Indoor PM2.5 Mortality in China when Outdoor Air Meets 2021 WHO AQG

The World Health Organization (WHO) Air Quality Guidelines (AQG) 2021 for PM2.5 is tightened to be 5 μg/m3. We firstly estimated deaths attributable to human exposure to PM2.5 (DAHP) to be 455 thousand (372-527) in urban China in 2019, of which indoor sources contributed 253 thousand (207-294) deaths. The economic losses related to PM2.5 from indoor sources were 0.98 trillion (0.80-1.14) RMB, accounting for 56% of the total economic losses. We then further projected the DAHP at 328 thousand (260-392) when the outdoor PM2.5 concentration is 5 μg/m3, while PM2.5 from indoor sources still causes 297 thousand (235-355) deaths and 1.27 trillion (1.00, 1.51) in economic losses each year. There are significant health hazards and economic losses caused by indoor PM2.5, even the outdoor air is clean enough. The formulation and implementation of more air pollution policies are therefore in urgent need to control indoor sources of PM2.5.

Household Air Pollution and Respiratory Health in Rural Crete, Greece: A Cross-Sectional FRESH AIR Study

Breathing polluted air is a risk to respiratory conditions. During the Greek financial crisis, the use of household fireplaces/wood stoves shifted from mostly decorative to actual domestic heating, resulting in increased indoor smoke production. We aimed to evaluate household air pollution (HAP), fuel use and respiratory symptoms in rural Crete, Greece. PM2.5 and CO were measured in 32 purposively selected rural households (cross-sectional study) at periods reflecting lesser (baseline) versus extensive (follow-up) heating. Clinical outcomes were assessed using questionnaires. Mean PM2.5 were not significantly different between measurements (36.34 µg/m3 vs. 54.38 µg/m3, p = 0.60) but exceeded the WHO air quality guidelines. Mean and maximal CO levels were below the WHO cut-offs (0.56 ppm vs. 0.34 ppm, p = 0.414 and 26.1 ppm vs. 9.72 ppm, p = 0.007, respectively). In total, 90.6% of households were using wood stoves or fireplaces for heating, but half also owned clean fuel devices. The differences between devices that were owned versus those that were used were attributed to financial reasons. In both cases, the most frequent respiratory symptoms were phlegm (27.3% vs. 15.2%; p = 0.34) and cough (24.2% vs. 12.1%; p = 0.22). Our findings demonstrate the magnitude of HAP and confirm the return to harmful practices during Greece’s austerity. Upon validation, these results can support strategies for fighting fuel poverty, empowering communities and strengthening local health systems.

Opinion: Insights into updating Ambient Air Quality Directive (2008/50EC)

As the evidence for the adverse health effects of air pollution continues to increase, World Health Organization (WHO) recently published its latest edition of the Global Air Quality Guidelines. Although not legally binding, the guidelines aim to provide a framework in which policymakers can combat air pollution by formulating evidence-based air quality management strategies. In the light of this, European Union has stated its intent to revise the current Ambient Air Quality Directive (2008/50/EC) to resemble closer to that of the newly published WHO guidelines. This article provides an informed opinion on selected features of the air quality directive that we believe would benefit from a reassessment. The selected features include discussion about 1) air quality sensors as a part of hierarchical observation network, 2) number of minimum sampling points and their siting criteria, and 3) new target air pollution parameters for future consideration.