Dhaka’s air-quality reading can change substantially within a day and from one neighbourhood to another. This guide explains what an AQI number generally indicates, which pollutants matter, how to decide whether outdoor activity is sensible, and how to build a simple routine for checking conditions before commuting, exercising, or sending children outside.
Overview
The Air Quality Index, or AQI, converts measurements of air pollutants into a scale that is easier to understand than a list of technical concentrations. A higher AQI generally means greater concern for health. The number is useful, but it is not a complete personal health assessment: exposure time, physical exertion, age, pregnancy, and existing conditions all affect risk.
Dhaka’s pollution can be influenced by traffic, construction and road dust, industrial activity, waste burning, weather conditions and pollution transported from nearby areas. Conditions can also differ between a busy road, an enclosed courtyard, a school ground and a residential street. Treat an AQI reading as a guide to the broader conditions around the monitoring station, not as a guarantee that every location in the city has identical air.
A further caution is that AQI systems do not always use the same calculation method or category names. Some apps use an international or US-style scale, while official Bangladesh reporting may present pollutant concentrations, colour bands or categories that require separate interpretation. Before acting on a number, check which scale the source uses, when the reading was recorded and whether it represents a current reading, an hourly average or a forecast.
A practical AQI comparison
The table below describes a commonly used AQI-style interpretation. It is a general planning aid, not a replacement for the category and health advice displayed by the relevant official monitoring service.
| AQI band | General meaning | Practical outdoor plan |
|---|---|---|
| 0–50 | Lower concern for the general population | Most people can follow normal outdoor routines. Continue to watch for personal symptoms. |
| 51–100 | Usually acceptable, with possible sensitivity for some people | Most activities may continue. People who are sensitive to pollution should monitor symptoms and consider reducing prolonged exertion. |
| 101–150 | Increasing concern, particularly for sensitive groups | Children, older adults, pregnant people and those with heart or lung conditions should limit strenuous or lengthy outdoor activity. |
| 151–200 | Health concern can extend beyond sensitive groups | Move exercise indoors or postpone it where possible. Reduce unnecessary time near traffic and dusty areas. |
| 201 and above | High concern | Avoid strenuous outdoor activity and keep outdoor exposure as short as practical. Follow current public-health advice. |
If a Bangladesh monitoring source uses different thresholds or labels, follow that source’s definitions rather than converting the result yourself.
What to track
Pollutants behind the reading
Fine particulate matter, commonly identified as PM2.5, is especially important because its small particles can travel deep into the respiratory system. PM10 refers to larger inhalable particles and is often associated with dust, construction and road activity. AQI systems may also account for gases such as nitrogen dioxide, ozone, sulphur dioxide and carbon monoxide. The pollutant driving the overall index can change, so look beyond the headline number when the dashboard provides a pollutant breakdown.
For daily planning, note three details: the current AQI or concentration, the dominant pollutant, and the forecast or recent trend. A single improved reading does not necessarily mean that conditions will remain improved throughout the day.
Time, place and exposure
Record the time of the reading and compare it with your planned activity. A short walk and a two-hour run do not create the same exposure. Hard exercise also increases breathing rate, which can increase the amount of polluted air inhaled. Roadside waiting, traffic congestion, open construction areas and smoky locations may add exposure even when the citywide reading appears moderate.
Indoor air is not automatically clean. Open windows, roadside pollution, cooking smoke, tobacco smoke, incense, poorly maintained air-conditioning systems and indoor dust can all affect it. During poor outdoor conditions, keep indoor sources controlled and use filtration or ventilation strategies that are suitable for the building.
Symptoms and precautions checklist
- Watch for: eye or throat irritation, coughing, wheezing, chest tightness, unusual shortness of breath, headache or worsening of an existing respiratory condition.
- Reduce exposure: shorten outdoor time, lower exercise intensity, choose less congested routes and avoid visible smoke or dust.
- Protect vulnerable people: plan flexible outdoor time for children, older adults, pregnant people and anyone with asthma, chronic lung disease or heart disease.
- Use a face covering carefully: a well-fitting particulate respirator may reduce exposure to particles, but ordinary loose face coverings may not provide the same protection. A mask does not remove the need to reduce time in polluted air.
- Seek medical help: get urgent care for severe breathing difficulty, chest pain, bluish lips, confusion or symptoms that are rapidly worsening.
Cadence and checkpoints
Use a three-step check before making an outdoor plan in Dhaka:
- Check an official or clearly identified monitoring source. Look for the Department of Environment’s published air-quality information or another reputable monitoring dashboard. Confirm the timestamp, station or area, pollutant and AQI method.
- Compare the reading with your activity. A necessary commute, a school sports period and an intense outdoor workout require different decisions. At higher readings, postpone non-essential exercise first and reduce time spent beside busy roads.
- Check again before leaving. Air quality is changeable. Recheck if several hours have passed, the weather has shifted, smoke or dust is visible, or the route has changed.
For families, write the chosen source and its update time into a morning routine. Schools and workplaces can use the same process, while allowing people with medical conditions to follow their clinician’s advice. During prolonged poor conditions, check at least once in the morning and again before afternoon or evening activities rather than relying on yesterday’s reading.
How to interpret changes
Do not treat a falling AQI as proof that all health risk has disappeared, or a rising number as a reason for panic. Look for a sustained pattern across several readings and, where available, several monitoring stations. Weather can affect how pollution accumulates or disperses, while rain may temporarily reduce some airborne dust without resolving every pollution source.
Seasonality also matters. Dhaka often experiences different pollution patterns during drier periods than during the monsoon, but the exact timing and severity can vary from year to year. Dry weather, stagnant air, construction activity, traffic and regional pollution may contribute to elevated readings. A monsoon improvement should not be assumed to apply to every day or every pollutant.
When two apps disagree, compare their source, location, timestamp and AQI scale before choosing one. A difference may reflect different stations or calculation methods rather than a simple error. For health decisions, prioritise transparent, recent data and consistent public-health guidance.
When to revisit
Return to this guide whenever Dhaka’s pollution conditions change, before a major outdoor event, or when a child or family member develops recurring symptoms. Editors should review the article at the start of each dry and monsoon season, and whenever Bangladesh changes its AQI categories, monitoring method or public-health recommendations. Monitoring sources, dashboard links and health guidance should also be checked on a regular monthly or quarterly schedule.
For a practical routine today, check the latest official reading, identify the dominant pollutant and timestamp, match the result to the planned activity, and make a lower-exposure alternative ready. If the AQI is elevated, replace outdoor exercise with indoor movement, shorten unnecessary trips, avoid congested roadside areas and give vulnerable household members more conservative options. Keep a note of which source and location you used so that tomorrow’s reading can be compared consistently.
