1 | 29 |
| Lead exposure | Idiopathic developmental intellectual disability | 0 | 8 | |
| Lead exposure | Systolic blood pressure | 0 | 3 | 1 |
Note: See original table for primary references. (Adapted from Appendix 1, Table 1 Stanaway et al. 2018).