Surat Air Quality
Surat, Gujarat, India · 7.8M population · Diamond & Textile Capital
Moderate
2024 avg
94
Annual AQI
2024 average
35 μg/m³
PM2.5
7× WHO annual limit
155
Winter Peak AQI
Dec–Jan average
Aug
Best Month
AQI 45 monsoon
Monthly AQI Pattern
Strong monsoon cleanout (Jul–Aug AQI 45–48) vs. winter inversion haze (Dec–Jan AQI 142–155)
Surat's Industrial Air Quality Profile
Textile Industry: 40% of India's Synthetics
Surat produces more synthetic fabric than anywhere else in India — over 25 million meters of polyester, nylon, and viscose fabric per day. Textile dyeing units historically used coal-fired boilers for process heat, releasing SO2, NOx, and particulate matter. GPCB has mandated cleaner fuel shifts, and many larger mills now use natural gas. However, thousands of smaller dyeing units in Katargam and Udhna continue to use cheaper fuels, contributing to Surat's industrial air load.
Hazira: Steel, Petrochemicals & Power
The Hazira industrial corridor hosts ArcelorMittal Nippon Steel (India's second-largest integrated steel plant), Shell's petrochemical complex, ONGC Hazira (LNG terminal and gas cracker), and several power plants. Steel production releases NOx, SO2, and particulate matter. Under favorable wind conditions, Hazira emissions contribute significantly to Surat city's pollution load — particularly during winter northerly winds that stagnate over the city.
Diamond Industry: Occupational Risk
Surat is the world's diamond cutting capital — 90% of globally polished diamonds pass through here. An estimated 500,000 artisans work in diamond polishing ghantis (workshops), many in poorly ventilated homes and small units. The primary health risk is occupational — workers inhale diamond and corundum (abrasive) dust. While not a major contributor to Surat's overall ambient AQI, the industry represents a significant indoor air quality and occupational health challenge.
Vehicles & Rapid Urbanization
Surat is one of India's fastest-growing cities — population grew from 2.4M in 2001 to over 7.8M today. This growth brought millions of vehicles onto roads that were not designed for this volume. The BRTS (Bus Rapid Transit) corridor operates in Surat, but most residents rely on two-wheelers and personal vehicles. Surat Municipal Corporation has been relatively proactive on electric vehicles and road improvement, which has modestly helped vehicle emission trends.
Gujarat City AQI Comparison
| City | Annual AQI | PM2.5 μg/m³ | Key Source |
|---|---|---|---|
| Surat | 94 | 35 | Textiles, Hazira industry |
| Ahmedabad | 130 | 42 | Vehicles, industry |
| Vadodara | 90 | 28 | Petrochemicals, vehicles |
| Rajkot | 85 | 26 | Engineering industry |
| Ankleshwar | 175 | 58 | Chemical industrial zone |
Health Guide for Surat Residents
Winter (Nov–Feb, AQI 120–155)
- Avoid outdoor exercise in morning hours when inversion is strongest
- Wear N95 mask for outdoor commuting
- Run HEPA air purifier at home with windows closed
- Children and elderly: limit outdoor time above AQI 150
- Check CPCB Sameer app for daily AQI before going out
Monsoon & Best Season (Jun–Sep)
- June–September offers Surat's best air quality (AQI 45–62)
- Outdoor exercise and activities are safest in these months
- Early morning exercise is particularly good in monsoon season
- Post-monsoon (October) sees AQI rise quickly — plan accordingly
Frequently Asked Questions
Why is Surat's air quality poor in winter?
Surat's winter air quality deterioration is caused by multiple converging factors: (1) Temperature inversions that trap pollutants close to ground level from November through February; (2) Increased emissions from the Hazira petrochemical and steel complex on the Arabian Sea coast; (3) Reduced wind speeds that limit dispersal; (4) Industrial activity in the textile dyeing and printing sector that peaks in cooler months. Winter AQI in Surat regularly exceeds 150 (Unhealthy for Sensitive Groups).
How does Surat's textile industry affect air quality?
Surat is India's largest textile hub, handling 40% of India's synthetic fiber production. Textile dyeing and processing mills release VOCs (volatile organic compounds), sulfur compounds, and fine particulate matter. Dyeing units historically burned coal and petroleum coke for process heat. GPCB (Gujarat Pollution Control Board) has pushed for cleaner fuels, and many larger mills have shifted to natural gas, but smaller units still burn cheaper fuels. The Textile Industry accounts for an estimated 20-25% of Surat's industrial PM2.5 load.
Is diamond polishing a source of air pollution in Surat?
Surat processes over 90% of the world's cut and polished diamonds, with an estimated 500,000+ artisans working in thousands of diamond polishing units (ghantis). The polishing process generates fine diamond dust and abrasive particles. While diamond dust poses occupational health risks to workers in poorly ventilated workshops, it is not a major contributor to city-wide ambient AQI. The dominant sources remain industrial combustion, vehicle emissions, and Hazira industrial zone emissions.
What is the Hazira industrial zone's impact on Surat?
The Hazira industrial estate, 28km southwest of Surat city center on the Arabian Sea coast, hosts Essar Steel (now ArcelorMittal Nippon), ONGC's Hazira plant, Shell's petrochemical complex, and multiple power plants. Together, these facilities emit NOx, SO2, and PM2.5. Southwesterly winds in summer and winter flow patterns can carry Hazira emissions into Surat's urban airshed. GPCB runs continuous emissions monitoring at Hazira, and pollution levels have declined as units installed flue gas desulfurization systems.
How does Surat compare to other Gujarat cities for air quality?
Among Gujarat's major cities, Ahmedabad (annual AQI ~130) is slightly better than Surat (~95 annual), while Vadodara (~90) and Rajkot (~85) have cleaner air due to less industrial concentration. Ankleshwar, a major chemical industrial zone south of Surat, has among Gujarat's worst air quality. Coastal Surat gets some benefit from Arabian Sea breezes, particularly in summer months, which is why its monsoon season sees AQI drop to 45–62.