---
title: "Reducing indoor air pollutants"
subject: "Energy Environment and Society"
chapter: 4
key: "semester_7/energy_environment_and_society:indoor-air-pollutant-reduction"
source: https://www.bctengineer.com/q/semester_7/energy_environment_and_society/indoor-air-pollutant-reduction
site: BCT Engineering
---

# Reducing indoor air pollutants

Energy Environment and Society · Chapter 4: Environmental Impact of Energy sources

- Asked in: year not given
- Video: [Explained: Indoor air pollution, health risks, and precautions you need](https://www.youtube.com/watch?v=oNQNAOVVY6o) — Times Of India
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/energy_environment_and_society/indoor-air-pollutant-reduction
- Whole chapter: https://www.bctengineer.com/md/semester_7/energy_environment_and_society/chapter-4

## Question

What may be the technical efforts to reduce indoor air pollutants?

## Short answer

Use improved cookstoves with chimneys, biogas or electric cooking, and low-VOC materials to reduce emissions at source. Improve ventilation with kitchen hoods and windows, and employ HEPA air purifiers and humidity control. Seal floors against radon and install CO and PM sensors for monitoring.

## Answer

Technical efforts to reduce indoor air pollutants fall into the following groups.

#### 1. Reduce emissions at source (cooking and heating)
- **Improved cookstoves (ICS)** with chimneys, efficient combustion and less smoke (promoted by AEPC and the Government of Nepal's Clean Cooking programme).
- **Biogas stoves**, LPG, **electric (induction) cooking** using hydroelectricity, and solar cookers.
- **Better fuel:** dry wood, briquettes, pellets, or gasifier stoves instead of wet wood, dung and coal.
- Use low-VOC paints, adhesives and building materials; avoid asbestos and lead paint.
- Ban or restrict smoking indoors.

#### 2. Ventilation
- Kitchen chimney or smoke hood, eaves gaps, windows, and exhaust fans.
- Mechanical ventilation and heat recovery ventilators in buildings.
- Building design with kitchens separated from living rooms and with cross ventilation.

#### 3. Air cleaning
- HEPA filters and activated carbon filters; air purifiers.
- Humidity control (dehumidifiers, ventilation) to reduce mould; keep relative humidity at 30–50%.

#### 4. Radon and moisture control
- Seal floors and cracks, and ventilate basements; waterproofing; regular cleaning.

#### 5. Monitoring and awareness
- Sensors for CO, CO₂, PM2.5; CO alarms; standards and regulation; training of households.

Combined use of clean stoves, chimneys, and better ventilation can reduce indoor PM2.5 by a large fraction.

## Check yourself

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

1. Which is a source-reduction measure?
   A. Improved cookstoves, biogas, LPG or induction cooking
   B. Opening a window only
   C. Installing a CO sensor only
   D. Using wet wood
   Answer: A. Reducing emissions at source is the first group of technical efforts. (Key point: Source control)

2. Which is a ventilation measure?
   A. HEPA filter
   B. Kitchen chimney, smoke hood and exhaust fans
   C. CO alarm
   D. Low-VOC paint
   Answer: B. Chimneys and hoods take smoke outside. (Key point: Ventilation)

3. What humidity level helps reduce mould?
   A. 70-90%
   B. 5-10%
   C. 30-50%
   D. Above 95%
   Answer: C. Humidity control and cleaning reduce mould. (Key point: Mould control)

4. How is radon controlled?
   A. Burn more firewood
   B. Use wet fuel
   C. Increase indoor humidity
   D. Seal floors and cracks and ventilate basements
   Answer: D. Radon enters through floors and cracks. (Key point: Radon)

## Related in Energy Environment and Society

- [Health impacts of indoor air pollutants](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Aindoor-air-pollutants-health) — Energy Environment and Society, chapter 4

## Related in other subjects

- [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
- [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
- [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
- [Severity of indoor air pollution in Nepal](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aindoor-air-pollution-severity) — Technology, Environment and Society, chapter 5