KARACHI: A severe public health threat has emerged across Pakistan as winter weather sets in, with the air in both Lahore and Karachi officially hitting unhealthy pollution levels.

The crisis has placed both metropolitan areas on the international leaderboard for the worst air quality:

Lahore currently ranks first globally, while Karachi sits at the fourth spot.

Lahore’s air quality is deemed severely polluted and outright hazardous to health, forcing residents to breathe toxic air. Karachi’s air, while slightly less severe, is still categorized as highly polluted and fundamentally unhealthy.

Pollution is measured by the concentration of fine particulate matter, which has reached alarming highs in both cities:

• Lahore: 251 micrograms per cubic meter (µg/m³) of polluted particles.
• Karachi: 195 micrograms per cubic meter (µg/m³) of polluted particles.

In the global ranking, Delhi occupies the second position, and Baghdad ranks third, placing them directly between the two Pakistani cities.

The numbers translate to specific risk levels on the international Air Quality Index (AQI):

• Readings from 150 to 200 signify that the air is Unhealthy (Karachi’s level).
• Readings from 200 to 300 mark Very Unhealthy or Severe Pollution (Lahore’s level).

Any reading above 300 is considered Hazardous, signaling emergency conditions where the entire population faces serious health risks.