Republic of Ghana · Environmental Protection Authority
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Take the Air Quality Quiz & Quick-Fire Challenge
Public health
Air pollution is now the world's largest single environmental health risk. The effects depend on the pollutant, concentration, and duration of exposure.
Hours to days
Years of exposure
Elevated risk
Daily protection guide
AQI 0–50
Normal outdoor activities. A great day to exercise outside.
AQI 51–100
Sensitive groups reduce prolonged outdoor exertion.
AQI 101–150
Limit outdoor exercise. Consider a mask if outdoors long.
AQI 151+
Avoid outdoor activity. Stay indoors, keep windows closed.
Outdoors
Sensors in the network primarily report particulate matter. Other pollutants matter too — especially near roads and industrial areas.
PM2.5
Microscopic particles 2.5 µm or smaller. They travel deep into the lungs and bloodstream and are the main basis for AQI on Delectis.
Common sources
Health: Linked to respiratory illness, heart disease, and premature mortality with long-term exposure. Short spikes can trigger asthma symptoms.
PM10
Larger particles up to 10 µm. Often visible as dust; irritates eyes, nose, and throat.
Common sources
Health: Less penetrating than PM2.5 but still harmful at high levels, especially for children and outdoor workers.
NO₂
A gas from high-temperature combustion, common near busy roads.
Common sources
Health: Can inflame airways and worsen asthma. Often elevated where traffic is dense.
O₃
Formed when sunlight reacts with pollution. Typically peaks on sunny afternoons.
Common sources
Health: Irritates lungs and reduces lung function during exercise. Not emitted directly from a single stack or tailpipe.
CO
Odourless gas from incomplete combustion.
Common sources
Health: Reduces oxygen delivery in the body at high concentrations. Critical indoors; outdoor levels are usually lower but can rise in traffic corridors.
Indoors
Outdoor readings do not capture what happens inside your home or workplace.
Main culprits: Gas combustion (NO₂, CO), cooking ultrafine particles, and frying smoke.
Main culprits: Dust, pet dander, tracked-in particles, VOCs from furniture and cleaners.
Main culprits: Dust mites, pet dander, VOCs from mattresses and furnishings.
Main culprits: Moisture, mold spores, VOCs from cleaners and personal care products.
Playbook
Whether indoors or out, improvements follow the same order: tackle sources first, ventilate when outdoor air allows, then filter and monitor what remains.
Step 1
Reduce pollution at its origin — the most effective step indoors and out.
Step 2
Use fresh air strategically to dilute what you cannot eliminate.
Step 3
Filter remaining particles and verify that your actions are working.
Network
Air quality sensors measure concentrations of pollutants in the air — most commonly PM2.5 and PM10 in the Delectis network. Light-scattering optical sensors estimate particle mass; reference instruments use more complex methods and are used to calibrate field units.
Each station reports readings at regular intervals. Data is timestamped, linked to a location, and published on the map and town pages when it passes quality checks.
Sensors are installed on rooftops, schools, hospitals, and other sites chosen to represent public exposure in a town or neighbourhood. Status indicators show whether a station is actively reporting.
On this site
Reference
The hub uses the US EPA Air Quality Index. Each band maps a PM2.5 range to a color and health message.
Example reading of 98 within its band on the scale.
Ideal for outdoor activity.
Acceptable for most; sensitive people may notice effects.
Sensitive groups should reduce prolonged outdoor exertion.
Everyone should limit prolonged outdoor exertion.
Avoid outdoor activity; keep windows closed when possible.
Health alert — remain indoors with clean air if possible.
