Covered in smoke, Porto Velho records the worst air quality in the country

At around 7am, the capital of Rondônia registered 125 points in air quality, classified as “unhealthy for sensitive groups”. Among the places with the highest levels of pollution in Porto Velho was the Olaria neighborhood. In the survey, Porto Velho surpassed Manaus (AM), which spent the week covered in smoke.

Amazonas broke fire records this year. In the first ten days of October, 1,380 outbreaks were registered: an increase of 271% compared to the same period in 2025, according to data from the Fire Panel, the Management and Operational Center of the Amazon Protection System (Censipam).

Lucas Coelho, meteorologist at Inmet, explains that the wind coming from the neighboring state towards Rondônia brings the smoke.

“If there are fires along the way in the direction in which the wind will pass and then reach Rondônia, the dispersion of these pollutants also ends up reaching the state of Rondônia, which coincides with what we have observed,” he explained.

According to Lucas, the drought and lack of large amounts of rain favor the scenario for fires.

"There is a lack of precipitation, there is a greater incidence of solar radiation reaching the surface and, as a result, surface temperatures rise. If there is a very long period, without precipitation, the vegetation itself becomes drier and becomes a more efficient fuel for the fire to spread", he concludes.

This Thursday (15), the Madeira River reached 2.45 meters, another meter below what was expected for this time of year. The scenario, caused by drought, placed the capital of Rondônia in an emergency situation. According to the Municipal Civil Defense, more than 22 thousand people are affected.

According to IQAir, the main pollutant identified is fine particulate matter PM2.5. Because they are extremely small, these particles are absorbed into the bloodstream and tend to be the most harmful to health.

In Porto Velho, the concentration of PM2.5. recorded was 45.3 micrograms per cubic meter (µg/m³), an amount times greater than the annual air quality guideline established by the World Health Organization (WHO) for this pollutant.