Air quality in the KMC is expected to remain poor throughout the week because of pollution trapped in the atmosphere.

There are currently high levels of PM2.5 — particulate matter with a diameter of 2.5 micrometers or smaller — in the air, according to the European Environment Agency’s Air Quality Index.

These particles, which are much smaller than the width of a human hair, often come from exhaust, industrial emissions and residential heating, including wood stoves.

They’re being trapped near the ground due to a weather phenomenon known as temperature inversion, according to the German Weather Service.

That’s when a layer of warm air sits above cooler air near the ground, instead of the usual scenario where air cools as altitudes increase.

A change in weather, like strong winds or precipitation, often disperses pollutants and clears the air.

However, conditions in the KMC are not expected to change until Thursday or Friday, according to the German Weather Service’s forecast.

PM2.5 can pose health risks, particularly to vulnerable individuals, including children, the elderly and those with respiratory or cardiac conditions.

The World Health Organization advises vulnerable individuals to minimize their outdoor time and for everyone to minimize strenuous activity outside when pollution levels are high.