Throughout human history, we have needed some form of shelter to protect us from the elements. We build a fire to keep us warm and to cook food that is more digestible and nutritious. But this fulfillment of basic needs can have severe health defects. This lecture will explain about indoor air pollution from use of solid fuels. Globally, the most important source of indoor air pollution is household use of solid fuel. That is mainly from biomass with poor combustion conditions in open fires or primitive stoves with low ventilation. The fuel can be wood, charcoal, dung, crops, rubs, straw, or coal. The use of kerosene lamps is another important source of indoor air pollution. More than three billion people still rely on such inefficient and polluting energy systems. Two and a half billion of those people live in the southeast Asia region and the western pacific. That largest fraction of the population exposed to household air pollution is in the African region. It is most women who cook and spend time near the fire. They are exposed to very high levels of house hold air pollution, three to seven hours per day, over many years. Young children are often carried on their mother's back or stay close to their mother during cooking. So children spend many hours breathing in harmful smoke from early infancy. The exposure to household air pollution is determined by the time spent and the concentration of pollutants in the household environment. This depends on the type of fuel, stove use, the kitchen location and the ventilation. The indoor air pollution consists of a variety of health-damaging components. Particulate matter, which is a complex mixture of chemicals in solid form and droplets. Carbon monoxide, nitrogen dioxide, sulfur dioxide, if coal is the fuel. Volatile or semi volatile organic compounds. Many are carcinogens such as polycyclic aromatic hydrocarbons, dioxin, benzene, formaldehyde and many others. The levels of PM2.5 are extremely high in indoor environments with use of solid fuel and limited Insulation. As an example, we have measured the levels in a Viking age house with an open fireplace. Near the fireplace there was 15,000 microgram PM2.5 per meter cubed and at the bed the levels were up to 5,000 microgram per meter cubed. That is orders of magnitude higher than outdoor air quality standards. The WHO guidelines recommend set PM2.5 should not exceed 10 micogram per meter cubed as an annual average and not 25 as a 24-hour mean value. The health consequences of living in such an environment are severe. More than four million people die every year due to indoor use of solid fuel. It is mainly women and children who are the victims. The Asia Pacific and African regions suffer most. The women and children suffer in particular from air way disease. The children often die from acute lower respiratory diseases especially pneumonia. Exposure to this air pollution from solid fuel, is responsible for half of the death of pneumonia in children under five years. The women develop chronic obstructive lung disease over time. The exposure also leads to cardiovascular diseases, lung cancer and cataract. Cataract, where the lens of the eye, becomes opaque, is the main cause of blindness in lower and middle income countries. And part of this disease can be attributed to indoor air pollution. The exposure has severe consequences in pregnancy, with perinatal mortality and low birth weight that conveys a large risk of cardiometabolic diseases later in life. Asthma, upper airway and middle ear infections. Nasopharyngeal cancers and tuberculosis have also been attributed to indoor use of solid fuels. With open fires in the household, there is also an obvious risk of burns, affecting especially children and women. This ineffective combustion of solid fuels in the household, not only has severe consequences for the dwellers, it also contributes significantly to outdoor air pollution. Actually, it contributes with 12% of the total outdoor levels of PM2.5. So this pollution also has significant earth effects on all other inhabitants in the area. And this is most often areas where the air is already polluted from a lot of other sources such as waste burning and high emitting motorized traffic. The use of solid fuel emits large amounts of black carbon to the atmosphere. Black carbon is a strong short lived greenhouse gas equivalent that contributes to global warming. So there's a lot to gain from reducing the indoor use of solid fuel. Four million lives and enormous suffering, as well as less global warming. WHO has set up indoor air quality guidelines on household fuel combustion. Reduction of exposure can be achieved through improved cook stoves with more efficient combustion, liquid petroleum gas, renewable energy, housing improvements and behavioral change. The promotion and dissemination of improved cook stoves reduces exposure. Although the improvement has not been as successful as expected. Even the best stoves are not as effective as use of alternative fuels like liquid petroleum gas and still have much higher emission rates. In some areas, uptake has been slow, possibly due to the design not well fit for the actual cooking tasks. Liquid petroleum gas is clean, burn efficiently, is easy to use, reduces cooking time and can significantly reduce emissions. This solution requires some infrastructure for distribution and pricing can be an obstacle. Renewable energy resources are the best solution. Solar, wind, hydro and geothermal power are safe and affordable sources of household energy and they also mitigate global climate change. Biogas produced from the breakdown of biodegradable materials under anaerobic conditions, is is also a renewable energy source that in addition provides fertilizer. Renewables require substantial investment where green climate funding can be an opportunity. Housing improvements and modification can reduce household air pollution exposure. Important modifications are flues or chimneys, smoke hoods, kitchen windows, enlarging roof spaces, raising cooking surfaces from ground level to waist height and separating cooking areas from other living spaces. Energy demands for heating can also be reduced by insulation of the buildings in cool climates. To be successful, this requires building standard that are enforced, which is difficult in many low income settings. The behavior around the solid fuel combustion can reduce childhood exposure to household air pollution exposure by 20 to almost 100%. A lot can be achieved by cooking outdoors. Reducing time spent in the cooking area, keeping the kitchen door open while cooking. Avoiding leaning over the fire while attending to the cooking. Avoiding carrying children while cooking. And keeping children away from the cooking area. So reducing the burden of disease from indoor use of solid fuel is a very important part of the sustainable development goals. Especially goal number three, good health and well-being. Number seven, affordable and clean energy. Number 10, reduced inequality and number 13, climate action. [MUSIC]
