Summary of epidemiological studies (chronological order) assessing the associations between cleaning occupation, tasks or agents and BHR and UTRS and LTRS
| Author, year | Country | Year of data collection | Study design | Study population | Method of data collection | Covariates | Type of exposure | Findings (95% CI in parenthesis) | GRADE score |
| BHR | |||||||||
| Zock et al, 200223 | 11 European countries and three outside Europe | 1990–1994 | Population-based survey (ECRHS) | 304 cleaners, 4492 office workers | Spirometry, methacholine challenge test | Age, gender, smoking, study centre | Cleaning occupation | Case-case analysis: OR=1.60 (p>0.05) | Moderate |
| Delclos et al, 200726 | US | 2003 | Workforce-based cross-sectional | 3650 healthcare professionals (862 physicians, 941 nurses, 968 occupational therapists, 879 respiratory therapists) | Questionnaire, BHR defined as 8-item, symptom-based predictor of PC20, JEM | Age, sex, race/ethnicity, professional group, years as a health professional (‘seniority’), smoking, obesity | Exposure to cleaning agents/tasks | Outcome: BHR related symptoms General cleaning: OR=1.63 (1.21–2.19) Cleaning products used on building surfaces: OR=1.74 (1.34–2.26) Instrument cleaning: OR=1.40 (1.09–1.79) Adhesives/solvents/gases in patient care: OR=1.86 (1.42–2.44) | High |
| Karadzinska-Bislimovska et al, 200735 | FYROM | 2004–2006 | Cross-sectional | Women, 43 cleaners,37 cooks, 45 controls (office workers) | Questionnaire | Smoking, BMI, baseline FEV1 | Female cleaners | Prevalence of BHR higher in cleaners than controls though not statistically significant (30.2% vs 17.7%) | Moderate |
| LRTS and URTS | |||||||||
| Nielsen and Bach, 199940 | Denmark | 1989–1991 | Workforce-based cohort | 1011 female cleaners employed at nursing homes, schools and offices | Questionnaire | Age, smoking | Female domestic cleaners Use of sprayers | Continuous use of sprayers Eye/nose/throat symptoms: OR=2.1 (1.1–3.8) Asthma symptoms: OR=3.0 (0.9–10) Bronchitis: OR=3.2 (1.0–10.4) | Moderate |
| Medina-Ramón et al, 200537 | Spain | 2001–2002 | Case-control, nested within a large population-based survey | Domestic cleaning women, 40 cases (with asthma and/or chronic bronchitis symptoms, 155 controls) | Questionnaire Lung function, methacholine challenge, serum IgE testing Personal measurements of airborne chlorine and ammonia | Age, smoking, bleach, cleaning products, washing dishes, inhalation accidents, non-domestic cleaning | Female domestic cleaners | Combined outcome: asthma/chronic bronchitis symptoms Bleach use Intermediate exposure: OR=3.3 (0.9–11) High exposure: OR=4.9 (1.5–15) | Moderate |
| Medina-Ramón et al, 200639 | Spain | 2001–2002 | Population-based cross-sectional panel | 43 female domestic cleaners recruited from a previous case-control study | Diary Lung function and allergy testing | Age, respiratory infections, medications | Domestic cleaners | LRTS more common on working days: OR=3.1 (1.4–7.1) LRTS predominantly associated with exposure to diluted bleach, degreasing sprays/atomisers and air fresheners | Moderate |
| Karadzinska-Bislimovska et al, 200735 | FYROM | 2004–2006 | Population-based cross-sectional | Women, 43 cleaners,37 cooks, 45 controls (office workers) | Questionnaire | Smoking, BMI, baseline FEV1 | Female cleaners | Significantly higher prevalence of phlegm (p=0.019) and dyspnoea (p=0.041) in cleaners compared with the control group | Moderate |
| Obadia et al, 200929 | Canada | Not specified | Workforce-based case control | 566 cleaners and 587 other building workers | Questionnaire | Age, gender, smoking | School or racetrack public building cleaners | LRTSs in female cleaners: OR=2.59 (1.6–4.3) LRTSs in male cleaners: OR 1.16 (95% CI 0.7 to 1.9) | High |
| Wieslander and Norback, 201038 | Sweden | Not specified | Population-based cross-sectional | 21 hospital cleaners | Questionnaire | Hospital cleaners | Significant increase in nasal symptoms (p<0.001) and throat symptoms (p<0.05) Significant increase in dyspnoea (p<0.01) | Low | |
| Vizcaya et al, 201130 | Spain | 2007–2008 | Cross-sectional study on employees of cleaning companies | 917 employees of 37 cleaning companies: 761 current cleaners, 86 former and 70 never cleaners (referents) | Spirometry during clinic visit | Sex, age, nationality, smoking status | Cleaning occupation | Wheeze without having a cold, current cleaners: OR=1.3 (9 0.5–3.3), former cleaners: OR=2.0 (0.6–6.5) Chronic cough, current cleaners: OR=1.8 (0.7–4.7), former cleaners: OR=1.9 (0.5–7.8) | Moderate |
| Lee et al, 201436 | USA | Not specified | Workforce-based cross-sectional | 183 hospital cleaners | Questionnaire, face to face interview | Age, gender, job title | Hospital cleaners. Exposure classified in tasks and cleaning products used | For chemical-related symptoms (respiratory tract, eye, skin, nervous and gastrointestinal systems): Medium exposure Cleaning tasks using sprays: OR=3.16 (1.24–8.04) Cleaning toilet bowls or sinks: OR=1.71 (0.72–4.01) Bleach: OR=1.29 (0.55–3.04) Disinfectants: OR=0.67 (0.28–1.62) Liquid multi-use cleaning products: OR=0.83 (0.35–1.95) High exposure Cleaning tasks using sprays OR=1.98 (0.87–4.51) Cleaning toilet bowls or sinks: OR=1.96 (0.82–4.69) Bleach: OR=1.68 (0.70–4.01) Disinfectants: OR=0.72 (0.30–1.74) Liquid multi-use cleaning products: OR=2.35 (1.02–5.43) | High |
| Svanes et al, 201521 | Norway, Sweden, Denmark, Iceland Estonia | 2010–2012 | Population-based cross-sectional (Respiratory Health In Northern Europe, part of ECRHS) | 2138 ever cleaners (from 13 499 respondents) | Questionnaire | Age, gender, smoking, educational level, parent’s educational level, BMI, centre | Occupational cleaner | Wheeze last 12 months: OR=1.44 (1.27–1.62) Asthma symptoms: OR=1.66 (1.46–1.90) Positive trend with duration of exposure for both outcomes | High |
| Abrahamsen et al, 201724 | Norway | February to August 2013 | Population-based cross-sectional study | 185 cleaners (among 16 099 responders) | Questionnaire | Age, gender, area of residence, smoking, home damp/mould, housing conditions | Female and male cleaners JEM | Wheezing OR=0.76 (0.47–1.2) Woken with dyspnoea OR=0.63 (0.27–1.4) | Medium |
| Whitworth et al, 201941 | USA | 2017 | Cross-sectional study | 56 Hispanic female domestic cleaners | Questionnaire | Age and ever smoking | Cleaning tasks and agents | Exposure to cleaning tasks was statistically insignificantly associated with BHR symptoms. Exposure to ammonia: OR=7.5 (1.6–35.9). Exposure to solvents and use of sprays for air freshening was also associated with BHR related symptoms | Medium |
BHR, bronchial hyper-responsiveness; ECRHS, European Community Respiratory Health Survey; JEM, job-exposure matrix; LTRS, lower tract respiratory symptom; PR, prevalence ratio; UTRS, upper tract respiratory symptom.