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.

Nudging for Cleaner Air: Experimental Evidence from an RCT on Wood Stove Usage

Air pollution from wood burning is a serious problem in the developing world. In the cities of south-central Chile, households experience extremely high ambient air pollution levels due to massive combustion of wood as fuel for residential heating. To address this problem, in recent years new residential wood stoves—equipped with improved combustion technologies that are designed to be less-polluting—have replaced high-polluting ones. However, users’ behaviour in operating these improved stoves is a key factor that drives actual emissions. When users ‘choke the damper’ to extend the burning time of their wood fuel, it constrains the air flow in the wood stoves and creates a highly polluting combustion process. To address this issue, a behavioural intervention was designed to provide users with real-time feedback on their wood stoves’ air pollution emissions with the goal of ‘nudging’ them to use their stoves in a less polluting way. The intervention consists of an information sign that aligns with the wood stove’s damper lever and informs users about pollution emission levels according to the chosen setting of the wood stove’s damper. The information sign is complemented by the visit of a field assistant that explains the sign and provides an informational flyer (fridge magnet). To assess the effectiveness of this behavioural intervention a randomized controlled trial was conducted with selected households in the city of Valdivia, Chile. Results from this intervention show that households that were provided with the information sign reduced the frequency with which they used the most polluting settings of their stoves, inducing a behavioural change that results in a 10.8% reduction in residential pollution emissions.

A New Design for Wood Stoves Based on Numerical Analysis and Experimental Research

This work proposes a comprehensive approach to modifying the design of wood stoves with a heating power up to 20 kW, including design works, simulations, and experimental research. The work is carried out in two stages. In the first part, a numerical model is proposed of the fireplace insert including fluid flow, the chemical combustion reaction, and heat exchange (FLUENT software is applied to solve the problem). The results of the simulation were compared with the experiment carried out on the test bench. A comparison of the experimental and numerical results was made for the temperature distribution along with the concentration of CO, CO2, and O2. Construction changes were proposed in the second stage, together with numerical simulations whose goal was an increase in the efficiency of the heating devices. The results obtained show that the average temperature in the chimney flue, which has a low value that is a determinant of the higher efficiency of the heating devices, was reduced relative to the initial design of the fireplace intake by 11%–16% in all cases. The retrofit enhanced stable heat release from the wood stove, which increased the efficiency and reduced the harmful components of combustion.