Summary of Blog
Air pollution is the most severe environmental threat to public health globally, impacting our health, development, and environment. The top 10 most polluted cities in 2025 include Byrnihat, India; Delhi, India; Karaganda, Kazakhstan; and many others discussed in the blog. Air pollution’s health impacts include respiratory conditions, cardiovascular diseases, and lung cancer, while environmental impacts encompass acid rain, eutrophication, and climate change. Economically, it leads to increased medical costs and reduced productivity. The top 5 most polluted countries are Bangladesh, Pakistan, India, Bahrain and Nepal. Major causes of pollution include fossil fuel use, vehicular emissions, industrial activities, agriculture, and poor waste management. Efforts like the Paris Agreement aim to combat these issues. The blog underscores the urgent need for sustainable practices and cleaner technologies from companies like Oizom, which offers advanced air quality monitoring devices and provides real-time accurate data. However, if we practice or adopt sustainability towards a cleaner future, we will achieve SDG -3, 11, 13, and 15 for the urban environment.
Use of air quality monitoring stations:
Air quality monitoring refers to gathering and analyzing samples of ambient air pollution. To assess the condition of the air, data from these samples are compared to clean air standards, historical data on air quality levels, and data on its effects on human health and the environment. First, let us understand the monitoring needs:
Identifying the purpose behind the monitoring of air quality:
- Your monitoring requirements could include tracking indoor pollution levels in your home or workplace, determining the outdoor air quality for environmental projects, or adhering to industrial safety rules. Your options might be significantly reduced by defining your unique needs.
Which types of pollutants do you want to monitor:
- The EPA created National Ambient Air Quality Standards (NAAQS) for six common air pollutants, sometimes called “criteria” air pollutants, to safeguard human health and welfare across the country. The contaminants are particulate matter, ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead.Â
Did you know Oizom has just launched its latest innovation in November 2024, Pollusense? It’s a portable air quality monitor designed to provide accurate, real-time data on pollutants and environmental conditions. Equipped with advanced sensor technology, Pollusense uses laser-based PID, MPS, and electrochemical sensors to detect particulate matter, gases like NO2, CH4, and VOCs. This compact portable device is perfect for industries, environmental audits, or anyone needing flexible air quality monitoring on the go. With this Pollusense, you get accurate insights wherever you are, ensuring you always stay informed.
The Top 10 Most Polluted Cities in the World:
It’s said that the air we breathe is the essence of life. However, for residents of the following cities, the air they breathe daily might be far from pure. Air pollution has become a primary global concern in the last few decades, leading to numerous health and environmental challenges. Here’s a look at the world’s top 10 most polluted cities and the pressing need for change. Below, I will discuss the most polluted cities in the world in 2025.
World’s Most Polluted Cities in 2024-25
According to the 2024 World Air Quality Report by IQAir, 91.3% of countries and regions failed to meet the WHO’s safe air quality standards for PM2.5 pollution. Byrnihat, India, located on the Assam-Meghalaya border, has been named the most polluted city in the world, with an alarming PM2.5 concentration of 128.2 µg/m³. Meanwhile, Delhi remains the world’s most polluted capital for the sixth year in a row, recording an annual PM2.5 level of 108.3 µg/m³. The report also highlights that 13 of the 20 most polluted cities worldwide are in India, emphasizing the urgent need for air quality improvements.
| Rank | City | Country | PM2.5 in 2024 |
|---|---|---|---|
| 1 | Byrnihat | India | 128.2 |
| 2 | Delhi | India | 108.3 |
| 3 | Karaganda | Kazakhstan | 104.8 |
| 4 | Mullanpur Dhaka | India | 102.3 |
| 5 | Lahore | Pakistan | 102.1 |
| 6 | Faridabad | India | 101.2 |
| 7 | Dera Ismail Khan | Pakistan | 93 |
| 8 | N’Djamena | Chad | 91.8 |
| 9 | Loni | India | 91.7 |
| 10 | New Delhi | India | 91.6 |
1.Byrnihat, India
- Byrnihat, a town on the Assam-Meghalaya border, is facing serious air pollution issues. In 2024, its PM2.5 levels averaged 128.2 µg/m³, far beyond the safe limits recommended by the World Health Organization (WHO).
- Right now, the Air Quality Index (AQI) in Byrnihat is 248, which falls under the ‘Unhealthy’ category. This means breathing the air here is as harmful as smoking nearly three cigarettes a day.
- Byrnihat’s air pollution is worse than in West Bengal, highlighting the urgent need for action to improve air quality and protect public health.
2.Delhi, India
- Delhi has long struggled with air pollution and was ranked the world’s most polluted capital for the sixth year in a row in 2024, with an average PM2.5 concentration of 108.8 µg/m³.
- As of March 17, 2025, Delhi’s air quality has improved, with the AQI dropping to 85 (‘Satisfactory’ level). This improvement has led to the lifting of Stage I air pollution control measures in the National Capital Region (NCR).
- However, the current PM2.5 level is 41 µg/m³, still 2.67 times higher than WHO’s safe limit of 15 µg/m³. Breathing Delhi’s air under these conditions is as harmful as smoking nearly two cigarettes a day.
- While conditions have improved, continued efforts are needed to keep the air cleaner and safer for residents.
3.Karaganda, Kazakhstan
- Karaganda, a key city in central Kazakhstan, is struggling with high air pollution levels. In 2024, it was ranked the third most polluted city in the world, with an average PM2.5 concentration of 104.8 µg/m³.
- As of March 2025, the Air Quality Index (AQI) is 115, which falls under the ‘Poor’ category, meaning it can affect sensitive groups like children, the elderly, and people with respiratory conditions.
- Breathing this air is as harmful as smoking nearly two cigarettes a day.
- Karaganda’s pollution levels highlight the urgent need for better air quality control to protect public health and improve living conditions.
5.Mullanpur Dhaka, India
- Mullanpur, a town in Punjab, India, is facing severe air pollution. In 2024, it was ranked the fourth most polluted city in the world, with an average PM2.5 concentration of 102.3 µg/m³.
- As of March 17, 2025, the Air Quality Index (AQI) is 124, which falls under the ‘Unhealthy’ category. This means sensitive groups like children, the elderly, and people with respiratory conditions are at higher risk, and even healthy individuals may experience discomfort with long exposure.
- Breathing this air is as harmful as smoking about two cigarettes a day.
- These pollution levels highlight the urgent need for better air quality management to ensure a safer environment for Mullanpur’s residents.
5.Lahore, Pakistan
- Lahore, Pakistan’s second-largest city, is facing serious air pollution problems. In November 2024, the Air Quality Index (AQI) shot up to 1,200, four times the hazardous level, making it extremely dangerous to breathe.
- As of March 17, 2025, Lahore’s AQI is 102, which falls under the ‘Poor’ category. This means the air is unsafe for sensitive groups like children, the elderly, and people with respiratory issues.
- The current PM2.5 level is 39 µg/m³. The current PM2.5 level in Lahore is 2.6x Above the recommended WHO guideline of 15 µg/m³. Breathing this air is as harmful as smoking about 1.7 cigarettes a day.
- Lahore needs urgent action to control pollution and protect public health from the risks of long-term exposure.
6.Faridabad, India
- Faridabad, a major city in Haryana, India, is facing serious air pollution problems. In 2024, its PM2.5 level averaged 101.2 µg/m³, which is over 10 times higher than the WHO’s safe limit of 10 µg/m³.
- As of March 17, 2025, the Air Quality Index (AQI) is 107, which falls under the ‘Poor’ category. This means that while the air is generally acceptable, sensitive groups like children, the elderly, and those with respiratory issues may experience health effects.
- The current PM2.5 level is 37 µg/m³, which is 2.47 times above the WHO’s safe limit. Breathing this air is as harmful as smoking about 1.9 cigarettes a day.
- Faridabad’s pollution levels highlight the urgent need for better air quality measures to protect public health and improve living conditions.
7.Dera Ismail Khan, Pakistan
- Dera Ismail Khan, a city in Khyber Pakhtunkhwa, Pakistan, is struggling with high air pollution levels. In 2024, it was ranked among the top 10 most polluted cities in the world, with an average PM2.5 level of 93 µg/m³.
- As of March 17, 2025, the Air Quality Index (AQI) is 96, which falls under the ‘Poor’ category. This means the air is mostly acceptable, but sensitive groups like children, the elderly, and people with respiratory issues may experience health effects.
- The current PM2.5 level is 28 µg/m³, which is 2.5 times higher than the WHO’s safe limit of 15 µg/m³. Breathing this air is as harmful as smoking about 1.4 cigarettes a day.
- Dera Ismail Khan needs urgent air quality improvements to ensure cleaner, healthier air for its residents.
8.N’Djamena, Chad
- N’Djamena, the capital of Chad, has been facing serious air pollution issues. In 2024, it was ranked among the most polluted capital cities, with an average PM2.5 level of 92 µg/m³, far above the WHO’s safe limit 24-hour mean concentration limit (daily exposure) of 15 µg/m³.
- As of March 17, 2025, the Air Quality Index (AQI) is 49, which falls under the ‘Good’ category. This means that the air is generally safe to breathe with minimal health risks for most people.
- The current PM2.5 level is 10 µg/m³, which is 0.5 times higher than the WHO’s recommended limit. While this is an improvement, ongoing
9.Loni, India
- Loni, a town in Ghaziabad, Uttar Pradesh, is currently experiencing high air pollution. As of March 17, 2025, the Air Quality Index (AQI) is 161, which falls under the ‘Unhealthy’ category. This means breathing the air may cause health problems, especially for people with asthma or other breathing issues.
- The main pollutant is PM2.5, with a level of 91.7 µg/m³, which is much higher than the WHO’s safe limit of 15 µg/m³. Breathing this air is like smoking about four cigarettes a day.
- To stay safe, people should limit outdoor activities, especially children, older adults, and those with breathing issues. Using masks and air purifiers can help reduce exposure to pollution.Â
10.New-Delhi, India
- As of March 17, 2025, New Delhi’s Air Quality Index (AQI) is 85, which falls under the ‘Satisfactory’ category. This means the air is mostly safe to breathe, but some sensitive people may feel slight discomfort.
- Due to this improvement, the Commission for Air Quality Management (CAQM) has lifted Stage 1 pollution control measures across the National Capital Region (NCR).
- However, PM2.5 levels are still at 40 µg/m³, which is 2.4 times higher than the WHO’s safe limit of 15 µg/m³. Breathing this air is like smoking about 1.9 cigarettes a day.
- While conditions have improved, residents should still be cautious, especially those with asthma or other breathing issues. Continuous efforts are needed to keep the air clean and improve Delhi’s air quality further.
Hey there! The data we’re analyzing was gathered in real-time on March 17th, 2025, through the AQI Bulletin of CPCB and real-time IQAir. Additionally, the refernce is also taken from IQAir Report. It’s a snapshot of that specific day, which means the numbers can fluctuate daily. So, while this gives us a solid glimpse into the situation on that particular day, remember that tomorrow’s data might tell a slightly different story. Real-time data can be quite dynamic.Â
The cities mentioned above are among the most polluted in the world. Additionally, I will include information about the top 5 polluted countries globally.Â
- Bangladesh
- Pakistan
- India
- Bahrain
- Nepal
Conclusion:
In conclusion, while these cities top the charts for their alarming pollution levels, it’s essential to note that air pollution is a global problem. Moreover, air quality and climate change are interrelated issues requiring collaborative solutions. Improving air quality can help with climate change mitigation efforts, and addressing climate change can also help with air quality. The human health risks due to rising air pollution further highlight the urgency of this crisis, emphasizing the need for immediate action.
This list serves as a wake-up call for governments, industries, and communities to prioritise sustainable practices, invest in cleaner technologies, and raise awareness about health. However, if we practise or adopt sustainability towards a cleaner future, we will achieve SDG -3, 11, 13, 15 for the urban environment.
To wrap things up, this blog dives into the top 10 least polluted cities in India. I hope you find these insights helpful and interesting!
FAQs
The top 5 polluted countries in the world areÂ
- Bangladesh
- Pakistan
- India
- Bahrain
- Nepal
The most polluted country in the world is Bangladesh.
The second-most polluted city in the world is Delhi, India. With a PM2.5 109µg/m³, which is considered severely polluted.
