Despite marginal gains in air quality, city still breathes toxic air: Report

Mumbai's air quality has slightly improved but remains unhealthy, with PM2.5 levels seven times higher than WHO standards, raising pollution concerns.

Mumbai: The city’s air may have shown slight improvement in recent years, but it remains far from breathable, according to a new assessment of air quality across Maharashtra.

Despite marginal gains in air quality, city still breathes toxic air: Report

The report, “Nayi Disha: Status of Ambient Air Quality across Maharashtra Cities,” released on Tuesday by the Waatavaran Foundation and Envirocatalyst, found that Mumbai recorded an annual average PM2.5 level of 35 micrograms per cubic meter (µg/m³) in 2024–25, within India’s national limit, but seven times higher than the World Health Organization’s (WHO) safe standard of 5 micrograms per cubic meter.

PM2.5 levels are fine particulate matter in the air, which is harmful to health because it can be inhaled deep into the lungs and enter the bloodstream.

PM10 levels stood at 91 micrograms per cubic meter, showing a modest 12% decline since 2019–20, yet pollution continued to spike sharply during winter months, frequently breaching unhealthy limits.

PM10 level refers to the concentration of particulate matter in the air that has a diameter of 10 micrometers or smaller.

Despite being among the best-funded cities under the National Clean Air Programme (NCAP), Mumbai has utilised only ₹574.64 crore of the ₹938.59 crore allocated since 2019, just 61%, raising concerns over the city’s slow and uneven implementation of clean-air measures.

Seasonal swings and slow action

Data from the Central Pollution Control Board’s monitoring stations show that Mumbai’s air quality fluctuates drastically across seasons, with PM2.5 levels often rising to 80–100 µg/m³ in winter compared to under 30 µg/m³ during the monsoon.

“Mumbai has seen very systematic and well-coordinated development in the last decade, but clean air has not been treated with the same urgency,” said Bhagwan Kesbhat, founder of Waatavaran Foundation.

“We cannot ignore the warning signs, if we continue on this path, Mumbai can be the next Delhi. Collective action is the only way forward. We have ample funds; we just need to use them smartly and locally.”

Construction, congestion and dust still choke the city

While PM10 levels have improved marginally, from 103 µg/m³ in 2019–20 to 91 µg/m³ in 2024–25, the report notes that gains have been offset by rising vehicular congestion, road dust, and delays in dust-mitigation projects.

Coastal winds offer natural ventilation, but Mumbai still endures five to six months of unhealthy air annually, particularly from October to February, when pollution levels rise two to three times above national standards.

“PM10 levels remain high because of rampant construction activity across Mumbai and the larger MMR region,” said Sunil Dahiya, founder of Envirocatalyst.

“The high PM10-to-PM2.5 ratio shows how the construction sector continues to be one of the main polluters. PM2.5, on the other hand, comes largely from fossil fuels and inefficient combustion in vehicles, industries, and power plants.”

Dahiya warned that these fine particles penetrate deep into the lungs and bloodstream, worsening respiratory and cardiac diseases.

“Dust control measures have helped only marginally. The city must go beyond short-term fixes and regulate construction, curb transport and industrial emissions, and invest efficiently in clean public transport,” he added.

Statewide picture: All 31 cities fail WHO norms

The study found that all 31 cities monitored in Maharashtra exceeded WHO’s safe limits for PM2.5, and 17 cities even breached the national limit of 40 µg/m³.

Malegaon (51 µg/m³) emerged as the most polluted, followed by Jalna (50 µg/m³) and Jalgaon (48 µg/m³).

Cleaner cities such as Sangli (28 µg/m³), Amravati (35 µg/m³) and Kolhapur (39 µg/m³) still failed to meet global standards.

Interestingly, smaller cities such as Amravati, Akola, and Solapur utilised over 95% of their NCAP funds, while Mumbai, Nagpur, and Nashik lagged behind despite larger allocations.

“A major reason behind the underutilised funds is the absence of elected representatives in several civic bodies, a key requirement for accessing NCAP funds,” Dahiya said.

“The money should have been used more strategically across multiple sectors, not just transport, to tackle pollution from construction, industries, and power generation.”