---
title: "Household smoke pollution and effects on residents"
subject: "Environment and Pollution Control"
chapter: 3
key: "semester_7/environment_and_pollution_control:household-smoke-pollution-effects"
source: https://www.bctengineer.com/q/semester_7/environment_and_pollution_control/household-smoke-pollution-effects
site: BCT Engineering
---

# Household smoke pollution and effects on residents

Environment and Pollution Control · Chapter 3: Indoor Air Quality

- Asked in: year not given, 8 marks
- Video: [Indoor air pollutants| Atmospheric pollution| AP Environmental science| Khan Academy](https://www.youtube.com/watch?v=nqRPRwO79kg) — Khan Academy
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/environment_and_pollution_control/household-smoke-pollution-effects
- Whole chapter: https://www.bctengineer.com/md/semester_7/environment_and_pollution_control/chapter-3

## Question

Explain household (indoor) smoke pollution from the use of biomass fuels. Describe its sources, health effects on the residents and measures to reduce it.

## Short answer

Indoor burning of wood, dung and crop residues in poorly ventilated kitchens emits particulate matter, carbon monoxide and carcinogens. It causes acute respiratory infections in children, chronic lung disease in women and low birth weight. Control measures include improved cookstoves with chimneys, switching to LPG or biogas, better ventilation and education.

## Answer

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
| Effect | Group most affected |
|---|---|
| Acute respiratory infection (pneumonia) | Children under 5 |
| Chronic obstructive pulmonary disease (chronic bronchitis) | Women |
| Lung cancer (mainly with coal) | Women |
| Low birth weight, stillbirth | Pregnant women |
| Eye irritation, cataract, tuberculosis | Adults |
| Heart disease, burns, headache | All |

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.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Why are concentrations high in biomass-fuelled kitchens?
   A. Complete combustion at high temperature
   B. Incomplete combustion at low temperature, no chimney and poor ventilation
   C. Use of LPG
   D. Large well-ventilated rooms
   Answer: B. Low-temperature incomplete burning plus no chimney or hood and small rooms gives high smoke levels. (Key point: Why exposure is high)

2. Which groups suffer most, and from what?
   A. Men - lung cancer only
   B. Children under 5 - acute respiratory infection; women - COPD
   C. Elderly - burns only
   D. Teachers - cataract
   Answer: B. Women and young children spend the most time near the fire; children get pneumonia, women get COPD. (Key point: Most affected groups)

3. Which pollutant in biomass smoke is a carcinogen?
   A. Benzo[a]pyrene (PAH)
   B. Nitrogen
   C. Water vapour
   D. Argon
   Answer: A. Polycyclic aromatic hydrocarbons such as benzo[a]pyrene are carcinogenic. (Key point: Pollutants)

4. Which measure best cuts indoor smoke exposure?
   A. Improved cookstoves with chimneys or clean fuels such as LPG and biogas
   B. Keeping windows shut
   C. Using wet wood
   D. Cooking in a smaller room
   Answer: A. Improved stoves vent smoke outside and burn better; clean fuels remove the smoke. (Key point: Control measures)

## Related in Environment and Pollution Control

- [Water pollution: sources and effects](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Awater-pollution-sources-effects) — Environment and Pollution Control, chapter 4
- [Indoor air pollutants and their sources](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aindoor-air-pollutants-sources) — Environment and Pollution Control, chapter 3
- [Particulate pollutants: sources and effects](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aparticulate-pollutants-sources-effects) — Environment and Pollution Control, chapter 1
- [Sources and effects of SO2, NOx and CO](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Agaseous-pollutants-so2-nox-co) — Environment and Pollution Control, chapter 1
- [Control strategies for indoor air quality](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aindoor-air-control-strategies) — Environment and Pollution Control, chapter 3

## Related in other subjects

- [Indoor air pollution in Nepal and counter measures](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aindoor-air-pollution-nepal) — Technology, Environment and Society, chapter 5
- [Sources, effects and remedies of water pollution](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollution-sources) — Engineering Chemistry, chapter 3, asked 2×
- [Biochemical conversion of biomass to fuels](https://www.bctengineer.com/question.md?key=semester_6%2Fenergy_resources%3Abiomass-biochemical-conversion) — Energy Resources, chapter 3
- [Indoor air pollution and Kathmandu air problems](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aindoor-air-kathmandu-health) — Technology, Environment and Society, chapter 5