Longitudinal changes in pulmonary function and respiratory symptoms in cotton textile workers. A 15-yr follow-up study

Longitudinal changes in lung function following post-9/11 military deployment in symptomatic veterans

RATIONALE

Exposure to burn pit smoke, desert and combat dust, and diesel exhaust during military deployment to Southwest Asia and Afghanistan (SWA) can cause deployment-related respiratory diseases (DRRDs) and may confer risk for worsening lung function after return.

METHODS

Study subjects were SWA-deployed veterans who underwent occupational lung disease evaluation (n = 219). We assessed differences in lung function by deployment exposures and DRRD diagnoses. We used linear mixed models to assess changes in lung function over time.

RESULTS

Most symptomatic veterans reported high intensity deployment exposure to diesel exhaust and burn pit particulates but had normal post-deployment spirometry. The most common DRRDs were deployment-related distal lung disease involving small airways (DDLD, 41%), deployment-related asthma (DRA, 13%), or both DRA/DDLD (24%). Those with both DDLD/DRA had the lowest estimated mean spirometry measurements five years following first deployment. Among those with DDLD alone, spirometry measurements declined annually, adjusting for age, sex, height, weight, family history of lung disease, and smoking. In this group, the forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) ratio declined 0.2% per year. Those with more intense inhalational exposure had more abnormal lung function. We found significantly lower estimated FVC and total lung capacity five years following deployment among active duty participants (n = 173) compared to those in the reserves (n = 26).

CONCLUSIONS

More intense inhalational exposures were linked with lower post-deployment lung function. Those with distal lung disease (DDLD) experienced significant longitudinal decline in FEV1/FVC ratio, but other DRRD diagnosis groups did not.

Assessment of pulmonary function and respiratory symptoms among INDIAN textile sizing mill workers

BACKGROUND

Textile-sizing mill workers are exposed to various hazards in the sizing units during their working hours and are at risk of acquiring lung impairments due to the usage of sizing chemicals in the sizing process.

OBJECTIVE

The main aim of this study is to assess the influence of cotton dust and sizing agents on lung function and breathing difficulties among Indian textile sizing mill workers.

METHODS

This cross-sectional study was carried out at a textile-sizing mill from August 2022 to September 2022. A modified questionnaire based American Thoracic Society's standard was used to assess respiratory symptoms among sizing mill workers and the pulmonary function test was conducted Spirometry. The chi-square test was used to find the difference between respiratory symptoms and the t-test was used to find the difference between spirometric parameters.

RESULTS

Textile sizing mill workers showed significant (P <  0.0001) decline in peak expiratory flow rate, forced vital capacity (FVC), ratio of FEV1 and forced vital capacity, and forced expiratory volume in 1 s (FEV1). There was an association between symptoms and duration of exposure to pulmonary abnormality. Sizing mill workers showed a significant decline in lung functions and an increase in pulmonary symptoms. As the service duration of exposure in terms of years increased, respiratory symptoms increased and spirometric abnormality also increased.

CONCLUSION

This study confirms that sizing agents such as polyvinyl alcohol (PVA), emulsifier, wax, carboxymethyl cellulose (CMC), and starch used in sizing mills are also responsible for respiratory illness and lung impairment among textile workers.

The health and economic burden of dust pollution in the textile industry of Faisalabad, Pakistan

BACKGROUND

Exposure to dust in textile mills adversely affects workers' health. We collected epidemiological data on textile workers suffering from respiratory diseases and assessed work absence associated with illnesses in Faisalabad, Pakistan.

METHODS

We recruited 206 workers using multistage sampling from 11 spinning mills in Faisalabad, Pakistan. The data were collected using 2-week health diaries and face-to-face interviews. The data pertains to socio-demographics, occupational exposures, the state of the workers' health, and other attributes. A theoretical framework of the health production function was used to estimate the relationship between cotton dust exposure and respiratory illnesses. We also estimated functional limitations (e.g., work absence) associated with dust exposure. STATA 12 was used to calculate descriptive statistics, an ordered probit for byssinosis, a probit model for chronic cough, and three complementary log-log models for blood phlegm, bronchitis, and asthma to measure dose-response functions. A Tobit model was used to measure the sickness absence function.

RESULTS

We found that cotton dust exposure causes a significant health burden to workers, such as cough (35%), bronchitis (17%), and different grades of byssinosis symptoms (22%). The regression analysis showed that smoking cigarettes and working in dusty sections were the main determinants of respiratory diseases. Dusty work sections also cause illness-related work absences. However, the probability of work absence decreases with the increased use of face masks.

CONCLUSION

The study's findings imply the significance of promoting occupational safety and health culture through training and awareness among workers or implementing the use of safety gadgets. Promulgating appropriate dust standards in textile mills is also a need of the hour.

Byssinosis and lung health among cotton textile workers: baseline findings of the MultiTex trial in Karachi, Pakistan

OBJECTIVES

To assess the association of exposure in cotton mills in Karachi with different definitions of byssinosis and lung health.

METHODS

This cross-sectional survey took place between June 2019 and October 2020 among 2031 workers across 38 spinning and weaving mills in Karachi. Data collection involved questionnaire-based interviews, spirometry and measurements of personal exposure to inhalable dust. Byssinosis was defined using both WHO symptoms-based (work-related chest tightness), and Schilling's criteria (symptoms with decreased forced expiratory volume in 1 s (FEV₁). Values of FEV₁/forced vital capacity ratio below the lower limit of normality on postbronchodilator test were considered as 'chronic airflow obstruction' (CAO).

RESULTS

56% of participants had at least one respiratory symptom, while 43% had shortness of breath (grade 1). Prevalence of byssinosis according to WHO criteria was 3%, it was 4% according to Schilling's criteria, and likewise for CAO. We found low inhalable dust exposures (geometric mean: 610 µg/m³). Cigarette smoking (≥3.5 pack-years), increasing duration of employment in the textile industry and work in the spinning section were important factors found to be associated with several respiratory outcomes.

CONCLUSION

We found a high prevalence of respiratory symptoms but a low prevalence of byssinosis. Most respiratory outcomes were associated with duration of employment in textile industry. We have discussed the challenges faced in using current, standard guidelines for identifying byssinosis.

Ever and cumulative occupational exposure and lung function decline in longitudinal population-based studies: a systematic review and meta-analysis

OBJECTIVES

Adverse occupational exposures can accelerate age-related lung function decline. Some longitudinal population-based studies have investigated this association. This study aims to examine this association using findings reported by longitudinal population-based studies.

METHODS

Ovid Medline, PubMed, Embase, and Web of Science were searched using keywords and text words related to occupational exposures and lung function and 12 longitudinal population-based studies were identified using predefined inclusion criteria. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Lung function decline was defined as annual loss of forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) or the ratio (FEV₁/FVC). Fixed and random-effects meta-analyses were conducted to calculate pooled estimates for ever and cumulative exposures. Heterogeneity was assessed using the I² test, and publication bias was evaluated using funnel plots.

RESULTS

Ever exposures to gases/fumes, vapours, gases, dusts, fumes (VGDF) and aromatic solvents were significantly associated with FEV₁ decline in meta-analyses. Cumulative exposures for these three occupational agents observed a similar trend of FEV₁ decline. Ever exposures to fungicides and cumulative exposures to biological dust, fungicides and insecticides were associated with FEV₁ decline in fixed-effect models only. No statistically significant association was observed between mineral dust, herbicides and metals and FEV₁ decline in meta-analyses.

CONCLUSION

Pooled estimates from the longitudinal population-based studies have provided evidence that occupational exposures are associated with FEV₁ decline. Specific exposure control and respiratory health surveillance are required to protect the lung health of the workers.

Antibodies to cartilage oligomeric matrix protein are pathogenic in mice and may be clinically relevant in rheumatoid arthritis

Objective

Cartilage oligomeric matrix protein (COMP) is an autoantigen in rheumatoid arthritis (RA) and experimental models of arthritis. This study was undertaken to investigate the structure, function, and relevance of anti‐COMP antibodies.

Methods

We investigated the pathogenicity of monoclonal anti‐COMP antibodies in mice using passive transfer experiments, and we explored the interaction of anti‐COMP antibodies with cartilage using immunohistochemical staining. The interaction of the monoclonal antibody 15A11 in complex with its specific COMP epitope P6 was determined by x‐ray crystallography. An enzyme‐linked immunosorbent assay and a surface plasma resonance technique were used to study the modulation of calcium ion binding to 15A11. The clinical relevance and value of serum IgG specific to the COMP P6 epitope and its citrullinated variants were evaluated in a large Swedish cohort of RA patients.

Results

The murine monoclonal anti‐COMP antibody 15A11 induced arthritis in naive mice. The crystal structure of the 15A11–P6 complex explained how the antibody could bind to COMP, which can be modulated by calcium ions. Moreover, serum IgG specific to the COMP P6 peptide and its citrullinated variants was detectable at significantly higher levels in RA patients compared to healthy controls and correlated with a higher disease activity score.

Conclusion

Our findings provide the structural basis for binding a pathogenic anti‐COMP antibody to cartilage. The recognized epitope can be citrullinated, and levels of antibodies to this epitope are elevated in RA patients and correlate with higher disease activity, implicating a pathogenic role of anti‐COMP antibodies in a subset of RA patients.

Contemporary Prevalence of Byssinosis in Low- and Middle-Income Countries: A Systematic Review

We aimed to identify the contemporary prevalence of byssinosis through a systematic review. We used Medline, Web of Science, Embase, and Global Health databases to identify studies published in any language between 2000 and 2019, reporting primary data on byssinosis among adults. We used the Joanna Briggs Institute checklist to estimate the risk of bias in studies and undertook a qualitative, narrative data analysis. The review considered the prevalence of byssinosis, chest tightness, and airflow obstruction in textile workers in low- and middle-income countries (LMICs). We found 26 relevant studies that included 6930 workers across 12 countries. Most of the studies (n = 19) were from Asia, and 7 from African countries. Twenty-five studies were cross-sectional surveys while 1 was a cohort study. The prevalence of byssinosis was reported by 18 studies, and ranged from 8% to 38%, without any clear associations, at the group level, between the prevalence of byssinosis and durations of workers’ exposures. Prevalence of chest tightness ranged between 4% and 58% and that of airflow obstruction between 10% and 30%. We found a strong correlation ( r = 0.72) between prevalence of byssinosis and cotton dust levels. Our findings indicate that byssinosis remains a significant, contemporary problem in some parts of the textile sector in LMICs.

Longitudinal Evaluation of Lung Function in Gulf War I Veterans Exposed to Depleted Uranium

OBJECTIVE

Gulf War I (GWI) Veterans exposed to depleted uranium (DU) have undergone biennial surveillance to assess for DU-related health effects. No DU-specific respiratory effects have been observed cross-sectionally, but longitudinal lung function decline has not been assessed.

METHODS

A dynamic cohort of 71 Veterans underwent spirometry testing between 1999 and 2019. Longitudinal rates of decline of spirometry values were compared among Veterans with high versus low uranium levels using a linear mixed model.

RESULTS

There was no significant difference in rate of decline of spirometry values between Veterans with high versus low uranium levels. The overall rate of decline was similar to that of the general population.

CONCLUSIONS

In 20 years of follow-up, there does not appear to be an accelerated rate of decline of lung function among veterans exposed to depleted uranium.

Assessment of respiratory dust exposure and lung functions among workers in textile mill (Thamine), Myanmar: a cross-sectional study

BACKGROUND

Airborne dusts are being potentially harmful for workers in occupational environment. Exposure to respirable dust is the most important concern in textile workers for the widespread of occupational lung diseases, especially more serious in developing countries. The aim of the study was to assess the respirable dust exposure and associated factors of lung functions among textile workers.

METHODS

A cross-sectional study was carried out at a textile mill (Thamine), Yangon Region, from April to December, 2018 and a total of 207 textile workers were randomly selected by using a multistage sampling procedure. Data were collected by using a structured questionnaire for respiratory symptoms, an air sampling pump for assessment of respirable dust exposure, and a spirometer for testing the lung functions. Logistic regression analysis was performed to assess the associated factors of lung functions. Odds ratios with a 95% confidence interval were computed for strength of associations at the significance level of α ≤ 0.05.

RESULTS

The mean (± standard deviation, SD) respirable dust exposure was 3.3 mg/m³ (± 0.69) and the prevalence of increased respirable dust exposure (> 3 mg/m³) was 50.7%. The level of respirable dust exposure was highest in the textile workers involving at twisting department. The means (± SD) spirometry values were FVC 82.8% (± 17.8), FEV₁ 83.6% (± 18.5), and FEV₁/FVC 0.9 (± 0.1). Overall magnitude of reduced lung functions was 40.1%, and the prevalence of reduced FVC, FEV_1, and FEV₁/FVC were 36.7, 34.3 and 3.9% respectively. The current working at twisting department, > 5 years of service duration, respiratory symptoms and increased respirable dust exposure were associated with reduction in FVC and FEV₁.

CONCLUSIONS

The current working department, service duration, respiratory symptoms and exposure to respirable dust were predictors of lung functions in textile workers. An adequate ventilation, good work practices, hygienic workplace, safety and health training regarding potential health effects, and periodically assessment of lung functions are the critical elements for control of respirable dust exposure and reduction of occupational lung diseases.

Respiratory symptoms and their association with exposure to respiratory dust among indigo-dyed cotton workers

Indigo-dyed cotton weavers are exposed to various dust particles that may contain chemical contaminants from indigo fermentation process and can be related to respiratory symptoms. This cross-sectional study thus investigates the prevalence of respiratory symptoms and their association with respiratory dust (RD) exposure among workers in northeastern Thailand. It recruited 146 indigo-dyed cotton weavers. The prevalence of respiratory symptoms was collected by a self-report questionnaire included cough, phlegm, chest tightness, wheezing, and dyspnea. The average RD was 47.9 ± 28.3 μg/m³. Logistic regression models revealed a strong association between RD exposure and respiratory symptoms after adjustment. An exposure to RD ≥50 µg/m³ was associated with 5.05-, 3.58-, 2.88-, and 3.30-fold increased odds ratio of cough, phlegm, chest tightness, and dyspnea, respectively. The study results reveal that RD exposure may contribute to respiratory symptoms among indigo-dyed cotton weavers.

Prevalence and Factors Associated with Respiratory Symptoms Among Bahir Dar Textile Industry Workers, Amhara Region, Ethiopia

INTRODUCTION

The expansions of labor-intensive investments in a developing countries, especially in textile production create a dusty work environment for workers, and those workers are from the low socio-economic group and need special safety concern.

OBJECTIVE

This study was aimed at assessing the prevalence of respiratory symptoms and associated factors among textile factories workers in Bahir Dar, Amhara region, Ethiopia, 2015.

METHODS

Institutional based cross-sectional study design was employed among randomly selected 384 textile workers using pre-tested interviewer-administered questionnaire. We stratified workers by their working section in the textile industries. Then the proportional numbers of workers were selected from each working section of the factory by using a random number generator. The identification number of workers from each factory was used for selection. The data were checked, coded, and entered to Epi-info Version 7 and exported to the Statistical Package for Social Science Version 20 for further analysis. Both bivariate and multivariate logistic regressions were used to identify associated factors. Variables having a P ⩽ .2 were fitted to multivariate logistic regression so as to assess the presence and strength of association with the respiratory symptom. Variables having a P < .05 were considered as significant.

RESULTS

Three hundred eighty-three (99.74%) of the study participants responded completely filling the questionnaire. In this study, the prevalence of cough, phlegm, bronchitis, chronic bronchitis, and chest pain among the respondents were 31 (8.1%), 45 (11.7%), 26 (6.8%), 2 (0.5%), and 21 (5.5%), respectively. Generally, 141 (36.81%) of the respondents have either of the above respiratory symptoms in the textile industry. Working in the spinning section (AOR = 3.26, 95% CI: 1.80, 5.89), being in the grade 11 and 12 level and below (AOR = 2.36, 95% CI: 1.50, 3.70) and personal protective equipment (PPE) utilization (AOR = 4.88 95% CI: 1.54-15.45) were significantly associated with respiratory symptoms in the multivariate analysis.

CONCLUSION

The prevalence of respiratory symptoms in Bahir Dar Textile workers was relatively high. Working department, educational status, and PPE use were variables significantly associated with respiratory symptoms in this study. Experience sharing across departments, employing educated workers and provision of personal protective equipment are important tasks to be followed to reduce respiratory symptoms in the industry.

Occupational exposures and 20-year incidence of COPD: the European Community Respiratory Health Survey

BACKGROUND

Occupational exposures have been associated with an increased risk of COPD. However, few studies have related objectively assessed occupational exposures to prospectively assessed incidence of COPD, using postbronchodilator lung function tests. Our objective was to examine the effect of occupational exposures on COPD incidence in the European Community Respiratory Health Survey.

METHODS

General population samples aged 20-44 were randomly selected in 1991-1993 and followed up 20 years later (2010-2012). Spirometry was performed at baseline and at follow-up, with incident COPD defined using a lower limit of normal criterion for postbronchodilator FEV1/FVC. Only participants without COPD and without current asthma at baseline were included. Coded job histories during follow-up were linked to a Job-Exposure Matrix, generating occupational exposure estimates to 12 categories of agents. Their association with COPD incidence was examined in log-binomial models fitted in a Bayesian framework.

FINDINGS

3343 participants fulfilled the inclusion criteria; 89 of them had COPD at follow-up (1.4 cases/1000 person-years). Participants exposed to biological dust had a higher incidence of COPD compared with those unexposed (relative risk (RR) 1.6, 95% CI 1.1 to 2.3), as did those exposed to gases and fumes (RR 1.5, 95% CI 1.0 to 2.2) and pesticides (RR 2.2, 95% CI 1.1 to 3.8). The combined population attributable fraction for these exposures was 21.0%.

INTERPRETATION

These results substantially strengthen the evidence base for occupational exposures as an important risk factor for COPD.

Systematic Review: Occupational illness in the waste and recycling sector

BACKGROUND

The waste and recycling sector is a growing part of industry. Whether health surveillance is indicated and how it should be undertaken is unclear.

AIMS

To undertake a review of the literature to identify hazards to health, biological effects and occupational illnesses for workers in the sector.

METHODS

A systematic review of the published literature and two UK databases.

RESULTS

Rates of fatal, non-fatal injuries and self-reported work-related illness were found to be higher in the waste and recycling sector than in UK industry as a whole. There was an increased prevalence of respiratory, gastro-intestinal and skin complaints in workers exposed to compost relative to controls. They may also be at increased risk of extrinsic allergic alveolitis, allergic bronchopulmonary aspergillosis, occupational asthma and abnormalities of lung function. Workers involved with the recycling of batteries and cables may be at risk of lead poisoning and exposure to other heavy metals. There were case reports of mercury poisoning from the recycling of fluorescent lights. Cases of occupational asthma have been reported in association with wood and paper recycling. The recycling of e-waste may cause exposure to heavy metals and organic pollutants, such as polybrominated diphenyl ethers, dioxins and polyaromatic hydrocarbons, which have been associated with damage to DNA and adverse neonatal outcomes.

CONCLUSIONS

Ill-health and adverse biological effects have been described in waste and recycling workers, but their true prevalence has probably not been captured. Targeted health surveillance may be required to assess exposure and to identify occupational illness.

Determinants of Knowledge and Safety Practices of Occupational Hazards of Textile Dye Workers in Sokoto, Nigeria: A Descriptive Analytic Study

Textile dye workers are subject to occupational hazards on a daily basis due to exposure to precarious conditions in the workplace. This study aimed to assess the knowledge, attitude and safety practices and its determinants among textile dye workers in Sokoto metropolis, Nigeria. This is a descriptive cross-sectional study conducted among 200 textile dye workers and the respondents were selected by multi stage sampling technique. Data was collected using an interviewer administered questionnaire. Data was processed using SPSS IBM version 20 and analyzed using descriptive and inferential statistics. Majority of the respondents (74.0%) had good knowledge of workplace hazards; (81.0%) had positive attitude and only 20% observed all the safety practices. Formal education (P=0.047); working less than 5 days a week (P=0.001) and permanent employment (P=0.013) were found to be determinants of respondents’ knowledge and attitude towards workplace hazards. Although the respondents had good knowledge and positive attitude, their lack of observance of safety practices brings to fore the need for direct safety instruction and training and retraining of textile dye workers on workplace hazards and safety practices.

The effect of organic dust exposure on long-term change in lung function: a systematic review and meta-analysis

Lung function is a predictor of morbidity and mortality, and the chronic nature of lung function decline allows for preventive initiatives. Proinflammatory constituents of organic dust are considered a possible cause of compromised respiratory health. The aim of this systematic review was to reveal the impact of organic dust exposure on long-term change in lung function. The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Predefined criteria concerned study design: longitudinal, ≥1 year follow-up, ≥50 exposed; exposure measures: organic dust, measured or estimated, in different occupational settings; and outcome measures: change in lung function measured by spirometry. Based on these criteria, 1580 potentially relevant publications were narrowed down to 20 included publications. Quality was evaluated and discussed based on six objectively defined criteria. Overall, 14 studies found some type of association between exposure to organic dust and long-term change in lung function. However, the results were inconsistent and no specific work exposure showed more clear associations to change in lung function. Meta-analysis revealed an overall small significant excess loss in forced expiratory volume in the 1st s for exposed compared with controls of 4.92 mL/year (95% CI 0.14 to 9.69). No significant association was seen overall for forced vital capacity. 12 studies revealed a significant exposure-response relation between organic dust and change in lung function. The results were inconsistent across varying study design and different exposure measures and outcomes. We therefore conclude that there is limited evidence of a causal association between general exposure to organic dust and long-term excess decline in lung function.

Occupational chronic obstructive pulmonary disease: a standard of care

BACKGROUND

Consistent evidence from population studies report that 10-15% of the total burden of chronic obstructive pulmonary disease (COPD) is associated with workplace exposures. This proportion of COPD could be eliminated if harmful workplace exposures were controlled adequately.

AIMS

To produce a standard of care for clinicians, occupational health professionals, employers and employees on the identification and management of occupational COPD.

METHODS

A systematic literature review was used to identify published data on the prevention, identification and management of occupational COPD. Scottish Intercollegiate Guidance Network grading and the Royal College of General Practitioner three star grading system were used to grade the evidence.

RESULTS

There are a number of specific workplace exposures that are established causes of COPD. Taking an occupational history in patients or workers with possible or established COPD will identify these. Reduction in exposure to vapours, gases, dusts and fumes at work is likely to be the most effective method for reducing occupational COPD. Identification of workers with rapidly declining lung function, irrespective of their specific exposure, is important. Individuals can be identified at work by accurate annual measures of lung function.

CONCLUSIONS

Early identification of cases with COPD is important so that causality can be considered and action taken to reduce causative exposures thereby preventing further harm to the individual and other workers who may be similarly exposed. This can be achieved using a combination of a respiratory questionnaire, accurate lung function measurements and control of exposures in the workplace.

Review: Endotoxin in the environment — exposure and effects

This review deals with endotoxin in the environment and its relation to disease among exposed persons. Data are presented on levels of endotoxin in different environments with maximum values of several μg/m3. The cellular reactions of importance for inhalation exposure effects are attachment to lipopolysaccharide binding protein, CD14 cell surface protein and TLR-4 receptors. The internalisation of endotoxin in macrophages and endothelial cells results in local production of inflammatory cytokines with subsequent migration of inflammatory cells into the lung and the penetration of cytokines into the blood. These events orchestrate clinical effects in terms of toxic pneumonitis, airways' inflammation and systemic symptoms. Inhalation challenges with pure endotoxin and field studies confirm the relation between these effects and exposure to dusts containing endotoxin. It is possible that polymorphism in genes determining endotoxin reactivity, particularly TLR-4, influences the risk for disease after environmental exposures. Some data suggest that the inflammation caused by inhaled endotoxin may decrease the risk for atopic sensitisation among children and lung cancer among workers exposed to organic dust. Additional research is needed to clarify the role of other environmental agents that are present in connection with endotoxin, particularly (1→3)-β-D-glucan from mold cell walls.

Occupational exposure and risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis

INTRODUCTION

Due to contradictory literature we have performed a systematic review and meta-analyse of population-based studies that have used Job Exposure Matrices to assess occupational exposure and risk of Chronic Obstructive Pulmonary Disease (COPD).

AREAS COVERED

Two researchers independently searched databases for published articles using predefined inclusion criteria. Study quality was assessed, and results pooled for COPD and chronic bronchitis for exposure to biological dust, mineral dust, and gases/fumes using a fixed and random effect model. Five studies met predetermined inclusion criteria. The meta-analysis showed low exposure to mineral dust, and high exposure to gases/fumes were associated with an increased risk of COPD. We also found significantly increased the risk of chronic bronchitis for low and high exposure to biological dust and mineral dust. Expert commentary: The relationship between occupational exposure assessed by the JEM and the risk of COPD and chronic bronchitis shows significant association with occupational exposure. However, the heterogeneity of the meta-analyses suggests more wide population-based studies with older age groups and longitudinal phenotype assessment of COPD to clarify the role of occupational exposure to COPD risk.

Impact of air quality guidelines on COPD sufferers

Background

COPD is one of the leading causes of morbidity and mortality in both high- and low-income countries and a major public health burden worldwide. While cigarette smoking remains the main cause of COPD, outdoor and indoor air pollution are important risk factors to its etiology. Although studies over the last 30 years helped reduce the values, it is not very clear if the current air quality guidelines are adequately protective for COPD sufferers.

Objective

This systematic review was to summarize the up-to-date literature on the impact of air pollution on the COPD sufferers.

Methods

PubMed and Google Scholar were utilized to search for articles related to our study’s focus. Search terms included “COPD exacerbation”, “air pollution”, “air quality guidelines”, “air quality standards”, “COPD morbidity and mortality”, “chronic bronchitis”, and “air pollution control” separately and in combination. We focused on articles from 1990 to 2015. We also used articles prior to 1990 if they contained relevant information. We focused on articles written in English or with an English abstract. We also used the articles in the reference lists of the identified articles.

Results

Both short-term and long-term exposures to outdoor air pollution around the world are associated with the mortality and morbidity of COPD sufferers even at levels below the current air quality guidelines. Biomass cooking in low-income countries was clearly associated with COPD morbidity in adult nonsmoking females.

Conclusion

There is a need to continue to improve the air quality guidelines. A range of intervention measures could be selected at different levels based on countries’ socioeconomic conditions to reduce the air pollution exposure and COPD burden.

Pulmonary effects of intermittent, seasonal exposure to high concentrations of cotton dust

AIM: To quantify the exposure levels and to assess pulmonary reactions associated with exposure to cotton dust and its biological contaminants.

METHODS: All employees (51 male workers) of a ginning industry as well as 51 referent unexposed subjects from clerical staff of an educational center were investigated. Atmospheric concentrations of cotton dust and bioaerosols were measured. Furthermore, bacterial and fungal genera and species were identified by an expert microbiologist and an experienced mycologist. A standard respiratory symptom questionnaire was filled out for the subjects and they underwent multiple spirometry tests, at the beginning and at the end of work season as well as prior to (pre-exposure base line values) and at end of the first shift of workweek (post exposure).

RESULTS: Gram negative bacteria including Enterobacter agglomerans and Pseudomonas spp. were found to be the dominant bacterial species and genera, respectively. Similarly, dominant fungi were identified to be Mucor sp. Rhizopus sp. and Aspergillus niger. Mean atmospheric concentrations of cotton dust in ginning and outdoor areas were found to be 35.2 and 6.8 mg/m³, respectively. The prevalence rates of cough, phlegm, wheezing, dyspenea and grade 1/2 byssinosis among the exposed subjects were significantly higher than their corresponding values for the unexposed employees (P < 0.05). Additionally, significant differences were noted in the mean baseline value (preshift) of vital capacity, forced expiratory volume in the first second (FEV1) and FEV1/forced vital capacity ratio of the exposed subjects when compared with those of their referent counterparts. Similarly, significant cross shift decrements were noted in most parameters of pulmonary function of the exposed subjects.

CONCLUSION: Seasonal exposure to cotton dust induces both acute, partially reversible, and chronic irreversible decrements in the lungs’ functional capacities as well as increased prevalence of respiratory symptoms.

Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case-control study

Objectives

Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke.

Methods

Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case–control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI.

Results

Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2).

Conclusions

This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene–environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

Diminished pulmonary function in long-term workers exposed to cotton dust determined in a cross-sectional study in small Pakistani enterprises

PURPOSE

While large cotton industry plants producing for the foreign market have undergone improvements of occupational hygiene lately, working conditions in power looms producing mainly for the local market are still poor. The respiratory health in workers of power looms has not been studied so far.

METHODS

In a cross-sectional study, 51 male cotton workers from power looms, 58 from large cotton factories and 52 controls were investigated by spirometry and a symptoms questionnaire. Spirometric measurements and respiratory symptoms were related to exposure duration in large and small factories by multivariate linear regression and logistic regression, respectively, with smoking, age and anthropometric parameters considered as confounders.

RESULTS

Work duration in power looms was associated with declines in forced expiratory volume in 1 s, peak flow, maximum midexpiratory flow and forced expiratory flow 75 and an increased risk of obstruction (OR 1.09/year; 95% CI: 1.002 to 1.18) by applying the Global Lung Initiative equations. Except cough that was only associated with smoking, all respiratory symptoms (chest tightness, shortness of breath, fever) increased as a function of duration of exposure in power looms but not in large factories.

CONCLUSIONS

Despite limitations inherent in the cross-sectional approach, there is evidence for workers in small weaving factories to face an increased risk of pulmonary function loss and respiratory symptoms. Industrial hygiene measures in these small enterprises should be encouraged. Failure to detect adverse respiratory outcomes from occupation in large factories could be due to a 'survivor' (healthy worker) effect.

Gene-environment interaction from international cohorts: impact on development and evolution of occupational and environmental lung and airway disease

Environmental and occupational pulmonary diseases impose a substantial burden of morbidity and mortality on the global population. However, it has been long observed that only some of those who are exposed to pulmonary toxicants go on to develop disease; increasingly, it is being recognized that genetic differences may underlie some of this person-to-person variability. Studies performed throughout the globe are demonstrating important gene-environment interactions for diseases as diverse as chronic beryllium disease, coal workers' pneumoconiosis, silicosis, asbestosis, byssinosis, occupational asthma, and pollution-associated asthma. These findings have, in many instances, elucidated the pathogenesis of these highly complex diseases. At the same time, however, translation of this research into clinical practice has, for good reasons, proceeded slowly. No genetic test has yet emerged with sufficiently robust operating characteristics to be clearly useful or practicable in an occupational or environmental setting. In addition, occupational genetic testing raises serious ethical and policy concerns. Therefore, the primary objective must remain ensuring that the workplace and the environment are safe for all.

Lack of a protective effect of cotton dust on risk of lung cancer: evidence from two population-based case-control studies

BACKGROUND

Lung cancer is the leading cause of cancer death in North America. Exposure to cotton dust has previously been reported to decrease the risk of lung cancer.

METHODS

We used data from two large case-control studies conducted in Montreal from 1979-1986 (Study 1) and 1996-2002 (Study 2) respectively, to examine the association between occupational exposure to cotton dust and risk of lung cancer. Cases were diagnosed with incident histologically-confirmed lung cancer (857 in Study 1, 1203 in Study 2). Population controls were randomly selected from electoral lists and frequency-matched to cases by age and sex (533 in Study 1, 1513 in Study 2). Interviews for the two studies used a virtually identical questionnaire to obtain lifetime occupational and smoking history, and several lifestyle covariates. Each participant's lifetime occupational history was reviewed by experts to assess exposure to a number of occupational agents, including cotton dust. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression, adjusting for potential confounders.

RESULTS

The lifetime prevalence of exposure to cotton dust was approximately 10%-15% in both studies combined, with some variation by study and by sex. Overall there was no decreased risk of lung cancer among subjects exposed to cotton dust. Rather, among all subjects there was a suggestion of slightly increased risk associated with any lifetime exposure to cotton dust (OR = 1.2, 95% CI: 1.0-1.5). This risk appeared to be concentrated among cases of adenocarcinoma (OR = 1.6, 95% CI: 1.2-2.2), and among moderate and heavy smokers (OR = 1.3, 95% CI: 1.0-1.7). There was no association when restricting to cases of either squamous cell or small cell cancer, or among never smokers and light smokers. An analogous examination of subjects exposed to wool dust revealed neither increased nor decreased risks of lung cancer.

CONCLUSIONS

There was no evidence that cotton dust exposure decreased risks of lung cancer.

Cross-Shift Changes in Lung Function Among Palestinian Farmers During High- and Low-Exposure Periods to Pesticides: A Longitudinal Study

The purpose of this study was to study cross-shift changes of lung function in relation to pesticide use. One hundred and ninety-five male farmers, from a total of 250 farmers, performed lung function tests both pre- and post-shift during high- and low-pesticide-exposure periods. There were no associations between lung function differences across shifts and estimated quantity of pesticides used. However, the cross-shift reduction in forced expiratory volume in 1 second (FEV1; ΔFEV1) was more pronounced during the period when pesticides were used on a larger scale, September 2006, compared with the exposure period with a lower level of pesticide use, April 2007, +50 mL (95% confidence interval [CI]: +24, +76) and +17 mL (95% CI: -13, +48), respectively. This contrast was statistically significant only among the subset of never-smoking participants below 50 years of age. This finding suggests a possible obstructive effect of pesticide exposure on lung function among this rural male population in Palestine. A follow-up of farmers' lung function in this part of the world along with high-quality measurements of exposure is needed.

Prevalence of asthma, local risk factors and agreement between written and video questionnaires among Turkish adolescents

BACKGROUND

There is currently no standard tool for the measurement of asthma in epidemiological studies. The objectives of this study were to determine the prevalence of asthma, to describe the potential local risk factors, and to assess the agreement between written and video questionnaires in 13- to 14-year-old schoolchildren.

METHODS

We performed a cross-sectional study involving 5427 adolescents in 26 schools. Prevalence of asthma symptoms were evaluated using the International Study of Asthma and Allergies in Childhood (ISAAC) written and video questionnaire. The adolescents were asked additional questions for risk factors of asthma.

RESULTS

The prevalence of lifetime wheeze, wheeze in the last 12 months and doctor-diagnosed asthma with written questionnaire were found as 13.5%, 6.3% and 11.2% respectively. Prevalence of lifetime wheeze, wheeze in the last 12 months, wheeze after exercise in the last 12 months, with video questionnaire were found as 9.6%, 5.5%, 11.9% and 1.9% respectively. The proportion of total agreement between the two questionnaires was high (0.77-0.81) with poor kappa value (0.25-0.50). In multivariate analysis, family history of atopy, stuffed toys and accompaniment of children to their parents after school hours in textile industry were found as risk factors for asthma. In addition kind of bird, such as canary was found as a risk factor.

CONCLUSION

Prevalence of asthma is moderate in Turkey. Agreement between the two questionnaires was high. Accompaniment of children to their parents in textile industry is a newly-described risk factor for asthma.

Prevalence and risk factors of respiratory symptoms among home-based garment workers in Bangkok, Thailand

This study aimed to determine the prevalence and risk factors associated with respiratory symptoms. A cross-sectional study with random sampling method was employed and 300 home-based garment workers (HBGWs) were recruited. Risk factors, including personal factors; knowledge, health preventive behaviors, and skill of self-health surveillance, working condition, and respiratory symptoms were assessed. Data were collected using self-reported questionnaires. Prevalence of respiratory symptom was 22.3%. Majority of participants were female (78%). Mean age and working experience were 37.38 years (SD = 10.70) and 13.58 years (SD = 8.71), respectively. Allergic respiratory symptoms (odds ratio [OR] = 16.5; 95% confidence interval [CI] = 8.61-31.7) and garment dust exposure (OR = 12.3; 95% CI = 6.49-23.3) were significantly associated with respiratory symptoms (P < .001). Logistic regression analysis indicated history of allergic predicted the respiratory symptoms (OR = 12.96; 95% CI = 4.24-39.55). HBGWs who had serious allergic symptoms and high exposure to dust were at risk of respiratory symptoms. Therefore, preventive program for garment dust exposure among HBGWs is needed.

Longitudinal pulmonary functional loss in cotton textile workers: a 5-year follow-up study

BACKGROUND

Occupational exposure to cotton dust causes several diseases affecting the lungs, but only limited information is available on effects of long-term exposure. In this study, we aimed to evaluate longitudinal changes in selected parameters of pulmonary function in textile workers.

MATERIAL AND METHODS

This prospective cohort study began with 196 textile workers in 2006 and was completed in 2011 with 49 workers. We used standardized tests for pulmonary function on participants on the first day of the workweek in June of 2006 and 2011. Environmental samples of cotton dust were gathered with a vertical elutriator. Loss of pulmonary function was assessed based on gender and smoking status.

RESULTS

The mean number of years participants worked in the textile factory was 7.61 ± 1.83 years, and the mean age was 35.3+5.8 years. The annual FEV1 loss of all workers was 53.2 ml, giving a ratio of annual FEV1 loss to baseline FEV1 of 1.4%. Pulmonary function parameters of all participants in 2011 were significantly lower than those in 2006 (for all, p<0.05). In both surveys, pulmonary function in current smokers was lower, but this difference was not significant (p>0.05).

CONCLUSIONS

This study provides the first data on pulmonary functional loss in Turkish textile workers and supports the findings of other cohort studies that workers with long-term exposure to cotton dust may lose some pulmonary function. The ratio of annual FEV1 loss to baseline FEV1 appears to be a more accurate and comparable method than annual FEV1 loss for evaluating pulmonary functional loss.

Long-term respiratory health effects in textile workers

PURPOSE OF REVIEW

Over 60 million people worldwide work in the textile or clothing industry. Recent studies have recognized the contribution of workplace exposures to chronic lung diseases, in particular chronic obstructive pulmonary disease (COPD). Early studies in textile workers have focused on the relationship between hemp or cotton dust exposure and the development of a syndrome termed byssinosis. The purpose of this review is to evaluate the effect of long-term exposure to organic dust in textile workers on chronic respiratory disease in the broader context of disease classifications, such as reversible or irreversible obstructive lung disease (i.e. asthma or COPD), and restrictive lung disease.

RECENT FINDINGS

Cessation of exposure to cotton dust leads to improvement in lung function. Recent animal models have suggested a shift in the lung macrophage:dendritic cell population ratio as a potential mechanistic explanation for persistent inflammation in the lung due to repeated cotton dust-related endotoxin exposure. Other types of textile dust, such as silk, may contribute to COPD in textile workers.

SUMMARY

Textile dust-related obstructive lung disease has characteristics of both asthma and COPD. Significant progress has been made in the understanding of chronic lung disease due to organic dust exposure in textile workers.

Cotton dust, endotoxin and cancer mortality among the Shanghai textile workers cohort: a 30-year analysis

BACKGROUND

Although occupational exposure to cotton dust and endotoxin is associated with adverse respiratory health, associations with cancer are unclear. We investigated cancer mortality in relation to cotton dust and endotoxin exposure in the Shanghai textile workers cohort.

METHODS

We followed 444 cotton textile and a reference group of 467 unexposed silk workers for 30 years (26 777 person-years). HRs for all cancers combined (with and without lung cancer) and gastrointestinal cancer were estimated in Cox regression models as functions of cotton textile work and categories of cumulative exposure (low, medium, high), after adjustment for covariates including pack-years smoked. Different lag years accounted for disease latency.

RESULTS

Risks of mortality from gastrointestinal cancers and all cancers combined, with the exclusion of lung cancer, were increased in cotton workers relative to silk workers. When stratified by category of cumulative cotton exposure, in general, risks were greatest for 20-year lagged medium exposure (all cancers HR=2.7 (95% CI 1.4 to 5.2); cancer excluding lung cancer HR=3.4 (1.7-7.0); gastrointestinal cancer HR=4.1 (1.8-9.7)). With the exclusion of lung cancer, risks of cancer were more pronounced. When stratified by category of cumulative endotoxin exposure, consistent associations were not observed for all cancers combined. However, excluding lung cancer, medium endotoxin exposure was associated with all cancers and gastrointestinal cancer in almost all lag models.

CONCLUSIONS

Cotton dust may be associated with cancer mortality, especially gastrointestinal cancer, and endotoxin may play a causative role. Findings also indirectly support a protective effect of endotoxin on lung cancer.

Evaluation of pulmonary function within a cohort of flavorings workers

OBJECTIVES

We present a re-analysis of a recent Health Hazard Evaluation (HHE) that was performed by the US National Institute for Occupational Safety and Health (NIOSH) regarding the pulmonary status of workers at a flavorings manufacturing facility. This facility has used acetaldehyde, acetoin, benzaldehyde, butyric acid, diacetyl and many other flavoring chemicals for many years.

METHODS

Ten years of spirometry testing and job descriptions data on 112 workers were analyzed by the authors and by NIOSH. Using NIOSH's exposure assessment criteria, we compared the prevalence of restrictive findings (as determined by spirometry testing) in production workers to an internal control group that had reduced or no potential for exposure to flavoring chemicals. NIOSH used multiple linear regression to evaluate changes in pulmonary function by the exposure group. After our review of the NIOSH findings, we evaluated associations between longitudinal changes in pulmonary health and workplace exposures through the use of generalized estimating equations. We then compared our results to those obtained by NIOSH.

RESULTS

We found that the prevalence of pulmonary restriction was similar in production workers and internal controls. We found no relationship between the magnitude of exposure to flavorings chemicals and observed decrements in pulmonary function. Our findings were contrary to those reported by NIOSH, most likely because of how we accounted for the longitudinal nature of the spirometric data.

CONCLUSION

Many years of exposures to flavoring chemicals in this workplace, including diacetyl, were not found to produce an increased risk of abnormal spirometric findings.

Evidence of a paradoxical relationship between endotoxin and lung cancer after accounting for left truncation in a study of Chinese female textile workers

INTRODUCTION

Occupational exposure to endotoxin, found in Gram-negative bacteria in organic material, has been associated predominantly with a reduced risk of lung cancer among workers. An inverse exposure-response gradient among women textile workers in Shanghai, China, has been reported previously. In this case-cohort study, we investigated the influence of left truncation, which can itself induce a downward trend, on the observed association.

METHODS

Subjects were enrolled between 1989 and 1991 and followed until 1998. The data were left-truncated as all subjects were hired before baseline. An analysis was performed with 3038 subcohort members and 602 cases of incident lung cancer. To evaluate left truncation, we compared lung cancer rates in those hired longer ago with those hired more recently among unexposed subjects. Cox proportional hazards modelling was used to estimate incident rate ratios (IRRs) and 95% CIs.

RESULTS

Among those who were never exposed to workplace endotoxin, we compared lung cancer rates in those hired >35 years before enrolment with workers hired ≤35 years before enrolment and observed a reduced risk in the former group, IRR=0.74, 95% CI (0.51 to 1.07). After accounting for this downward bias from left truncation, the reduced risk associated with endotoxin remained among those hired ≤50 years before enrolment. In contrast, there was suggestion of an increased risk of lung cancer among those hired >50 years ago.

CONCLUSIONS

After examination of left truncation bias, an inverse dose-response between endotoxin and lung cancer remained for all subjects except those hired longest ago.

Smoking cessation and environmental hygiene

Although there are nonmodifiable genetic risk factors for COPD, most known risk factors for development and progression of COPD can be corrected. Continued efforts to encourage smoking cessation and measures to reduce exposure to SHS, outdoor air pollution, biomass smoke, and occupational and related amateur exposures will have a significant impact on worldwide health.

Bespoke latex allergen testing improves assessment of respiratory symptoms in textile-braiding workers

BACKGROUND

Latex allergy is poorly understood in latex-exposed textile workers.

METHODS

A cross-sectional study was carried out to better characterize respiratory symptoms, using personal breathing zone latex allergen measurement and specific IgE to latex allergens.

RESULTS

Forty-four of the 86 (51% participation rate) participated. Ten of 39 workers who gave a blood sample (25.6%) were found to have IgE to at least one workplace allergen (5/39 positive to either latex braiding coated with silica or talc, 4/39 were positive to the dyed cotton extract, and 1/39 to latex braiding coated with silica or talc and dyed cotton extract), whilst only 2 of these 10 had specific IgE to the commercial latex extract.

CONCLUSIONS

The presence of symptoms with evidence of sensitization was strongly dictated by current latex exposure. Bespoke workplace allergen IgE testing identified cases of WR respiratory symptoms with sensitization that otherwise would not have been identified.

Pneumoproteins in sewage workers exposed to sewage dust

Purpose

The association between exposure to bacteria and endotoxins in sewage dust and the serum concentrations of pneumoproteins in sewage treatment plant workers were studied.

Methods

Forty-four workers from eight sewage treatment plants and 38 reference workers participated in the study. Microbial aerosol was collected by personal inhalable samplers. The concentrations of bacteria and endotoxins were determined by fluorescence microscopy and the Limulus assay, respectively. Pneumoproteins (Clara cell protein: CC16, and Surfactant proteins A and D: SP-A, SP-D) were determined by ELISA in blood samples collected post-shift.

Results

The exposure to dust ranged from 0.02 to 9.3 (geometric mean (GM) 0.3 mg/m³, of bacteria from 0.3 to 4,900 × 10³ (GM 27 × 10³) cells/m³ and endotoxins from 1 to 3,160 (GM 28) EU/m³. The exposed workers had lower CC16 [arithmetic mean (AM) 4.9 ng/ml] compared to the referents (AM 6.4 ng/ml, p < 0.01). No significant difference was observed for SP-D and SP-A. Exposure to bacteria was positively associated with CC16 (p < 0.05) and SP-D (p < 0.05), adjusting for possible confounders.

Conclusions

This study showed that exposed workers had lower serum concentration of CC16 as compared to the referents, which may reflect a long-term effect on secretion of these pneumoproteins. The positive association between exposure to bacteria and the serum concentrations of CC16 and SP-D may be explained by a transient increased permeability of the lung–blood barrier.

Ventilatory functions in cotton textile workers and the role of some inflammatory cytokines

Exposure to cotton dust in industrial environments causes inflammation in the airways of the exposed workers. This may manifest as respiratory complaints and changes in the respiratory functions after work shift and in the baseline of their ventilatory functions. The study aimed to investigate the effect of occupational exposure to cotton dust on respiratory symptoms, ventilatory functions and pro-inflammatory cytokine levels (tumor necrosis factor α, interleukin 6 and interleukin 1β). The study was conducted on 63 textile workers and 65 nonexposed subjects. Both groups were matched for age, socioeconomic status and smoking habit. The respirable dust measured in the workplace did not exceed the permissible values of the Egyptian law 1994. The bacterial counts detected were within the occupational exposure limits of the industrial settings. The results revealed that the percentage of respiratory symptoms was higher in textile workers. Respiratory complaints were chronic cough (33.2%), chronic bronchitis (39.7%) and dyspnea (23.8%) in textile workers compared to (6.2%, 6.2% and 1.5%), respectively, in controls. There was a marked reduction in the ventilatory functions (forced vital capacity and forced expiratory volume in 1 s) in the textile workers compared to the controls. The additive effect of smoking on the ventilatory functions was not apparent. The ventilatory functions of the workers were significantly positively correlated with the duration of exposure. The cytokines were insignificantly higher in the textile workers compared to their controls. The textile workers with respiratory complaints showed significant decline in ventilatory functions and elevation in the cytokine levels compared to the nonsymtomatizing workers with significant difference in interleukin 1β and interleukin 6. In conclusion, the results supported the fact that exposure to cotton dust deteriorates ventilatory functions and elevates proinflammatory cytokine levels. Analysis of the release of cytokines can be used to evaluate the immune responses to organic dust-induced airway inflammation.

A cross-shift study of lung function, exhaled nitric oxide and inflammatory markers in blood in Norwegian cement production workers

OBJECTIVES

To study possible effects of aerosol exposure on lung function, fractional exhaled nitric oxide (FeNO) and inflammatory markers in blood from Norwegian cement production workers across one work shift (0 to 8 h) and again 32 h after the non-exposed baseline registration.

METHODS

95 workers from two cement plants in Norway were included. Assessment of lung function included spirometry and gas diffusion pre- and post-shift (0 and 8 h). FeNO concentrations were measured and blood samples collected at 0, 8 and 32 h. Blood analysis included cell counts of leucocytes and mediators of inflammation.

RESULTS

The median respirable aerosol level was 0.3 mg/m(3) (range 0.02-6.2 mg/m(3)). FEV(1), FEF(25-75%) and DL(CO) decreased by 37 ml (p=0.04), 170 ml/s (p<0.001) and 0.17 mmol/min/kPa (p=0.02), respectively, across the shift. A 2 ppm reduction in FeNO between 0 and 32 h was detected (p=0.01). The number of leucocytes increased by 0.6×10(9) cells/l (p<0.001) across the shift, while fibrinogen levels increased by 0.02 g/l (p<0.001) from 0 to 32 h. TNF-α level increased and IL-10 decreased across the shift. Baseline levels of fibrinogen were associated with the highest level of respirable dust, and increased by 0.39 g/l (95% CI 0.06 to 0.72).

CONCLUSIONS

We observed small cross-shift changes in lung function and inflammatory markers among cement production workers, indicating that inflammatory effects may occur at exposure levels well below 1 mg/m(3). However, because the associations between these acute changes and personal exposure measurements were weak and as the long-term consequences are unknown, these findings should be tested in a follow-up study.

Reduced lung cancer mortality and exposure to synthetic fluids and biocide in the auto manufacturing industry

OBJECTIVES

Water-based soluble and synthetic metalworking fluids (MWF) used in auto manufacturing may be contaminated by endotoxin from Gram-negative bacteria, a possible anticarcinogen via increased immuno-surveillance. The effectiveness of biocide, generally added to limit bacterial growth is unknown. We investigated whether an inverse relationship between lung cancer and synthetic MWF and biocide - as surrogates of endotoxin exposure - persisted in an extended follow-up of autoworkers.

METHODS

A nested case-control analysis was performed within a retrospective cohort study of 46 399 auto manufacturing workers. Follow-up began in 1941 and was extended from 1985-1995. Mortality rate ratios (MRR) were estimated in Cox regression models for lung cancer as discrete and smoothed functions of cumulative exposure to synthetic MWF (mg/m (3)per year) and years exposed to biocide with both synthetic and soluble MWF. The analysis was also restricted to the subcohort hired on or after 1941 and stratified by follow-up period.

RESULTS

The splines suggested a non-linear inverse exposure-response for lung cancer mortality with increasing endotoxin exposure. Overall, the greatest reduction in mortality was observed among those with the highest exposure [MRR 0.63, 95% confidence interval (95% CI) 0.39-0.98] at the 99 (th)percentile of exposure (15.8 mg/m (3)per year). Evidence for an inverse effect was limited to the earlier follow-up period. Effect modification by biocide was marginally significant (P=0.07); the protective effect of synthetic MWF was observed only for those who were co-exposed.

CONCLUSIONS

The protective effect of synthetic MWF against lung cancer mortality persisted through the extended period of follow-up, although attenuated, and was observed only among workers with co-exposure to biocide and synthetic MWF.

Chronic lung function decline in cotton textile workers: roles of historical and recent exposures to endotoxin

BACKGROUND

Long-term occupational exposure to cotton dust that contains endotoxin is associated with chronic respiratory symptoms and excessive decline in forced expiratory volume in 1 sec (FEV1), but the mechanisms of endotoxin-related chronic airflow obstruction remain unclear.

OBJECTIVE

In the current study, we examined temporal aspects of the exposure-response relationship between airborne endotoxin exposure, longitudinal change in FEV1, and respiratory symptoms in a cohort of Chinese cotton textile workers.

METHODS

This prospective cohort study followed 447 cotton textile workers from 1981 to 2006. at approximately 5-year intervals. We used a generalized estimating equations approach to model FEV1 level and respiratory symptoms as a function of past exposure (cumulative exposure up to the start of the most recent 5-year survey interval) and cumulative exposure (within the most recent interval) to endotoxins, after adjusting for other covariates. Models were stratified by active versus retired work status and by years employed before the baseline survey (< 5 and > or = 5 years).

RESULTS AND CONCLUSIONS

Past exposure to endotoxin was associated with reduced FEV1 level among retired cotton workers. Among all cotton workers, past exposure was more strongly associated with reduced FEV1 for those hired < 5 years before baseline than for those who were hired > or = 5 years after baseline. Recent endotoxin exposure was significantly associated with byssinosis, chronic bronchitis, and chronic cough.

Prevalence and risk factors for obstructive respiratory conditions among textile industry workers in Zimbabwe, 2006

Introduction: Workers in the cotton processing industries risk developing obstructive respiratory conditions due to prolonged exposure to cotton dust. We noted a tenfold increase in asthma among workers in a Textile Manufacturing Company. We determined the prevalence of respiratory obstructive conditions among workers in various sections. Methods We conducted a cross sectional analytic study. Workers were randomly sampled and data was collected using interviewer-administered questionnaires. Respiratory function was assessed using spirometry and chest auscultation. A walk through survey was conducted and a checklist was used to capture hazards and control measures in the work place. Results A total of 194 workers participated. The prevalence of severe respiratory obstruction was 27.8%. It was 50.0% among the blowers, 35.3% in waste recovery, 32.5% in carders, 15.0% in spinners and 7.5% among weavers. The mean years of exposure between the affected and the non-affected were significantly different (T =2.20; p< 0.05). Working in the blowing department was significantly associated with developing respiratory obstruction (OR=3.53; 95% CI= 1.61-7.79) but working in the weaving department was significantly protective (OR 0.16; CI 0.04-0.59).Working in a department for less than 10 years was protective (OR =0.94; 95% CI= 0.48-1.85), but not significant. Conclusion Obstructive respiratory conditions are common among textile workers, with those in blowing and waste recovery sections being the most affected. We recommended worker rotation every six months, regular spirometric screening employment of a medical officer.

Reduction in cotton dust concentration does not totally eliminate respiratory health hazards: the Greek study

A number of epidemiological studies have shown that byssinosis is associated with exposure to high levels of cotton dust. In this first survey, the prevalence of respiratory symptoms in cotton workers under low concentration of cotton dust was investigated. A respiratory questionnaire consisting of 47 questions was given to 443 cotton workers. Their lung function was measured with spirometry. Breathing zone cotton dust concentration was measured by personal samplers and static sampling was used to define the level of the work area concentration. Workers with abnormalities in the pulmonary function parameters, including forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC) and peak expiratory flow rate (PEFR), were 5.9%. In this group of operatives 7.7% had symptoms compatible with byssinosis, 65.4% of them were smokers, 69.2% of them had symptoms of allergic rhinitis, while 72.2% of them were smokers. Asthma, which appeared after the age of 30, was reported by 57.7%, while 60% of them were smokers. Mean breathing zone cotton dust concentration was 0.16 mg/m³ and the mean work area cotton dust concentration 0.14 mg/m³. Despite the reduction in cotton dust concentration, byssinosis symptoms, allergic rhinitis, asthma and impaired pulmonary function are the most common findings in our cotton workers depending on the duration of exposure, whether they are smokers or not and the nature of the cotton dust.

A probabilistic approach to quantitatively assess the inhalation risk for airborne endotoxin in cotton textile workers

Endotoxin, a component of gram-negative bacterial cell walls, is a proinflammatory agent that induces local and systemic inflammatory responses in normal subjects which can contribute to the risk of developing asthma and chronic obstructive lung diseases. A probabilistic approach linking models of exposure, internal dosimetry, and health effects were carried out to quantitatively assess the potential inhalation risk of airborne endotoxin for workers in cotton textile plants. Combining empirical data and modeling results, we show that the half-maximum effects of the endotoxin dose (ED50) were estimated to be 3.3 x 10(5) (95% confidence interval (CI): 1.9-14.7 x 10(5)) endotoxin units (EU) for the blood C-reactive protein (CRP) concentration, 1.1 x 10(5) (95% CI: 0.6-1.7 x 10(5))EU for the blood polymorphonuclear neutrophil (PMN) count, and 1.5 x 10(5) (95% CI: 0.4-2.5 x 10(5))EU for the sputum PMN count. Our study offers a risk-management framework for discussing future establishment of limits for respiratory exposure to airborne endotoxin for workers in cotton textile plants.

Long-term effects of work cessation on respiratory health of textile workers: a 25-year follow-up study

RATIONALE

The degree to which chronic respiratory health effects caused by exposures to cotton dust and endotoxin is reversible after cessation of textile work is unknown.

OBJECTIVES

To investigate changes in lung function and respiratory symptoms after cessation of textile work and to determine whether past exposure to cotton dust and endotoxin or smoking history modify the associations.

METHODS

We performed a prospective cohort study consisting of 447 cotton textile workers exposed to cotton dust and 472 unexposed silk textile workers, with a 25-year follow-up. Spirometry testing and respiratory questionnaires were conducted at 5-year intervals. Generalized estimated equations were used to model the average 5-year change in FEV(1) and odds ratios of respiratory symptom prevalence.

MEASUREMENTS AND MAIN RESULTS

Years since cessation of textile work was positively associated with 11.3 ml/yr and 5.6 ml/yr gains in 5-year FEV(1) change for cotton and silk workers, respectively. Among male cotton workers, smokers gained more FEV(1) per year after cessation of exposure than did nonsmokers, and the risk of symptoms of chronic bronchitis and byssinosis was larger for smoking than for nonsmoking male cotton workers.

CONCLUSIONS

Cessation of textile work was significantly associated with improvement in lung function and respiratory symptoms. The positive effect of work cessation was greater for cotton workers than for silk workers. For cotton workers, the improvement in lung function loss after cessation of textile work was greater among smokers, but no differences were observed for silk workers.

Effect of occupation and smoking on respiratory symptoms in working children

OBJECTIVES

To compare the respiratory symptoms and the lung function of children who work in different occupational groups.

METHODS

The study was performed among children attending vocational training centers. The participants were evaluated in six different occupation groups. Chronic cough, wheezing and shortness of breath were evaluated by questionnaire. The association of independent variables with the respiratory symptoms was investigated through both univariate and multivariate methods.

RESULTS

Among 642 children, 534 were males; the mean age was 17.7 +/- 1.0 years. Using an internal reference group, the odds ratios of chronic cough were significantly higher in the lathe (OR: 2.0, 95%CI: 1.07-3.74), coiffure (OR: 1.94. 95%CI: 1.01-3.70), and electricity-construction (OR: 2.63, 95%CI: 1.06-6.54) groups after adjustment for smoking, age, gender, and work characteristics. There were no significant differences in spirometric values between occupational groups in either smoking or non-smoking males. In non-smoking females, median values of FEV(1) (P: 0.046), PEF (P: 0.005) and FEF(25-75%) (P: 0.019) were lower in the textile compared to the coiffure group. There was no significant association between the total working time and spirometric values. There was no statistically significant relationship between the work-related factors and the smoking status.

CONCLUSIONS

The prevalence of chronic cough was higher in the lathe, coiffure, and electricity-construction groups and pulmonary function tests were lower in the non-smoking textile female group. Working children should be screened for respiratory symptoms and disease.