Sierra Clark attended McGill University for both her Undergraduate Bachelor of Arts Degree {honours) in Geography and Geographic Information Systems and her Masters Degree in Epidemiology. During her Masters, Sierra was also a graduate program member at the Institute for Health and Social Policy at McGill, a National Geographic Young Explorer, and a Mitacs Canada Globalink International Intern. Sierra is passionate about finding evidenced-based solutions to address preventable environmental exposures, such as air pollution, which are harmful to human health and contribute to climate change. Sierra is passionate about science outreach, communication, and translation, and is a volunteer with the Science-Policy Exchange at McGill.

“While working with Indigenous communities in Uganda and China, I was overwhelmed by the fact that the simple act of cooking a meal or heating one’s home with solid fuels (i.e., wood, coal}, could result in daily exposure to high levels of toxic pollution. When I visited the homes of community members, I immediately reacted to the smoke; my eyes burned, my throat closed up, and I had a persistent cough.

While my reactions were acute, half of the world’s population is chronically exposed to household air pollution (HAP}, which claims the lives of 2.8 million people yearly. Exposure to HAP is mostly concentrated in low-income countries2, but also prevalent in rural and northern communities in countries like Canada3,4. I am inspired to write this policy proposal on effective interventions to reduce HAP in Canada because cooking should be health sustaining, not harming.”

Half of the world’s population still cooks with solid fuels {i.e., wood, coal, crop residues) in inefficient stoves or open fires2. Through incomplete fuel combustion, this practice results in high concentrations of pollutants released inside the home5, which are a mixture of aerosols and gases that contain many hazardous chemical compounds, including teratogens, mutagens, carcinogens {i.e., polycyclic aromatic hydrocarbons {PAHs)) and free radicals6. This practice is common in low-income countries, but is also prevalent among rural populations in high-income countries, such as among Canada’s First Nations, Metis, and Northern Inuit communities3,4,7,8. Poor supply networks and affordability of gaseous fuels and electricity, local abundance of raw biomass resources, and traditional cooking practices, contribute to the choice of households to use solid fuels to meet every day energy demands9,10. Among Canada’s rural and Indigenous communities, particularly in the North and Arctic regions, residential wood burning for cooking and heating is common11.

Previous studies have linked exposure to HAP to a range of chronic and acute health events and
cause-specific mortality, including, respiratory infections, chronic obstructed pulmonary disease {COPD), exacerbated asthma symptoms, cardiovascular diseases, breast and lung cancer, eye irritation and cataracts, and low birth weight5,12,13 and similar associations were found among rural communities in Canada and the USA, where residential wood burning is common8,14,15 . For example, in three rural and semi-rural communities in British Columbia, an increase in daily pollution levels of fine particulate matter
{PM2.5) from residential wood burning was associated with an increased risk of hospitalization for Myocardial Infarctions {MI) among elderly adults3. Furthermore, many respiratory conditions, such as childhood asthma16, are more prevalent among Canada’s first nations, Inuit, and Metis communities, compared to the general Canadian population. Thus, interventions that can reduce HAP in these communities are likely to reduce persistent health inequalities.

Household air pollution from burning solid fuels in inefficient stoves also contributes to ambient air pollution conditions; in Canada this contribution is around 10%17. Ambient air pollution from residential solid fuel burning is also a major contributor to climate change18 from the release of black carbon, also known as soot19. When black carbon is released into the atmosphere and later deposited on the surface of snow and ice, the dark particles absorb incoming and scattered heat from the sun. Due to black carbon’s albedo reducing effects, it is also a major contributor to glacial melting, particularly in high latitudinal regions like the arctic circle in Canada19. Interventions to reduce emissions of climate forcing pollutants, such as black carbon, should be a key priority in Canada’s actions against climate change20, particularly among Canada’s Northern and Inuit populations who are experiencing the most rapid and extreme changes to their local environments, and traditional ways of life21,22,23.

Household air pollution from inefficient wood burning is preventable. Improving household infrastructure to effectively ventilate smoke from stoves outside the home, and block polluted air from coming back inside, has proven effective from previous intervention trials of air cleaners and filters24,25. For example, a study conducted in rural communities in Montana and Idaho, found that household concentrations of PM2.5 were reduced by 68% among homes that received an air filtration unit26, and by 40% from a study in Vancouver27. Also in lower- and middle-income countries, there are large scale efforts to design and distribute millions of higher efficiency advanced combustion solid fuel burning cooking and heating stoves28,29,30. A global review found that interventions of improved solid fuel burning stoves with chimneys and advanced-combustion gasifier biomass burning stoves, reduced household concentrations of fine particulate matter {PM2.5) by 62% {range: -89,-14) and 41% {range: -49, -29), respectively31. While few interventions have been carried out in Canada, most of the strategies related to providing incentives for changing-out old heating units for newer ones. For example, Natural Resources Canada provided financial support of $375 {1st system) and $190 {2nd system) for single-family homes to encourage Canadians to replace their conventional wood-burning appliance with a certified wood- burning or indoor wood pellet-burning appliance11.

STEP 1: Identify affected communities. Hong and colleagues recently developed a tool to identify communities impacted by residential wood smoke through the quantification of historical satellite imagery32. Commercialization and use of such tools by planners and public health experts could be a cost effective means of identifying communities that may benefit the most from household energy interventions in Canada.

STEP 2: Consult with local communities on household and community preferences for cookstove design and features. Past research has clearly shown that top-down cookstove design and distribution efforts do not work and “cleaner” technologies need to be designed with the local cooking needs as a design priority9,10,33. In Canada, policy makers, public health experts, and an advisory board of local community members, can partner with engineer researchers specializing in building science and combustion science to design effective, efficient, but contextually appropriate stoves and air filtration units for a combined package intervention.

STEP 3: Consult Generate demand for cleaner cooking technologies. Local demand for cleaner household energy options and air filtration units must be fostered prior to intervention in order to ensure long-term exclusive and sustained use. For example, implementers can first hold public education forums, hold community filter training days {where people can come and test out the technologies), create radio advertisements, and partner with influential members of the community to support the intervention.

STEP 4: Ongoing monitoring of the intervention package will be key to informing future implementations and provide an on-going interface between community members and implementers. As well, local members of the community should be trained in the maintenance and up-keep of the intervention stove and air filtration unit in order to respond to immediate maintenance issues as they arise.