Women and occupational lung disease: sex differences and gender influences on research and disease outcomes

Estrogen contributes to sex differences in M2a macrophages during multi-walled carbon nanotube-induced respiratory inflammation

Lung diseases characterized by type 2 inflammation are reported to occur with a female bias in prevalence/severity in both humans and mice. This includes previous work examining multi-walled carbon nanotube (MWCNT)-induced eosinophilic inflammation, in which a more exaggerated M2a phenotype was observed in female alveolar macrophages (AMs) compared to males. The mechanisms responsible for this sex difference in AM phenotype are still unclear, but estrogen receptor (ER) signaling is a likely contributor. Accordingly, male AMs downregulated ERα expression after MWCNT exposure while female AMs did not. Thus, ER antagonist Fulvestrant was administered prior to MWCNT instillation. In females, Fulvestrant significantly attenuated MWCNT-induced M2a gene expression and eosinophilia without affecting IL-33. In males, Fulvestrant did not affect eosinophil recruitment but reduced IL-33 and M2a genes compared to controls. Regulation of cholesterol efflux and oxysterol synthesis is a potential mechanism through which estrogen promotes the M2a phenotype. Levels of oxysterols 25-OHC and 7α,25-OHC were higher in the airways of MWCNT-exposed males compared to MWCNT-females, which corresponds with the lower IL-1β production and greater macrophage recruitment previously observed in males. Sex-based changes in cholesterol efflux transporters Abca1 and Abcg1 were also observed after MWCNT exposure with or without Fulvestrant. In vitro culture with estrogen decreased cellular cholesterol and increased the M2a response in female AMs, but did not affect cholesterol content in male AMs and reduced M2a polarization. These results reveal the modulation of (oxy)sterols as a potential mechanism through which estrogen signaling may regulate AM phenotype resulting in sex differences in downstream respiratory inflammation.

Animal models of silicosis: fishing for new therapeutic targets and treatments

Silicosis as an occupational lung disease has been present in our lives for centuries. Research studies have already developed and implemented many animal models to study the pathogenesis and molecular basis of the disease and enabled the search for treatments. As all experimental animal models used to date have their advantages and disadvantages, there is a continuous search for a better model, which will not only accelerate basic research, but also contribute to clinical aspects and drug development. We review here, for the first time, the main animal models developed to date to study silicosis and the unique advantages of the zebrafish model that make it an optimal complement to other models. Among the main advantages of zebrafish for modelling human diseases are its ease of husbandry, low maintenance cost, external fertilisation and development, its transparency from early life, and its amenability to chemical and genetic screening. We discuss the use of zebrafish as a model of silicosis, its similarities to other animal models and the characteristics of patients at molecular and clinical levels, and show the current state of the art of inflammatory and fibrotic zebrafish models that could be used in silicosis research.

Aiming to Improve Equity in Lung Health: Sex and Gender

Sex and gender impact risk factors, presentations of, and response to therapy in lung diseases such as chronic obstructive pulmonary disease, asthma, lung cancer, interstitial lung disease, and obstructive sleep apnea. Many physicians lack training in the impact of sex and gender on lung disease, resulting in diagnostic delays. Scales and indices taught in the health care system are largely validated in male populations, thereby limiting their application to females. For transgender and lesbian, gay, bisexual, transgender, and questioning + patients, high rates of bias in health care may limit patients' willingness to seek health care.

The Association Between Urinary Concentrations of Organophosphate Metabolites and Asthma-Related Outcomes Among Schoolchildren From Informal Settlements

Objectives: There is inconsistent evidence on the relationship between pesticide exposure and childhood respiratory outcomes in non-agricultural settings. This study investigated the association between organophosphate (OP) pesticide exposure and asthma-related outcomes in children residing in four informal settlements. Methods: The study was a longitudinal study of 590 schoolchildren, with a 12 months follow-up period. A standardised questionnaire adopted from the International Study of Asthma and Allergies in Childhood was administered to caregivers for child's respiratory symptoms and household characteristics. Spirometry and fractional-exhaled nitric oxide, including a phadiatop test (atopy status) and urinary dialkyl phosphate (DAP) metabolites were measured at baseline and follow-up. DAP metabolites included diethylphosphate (DEP) and dimethyl phosphate (DMP) measured at baseline and follow-up and dimethylthiophosphate (DMTP) measured only at baseline. Results: The mean ages of schoolchildren were 9.9 ± 0.91 years and the overal incidence proportions of new doctor diagnosed asthma was 2.2%. No consistent patterns of increased risk of asthma outcomes with increasing DAP concentrations was found in multivariate analysis. Conclusion: Future studies with longer follow-up periods and repeated OP biomonitoring are recommended.

Targeting protein glycosylation to regulate inflammation in the respiratory tract: novel diagnostic and therapeutic candidates for chronic respiratory diseases

Protein glycosylation is a widespread posttranslational modification that can impact the function of proteins. Dysregulated protein glycosylation has been linked to several diseases, including chronic respiratory diseases (CRDs). CRDs pose a significant public health threat globally, affecting the airways and other lung structures. Emerging researches suggest that glycosylation plays a significant role in regulating inflammation associated with CRDs. This review offers an overview of the abnormal glycoenzyme activity and corresponding glycosylation changes involved in various CRDs, including chronic obstructive pulmonary disease, asthma, cystic fibrosis, idiopathic pulmonary fibrosis, pulmonary arterial hypertension, non-cystic fibrosis bronchiectasis, and lung cancer. Additionally, this review summarizes recent advances in glycomics and glycoproteomics-based protein glycosylation analysis of CRDs. The potential of glycoenzymes and glycoproteins for clinical use in the diagnosis and treatment of CRDs is also discussed.

Underdiagnosis of silicosis revealed by reinterpretation of chest radiographs in Thai ceramic workers

Background

In Thailand, epidemiological data on silicosis in the ceramic sector is lacking and the underdiagnosis of silicosis remains an extensive concern. Therefore, this study aimed to determine the prevalence of silicosis and the extent of underdiagnosis among Thai ceramic workers by reinterpreting chest radiographs previously taken by a health check-up unit.

Methods

This retrospective cross-sectional study was conducted on ceramic workers undergoing health surveillance using chest radiographs in one ceramic factory in September 2018. All chest radiographs were done retrospectively, then were reinterpreted by professional readers specially trained in using the ILO International Classification of Radiograph of Pneumoconioses (ILO/ICRP). Chest radiographs with a profusion of 1/1 or greater were suggestive of silicosis.

Results

Out of the 244 participants undergoing chest radiography, the prevalence of silicosis was 2.9%. Overall, the mean age of the participants was 41 years, and 72.1% were female. Among individuals with silicosis, the median age was 43 years; 71.4% were male; the average employment duration was 26.9 years; while the male sex was the significant variable associated with silicosis with an odds ratio of 7.01 (95% confidence interval 1.31 to 37.4). Regarding the underdiagnosis, the health check-up unit failed to recognize all individuals with silicosis, and could not detect any radiographic chest abnormalities in 57.1% of those with silicosis.

Conclusions

Despite the low prevalence of silicosis among Thai ceramic workers, this finding indicates ongoing exposure to silica in the ceramic industry. In addition, a significant proportion of the silicosis cases were underrecognized. Future efforts to prevent underdiagnosis and improve an occupational health surveillance service in Thailand are needed.

Association of respiratory symptoms with body mass index and occupational exposure comparing sexes and subjects with and without asthma: follow-up of a Norwegian population study (the Telemark study)

BACKGROUND

Occupational exposure and increased body mass index (BMI) are associated with respiratory symptoms. This study investigated whether the association of a respiratory burden score with changes in BMI as well as changes in occupational exposure to vapours, gas, dust and fumes (VGDF) varied in subjects with and without asthma and in both sexes over a 5-year period.

METHODS

In a 5-year follow-up of a population-based study, 6350 subjects completed a postal questionnaire in 2013 and 2018. A respiratory burden score based on self-reported respiratory symptoms, BMI and frequency of occupational exposure to VGDF were calculated at both times. The association between change in respiratory burden score and change in BMI or VGDF exposure was assessed using stratified regression models.

RESULTS

Changes in respiratory burden score and BMI were associated with a β-coefficient of 0.05 (95% CI 0.04 to 0.07). This association did not vary significantly by sex, with 0.05 (0.03 to 0.07) for women and 0.06 (0.04 to 0.09) for men. The association was stronger among those with asthma (0.12; 0.06 to 0.18) compared with those without asthma (0.05; 0.03 to 0.06) (p=0.011). The association of change in respiratory burden score with change in VGDF exposure gave a β-coefficient of 0.15 (0.05 to 0.19). This association was somewhat greater for men versus women, with coefficients of 0.18 (0.12 to 0.24) and 0.13 (0.07 to 0.19), respectively (p=0.064). The estimate was similar among subjects with asthma (0.18; -0.02 to 0.38) and those without asthma (0.15; 0.11 to 0.19).

CONCLUSIONS

Increased BMI and exposure to VGDF were associated with increased respiratory burden scores. The change due to increased BMI was not affected by sex, but subjects with asthma had a significantly larger change than those without. Increased frequency of VGDF exposure was associated with increased respiratory burden score but without statistically significant differences with respect to sex or asthma status.

Sex and gender in interstitial lung diseases

Sex and gender differences influence key domains of research, lung health, healthcare access and healthcare delivery. In interstitial lung diseases (ILDs), mouse models of pulmonary fibrosis are clearly influenced by sex hormones. Additionally, short telomeres, a biomarker of telomere regulation gene mutations, are impacted by sex, while heritability unexplained by genetic variation may be attributable to gendered environmental factors that drive epigenetic control. Diseases like idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, occupational ILDs, connective tissue-associated ILDs and lymphangioleiomyomatosis have different prevalence and prognosis between men and women. These differences arise from a complex interplay between biological sex and sociocultural gender influencing genetics, epigenomic modifiers, hormones, immune function, response to treatment and interaction with healthcare systems. Much work remains to be done to systematically integrate sex and gender analysis into relevant domains of science and clinical care in ILD, from strategic considerations for establishing research priorities to guidelines for establishing best clinical practices. Accounting for sex and gender in ILD is essential to the practice of individualised, patient-centred medicine.

History of work-related health problems in a population-based sample of women: An exploratory factor analysis

BACKGROUND

Beyond the health-enhancing effects, work also has the potential of causing or worsening different health conditions in the same individual. However, research on within-worker aggregation of work-related health problems is scarce.

OBJECTIVE

To describe the history and aggregation of work-related health problems in a population-based sample of women.

METHODS

A total of 4330 women were asked whether they had ever had "a physical or mental health problem that was caused or made worse by your work". The aggregation of work-related health problems was assessed using an exploratory factor analysis.

RESULTS

Five groups were identified. Factor 1 included all items on musculoskeletal disorders - lower socioeconomic position, higher BMI, smokers and history of occupational accidents. Factor 2 included mental disorders together with headache and/or eyestrain - higher socioeconomic position. Factor 3 included the other disorders item with some loading from digestive disorders - older and public sector workers. Factor 4 included respiratory disorders - lower socioeconomic position and history of occupational accidents. Factor 5 included hearing and ear problems - blue-collar workers.

CONCLUSION

There was a relevant aggregation of work-related health problems, which may inform the selection of specific components for interventions that aim to improve women's work-related health.

Sex-Based Differences in Interstitial Lung Disease

Interstitial lung diseases comprise a family of progressive pulmonary disorders that are often idiopathic or associated with various systemic diseases and that is characterized by bilateral lung involvement with inflammation and tissue remodeling or fibrosis. The impact of sex, including the anatomic and physiologic traits that one is born with, on the development and progression of interstitial lung diseases is not entirely clear. Variances between men and women are driven by differences in male and female biology and sex hormones, among other differences, but their role remains uncertain. In this review, we summarize sex-related differences in the epidemiology and progression of certain interstitial lung diseases with a focus on the connective tissue related interstitial lung diseases, idiopathic pulmonary fibrosis, and sarcoidosis. We also discuss cellular and pre-clinical studies that might shed light on the potential mechanisms responsible for these differences in the hope of unveiling potential targets for intervention and stimulating research in this needed field of investigation.

Silicosis and pulmonary tuberculosis in deceased female South African miners

BACKGROUND

Implementation of South Africa's 2002 Mining Charter increased women's participation in underground mining. However, occupational lung diseases (OLDs) in female gold miners have not been studied.

AIMS

To compare autopsy-diagnosed pulmonary silicosis, lymph gland silicosis (a precursor of pulmonary silicosis) and active pulmonary tuberculosis (PTB) in South African gold miners.

METHODS

The law allows for autopsies on miners for OLD compensation. Information is stored on the Pathology Automation (PATHAUT) database. We selected records of deceased miners who had worked only in gold mines, started employment from 2002, and were autopsied between 2005 and 2015. Using descriptive statistics, we compared demographic and employment characteristics, and disease proportions by sex.

RESULTS

The study comprised 847 gold miners: 68 women and 779 men. There were no statistically significant differences in proportions of autopsy-diagnosed pulmonary silicosis [3 (4%) in women and 54 (7%) in men], lymph gland silicosis [11 (16%) and 171 (22%)] or PTB [29 (43%) and 254 (33%)]. Age and employment duration in women and men with disease were similar. Most miners with pulmonary silicosis had started employment from 2003 [315 (77%)] and worked for under 10 years.

CONCLUSION

It is important to report research findings by sex. Proportions of silicosis and PTB were comparable in women and men, suggesting similar exposures. Silicosis detection after short employment indicates inadequate dust control, particularly as most entered the industry after implementation of interventions to control silica dust in 2003.

The role of sex in particle-induced inflammation and injury

The use of engineered nanomaterials within various applications such as medicine, electronics, and cosmetics has been steadily increasing; therefore, the rate of occupational and environmental exposures has also increased. Inhalation is an important route of exposure to nanomaterials and has been shown to cause various respiratory diseases in animal models. Human lung disease frequently presents with a sex/gender-bias in prevalence or severity, but investigation of potential sex-differences in the adverse health outcomes associated with nanoparticle inhalation is greatly lacking. Only ~20% of basic research in the general sciences use both male and female animals and a substantial percentage of these do not address differences between sexes within their analyses. This has prevented researchers from fully understanding the impact of sex-based variables on health and disease, particularly the pathologies resulting from the inhalation of particles. The mechanisms responsible for sex-differences in respiratory disease remain unclear, but could be related to a number of variables including sex-differences in hormone signaling, lung physiology, or respiratory immune function. By incorporating sex-based analysis into respiratory nanotoxicology and utilizing human data from other relevant particles (e.g., asbestos, silica, particulate matter), we can improve our understanding of sex as a biological variable in nanoparticle exposures. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

How to study the impact of sex and gender in medical research: a review of resources

There is a growing appreciation by the biomedical community that studying the impact of sex and gender on health, aging, and disease will lead to improvements in human health. Sex- and gender-based comparisons can inform research on disease mechanisms and the development of new therapeutics as well as enhance scientific rigor and reproducibility. This review will assist basic researchers, clinical investigators, as well as epidemiologists, population, and social scientists by providing an annotated bibliography of currently available resource tools on how to consider sex and gender as independent variables in research design and methodology. These resources will assist investigators applying for funding from the National Institutes of Health since all grant applicants will be required (as of January 25, 2016) to address the role of sex as a biological variable in vertebrate animal and human studies.

Gender Differences in the Association of Individual and Contextual Exposures with Lung Function in a Rural Canadian Population

INTRODUCTION

To investigate the association of individual and contextual exposures with lung function by gender in rural-dwelling Canadians.

METHODS

A cross-sectional mail survey obtained completed questionnaires on exposures from 8263 individuals; a sub-sample of 1609 individuals (762 men, 847 women) additionally participated in clinical lung function testing. The three dependent variables were forced expired volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC ratio. Independent variables included smoking, waist circumference, body mass index, indoor household exposures (secondhand smoke, dampness, mold, musty odor), occupational exposures (grain dust, pesticides, livestock, farm residence), and socioeconomic status. The primary analysis was multiple linear regression, conducted separately for each outcome. The potential modifying influence of gender was tested in multivariable models using product terms between gender and each independent variable.

RESULTS

High-risk waist circumference was related to reduced FVC and FEV₁ for both genders, but the effect was more pronounced in men. Greater pack-years smoking was associated with lower lung function values. Exposure to household smoke was related to reduced FEV₁, and exposure to livestock, with increased FEV₁. Lower income adequacy was associated with reduced FVC and FEV₁.

CONCLUSION

High-risk waist circumference was more strongly associated with reduced lung function in men than women. Longitudinal research combined with rigorous exposure assessment is needed to clarify how sex and gender interact to impact lung function in rural populations.

Gender differences in work-related asthma: surveillance data from California, Massachusetts, Michigan, and New Jersey, 1993-2008

OBJECTIVE

To characterize work-related asthma by gender.

METHODS

We analyzed state-based sentinel surveillance data on confirmed work-related asthma cases collected from California, Massachusetts, Michigan, and New Jersey during 1993-2008. We used Chi-square and Fisher's Exact Test statistics to compare select characteristics between females and males.

RESULTS

Of the 8239 confirmed work-related asthma cases, 60% were female. When compared to males with work-related asthma, females with work-related asthma were more likely to be identified through workers' compensation (14.8% versus 10.6%) and less likely to be identified through hospital data (14.2% versus 16.9%). Moreover, when compared to males, females were more likely to have work-aggravated asthma (24.4% versus 13.5%) and less likely to have new-onset asthma (48.0% versus 56.5%). Females were also more likely than males with work-related asthma to work in healthcare and social assistance (28.7% versus 5.2%), educational services (11.8% versus 4.2%), and retail trade (5.0% versus 3.9%) industries and in office and administrative support (20.0% versus 4.0%), healthcare practitioners and technical (13.4% versus 1.6%), and education training and library (6.2% versus 1.3%) occupations. Agent groups most frequently associated with work-related asthma were miscellaneous chemicals (20.3%), cleaning materials (15.3%), and indoor air pollutants (14.9%) in females and miscellaneous chemicals (15.7%), mineral and inorganic dusts (13.2%), and pyrolysis products (12.7%) in males.

CONCLUSIONS

Among adults with work-related asthma, males and females differ in terms of workplace exposures, occupations, and industries. Physicians should consider these gender differences when diagnosing and treating asthma in working adults.

Employed adults with asthma who have frequent workplace exposures

Abstract Objective: The recent increase in asthma prevalence is thought to be partially due to environmental changes such as changes in air pollution and occupational exposures. Nationally representative information on workplace exposures among US adults with asthma is limited.

METHODS

We examined 2010 National Health Interview Survey data to determine the proportion of employed adults with asthma who had frequent workplace exposures.

RESULTS

Among adults with current asthma, 19.6% frequently worked outdoors, 17.5% were frequently exposed to workplace secondhand smoke and 28.1% were frequently exposed to workplace vapors, gas, dust or fumes. Adults ever told by a health professional that asthma is probably work-related, when compared to adults who were not, had increased odds of frequent work outdoors [prevalence odds ratio (POR)=2.76], frequent workplace exposure to secondhand smoke (POR=3.08) and frequent workplace exposure to vapors, gas, dust or fumes (POR=3.56).

CONCLUSIONS

To our knowledge, this is the first population-based study in USA that estimates the proportion of working adults with asthma that have frequent workplace exposures. Increasing the understanding of workplace exposures among adults with asthma will help enable prevention of asthma through workplace exposure reduction or avoidance. Future studies should further examine industries and occupations of individuals with asthma and frequent workplace exposures.

Frontiers in occupational and environmental lung disease research

Two central challenges in the field of occupational and environmental epidemiology include accurately measuring biologic responses to exposure and preventing subsequent disease. As exposure-related lung diseases continue to be identified, advances in exposure biology have introduced toxicogenomic approaches that detect biomarkers of exposure at the gene, protein, and metabolite levels. Moreover, genetic epidemiology research has focused more recently on common, low-penetrant (ie, low-relative-risk) genetic variants that may interact with commonly encountered exposures. A number of such gene by environment interactions have been identified for airways and interstitial lung diseases, with the goal of preventing disease among susceptible populations that may not otherwise have been identified. Exhaled breath condensate analysis has provided another noninvasive means of assessing toxicant exposures and systemic effects. As these technologies become more refined, clinicians and public health practitioners will need to appreciate the social implications of the individual- and population-level risks conferred by certain genetic polymorphisms or by biomarker evidence of exposure. At present, the primary approach to occupational and environmental lung disease prevention remains elimination or reduction of known hazardous exposures and requires continued application of local and international resources toward exposure control.

Reciprocal association between atopy and respiratory symptoms in fully employed female, but not male, workers in swine operations

In large commercial swine operations, workers are exposed to indoor air-contaminants during their work-shift. In recently developed large swine operations, exposures are typically 8 or 12 hours/day and females account for a sizeable proportion of the workers. Implications of enhanced exposures and gender require evaluation. Two hundred and forty male and 134 female swine barn workers and 184 male and 227 female nonfarming rural dwellers (controls) (mean age +/- SD males: 36.2 +/- 11.9; females: 34.9 +/- 10.7) completed respiratory questionnaires. Of these, 348 workers (93.0%) and 401 controls (97.6%) underwent allergy skin prick tests (house dust mite, Alternaria sp., hog, cat, mixed grass). The number of hours worked per day was 8.2 for female workers and 7.7 for male workers. Atopy was present in 38.7% and 29.4% of male and female workers, and 46.9% and 38.3% of male and female controls. There was a 72% reduction in risk for chronic phlegm and 70% reduction in usual phlegm in female workers with atopy in comparison to female controls without atopy. There was a significantly increased risk for chronic and usual phlegm, and chronic and usual cough in male workers with atopy. Female workers with atopy were at increased risk for asthma. These findings, that atopy in exposed female workers may be protective of symptoms suggestive of chronic bronchitis but that atopic female workers may be more susceptible to the development of asthma, suggest that exposures to inhaled substances in the workplace may be mediated differently in male and female workers.

Excess respiratory symptoms in full-time male and female workers in large-scale swine operations

BACKGROUND

The respiratory health effects of working in swine operations have been previously investigated mainly in male owner/operators with intermittent exposure to indoor air contaminants.

OBJECTIVES

To examine the respiratory health of male and female workers employed full time in large-scale intensive swine operations in Saskatchewan.

DESIGN

A cross-sectional study of male and female swine workers employed full time and nonfarming control subjects.

RESULTS

In total, 374 swine farmers (240 men and 134 women) and 411 nonfarming rural control subjects (184 men and 227 women) participated in the study. After controlling for age and smoking, male and female workers were significantly more likely to have chronic and usual cough, and chronic and usual phlegm in comparison to male and female nonfarming control subjects, respectively. The risks of these symptoms were greater in female workers (chronic cough: odds ratio [OR], 5.14; 95% confidence interval, 2.67 to 9.89; chronic phlegm: OR, 4.26; 95% confidence interval, 1.86 to 9.73) than in male workers (chronic cough: OR, 3.47; 95% confidence interval, 1.77 to 6.81; chronic phlegm: OR, 3.22; 95% confidence interval, 1.76 to 5.89). These increased risks were not observed for asthma and asthma-like symptoms in female workers. Male workers had an increased risk of shortness of breath in comparison to their nonfarming counter parts.

CONCLUSIONS

Swine workers had increased risk of chronic and usual bronchitis-like symptoms. Female workers in swine operations appear to have greater risk of these symptoms. Future surveillance programs should include both male and female workers.

Are there sex and gender differences in acute exposure to chemicals in the same setting?

We have little understanding of the influence that sex and gender may have on exposure to and measurement of occupational chemicals. If men and women are in the same physical environment, whether that be an occupational or an environmental setting, researchers need to question whether their acute exposure, as measured by administered and/or biologically effective dose, is the same. Not doing so may result in incorrect inferences being made about the risks associated with that exposure. Three critical questions arise specifically, do men and women differ in (1) their personal environments (immediate physical environments and personal attributes), (2) their absorption of the substance across the various biological barriers, and (3) the amount of active substance that reaches the target sites? Both contextual (e.g., smoking habits, diet, use of personal care products and jewellery, hobbies, stress, and use of medications) and biological (e.g., endocrine status) factors should be considered in answering these questions. Examples from the literature are provided to show that, depending on the chemical compound, there may be sex and gender differences in exposure to chemicals which can be manifested in sex differences in absorption, distribution, metabolism, storage, and excretion. An argument is developed to support the need to make information available, such as pharmacokinetic modeling studies in both men and women including appropriate age groups representing the spectrum of life stages and reproductive status.

Gender differences in respiratory symptoms-does occupation matter?

Little attention has been given to gender differences in respiratory health, particularly in occupational settings. The purpose of this paper was to evaluate gender differences in respiratory morbidity based on surveys of hospitality workers, radiographers, and respiratory therapists. Data were available from mail surveys of 850 hospitality industry workers (participation rate 73.9%; 52.6% female), 586 radiographers (participation rate 63.6%; 85% female), and 275 respiratory therapists (participation rate 64.1%; 58.6% female). Cross-tabulations by gender were evaluated by chi(2) analysis and logistic regression with adjustment for personal and work characteristics. Women consistently had greater respiratory morbidity for symptoms associated with shortness of breath, whereas men usually had a higher prevalence of phlegm. There were few differences in work exposures apart from perception of exposure to ETS among hospitality workers. Gender differences in symptoms were often reduced after adjustment for personal and work characteristics but for respiratory therapists there were even greater gender disparities for asthma attack and breathing trouble. Population health findings of elevated symptoms among women were only partially supported by these occupational respiratory health surveys. The influence of differential exposures and personal factors should be considered when interpreting gender differences in health outcomes.