The aim is to eliminate use of these fuels. That's not practical in many areas. Moving from open fires to more efficient enclosed fires is the first step toward elimination, used only in places where cleaner fuels are not available.
Here they're clearly talk about reducing all use of these fuels.
"It is recognized that other types of intervention, including improved ventilation and behaviour changes, may contribute to reducing levels of HAP, or exposure, or both, and are an important part of all interventions. However, reducing emission rates remains central to achieving AQGs because pollutants generated in the home enter the ambient environment, contributing to outdoor air pollution exposures, and re-enter homes, exacerbating indoor pollution. Furthermore, it is important that information, training, support and other measures to ensure best use of new technologies and fuels will be an integral part of any promotion effort, whether these are delivered through public, NGO or private sector initiatives, or – as is often likely to be the case – a mix of these."
This step-wise approach is more clearly defined here:
− behavioural modifications to reduce exposure (e.g. encouraging mothers to keep their young babies away from the fire);
− household changes to improve ventilation (e.g. increasing the number of window openings in the kitchen, providing gaps between the roof and walls, or moving the stove out of the living area);
− improvements to cooking stoves (e.g. ventilation by flues, hoods or chimneys, or increases in combustion efficiency - nearly all pollutants damaging to health are products of incomplete combustion);
− interventions to enable people to use higher-quality, lower-emission liquid or gaseous fuels (e.g. petroleum-based kerosene and liquid petroleum gas, or biomass-based alcohol and bio-gas).
> Programmes can be designed to encourage urban and periurban households that use solid fuels to move up the “energy ladder” to cleaner fuels (such as kerosene or liquid petroleum gas), and do so at lower income levels (i.e. sooner) than would occur without intervention. This approach requires that the availability and affordability of cleaner fuels be enhanced. On the other hand, the poorest rural populations with nearly no cash income, but access to wood and/or agricultural wastes, are unlikely to acquire improved cooking stoves – let alone cleaner fuels – without large subsidies, which are often unsustainable in the long term. There do seem to be large populations between these extremes, however, that can be effectively targeted by efforts to disseminate improved stoves.
The aim is to eliminate use of these fuels. That's not practical in many areas. Moving from open fires to more efficient enclosed fires is the first step toward elimination, used only in places where cleaner fuels are not available.
Here they're clearly talk about reducing all use of these fuels.
"It is recognized that other types of intervention, including improved ventilation and behaviour changes, may contribute to reducing levels of HAP, or exposure, or both, and are an important part of all interventions. However, reducing emission rates remains central to achieving AQGs because pollutants generated in the home enter the ambient environment, contributing to outdoor air pollution exposures, and re-enter homes, exacerbating indoor pollution. Furthermore, it is important that information, training, support and other measures to ensure best use of new technologies and fuels will be an integral part of any promotion effort, whether these are delivered through public, NGO or private sector initiatives, or – as is often likely to be the case – a mix of these."
This step-wise approach is more clearly defined here:
https://www.who.int/quantifying_ehimpacts/publications/en/In...
− behavioural modifications to reduce exposure (e.g. encouraging mothers to keep their young babies away from the fire);
− household changes to improve ventilation (e.g. increasing the number of window openings in the kitchen, providing gaps between the roof and walls, or moving the stove out of the living area);
− improvements to cooking stoves (e.g. ventilation by flues, hoods or chimneys, or increases in combustion efficiency - nearly all pollutants damaging to health are products of incomplete combustion);
− interventions to enable people to use higher-quality, lower-emission liquid or gaseous fuels (e.g. petroleum-based kerosene and liquid petroleum gas, or biomass-based alcohol and bio-gas).
> Programmes can be designed to encourage urban and periurban households that use solid fuels to move up the “energy ladder” to cleaner fuels (such as kerosene or liquid petroleum gas), and do so at lower income levels (i.e. sooner) than would occur without intervention. This approach requires that the availability and affordability of cleaner fuels be enhanced. On the other hand, the poorest rural populations with nearly no cash income, but access to wood and/or agricultural wastes, are unlikely to acquire improved cooking stoves – let alone cleaner fuels – without large subsidies, which are often unsustainable in the long term. There do seem to be large populations between these extremes, however, that can be effectively targeted by efforts to disseminate improved stoves.