Recommendation | Key evidence summary from January 1, 2013 to January 1, 2019 | Overall strength of evidence |
Strategies to minimise personal exposure to ambient air pollution | ||
1. Use close-fitting particulate respirators such as N95 facemasks when ambient air pollution levels are high or when travelling to areas with high ambient levels of air pollution | Four small-scale studies in healthy adults, mostly randomised and noncontrolled in design, suggest use of close-fitting N95 particulate respirators may reduce the impact of ambient air pollution on respiratory and cardiovascular health outcomes. | C |
2. Shift from motorised to active travel such as cycling or walking | Several systematic reviews, health impact assessments and epidemiological studies suggest that the benefits of physical activity when actively commuting versus using motorised transport outweighed the risks associated with an increased inhaled dose of air pollution. In highly polluted cities (PM2.5 160 μg·m−3) up to 30 min of cycling and 6.25 h of walking per day would lead to a net reduction in all-cause mortality versus staying at home. Also, shift to active travel could improve air quality by reducing emissions. | C |
3. Choose travel routes that minimise near-road air pollution exposure such as low-traffic routes and routes with open spaces, minimise travel during peak times, and avoid delays in areas of high air pollution where possible | While there is evidence that using low-traffic versus high-traffic routes can minimise air pollution exposure when cycling or walking, few studies have demonstrated respiratory health benefits, particularly for susceptible individuals. Only one randomised controlled study found that older subjects and adults with COPD should select walking routes with low levels of traffic versus high levels to avoid negating the cardiorespiratory benefits of exercise. | C |
4. Optimise driving style and vehicle settings, e.g. drive with windows closed when in traffic, maintain car air filtration systems and avoid engine idling | To minimise individual exposure to traffic-related air pollution, evidence from comparative studies supports driving with windows closed when in traffic, maintaining car air filtration systems, keeping the air on internal circulation and avoiding engine idling. However, no studies were identified that examined the effect of driving style, vehicle or engine settings on pulmonary function. Despite a lack of clinical studies on health outcomes, the potential benefit of reducing air pollution levels means that this is an action to consider. | D |
5. Exercise regularly but moderate outdoor activity when and where air pollution levels are high | Current evidence from epidemiological and comparative studies suggests that engaging in physical activity in an air-polluted environment may not completely negate the positive effects of exercise. Individuals should be advised to exercise away from traffic whenever possible and plan outdoor activities around local forecasts. | C |
6. Be aware of local air pollution levels | Individuals should be encouraged to check their local air quality forecast and maps, and use this information to make informed decisions to reduce their exposure such as seeking alternative low air pollution routes or moderating outdoor activities. No studies were identified that examined an association between Air Quality Index awareness and respiratory health outcomes; however, the potential benefit of knowing when air pollution levels are high and implementing strategies to minimise exposure means that this is an action to consider. | D |
Strategies to minimise personal exposure to household air pollution | ||
7. Use clean fuels, ensure adequate household ventilation where possible and adopt improved cookstoves where resources remain sufficient | Some small-scale, noncrossover intervention studies suggest that transitioning away from cooking with solid fuels to electric or clean-burning gas (liquid petroleum gas) stoves can improve respiratory health outcomes in adults and children. The Global Initiative for Chronic Obstructive Lung Disease guidelines recommend use of nonpolluting cooking stoves and efficient ventilation to minimise exposure to indoor air pollution as a risk factor for developing COPD [149]. | C/D |
8. Use portable air cleaners combined with measures to reduce the source of household air pollution and strategies to improve ventilation | There is evidence from mostly randomised, crossover intervention studies to support the use of portable air cleaners to reduce respiratory health effects among the general population who face regular exposure to household air pollution although evidence for benefit in older individuals is lacking. Portable air cleaners fitted with HEPA filters are most effective for filtering particles in the home. | C |
Effect modifiers | ||
9. Treat and manage respiratory conditions | Effective management of COPD and asthma in patients is vital for mitigating the increased risk from ambient or indoor air pollution exposure. The implementation of established primary, secondary and tertiary interventions for cardiopulmonary diseases (e.g. controlling hypertension, lowering lipids, reducing obesity, promoting physical activity, smoking cessation and avoidance of second-hand smoke) will serve to reduce the overall burden of disease associated with air pollution exposure. | D |
10. Modify diet and supplement with antioxidants or anti-inflammatory agents | A healthy, balanced diet is favoured as a key determinant to health throughout life and associated with reductions in the risk of chronic lung diseases known to be compounded by air pollution. | D |
PM2.5: particles with a 50% cut-off aerodynamic diameter <2.5 µm; COPD: chronic obstructive pulmonary disease; HEPA: high-efficiency particulate air.