The number shown beside the risk assessment does not come from one sensor or from simply multiplying pollen concentration by a factor. It is an orientative model with several stages. It combines:
- pollen concentrations by plant type,
- plant-specific thresholds, because the same number of grains does not mean the same exposure for birch and ragweed,
- weather, which can raise or lower exposure,
- air quality, which can irritate the airways independently,
- and — optionally — the sensitivity to an allergen selected by the user.
1. Pollen data
For Polish cities we use the European CAMS (Copernicus Atmosphere Monitoring Service) model through Open-Meteo. CAMS estimates concentrations on a model grid; these are not grains counted by a local station. Every value in the Polish forecast is therefore modeled, not measured, and should be treated as orientative. Actual concentrations can differ between districts and from the model output.
For each allergen (for example birch, grasses, ragweed, mugwort, alder, and olive) we show a numeric value when available and a descriptive level. The displayed level comes from the source data; risk calculations use one comparable threshold scale.
2. Plant-specific thresholds — DWD and EAACI
The same value does not represent the same exposure for every pollen type. The model uses thresholds based on the DWD (Pollenflug-Gefahrenindex) classification and its comparison with EAACI recommendations. Examples of daily averages in grains/m³:
| Plant | Low | Moderate | High |
|---|---|---|---|
| Hazel, alder | 1–10 | 11–100 | >100 |
| Birch | 1–10 | 11–50 | >50 |
| Ash | 1–50 | 51–75 | >75 |
| Olive | 1–10 | 11–100 | >100 |
| Grasses | 1–5 | 6–30 | >30 |
| Rye | 1–2 | 3–6 | >6 |
| Ragweed, mugwort | 1–5 | 6–10 | >10 |
The high threshold is the reference point. A numeric value is divided by the high threshold and clamped to 0–1. A reading with no number, represented only by a level, uses the midpoint of that band. This is a technical way to keep values comparable, not a claim about an individual’s symptom threshold.
3. From values to pollen score — the saturation curve
Each allergen enters the next stage as a normalized value x from 0 to 1. We do not assume that twice as much pollen always means twice the score. Instead, we use a concave saturation curve:
score = (1 − e^(−2.5 × x)) / (1 − e^(−2.5))
The curve output is limited to 0–1. It rises quickly at low and moderate concentrations, then gradually flattens near the high threshold. The pollen result is then multiplied by 75. A single allergen at its high threshold therefore contributes 75 points and leaves room for weather and air-quality modifiers.
4. Several allergens at once — soft-max
We do not keep only the highest value, but we also do not fully add every allergen. We sort the normalized values and calculate:
aggregate = highest_value + 0.5 × second_highest
The aggregate is capped at 1.0. Two allergens at 0.5 therefore produce 0.75; a third and later allergen does not increase the aggregate. A user’s sensitivity setting is applied before this stage: an allergen can be multiplied by 0 (excluded), 1 (normal), or 2 (sensitive), after which the model’s scale clamp applies.
5. Weather and air quality
One modifier is added to the pollen result. The current implementation applies exactly these rules:
| Condition | Change |
|---|---|
| Wind > 25 km/h | +15 |
| Wind 15–25 km/h | +8 |
| Wind < 5 km/h | −5 |
| Humidity < 40% | +10 |
| Humidity > 75% | −8 |
| Rain > 5 mm/24 h | −20 |
| Rain 1–5 mm/24 h | −10 |
| Temperature ≥ 30°C | +8 |
| Temperature ≥ 25°C | +5 |
| European AQI 41–60 | +3 |
| European AQI 61–80 | +6 |
| European AQI > 80 | +10 |
These rules are not a symptom forecast. They are a simplified representation of wind carrying pollen, rain washing it out, and dry, hot air and pollution adding airway strain. Poorer air quality raises the score, while clean air does not lower it below the baseline. AQI data comes from the Open-Meteo/CAMS air-quality service; practical exposure-reduction steps are in how to protect yourself from pollen in Poland.
The combined modifier ranges from −33 to +43. The pollen result plus the modifier is finally capped at 0–100.
6. Final score and guidance
| Points | Level | Orientative outdoor guidance |
|---|---|---|
| < 30 | SAFE | No limit |
| 30–49 | LOW | Up to 6 hours |
| 50–69 | MODERATE | 2–3 hours |
| 70–84 | HIGH | At most 1 hour |
| ≥ 85 | VERY HIGH | Avoid outdoor activity |
The guidance is orientative, based on an average person with allergic rhinitis. People with asthma, severe symptoms, or other conditions should follow an individual plan agreed with a clinician. Someone without pollen allergy may have no symptoms even at a high score.
Sources and limitations
- DWD: pollen hazard index information — pollen bands.
- EAACI: guidelines on environmental science, allergy, and asthma — clinical and environmental context.
- Open-Meteo Air Quality API — air-quality data and CAMS source.
- Copernicus CAMS — European atmospheric modeling.
The model does not know a person’s full allergy profile, medication, or delayed reactions. It does not replace local measurement, diagnosis, or treatment. For symptoms and therapy, consult a doctor or allergist.