Household smoke pollution and effects on residents

In many rural homes of developing countries, including the hill and Terai areas of Nepal, wood, dung and crop residue are burnt for cooking and heating on open fires or traditional mud stoves with no chimney. The smoke released inside poorly ventilated, often windowless kitchens gives very high exposure; women and young children are the most affected because they spend the most time near the fire.

Pollutants in biomass smoke

• Particulate matter (PM2.5 and PM10); levels of several hundred to thousands of $\mu\text{g/m}^3$ during cooking are common, far above guideline values.
• Carbon monoxide, nitrogen oxides, formaldehyde, benzene and other VOCs, and polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyrene (a carcinogen).

Reasons for high concentrations: incomplete combustion at low temperature, no chimney or hood, small rooms, low openings and poor ventilation.

Health effects

Smoke also darkens walls and roofs, and burning biomass adds to forest loss and the time spent collecting fuel.

Control measures

1. Improved cookstoves (ICS) with chimneys that vent smoke outside, giving better combustion.
2. Clean fuels: LPG, biogas, electric or induction cookers, solar cookers.
3. Ventilation: smoke hoods, windows, ventilators near the roof, and a separate kitchen.
4. Behaviour: use dry wood, keep children away from the fire, and cook outdoors where possible.
5. Awareness and policy: health education, subsidies for biogas and improved stoves.