Air pollution interventions and respiratory health: a systematic review

Abstract

BACKGROUND: Indoor and ambient air pollution exposure is a major risk to respiratory health worldwide, particularly in low- and middle-income countries (LMICs). Interventional trials have mainly focused on alternatives to cooking stoves, with mixed results. Beyond cooking, additional sources of particulate matter also contribute to the burden of air pollution exposure. This review explores evidence from current randomised controlled trials (RCTs) on the clinical effectiveness of interventions to reduce particulate matter in LMICs.METHODS: Twelve databases and the grey literature (e.g., Government reports and policy papers) were searched. Eligible studies were RCTs conducted in LMICs aiming to reduce particulate exposure from any source and reporting on at least one clinical respiratory outcome (respiratory symptoms, lung function or clinical diagnoses). Data from relevant studies were systematically extracted, the risk of bias assessed and narrative synthesis provided.RESULTS: Of the 14 included studies, 12 tested ‘improved' cookstoves, most using biomass, but solar and bioethanol cookers were also included. One trial used solar lamps and another was an integrated intervention incorporating behavioural and environmental components for the treatment and prevention of chronic obstructive pulmonary disease. Of the six studies reporting child pneumonia outcomes, none demonstrated significant benefit in intention-to-treat analysis. Ten studies reported respiratory symptom outcomes with some improvements seen, but self-reporting made these outcomes highly vulnerable to bias. Substantial inter-study clinical and methodological heterogeneity precluded calculation of pooled effect estimates.CONCLUSION: Evidence from the RCTs performed to date suggests that individual household-level interventions for air pollution exposure reduction have limited benefits for respiratory health. More comprehensive approaches to air pollution exposure reduction must be developed so their potential health benefits can be assessed.

<p>Characteristics of Patients with Chronic Obstructive Pulmonary Disease Exposed to Different Environmental Risk Factors: A Large Cross-Sectional Study</p>

“…29,30 Another survey indicates that household-level interventions for biomass smoke reduction have benefits for respiratory health. 31 In particular, poor kitchen ventilation in rural or remote areas of China with impoverished living conditions leads to very high biomass smoke concentrations. Additionally, strong sex differences were observed between COPD patients exposed to biomass smoke alone and other COPD patients.…”

Which public health interventions are effective in reducing morbidity, mortality and health inequalities from infectious diseases amongst children in low- and middle-income countries (LMICs): An umbrella review

“…The vast majority of included reviews covered interventions aiming at preventing infectious diseases in children [ 49 , 50 , 54 – 59 , 62 , 64 , 65 , 68 , 69 , 71 – 82 , 84 – 99 , 101 , 102 , 104 , 106 , 108 – 110 ]. Over a quarter included health promoting interventions [ 48 , 49 , 60 – 64 , 66 , 67 , 70 , 72 , 78 , 83 , 92 , 103 , 107 ] and only two covered health protection interventions [ 100 , 105 ]. The description of the various interventions covered can be found in Tables 3 – 5 .…”

Health Effect of Biomass Fuel Smoke

“…Randomized control trials of interventions of improved cook stoves to reduce exposure to BMF smoke in order to prevent childhood ALRIs are emerging. A recent meta-analysis, of the six studies reporting child pneumonia outcomes, demonstrated no significant benefit in intention-to-treat analysis [44].…”