Domestic, hospital, and occupational cleaning as an occupation employs a large workforce worldwide [1]. Cleaning workers are under constant exposure to various chemical agents which are detrimental to respiratory health in both acute and long-term scenarios. The various places where cleaning tasks are performed include homes, schools, offices, shops, hotels, hospitals, pharmacies, industries, cafes, restaurants, and kitchens [1]. Studies have found that among domestic cleaners, excess asthma and respiratory symptoms have been documented [2]. Research has also demonstrated that women compared to men displayed accelerated decline in spirometric parameters in both domestic and occupational settings [3]. Cleaning is recognized as one of the high-risk occupations causing various diseases among workers [4]. Cleaning products are used universally and are proven to have deleterious health effects including chronic obstructive pulmonary disease (COPD) and asthma. Exposure may occur either through direct use or even by indirect inhalation from their usage by others [5]. It has been stated that cleaning products in domestic settings can increase the severity of symptoms in pre-existing asthmatics and also increase the risk of new-onset asthma [5]. Respiratory disorders are prevalent among cleaners, being the most common occupational diseases [7]. Over the past decade, there has been increasingly consistent evidence pointing to an epidemic of 'asthma-like' respiratory symptoms among cleaners worldwide [9]. The issue of health effects holds significant importance for clinical and public health, especially due to the substantial and growing number of professional cleaners, many of whom belong to vulnerable groups such as women, immigrants, and individuals of low socioeconomic status [10]. Health issues related to cleaning have primarily been reported among female professional cleaners, without specific age or ethnic patterns noted. Factors such as atopy and smoking habits do not appear to be associated with an increased risk [10]. Chemical Exposure and Mechanisms A diverse array of cleaning products containing various chemical agents is used in both workplace and domestic settings. Chemical agents frequently found in cleaning products include alkalis like bleach and ammonia, acids such as acetic acid, and aldehydes like glutaraldehyde and formaldehyde [5]. Cleaners are frequently exposed to a range of agents including ethanolamines, chloramine-T, aldehydes, and quaternary ammonium compounds (QACs), which may contribute to both new-onset asthma through sensitization or irritation, and exacerbation of pre-existing asthma [10]. The generation and inhalation of cleaning-related gases and particles occur during the use of cleaning products. These can enter the air either as volatile compounds or as an aerosol containing both volatile and non-volatile compounds [10]. Even under typical usage conditions, products containing hypochlorite and ammonia can generate airborne concentrations of chlorine and ammonia that surpass recommended short-term occupational exposure limits [10,33]. Mechanisms of Adverse Respiratory Effects Sensitizer-Induced (Allergic) Rhinitis and Asthma: Certain cleaning agents can trigger immunological sensitization leading to allergic rhinitis or asthma. Positive bronchial and nasal provocation tests have been documented for substances such as chloramine-T, quaternary ammonium salts, triclosan, amines, glutaraldehyde, ortho-phthalaldehyde, fragrances, and enzymes [10,34]. Irritant-Induced Respiratory Disorders: Irritant substances provoke irritation through direct action on neurons or other cells. They can cause conjunctivitis, rhinitis, sinusitis, pharyngitis, vocal cord dysfunction, asthma, bronchitis, COPD, and in rare cases, pneumonitis [10]. Sensory Irritation: Through stimulation of afferent trigeminal or vagal nerves that supply the airway and ocular mucosa, activation can lead to eye irritation and trigger defensive reflex responses such as coughing, sneezing, increased mucus production, and bronchoconstriction [10,35]. Tissue Irritation: Direct damage to the airway epithelium by irritants leads to neurogenic inflammation. Acute high-level exposure to irritants can result in reactive airways dysfunction syndrome [10]. Most cleaning agents can irritate the mucous membranes of the airways. One potential reason for the accelerated decline in lung function among cleaners is the repeated exposure to these mild irritants over time, which can result in persistent alterations to the airways [6]. However, the underlying mechanistic pathways are not well understood, and there is ongoing debate regarding whether prolonged exposure to irritant agents in cleaning products could initiate and perpetuate chronic airway inflammation, leading to persistent fixed airway obstruction [9]. Identifying and quantifying the portion of the workforce vulnerable to these risks, and monitoring any changes in risk levels over time, is crucial for informing effective prevention and control measures [5]. The long-term impacts of cleaning agents on respiratory health are not well-documented, indicating a need for further research [6]. There are very few studies in India looking into all the respiratory ill effects of cleaning occupation which has a large number of workers, but is easily overlooked regarding their respiratory health. Therefore, this study undertakes a comprehensive evaluation of respiratory effects of cleaning in domestic and hospital setting cleaners.

Study Design and Setting A hospital-based cross-sectional observational study was conducted among cleaners working at Prathima Institute of Medical Sciences and domestic settings in Karimnagar district of Telangana state. A total of 102 subjects were enrolled in the study from January 1, 2022, to May 30, 2024. These subjects attended the Respiratory Medicine Department Outpatient Department (OPD) at Prathima Institute of Medical Sciences, a tertiary care institute in Karimnagar. Inclusion Criteria 1. Domestic and hospital setting cleaners working for more than one year 2. Cleaners aged 18 years and above 3. Cleaners willing to participate in the study Exclusion Criteria 1. Cleaners with active respiratory infections at the time of the study 2. Cleaners with contraindications to perform spirometry Ethical Considerations Informed consent in the subject's own language was obtained, and strict confidentiality was maintained regarding the subject's results. Institutional Ethics Committee clearance from Prathima Institute of Medical Sciences, Karimnagar, was obtained as per guidelines. Permission from respective housekeeping personnel in-charges was obtained prior to the study. Data Collection A comprehensive questionnaire was administered to collect data on: 1. Demographic information: Age, sex, marital status, residence, education level 2. Occupational history: Workplace setting, duration of service, hours of work per day, days of work per week, exposure to dust and chemicals 3. Respiratory symptoms: Cough, breathlessness, wheeze, chest tightness, sputum production, nasal allergy, burning eyes 4. Medical history: Past respiratory illnesses, comorbidities, current medications 5. Personal habits: Smoking history (type, duration, smoking index), passive smoking, tobacco chewing, alcohol consumption 6. Cleaning activities and products used: Types of cleaning activities performed and cleaning products used Clinical Examination All subjects were examined for height and weight. Vital signs including pulse rate, respiratory rate, blood pressure (systolic and diastolic), and oxygen saturation (SpO₂) at room air were recorded. A thorough upper and lower respiratory tract examination was performed, including auscultation for any abnormal breath sounds. Spirometry Pulmonary function testing was performed using an NDD EASY ONE CONNECT PC-based spirometer. The procedure was done according to standard guidelines before and after levosalbutamol inhalation. Data recorded included pre- and post-bronchodilator Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV₁), post-bronchodilator response (PBDR), FEV₁/FVC ratio, Peak Expiratory Flow (PEF), and Forced Expiratory Flow (FEF 25-75%), interpreted according to ATS guidelines [24]. Spirometric patterns were categorized as: - Normal: FEV₁/FVC ratio >70% and FVC >80% predicted - Obstructive: FEV₁/FVC ratio <70% and FVC >80% predicted - Restrictive: FEV₁/FVC ratio >70% with FVC <80% predicted - Mixed: FEV₁/FVC ratio <70% and FVC <80% predicted [36] Based on FEV₁, obstructive disease was further categorized as: - Mild: ≥80% - Moderate: 50-80% - Severe: 30-50% - Very severe: <30% [25] Similarly, based on FVC values, subjects with restrictive lung disease were classified according to ATS 2022 guidelines [24]. The same criteria were used to categorize Small Airway Disease (SAD), where FEF 25-75% was taken as an indicator. Six-Minute Walk Test (6MWT) The six-minute walk test adhered to ATS guidelines [26] and was supervised by a trained respiratory technician. Prior to the test, vital signs including oxygen saturation, pulse rate, blood pressure, height, and weight were recorded. Participants were instructed to walk at their own pace along a straight, 30-meter hospital hallway marked at four-meter intervals, aiming to cover as much distance as possible in six minutes. Predicted distance was calculated using the formulas: - Males: 561.022 - (2.507 × age in years) + (1.505 × weight in kg) - (0.055 × height in cm) - Females: -30.425 - (0.809 × age in years) - (2.074 × age in years) + (4.235 × height in cm) [27] Percentage of predicted value was calculated and subjects were categorized as: - Normal: >80% - Mild impairment: 60-79% - Moderate impairment: 40-59% - Severe impairment: <40% [27] Statistical Analysis Data were coded and entered into Microsoft Excel spreadsheet. Statistical analysis was conducted using Statistical Package for the Social Sciences (SPSS) version 25 for MS Windows. Descriptive statistical analysis was employed to examine the distribution of various categorical and quantitative variables. Categorical data were expressed as n (%) and quantitative variables as mean ± standard deviation. Categorical data were analyzed using Pearson's chi-square test, and differences between two groups were assessed using Student's t-test. A p-value of <0.05 was considered statistically significant.

Demographic Characteristics A total of 102 cleaners were included in the study. The majority were females, comprising 61.8% (n=63), while males comprised 38.2% (n=39). The mean age was 44.64±11.13 years. Of the total cleaners, the majority worked in hospital settings (55.3%), while 36.9% worked in domestic settings and 7.8% worked in other occupations like hotels, schools, pharmacies, and canteens. Regarding age distribution, the majority of subjects were between 50-59 years (30.4%, n=31), followed by 40-49 years (28.4%, n=29), 30-39 years (21.6%, n=22), and less than 30 years (15.7%, n=16). Among the subjects, the majority (55.9%, n=57) were classified as illiterate, while primary education and secondary education were completed by 21.6% (n=22) each, and 1% completed 12th grade. A significant majority (77.2%) lived in rural areas, while 22.8% resided in urban locations (Table 1). Work-Related Characteristics Based on duration of work, subjects were categorized as: less than 5 years (15.7%), 5-9 years (34.3%), 10-15 years (32.4%), 16-20 years (8.8%), and more than 20 years (8.8%). The majority of workers (66.7%) had work duration between 5-15 years. Based on hours of work per day, subjects were divided into: less than 5 hours (2.9%), 5-9 hours (26.5%), and 10-15 hours (70.6%). In the present study, 95% of subjects worked for more than 5 hours per day. Female individuals were predominant across all categories of work duration. In subjects with less than 5 years of work, males comprised 43.8% and females 56.3%. In the 5-9 years category, males comprised 28.6% and females 71.4%. In the 10-15 years category, males comprised 48.5% and females 51.5%. Table 1: Demographic Characteristics of the Study Subjects Variable Values Total number of subjects 102 Age (Mean ± SD) in years 44.64 ± 11.13 Education Illiterate 55.9% Primary 21.6% Secondary 21.6% 12th 1% Residence Urban 22.8% Rural 77.2% Workplace Hospital 57 (55.3%) Domestic 38 (36.9%) Others 8 (7.8%) Duration of Work <5 years 15.7% 5-9 years 34.3% 10-15 years 32.4% 16-20 years 8.8% >20 years 8.8% Smoking History Yes 13.7% No 86.3% Prior dust exposure at workplace was reported by 30 (29.4%) subjects. During their present work, exposure to dust was complained of by 97 (95.1%) subjects. Household dust exposure from biomass fuel burning was reported by 44 (30.8%) subjects. Disability during work was seen in 74.5% (n=76) subjects, with dyspnea being the most reported symptom (36.2%). Respiratory and Other Symptoms Among the 102 subjects, 46.2% were asymptomatic. The most common symptoms reported were: - Nasal allergic symptoms: 18.6% (n=19) - Cough: 14.9% (n=15) - Breathlessness: 10.8% (n=11) - Wheeze: 9.9% (n=10) - Burning eyes: 9.9% (n=10) - Chest tightness: 8.8% (n=9) - Sputum: 8.8% (n=9) - Skin allergy: 7.8% (n=8) Among those with cough, the duration was less than one week in 35.7%, one to two weeks in 35.7%, two to four weeks in 7.1%, and more than four weeks in 21.4%. Chronic bronchitis was seen in 2.9% (n=3) subjects. Nocturnal attacks were seen in 10 subjects (9.8%), and seasonal attacks were reported by 21 (20.6%) subjects. Smoking and Other Habits Among the subjects, 13.7% (n=14) were smokers. All smokers were males. Regarding smoking index: 7.7% had <50, 30.8% had 50-100, 15.4% had 100-150, 15.4% had 150-200, and 30.8% had >200. Passive smoking was seen in 11.8% (n=12) subjects. Tobacco chewing was seen in 23.5% (n=24) subjects, and alcohol consumption was seen in 24.5% (n=25) subjects. When smoking was correlated to spirometry findings, among 14 smokers, 6 subjects (42.8%) had COPD, 5 subjects (35.7%) had Small Airway Disease, and 21.4% had no abnormality. Past Medical History Regarding respiratory illness history, 67.4% (n=69) had no prior respiratory illness, 16.6% (n=17) had nasobronchial allergy, 12.7% (n=13) had a history of COVID-19 disease, and 2.9% (n=3) had pulmonary tuberculosis previously. Out of the total subjects, there was no systemic illness in 73.5% (n=75) subjects. Comorbidities included: hypertension 37% (n=10), hypothyroidism 29.6% (n=8), diabetes mellitus 11.1% (n=3), coronary artery disease 14.8% (n=4), and renal disease 3.7% (n=1). Spirometric Abnormalities Spirometry was performed by 78.2% (n=79) subjects, while 10.9% (n=11) were unable to perform and in 10.9% (n=11) subjects spirometry was not performed. Out of the 79 subjects who performed spirometry, 17 (21.5%) subjects had no abnormality. A total of 62 subjects (78.5%) were diagnosed with obstructive airway disease (OAD), among whom: - Small Airway Disease (SAD): 41.7% (n=33) - Chronic Obstructive Pulmonary Disease (COPD): 27.8% (n=22) - Bronchial Asthma: 8.8% (n=7) Table 2: Spirometric Abnormalities Among the Study Subjects Abnormality Number Percent Normal 17 21.5 Bronchial Asthma 7 8.8 COPD 22 27.8 Small Airway Disease 33 41.7 Total 79 100.0 Severity Grading Among 62 subjects diagnosed with OAD: - Mild severity: 2 (3.2%) subjects - Moderate severity: 53 (67%) subjects - Severe OAD: 7 (8.8%) subjects In subjects diagnosed with Bronchial Asthma: - Mild severity: 1 subject (14.3%) - Moderate severity: 4 subjects (57.1%) - Severe obstruction: 2 subjects (28.6%) In subjects diagnosed with Small Airway Disease: - Moderate severity: 23 subjects (69.6%) - Severe obstruction: 6 subjects (18.1%) - Very severe obstruction: 4 subjects (12.1%) COPD grade A was seen in all 22 (21.5%) subjects with COPD. Relationship Between Work Hours and Spirometric Abnormalities For individuals exposed less than 5 hours per day, 66.7% had Small Airway Disease and 33.3% had no disease. In the 5-9 hours exposure range, 50% had no disease, 4.5% had Bronchial Asthma, 13.6% had COPD, and 31.8% had Small Airway Disease. In the 10-15 hours exposure group, 46.15% were diagnosed with Small Airway Disease, followed by 36.5% with COPD, 11.5% with Bronchial Asthma, and 9.6% with no disease. Overall, 8.8% of subjects had SAD who worked for <9 hours/day, whereas 23.5% had SAD who were working for >10 hours/day. As the number of working hours increased, there was a corresponding increase in SAD diagnoses. These findings showed statistical significance (Chi-Square=20.66, df=9, p=0.014). Disease Categorization Among 102 subjects, the disease distribution was: - No disease: 30.3% (n=31) - Small Airway Disease: 33.3% (n=33) - COPD: 21.5% (n=22) - Bronchial Asthma: 6.8% (n=7) - Nasal allergy only: 6.8% (n=7) - Chronic bronchitis only: 1.96% (n=2) Overall, 69.7% of subjects had one or the other disease. Table 3: Disease Categorization Among the Study Subjects Disease Categorization Number Valid Percent No Disease 31 30.3 Bronchial Asthma 7 6.8 COPD 22 21.5 Small Airway Disease 33 33.3 Nasal Allergy Only 7 6.8 Chronic Bronchitis Only 2 1.96 Total 102 100.0 Gender Distribution of Diseases SAD was most prevalent in females, comprising 75.8% (n=25) compared to 24.2% (n=8) in males. This was followed by COPD with 59.1% (n=13) in females and 40.9% (n=9) in males. Bronchial asthma was seen in 57.1% (n=4) females and 42.9% (n=3) males. Nasal allergy comprised 71.4% (n=5) females and 28.6% (n=2) males. Chronic bronchitis was equally distributed in both sexes, comprising one case each. Relationship Between Years of Work and Disease Among workers with Bronchial Asthma, 57.1% were reported during 10-15 years of work, followed by 14.3% each in <5 years, 5-9 years, and 16-20 years categories. Among COPD subjects, 50% majority were reported during 10-15 years category, followed by 31.8% in 5-9 years category and 9.1% in >20 years category. SAD was seen maximum in 5-9 years of work group (36.4%), followed by 10-15 years (27.3%), <5 years (18.2%), >20 years (12.1%), and 16-20 years (6.1%). Table 4: Disease Categorization in Relation to Years of Work Diagnosis <5 years 5-9 years 10-15 years 16-20 years >20 years Total No Disease 6 (19.4%) 12 (38.7%) 7 (22.6%) 4 (12.9%) 2 (6.5%) 31 (100%) Bronchial Asthma 1 (14.3%) 1 (14.3%) 4 (57.1%) 1 (14.3%) 0 (0%) 7 (100%) COPD 1 (4.5%) 7 (31.8%) 11 (50%) 1 (4.5%) 2 (9.1%) 22 (100%) Small Airway Disease 6 (18.2%) 12 (36.4%) 9 (27.3%) 2 (6.1%) 4 (12.1%) 33 (100%) Nasal Allergy Only 1 (14.3%) 3 (42.9%) 1 (14.3%) 1 (14.3%) 1 (14.3%) 7 (100%) Chronic Bronchitis 1 (50%) 0 (0%) 1 (50%) 0 (0%) 0 (0%) 2 (100%) Total 16 (15.7%) 35 (34.3%) 33 (32.4%) 9 (8.8%) 9 (8.8%) 102 (100%) Cleaning Activities and Products Among various types of cleaning activities done at the workplace: - Mopping/wet cleaning/damp wiping: 22.2% - Dusting/sweeping/vacuuming: 21.9% - Cleaning windows or mirrors: 15.7% - Cleaning toilet bowl: 14.0% - Cleaning kitchen: 13.7% - Washing or soaking clothes/linen by hand: 12.5% Multiple cleaning activities were performed by 89.2% of cleaners. Among various cleaning products used: - Phenyl: 21.5% - Bleach: 18.2% - Detergents/washing powders: 17.2% - Decalcifiers/acids: 16.4% - Soap: 13.6% - Liquid multiuse cleaner: 10.4% - Stain remover: 2.8% Multiple cleaning products were used by 87.1% of cleaners. Six-Minute Walk Test Among 97 subjects who performed 6MWT: - No impairment: 37.1% - Mild impairment: 57.7% - Moderate impairment: 5.2% - No subject had severe impairment

Many occupations are associated with the use or release of substances which are irritant and toxic to the respiratory system. Cleaners working in hospital and domestic setups have been the natural choice as subjects for studying such adverse health effects, as occupational respiratory diseases typically result from prolonged exposure to irritating or toxic substances, leading to acute or chronic respiratory conditions. Comparison with Other Studies Study Population and Demographics The number of cleaning personnel in our study (n=102) is comparable to several studies: Getahun et al. (n=70) [7], Ajay et al. (n=50) [13], and Mariammal et al. (n=56) [15]. Larger scale studies include Brooks et al. with 425 cleaners [1], Medina et al. with 4,521 subjects [11], and the European Community Respiratory Health Survey (ECRHS) with 6,230 participants [6]. Our study included cleaners aged 20-60 years, which is comparable to Mariammal et al. (20-60 years) [15], Bernstein et al. (18-65 years) [22], and Getahun et al. (20-45 years) [7]. The mean age in our study was 44.64±11.13 years, similar to Neilsen et al. (45 years) [19] and Vizcaya et al. (42±10 years) [20]. Our study showed female predominance (61.8%), comparable to ECRHS (53%) [6], Cummings et al. (53%) [2], and significantly lower than Zock et al. (83.6%) [18] and Brooks et al. (77.2%) [1]. This gender distribution reflects the global trend of cleaning being a predominantly female occupation. Respiratory Symptoms When respiratory symptoms were compared, our study group had 14.9% subjects with cough, comparable to Medina et al. (10.4%) [11], Karadzinska et al. (20.9%) [17], and Brooks et al. (22%) [1], but lower than Vizcaya et al. (38%) [20]. Breathlessness in our study was seen in 10.8%, nearly similar to Medina et al. (11.8%) [11], Neilsen et al. (7%) [19], Mariammal et al. (37%) [15], and Brooks et al. (17%) [1]. Wheeze was complained of by 9.9% of our subjects, comparable to Karadzinska et al. (16.3%) [17] and Medina et al. (18.1%) [11], but lower than Brooks et al. (39.8%) [1]. Nasal allergic symptoms were seen in 18.6% of cleaners in our study, comparable to Mariammal et al. (17%) [15], but lower than Medina et al. (36%) [11], Neilsen et al. (44%) [19], and Bernstein et al. (84%) [22]. The high prevalence of nasal allergy symptoms in our study can be attributed to exposure to different types of dust and chemicals during cleaning activities. Chronic bronchitis was seen in 2.9% of our subjects, lower than Medina et al. (15.2%) [11], Neilsen et al. (10%) [19], and Zock et al. (6.6%) [18]. Table 5: Comparison of Various Symptoms Across Studies Study Cough SOB Wheeze Sputum Nasal Allergy Chronic Bronchitis Present study 14.9% 10.8% 9.9% 8.8% 18.6% 2.9% Medina et al. [11] 10.4% 11.8% 18.1% 8.8% 36% 15.2% Karadzinska et al. [17] 20.9% 18.6% 16.3% 16.3% - - Brooks et al. [1] 22% 17% 39.8% - - - Vizcaya et al. [20] 38% - - 24% - - Neilsen et al. [19] - 7% - - 44% 10% Mariammal et al. [15] - 37% - - 17% - Zock et al. [18] - - - - - 6.6% Duration and Intensity of Exposure The number of years of work by cleaners in our study ranged from 5-20 years, similar to Casimirri et al. (7-16 years) [21] and Karadzinska et al. (8-20 years) [17]. The majority of workers (66.7%) had work duration between 5-15 years. Number of hours per day of work in our study ranged between 5-15 hours, with 95% of subjects working for more than 5 hours per day. This is notably higher than Neilsen et al. (20-29 hours per week in 40% of subjects) [19] and Bernstein et al. (1.5 hours per day) [22], suggesting more intensive exposure in our study population. Smoking Status Smoking history was present in 13.7% of subjects in our study, comparable to Karadzinska et al. (10%) [17] and Neilsen et al. (18% current smokers) [19], but lower than Medina et al. (18.7%) [11], Casimirri et al. (31.8%) [21], Vizcaya et al. (50%) [20], and Brooks et al. (41.9% current smokers) [1]. All smokers in our study were males. When smoking was correlated with spirometry findings, among 14 smokers, 42.8% had COPD and 35.7% had Small Airway Disease, demonstrating the compounding effect of smoking with occupational exposure. Spirometric Findings and Disease Prevalence The present study revealed that among 79 subjects who performed spirometry, 78.4% had obstructive airway disease, which is significantly higher than previously reported. Specifically: - Small Airway Disease (SAD): 41.7% in our study - COPD: 27.8% in our study compared to 3.6% in Zock et al. [18] - Bronchial Asthma: 8.8% in our study compared to 14.1% in Zock et al. [18] The high prevalence of SAD in our study is a significant finding. Small airways are more vulnerable to irritant and toxic effects of cleaning chemicals, and SAD may represent an early stage of obstructive airway disease that could progress to more severe conditions if exposure continues. Ajay et al. reported that actual values of FVC, FEV₁, and PEFR showed significant decreases compared to control groups [13]. Similarly, Getahun et al. found that both actual values and percent predicted values for all spirometric parameters were significantly lower in cleaners compared to controls [7]. Our study corroborates these findings with the high prevalence of spirometric abnormalities. A systematic review by Archangelidi et al. revealed a 50% heightened pooled relative risk of asthma among cleaners and a 43% increased risk of COPD [9]. The European Community Respiratory Health Survey found that women engaged in occupational or domestic cleaning experienced accelerated declines in FEV₁ and FVC compared to women who did not participate in cleaning activities [6]. These longitudinal findings support our cross-sectional observation of high disease prevalence. Impact of Work Hours and Duration Our study found a statistically significant relationship between hours of work per day and spirometric abnormalities (p=0.014). As the number of working hours increased, there was a corresponding increase in SAD diagnoses. Subjects working ≥10 hours/day had 23.5% prevalence of SAD compared to 8.8% in those working <9 hours/day. Regarding years of work, SAD was maximum in the 5-9 years work group (36.4%), while COPD was predominant in the 10-15 years category (50%). This suggests a progression from SAD to more severe obstructive diseases with prolonged exposure, supporting the hypothesis that chronic exposure to cleaning agents leads to cumulative respiratory damage. Gender Differences Female predominance was observed in overall subject numbers and in diagnosis of obstructive airway diseases. Specifically, SAD was most prevalent in females (75.8%) compared to males (24.2%). This is consistent with findings from Svanes et al., who reported that cleaning was associated with accelerated lung function decline specifically among women [6], and Cummings et al., who found similar gender-specific effects [2]. The gender disparity may be attributed to several factors: (1) women constitute the majority of cleaning workforce globally, (2) potential biological differences in airway response to irritants, (3) differences in exposure patterns and cleaning products used, and (4) hormonal factors affecting airway reactivity. Cleaning Products and Activities In our study, phenyl (21.5%) and bleach (18.2%) were the most commonly used cleaning products, followed by detergents (17.2%) and decalcifiers/acids (16.4%). Importantly, 87.1% of cleaners used multiple cleaning products, and 89.2% were involved in multiple cleaning activities. Brooks et al. found that cleaners who worked in hospitals/pharmacies or regularly used bleach, furniture sprays, and floor sprays had significantly lower FEV₁ (% predicted) [1]. Vizcaya et al. reported that bleach was the most commonly used product (93%), with glass cleaners (40%), soaps/detergents (50%), and degreasers (59%) also frequently used [20]. The use of multiple products is particularly concerning because chemical interactions can produce more harmful compounds. For example, mixing bleach and ammonia releases asthmagenic chloramines [5]. The chemical composition of these products includes irritants and sensitizers such as hypochlorite, aldehydes, acids, alkalis, quaternary ammonium compounds, and preservatives [8]. Neilsen et al. found that the use of sprayers was associated with increased risk of eye and respiratory symptoms [19]. However, in our study, sprays were not frequently used, which may explain our relatively lower prevalence of certain upper respiratory symptoms compared to some other studies. Mechanisms of Respiratory Damage The high prevalence of obstructive airway diseases in our study can be explained by multiple pathophysiological mechanisms: 1. Chronic Irritation: Most cleaning agents can irritate the mucous membranes of the airways. Repeated exposure to mild irritants over time results in persistent alterations to the airways [6]. 2. Sensitization: Certain cleaning agents possess sensitizing properties operating through specific immunological mechanisms. Quaternary ammonium compounds, for instance, are known to both irritate and sensitize airways [10]. 3. Oxidative Stress: Casimirri et al. demonstrated that professional exposure to chlorinated agents increases oxidative stress and inflammation biomarkers in exhaled breath condensate [21]. 4. Airway Remodeling: Continuous exposure may lead to structural changes in airways, potentially accelerating decline in lung function as measured by FVC and FEV₁ [6]. 5. Loss of Elastic Recoil: The decrease in FEV₁ and PEFR associated with chronic cleaning exposure can be partially explained by loss of lung elastic recoil pressure, linked to microscopic enlargement of air spaces [29]. The reduced FVC in cleaners may be attributed to air trapping caused by airway obstruction. The study by Svanes et al. emphasized a more pronounced decline in FVC relative to FEV₁ among women involved in cleaning activities [6]. Six-Minute Walk Test Findings Our study showed functional impairment in 62.9% of subjects based on 6MWT: 57.7% had mild impairment and 5.2% had moderate impairment. These findings indicate that respiratory disease in cleaners not only affects pulmonary function but also impacts functional exercise capacity, which has implications for work productivity and quality of life. Limitations 1. Cross-sectional design: Our study cannot establish temporal relationships or causality between cleaning exposure and respiratory disease. 2. Sample size: Although comparable to several similar studies, the relatively modest sample size may limit generalizability. 3. Spirometry non-completion: Approximately 21.8% of subjects either could not perform or did not undergo spirometry, which may introduce selection bias. 4. Exposure assessment: We relied on self-reported exposure data rather than quantitative measurement of chemical exposures. Direct measurement of airborne concentrations of cleaning agents would provide more precise exposure assessment. 5. Lack of control group: The study did not include a matched control group of non-cleaners for direct comparison, though we compared our findings with reference values and other published studies. 6. Recall bias: Self-reported symptoms and exposure history may be subject to recall bias. 7. Confounding factors: Although we collected information on smoking and other potential confounders, residual confounding cannot be entirely excluded. 8. Longitudinal data: The cross-sectional nature precludes assessment of disease progression or lung function decline over time. Despite these limitations, our study provides valuable data on respiratory health among cleaning workers in India, where such information is scarce.

This study demonstrates a high prevalence of respiratory ill effects among domestic and hospital setting cleaners. Key findings include: 1. High Disease Burden: A significant portion of cleaning workers, accounting for 69.7%, suffered from respiratory diseases, predominantly obstructive airway diseases. 2. Prevalence of Small Airway Disease: Small Airway Disease (SAD) emerged as the most prevalent spirometric abnormality, with a prevalence rate of 41.7%. This suggests that small airways are particularly susceptible to exposure to cleaning products and may serve as an early indicator of occupational lung disease. 3. Dose-Response Relationship: A statistically significant association was observed between the number of hours worked per day and spirometric abnormalities (p=0.014). As the working hours increased, the prevalence of SAD also rose. 4. Progression with Exposure Duration: The distribution of disease across different work duration categories indicated a progression from SAD to more severe obstructive diseases, such as COPD, with prolonged exposure. 5. Gender Disparity: Female cleaners exhibited a higher prevalence of obstructive airway diseases, particularly SAD, with a prevalence rate of 75.8% among females compared to 24.2% among males. 6. Multiple Exposures: A substantial majority of cleaners, comprising 87.1%, utilized multiple cleaning products and engaged in multiple cleaning activities (89.2%). This complexity of chemical exposures further increased the potential for adverse effects. 7. Common Products: Among the most frequently used cleaning products were phenyl (21.5%), bleach (18.2%), and detergents (17.2%). 8. Functional Impairment: The six-minute walk test revealed functional impairment in 62.9% of the subjects, indicating a significant impact on their exercise capacity. 9. Smoking Potentiation: Among smokers, a notable 78.5% were diagnosed with either COPD or SAD, highlighting the compounding effect of smoking with occupational exposure. The findings of this study highlight that cleaning, though often overlooked as a high-risk occupation, is associated with substantial respiratory morbidity. Protecting the respiratory health of cleaning workers requires a multi-faceted approach involving regulatory authorities, employers, occupational health professionals, and the workers themselves. Given the large and growing cleaning workforce globally, addressing occupational respiratory health in this vulnerable population should be a public health priority.

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The International Journal of Mycobacteriology. 2018 Apr;17(2):128-33. --- Conflicts of Interest: The authors declare no conflicts of interest. Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Ethical Approval: This study was approved by the Institutional Ethics Committee of Prathima Institute of Medical Sciences, Karimnagar. All participants provided written informed consent.