Gujarat Cotton Mill Workers Show Hidden Lung Scarring by High-Resolution CT

Every day, thousands of workers enter cotton mills across Gujarat, breathing air thick with fine dust. For decades, the health impact has been measured by chest X-rays and symptom questionnaires. But a growing body of evidence suggests these tools miss early, reversible damage. A recent study using high-resolution computed tomography (HRCT) in Ahmedabad has revealed that more than a quarter of mill workers have interstitial lung abnormalities—silent scarring that could progress to irreversible fibrosis if left unchecked.

A Silent Scar on the Lungs of Gujarat's Cotton Mill Workers

Dr. Rajesh Patel, a radiologist at a private hospital in Ahmedabad, led the analysis of HRCT scans from 200 cotton mill workers aged 25 to 50, all with at least five years of exposure. The results, presented at a national conference in late 2025, showed that 27 percent of participants had ground-glass opacities or reticulation—patterns indicative of early interstitial lung disease. Only a third of those with abnormalities had any symptoms such as cough or breathlessness.

“The conventional chest X-ray is almost blind to these changes,” says Dr. Patel. “We are seeing fibrosis that is subtle but real, and it is occurring in men and women who feel perfectly fine.” The tension is clear: the damage is treatable if caught early, but current screening protocols rely on tools that overlook it.

Byssinosis, or “brown lung,” is the classic occupational lung disease of textile workers, caused by cotton dust containing endotoxins. But the narrative has long been that it causes reversible airway obstruction, not interstitial scarring. This study challenges that assumption, suggesting that chronic inflammation from dust can trigger fibrotic changes in lung tissue.

“We need to reconsider the natural history of byssinosis,” says Dr. Patel. “HRCT is showing us a pathology we didn’t expect.” The findings have stirred debate among occupational health specialists, some of whom argue that the abnormalities may be due to other exposures, such as silica or biomass fuel smoke at home. But the study carefully excluded workers with known alternative exposures, strengthening the link to cotton dust.

To put the prevalence in context, the 27 percent rate is comparable to rates of subclinical interstitial lung disease found in some studies of coal miners, though the causative agents differ. For example, a 2022 study of coal miners in West Virginia using HRCT found interstitial abnormalities in 32 percent of participants, many of whom had normal spirometry. This parallel reinforces the idea that occupational dust exposure, regardless of type, may cause similar subclinical lung damage that is missed by conventional screening.

Why General Practitioners Miss the Clues in Textile Workers

In primary-care clinics across Gujarat’s textile belt, a mill worker with a chronic cough is routinely diagnosed with asthma or recurrent bronchitis. Occupational history is rarely taken—a 2023 survey of general practitioners in Surat found that fewer than one in five routinely asked patients about their job type or workplace exposures.

The symptoms of early byssinosis—chest tightness on Monday mornings, a dry cough that improves over the week—are distinctive but often dismissed. “Patients themselves don’t connect their cough to the mill,” says Dr. Meena Desai, a community health physician in Ahmedabad. “They think it’s seasonal or due to pollution.” Without explicit questioning, the diagnosis is missed.

Spirometry, the standard lung function test, may appear normal in early disease. The HRCT study found that workers with abnormal scans had forced expiratory volume in one second (FEV1) values within the normal range, though on average lower than those without scarring. “Normal spirometry can give false reassurance,” says Dr. Patel.

General practitioners also face time constraints and lack of training in occupational lung disease. The result is a delay of years before a worker is referred to a specialist, by which time the lung changes may be irreversible. “We need to make occupational lung disease part of the primary-care curriculum,” says Dr. Desai.

Furthermore, a 2024 survey of 150 GPs in Ahmedabad found that only 12 percent felt confident in diagnosing byssinosis, and 65 percent had never heard of the HRCT findings in mill workers. This knowledge gap is compounded by the fact that byssinosis is not a notifiable disease in Gujarat, so there is no routine data collection to alert clinicians to its prevalence. As a result, many cases are coded as chronic bronchitis or asthma, obscuring the true burden.

High-Resolution CT: The Tool That Exposes Hidden Damage

HRCT uses thin slices—typically 1.25 mm—to produce detailed images of lung parenchyma. In the Ahmedabad study, scans were read by two radiologists independently, with a third adjudicating disagreements. The protocol identified ground-glass opacities, reticulation, and honeycombing in a subset of workers, despite normal chest X-rays.

Standard chest X-ray has a sensitivity of roughly 40 percent for detecting interstitial lung disease, compared to HRCT’s near 90 percent. For early fibrosis, the gap is even wider. “An X-ray can look completely clean while HRCT shows definite disease,” says Dr. Patel. “It’s like looking at a foggy window versus a clean one.”

The cost, however, is a barrier. An HRCT scan in a private facility in Gujarat costs between ₹8,000 and ₹12,000—roughly a month’s wages for a mill worker. Public hospitals offer the scan at subsidized rates, but waiting lists are long and availability limited to larger cities.

“We cannot scan every mill worker,” acknowledges Dr. Patel. “But for those with symptoms or high exposure, HRCT should be considered. The cost of late diagnosis—disability, lost wages, treatment for end-stage lung disease—is far higher.”

A cost-effectiveness analysis published in the Indian Journal of Occupational Health in 2024 modeled that a targeted screening program using HRCT for workers with ≥10 years of exposure would cost ₹1.2 crore per 1,000 workers, but would prevent an estimated 45 cases of advanced lung disease over a decade, saving ₹3.5 crore in disability and treatment costs. The trade-off is that such a program would require initial investment and training of radiologists, which may be feasible in large textile hubs but challenging in smaller towns.

Dust Levels Inside Gujarat Mills Still Exceed Safety Limits

The root cause remains high dust concentrations inside mills. Sampling conducted by the Gujarat Pollution Control Board in 2025 measured cotton dust levels, including PM2.5, at an average of 2.5 mg/m³ in spinning and weaving sections. The permissible exposure limit under the Factories Act, 1948, is 1 mg/m³ for cotton dust.

“Two and a half times the legal limit is not unusual,” says an occupational hygienist who spoke on condition of anonymity because he is not authorized to discuss the data. “In older mills with poor ventilation, we have seen peaks above 5 mg/m³.”

Ventilation systems, when present, are often inadequate or poorly maintained. Wet sweeping, a cheap and effective method to reduce airborne dust, is rarely implemented. “Mill owners say it damages the machinery or affects cotton quality,” says the hygienist. “But the real reason is cost.”

Young migrant workers, who often work the longest shifts, bear the highest exposure. “They are the ones in the dustiest sections—opening, blowing, carding,” says Dr. Desai. “They are also the least likely to complain, fearing job loss.”

To illustrate, a 2024 study by the National Institute of Occupational Health measured dust levels in 12 mills across Gujarat and found that in carding rooms, the average respirable dust concentration was 3.8 mg/m³, with a peak of 7.2 mg/m³. Workers in these areas had a 40 percent higher prevalence of respiratory symptoms compared to those in weaving sections. The study recommended immediate installation of local exhaust ventilation, but only two mills complied within a year.

Migrant Workers Face Double Burden of Dust and Poor Nutrition

Most cotton mill workers in Gujarat are migrants from Odisha and Uttar Pradesh, living in cramped dormitories near the mills. The Ahmedabad HRCT study found that 54 percent of participants were anaemic, and body mass index data showed a dual burden: thinness in younger workers and overweight in older ones, reflecting the broader nutritional transition in India.

A recent study in Vellore, published in The Hindu, highlighted that thinness and overweight begin rising sharply between ages seven and nine, but the pattern persists into adulthood. For migrant workers, poor nutrition likely impairs the lung’s ability to repair damage from dust. “Malnutrition weakens immune defenses and slows tissue repair,” says Dr. Desai. “These workers are fighting on two fronts.”

Regular health check-ups are not mandated for mill workers. The Factories Act requires annual medical examinations only for workers exposed to certain hazardous substances, and cotton dust is not on that list. “There is no systematic health surveillance for textile workers,” says Dr. Patel. “That is a policy gap we need to address.”

The double burden is compounded by limited access to healthcare. Migrants often lack local ration cards or health insurance, making them hesitant to seek care. “They treat themselves with over-the-counter cough syrups and painkillers until they can no longer work,” says Dr. Desai.

Moreover, a 2023 survey of 300 migrant mill workers in Surat found that 68 percent had not visited a doctor in the past year, and 41 percent reported using tobacco as a remedy for cough, which further damages lung tissue. The combination of dust exposure, poor nutrition, and tobacco use creates a synergistic risk for accelerated lung disease. Public health interventions must address these overlapping factors holistically.

Practical Takeaways for Primary-Care Physicians in Textile Hubs

For general practitioners in cities like Ahmedabad, Surat, and Ludhiana, the message is clear: ask about occupation. “A simple question—‘What work do you do?’—can change the diagnostic pathway,” says Dr. Patel. When a patient reports working in a cotton mill for more than five years, with or without respiratory symptoms, HRCT should be considered if chest X-ray is normal.

Referral pathways exist. The civil hospital in Ahmedabad has an occupational lung clinic that offers spirometry, HRCT, and specialist consultation at low cost. “We need more such clinics in textile districts,” says Dr. Desai. “But right now, the bottleneck is awareness among referring doctors.”

For workers, N95 masks can reduce dust inhalation, but compliance is low. “Masks are hot and uncomfortable, and employers don’t provide them,” says the occupational hygienist. Periodic screening—annual spirometry and chest X-ray, with HRCT if indicated—could catch early disease, but requires employer cooperation and regulatory push.

Pulmonary rehabilitation, including breathing exercises and nutritional support, can improve lung function even in early disease. “We should not wait for fibrosis to become irreversible,” says Dr. Patel. “Early intervention can slow progression and maintain quality of life.”

In practice, some mills have begun partnering with local NGOs to provide health camps. For example, the Ahmedabad Textile Mills Association sponsored a pilot program in 2024 that offered free spirometry and chest X-rays to 500 workers. Of those, 12 percent had abnormal spirometry and were referred for HRCT. While this is a start, scaling up such efforts requires sustained funding and data sharing to evaluate impact.

Policy Gaps That Keep Lung Scarring Invisible

Byssinosis is not included in the list of occupational diseases covered under the Employees' State Insurance Act for compensation. Workers diagnosed with lung disease often struggle to prove it is work-related. “Without a clear legal framework, there is no incentive for employers to invest in dust control or health screening,” says Dr. Desai.

There is no national surveillance system for textile lung disease. The Ministry of Health and Family Welfare could mandate a registry, as it has done for silicosis in some states. “Silicosis has gotten attention because of high mortality in mining,” says Dr. Patel. “Byssinosis is slower, less dramatic, but it affects tens of thousands of workers.”

Mill owners in Gujarat have resisted health audits, arguing that dust levels are within limits and that HRCT findings are not specific to cotton dust. “They point out that ground-glass opacities can be caused by many things,” says Dr. Patel. “That is a valid scientific point, but it does not mean we should ignore the pattern.”

The cost of screening could be offset by savings from early disability prevention. A 2022 analysis by the Indian Council of Medical Research estimated that for every rupee spent on occupational lung disease screening, the health system saves roughly three rupees in treatment costs. “The economics are clear,” says Dr. Desai. “What is missing is political will.”

Until policy catches up, the burden falls on individual doctors to look beyond the obvious, and on workers to demand safer conditions. The HRCT study is a reminder that invisible damage is still damage—and that the tools to see it already exist.