Nairobi residents have been advised to keep a close watch on the quality of the air they breathe after county authorities reported deteriorating pollution levels in parts of the city.

According to the Nairobi City County Air Quality Index (AQI) recorded at 11:44 a.m. on Monday, the overall air quality was rated as moderate. However, three areas Parklands, Fire Station and Dandora Phase II were classified as “unhealthy for sensitive groups”, prompting urgent health advisories.

Speaking during a briefing, Nairobi County Chief Officer for Environment, Geoffrey Mosiria, urged residents to take the situation seriously and remain informed through the county’s digital monitoring platforms.

“Monitor the quality of air you breathe by visiting the Nairobi County website under the Air Quality section. Stay informed and take the necessary precautions to protect your health,” Mosiria said.

Mosiria issued an advisory recommending the use of protective masks in the affected neighbourhoods especially for individuals with pre-existing conditions like asthma.

“Individuals are advised to wear masks in such areas to reduce their exposure to harmful particles,” Moseiria said, adding that the county had already dispatched its environment team to the identified zones to assess and mitigate pollution levels.

In addition to advising residents, the county government issued a stern warning to public transport operators, particularly matatu drivers, against contributing to pollution by keeping engines running unnecessarily.

“Matatu operators are advised to switch off their vehicles while not in use to avoid pollution. If not, they will face the full force of the law against pollution,” Mosiria cautioned.

Vehicle emissions remain one of Nairobi’s biggest pollution sources, with idling engines and poorly maintained vehicles pumping particulate matter and toxic gases such as carbon monoxide and nitrogen oxides into the atmosphere.

The county has said it will intensify inspections on major routes and impose penalties on non-compliant operators.

Mosiria emphasized that improving Nairobi’s air quality is not solely the responsibility of the county government but a shared duty. He urged residents to remain vigilant, adjust their routines and adopt eco-friendly habits to help combat the problem.

“All residents are advised to visit the Nairobi Air Quality website so as to be updated and advised on areas of concern,” he said.

Mosiria encouraged Nairobians to make regular use of the tool, stressing that awareness and timely action are crucial for safeguarding public health.

Air pollution has become a growing public health challenge in Nairobi, where rapid urbanization, heavy traffic congestion, open burning of waste, and industrial activities continue to degrade air quality.

The county government has pledged to scale up its monitoring network by installing more air quality sensors across Nairobi, particularly in high-risk areas. It also intends to strengthen enforcement of anti-pollution laws, promote cleaner public transport and encourage renewable energy adoption in industries and households.