SmogRank / World / South America / Chile / Biobio

Most polluted cities in Biobio, Chile

13 measured cities, this year; 13 above the WHO annual guideline. Worst: Hualpén at 44.0 µg/m³, #58 in the world.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

Maule Region: 4 measured citiesÑuble: 2 measured citiesAraucania: 2 measured citiesBiobio: 13 measured cities#13 Lota: 21.7 µg/m³#11 Concepción: 23.5 µg/m³#12 Chiguayante: 23.5 µg/m³#10 Tomé: 24.6 µg/m³#9 San Pedro de la Paz: 24.9 µg/m³#8 Coronel: 29.9 µg/m³#7 Talcahuano: 30.1 µg/m³#6 Los Ángeles: 31.7 µg/m³#5 Hualqui: 33.9 µg/m³#4 Curanilahue: 39.7 µg/m³#3 Laja: 41.0 µg/m³#2 Nacimiento: 43.8 µg/m³#1 Hualpén: 44.0 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Hualpén 49% 40%0
Every measured city in Biobio, Chile, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Hualpén 49%
  2. 2Nacimientolast full day 30 Sept 48%
  3. 3Lajalast full day 30 Sept 45%
  4. 4Curanilahue 41%
  5. 5Hualqui 37%
  6. 6Coronel 26%
  7. 7Los Ángeles 26%
  8. 8Talcahuano 23%
  9. 9San Pedro de la Paz 12%
  10. 10Tomé 12%
  11. 11Concepción 12%
  12. 12Chiguayante 11%
  13. 13Lota 9%
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Biobio cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Villa Mercedes≈ 12 µg/m³Moderate
Penco≈ 20 µg/m³Moderate
Cañete≈ 12 µg/m³Moderate
Cabrero≈ 17 µg/m³Moderate
Mulchén≈ 16 µg/m³Moderate
Arauco≈ 16 µg/m³Moderate
Lebu≈ 17 µg/m³Moderate
Los Álamos≈ 17 µg/m³Moderate

Bad-air episodes in Biobio

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

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SmogRank, most polluted cities in Biobio, Chile, PM2.5, this year to 6 Oct 2026, 22:00 UTC, smogrank.com/cl/region/biobio?w=year.

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.