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1. Understanding AQI: What the categories actually mean

AQI (Air Quality Index) is a way to translate pollution measurements into health-relevant categories. Higher AQI means higher health risk.

AQI vs µg/m³

AQI is the "risk score" (0–500), while µg/m³ is the physical weight of pollution in the air. On Диши.мк, we use AQI to give you a quick answer: "Is it safe to go outside?"

Good (0–50)

Air pollution levels are low. Most people can go about daily activities without concern.

Moderate (51–100)

Air quality is acceptable for most. However, sensitive individuals may notice mild symptoms.

Unhealthy for Sensitive Groups (101–150)

Children, older adults, pregnant people, and those with heart/lung disease should limit intense outdoor activity.

Unhealthy (151–200)

Everyone may feel effects. Sensitive groups are at risk of coughing, chest tightness, or fatigue.

Very Unhealthy (201–300)

Health alert. Outdoor activity should be minimized for everyone.

Hazardous (301+)

Serious health risk for the entire population. Avoid outdoor exposure as much as possible.

Important: AQI categories reflect short-term risk. Repeated exposure to “unhealthy” days over months and years contributes to long-term health problems.

2. How air pollution affects human health

Because pollution is often invisible, it’s easy to underestimate it. Fine particles (PM2.5) are small enough to reach deep into the lungs and cause inflammation throughout the body.

Heart

Heart & Cardiovascular

Fine particle exposure is linked to higher risks of heart attacks, strokes, and high blood pressure. Pollution acts like extra “pressure” on your heart.

Research suggests long-term exposure raises hospitalization risk in seniors [2][3].

Brain

Brain & Cognition

Evidence grows that long-term exposure is linked to cognitive decline and neurodegenerative conditions like Alzheimer’s. It affects brain health over years [4].

Lungs

Lungs & Breathing

Pollution irritates airways, worsening asthma and COPD. It increases vulnerability to infections, which is why smoggy periods often feel like “everyone is coughing.”

Baby

Pregnancy & Infants

Exposure during pregnancy is linked to low birth weight and preterm birth. Early life stages are particularly sensitive to environmental stress.

Who is most at risk?

Children: Lungs/immune systems are still developing; they breathe more air per body weight.
Older adults: Higher baseline risk for heart/lung events.
People with chronic conditions: Asthma, COPD, heart disease, diabetes.
Outdoor workers: Higher exposure time.

Is there a “safe” level?

No. Many studies find risks even at low concentrations. Public health guidance says "lower is better" rather than a simple safe/unsafe switch.

Global Emergency

Harvard researchers reported that fossil fuel air pollution was responsible for about 1 in 5 deaths worldwide in 2018 [5]. It is a large-scale public health issue.

3. The key pollutants in Skopje

Skopje’s air is dominated by particles (PM₂.₅, PM₁₀) and nitrogen dioxide (NO₂).

PM₂.₅

Fine particles ≤ 2.5 µm

Reaches deep into lungs/bloodstream. Peaks in winter from heating/traffic.

PM₁₀

Coarse particles ≤ 10 µm

Irritates upper airways. Sources: road dust, construction, burning.

NO₂

Nitrogen dioxide

Gas from vehicle exhaust. Highest near busy roads/intersections.

O₃

Ozone

Summer issue formed by sun reactions. Irritates lungs.

4. Why Skopje’s pollution is so intense

1) Valley + Inversion

Skopje is a basin. In winter, a "lid" of warm air traps cold air and pollution near the ground.

2) Heating + Traffic

Wood/coal heating combined with old diesel cars creates massive PM emissions that get trapped.

5. Using the map effectively

Step 1

Hotspots

Check if it's a city-wide episode or just one local station.

Step 2

Hourly Trend

Is it rising (evening peak) or falling (wind clearing it)?

Step 3

Context

Compare to past years to see if structural changes are working.

6. Everyday decisions

Ventilation

Good/Mod: Air freely.

Unhealthy: Shorten outdoor time, shift intense cardio indoors, ventilate briefly during dips.

Action

Use data to argue for clean heating, better transit, and insulation policies.

Scientific Sources & References (5)

[1] WHO — “Billions of people still breathe unhealthy air” (99% statement).
[2] Harvard T.H. Chan — “The dangers of air pollution for heart health.”
[3] Harvard T.H. Chan — “Chronic exposure... risk of cardiovascular hospitalization among seniors.”
[4] Harvard T.H. Chan — “How air pollution impacts our brains.”
[5] Harvard T.H. Chan — “Fossil fuel air pollution responsible for 1 in 5 deaths worldwide.”

How to read Skopje’s air