The key facts

  • On the night of October 29–30, the AQI in Tashkent dropped to the 'unhealthy' level, and in some places to 'very unhealthy'
  • The causes cited were a drop in temperature, very weak wind, and a strong temperature inversion; no dust sources were found in satellite data
  • PM2.5 measurements were carried out in six districts of the city; for October 30, the 'unhealthy' level on the international AQI is forecast to persist

What happened on the night of October 29–30

On the night of October 29–30, under the influence of unfavorable meteorological conditions, the quality of ambient air in Tashkent deteriorated noticeably. According to Zamon.uz citing monitoring data, in the evening hours the readings on the international Air Quality Index (AQI) were mostly at the level of 'unhealthy for sensitive groups,' and after midnight at the level of 'unhealthy'; at some observation points, values of 'very unhealthy' were also recorded. On the national air quality index, the city's average PM2.5 indicator was at the 'yellow' level, and PM10 at the 'dark yellow' level.

Causes and sources of pollution

The deterioration in air quality is attributed to a drop in temperature, very weak wind, and a strong temperature inversion: these factors limited air exchange in the lower layers of the atmosphere and led to the accumulation of PM particles and local emissions in the surface layer. At the same time, according to meteorological satellite images, no significant dust sources were observed in Tashkent and its surroundings — meaning the pollution arose mainly from local sources and the weather conditions themselves, rather than from dust brought in from outside.

Measurements by district and forecast

Specialists of the state institution 'National Center for Environmental Monitoring' carried out instrumental measurements of ambient air in the Yunusabad, Almazar, Mirzo-Ulugbek, Shaykhantahur, Mirabad, and Yangihayot districts; in the observations, PM2.5 readings mostly corresponded to the 'unhealthy' category. For October 30, air quality in Tashkent is expected to remain at the 'unhealthy' level on the international AQI, and mostly at the 'yellow' level on the national index. At present, ambient air quality is under continuous monitoring by the Special Commission.