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Indoor air pollution: The 'killer in the kitchen'

Image credit Clean Cooking Alliance.

Approximately 3 billion people around the world rely on biomass fuels such as wood, charcoal and animal dung which they burn on open fires and using inefficient stoves to meet their daily cooking needs.

Relying on these types of fuels and cooking technologies is a major contributor to indoor air pollution and has serious negative health impacts, including acute respiratory illnesses, pneumonia, strokes, cataracts, heart disease and cancer.

The World Health Organization estimates that indoor air pollution causes nearly 4 million premature deaths annually worldwide – more than the deaths caused by malaria and tuberculosis combined. This led the World Health Organization to label household air pollution “The Killer in the Kitchen”.

As illustrated on the map below, most deaths from indoor air pollution occur in low- and middle-income countries across Africa and Asia. Women and children are disproportionately exposed to the risks of indoor air pollution as they typically spend the most time cooking.

Number of deaths attributable to indoor air pollution in 2017. Image credit Our World in Data

Replacing open fires and inefficient stoves with modern, cleaner solutions is essential to reduce indoor air pollution and personal exposure to emissions. However, research suggests that only significant reductions in exposure can tangibly reduce negative health impacts. 

The Clean Cooking Alliance, established in 2010, has focused mainly on the dissemination of improved cookstoves (ICS) – wood-burning or charcoal stoves designed to be much more efficient than more traditional models – with some success. 

Randomised control trials of sole use of ICS have shown reductions in pneumonia and the duration of respiratory infections in children. However, other studies, including some funded by the Alliance, have shown that ICS have not performed well enough in the field to sufficiently reduce indoor air pollution to lessen health risks such as pneumonia and heart disease.

Alternative fuels such as liquid petroleum gas (LPG), biogas and ethanol present other options for cooking with LPG already prevalent in many countries across the world.

LPG is clean-burning and produces much less carbon dioxide than burning biomass but is still a fossil fuel. 

Biogas is a clean, renewable fuel made from organic waste, and ethanol is a clean biofuel made from a variety of feedstocks. 

Image credit PEEDA

Electric cooking, once seen as a pipe dream for developing countries, is becoming more feasible and affordable due to improvements and reductions in costs of technologies like solar panels and batteries.

Improved cookstoves, alternative fuels and electric cooking have been gaining traction but there is still a long way to go to solving the deadly problem of indoor air pollution. 

This blog is written by Cabot Institute member Peter Thomas, Faculty of Engineering, University of Bristol. Peter's research focusses on access to energy in humanitarian relief. This blog is co-written by Will Clements, Faculty of Engineering.
Peter Thomas

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