Trends in occupational respiratory conditions with short latency in the UK.

BACKGROUND: Occupational short-latency respiratory disease (SLRD; predominantly asthma, rhinitis, hypersensitivity pneumonitis, and occupational infections) prevalence is difficult to determine but certain occupations may be associated with increased susceptibility. AIMS: This study aimed to examine which occupations and industries are currently at high risk for SLRD and determine their respective suspected causal agents. METHODS: SLRD cases reported to the SWORD scheme between 1999 and 2019 were analysed to determine directly standardized rate ratios (SRR) by occupation against the average rate for all other occupations combined. RESULTS: 'Bakers and flour confectioners' and 'vehicle spray painters' showed significantly raised SRR for SLRD in general, mostly due to occupational rhinitis (234.4; 95% CI 200.5-274.0) and asthma (63.5; 95% CI 51.5-78.3), respectively. Laboratory technicians also showed significantly raised SRR for occupational rhinitis (18.7; 95% CI 15.1-23.1), primarily caused by laboratory animals and insects. Metal machining setters and setter-operators showed increased SRR for occupational hypersensitivity pneumonitis (42.0; 95% CI 29.3-60.3), largely due to cutting/soluble oils. The occupation mostly affected by infectious disease was welding trades (12.9; 95% CI 5.7-29.3), mainly attributable to microbial pathogenicity. CONCLUSIONS: This study identified the occupational groups at increased risk of developing an SLRD based on data recorded over a recent two-decade period in the UK. Occupational asthma and rhinitis were identified as the prevailing conditions and hypersensitivity pneumonitis as a potentially rising respiratory problem in the metalworking industry.

A national Health and Work Strategy: a search for evidence.

BACKGROUND: The Health and Safety Executive's new Health and Work Strategy is based on an up-to-date assessment of workplace health priorities. Rather than replicating traditional prioritization approaches, a broader assessment of health and work priorities was carried out using a range of stakeholders. AIMS: To develop a set of health priorities for further research and intervention activity. METHODS: Four exercises were carried out, including internal prioritization, two external web-hosted questionnaire studies of younger workers and occupational health professionals, focus groups and tele-depth interviews with workplace health and safety professionals. RESULTS: The highest rated internal priorities (weighted priority scores) were identified as mesothelioma (70), lung cancer (69.25), chronic obstructive pulmonary disease (COPD; 69), musculoskeletal disorders (MSDs; 66.25), hearing loss (65.75), stress (65.5), asthma (64.5) and hand-arm vibration syndrome (61.5). Using the three highest ranked criteria developed by occupational health professionals ((i) the preventability of the condition, (ii) the impact of the condition and (iii) the number of workers affected), mesothelioma, lung cancer, COPD, MSDs, hearing loss, stress and asthma were identified as the top seven priorities. Generic issues identified included ageing and work, obesity, newer technologies, and ethnicity and cultures of workforces. Apprentices identified stress, depression, anxiety, musculoskeletal and respiratory disorders, fatigue and workload as important workplace health considerations. CONCLUSIONS: This process identified a number of expected and new areas of health research interest. We believe the findings reflect the real world requirements of work as assessed by occupational health and safety practitioners and workers.

Underestimation of spirometry if recommended testing guidance is not followed.

Background: Lung function measured at work is used to make important employment decisions. Improving its quality will reduce misclassification and allow more accurate longitudinal interpretation over time. Aims: To assess the amount by which lung function (forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC]) values will be underestimated if recommended spirometry testing guidance is not followed. Methods: Lung function was measured in a population of workers. Knowledge of the final reproducible FEV1 and FVC for each worker allowed estimation of the underestimates that would have occurred if less forced manoeuvres than recommended had been performed. Results: A total of 667 workers (661 males, mean age 43 years, range 18-66) participated. Among them, 560 (84%) achieved reproducible results for both FEV1 and FVC; 470 (84%) of these did so after three technically acceptable forced expiratory manoeuvres, a cumulative total of 533 after four, 548 after five, 557 after six, 559 after seven and 560 after eight blows. If only one (or first two) technically acceptable blow(s) had been performed, mean underestimates were calculated for FEV1 of 115.1 ml (35.4 ml) and for FVC of 143.4 ml (42.3 ml). Conclusions: In this study, reproducible spirometry was achievable in most workers. Not adhering to standards underestimates lung function by clinically significant amounts.

Asthma in furniture and wood processing workers: a systematic review.

BACKGROUND: Wood dust is a common cause of occupational asthma. There is potential for high exposure to wood dust during furniture and wood manufacturing processes. AIMS: To evaluate the evidence for non-neoplastic respiratory ill health associated with work in the furniture and wood manufacturing sector. METHODS: A systematic review was performed according to PRISMA guidelines. Articles were graded using SIGN (Scottish Intercollegiate Guideline Network) and MERGE (Methods for Evaluating Research Guidelines and Evidence) criteria, with data grouped by study outcome. RESULTS: Initial searches identified 1328 references, from which 55 articles were included in the review. Fourteen studies were graded A using MERGE or >2++ using SIGN. All but one paper describing airway symptoms reported an increased risk in higher wood dust exposed workers in comparison to lower or non-exposed groups. Five studies reporting asthma examined dose response; three found a positive effect. The relative risk for asthma in exposed workers in the single meta-analysis was 1.5 (95% CI 1.25-1.87). Two studies reported more obstructive lung function (forced expiratory volume in 1 s [FEV1]/forced vital capacity < 0.7) in exposed populations. Excess longitudinal FEV1 decline was reported in female smokers with high wood dust exposures in one study population. Where measured, work-related respiratory symptoms did not clearly relate to specific wood immunoglobulin E positivity. CONCLUSIONS: Work in this sector was associated with a significantly increased risk of respiratory symptoms and asthma. The evidence for wood dust exposure causing impaired lung function is less clearly established. Further study is required to better understand the prevalence, and causes, of respiratory problems within this sector.

UK asbestos imports and mortality due to idiopathic pulmonary fibrosis.

BACKGROUND: Previous studies have demonstrated that the rising mortality due to mesothelioma and asbestosis can be predicted from historic asbestos usage. Mortality due to idiopathic pulmonary fibrosis (IPF) is also rising, without any apparent explanation. AIMS: To compare mortality due to these conditions and examine the relationship between mortality and national asbestos imports. METHODS: Mortality data for IPF and asbestosis in England and Wales were available from the Office for National Statistics. Data for mesothelioma deaths in England and Wales and historic UK asbestos import data were available from the Health & Safety Executive. The numbers of annual deaths due to each condition were plotted separately by gender, against UK asbestos imports 48 years earlier. Linear regression models were constructed. RESULTS: For mesothelioma and IPF, there was a significant linear relationship between the number of male and female deaths each year and historic UK asbestos imports. For asbestosis mortality, a similar relationship was found for male but not female deaths. The annual numbers of deaths due to asbestosis in both sexes were lower than for IPF and mesothelioma. CONCLUSIONS: The strength of the association between IPF mortality and historic asbestos imports was similar to that seen in an established asbestos-related disease, i.e. mesothelioma. This finding could in part be explained by diagnostic difficulties in separating asbestosis from IPF and highlights the need for a more accurate method of assessing lifetime occupational asbestos exposure.

Health surveillance for occupational asthma in the UK.

BACKGROUND: Periodic health surveillance (HS) of workers can identify early cases of occupational asthma. Information about its uptake and its content in the UK is lacking. AIMS: To identify the overall levels of uptake and quality of HS for occupational asthma within three high-risk industry sectors in the UK. METHODS: A telephone survey of employers, and their occupational health (OH) professionals, carried out in three sectors with exposures potentially capable of causing occupational asthma (bakeries, wood working and motor vehicle repair). RESULTS: A total of 457 organizations participated (31% response rate). About 77% employed <10 people, 17% between 10 and 50 and 6% >50. Risk assessments were common (67%) and 14% carried out some form of HS for occupational asthma, rising to 19% if only organizations reporting asthma hazards and risks were considered. HS was carried out both by in-house (31%) and external providers (69%). Organizational policies were often used to define HS approaches (80%), but infrequently shared with the OH provider. OH providers described considerable variation in practice. Record keeping was universal, but worker-held records were not reported. HS tools were generally developed in-house. Lung function was commonly measured, but only limited interpretation evident. Referral of workers to local specialist respiratory services was variable. CONCLUSIONS: This study provided new insights into the real world of HS for occupational asthma. We consider that future work could and should define simpler, more practical and evidence-based approaches to HS to ensure maximal consistency and use of high-quality approaches.

Development of an occupational airborne chemical exposure matrix.

BACKGROUND: Population-based studies of the occupational contribution to chronic obstructive pulmonary disease generally rely on self-reported exposures to vapours, gases, dusts and fumes (VGDF), which are susceptible to misclassification. AIMS: To develop an airborne chemical job exposure matrix (ACE JEM) for use with the UK Standard Occupational Classification (SOC 2000) system. METHODS: We developed the ACE JEM in stages: (i) agreement of definitions, (ii) a binary assignation of exposed/not exposed to VGDF, fibres or mists (VGDFFiM), for each of the individual 353 SOC codes and (iii) assignation of levels of exposure (L; low, medium and high) and (iv) the proportion of workers (P) likely to be exposed in each code. We then expanded the estimated exposures to include biological dusts, mineral dusts, metals, diesel fumes and asthmagens. RESULTS: We assigned 186 (53%) of all SOC codes as exposed to at least one category of VGDFFiM, with 23% assigned as having medium or high exposure. We assigned over 68% of all codes as not being exposed to fibres, gases or mists. The most common exposure was to dusts (22% of codes with >50% exposed); 12% of codes were assigned exposure to fibres. We assigned higher percentages of the codes as exposed to diesel fumes (14%) compared with metals (8%). CONCLUSIONS: We developed an expert-derived JEM, using a strict set of a priori defined rules. The ACE JEM could also be applied to studies to assess risks of diseases where the main route of occupational exposure is via inhalation.

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.

Production and function of IL-12 in islets and beta cells.

AIMS/HYPOTHESIS: IL-12 is an important cytokine in early inflammatory responses and is implicated in the immune-mediated pathogenesis of pancreatic islets in diabetes. However, little is known about the direct effects of IL-12 on islets and beta cells. METHODS: In this study, beta cell function, gene expression and protein production were assessed in primary human donor islets and murine beta cell lines in response to stimulation with IL-12 or a pro-inflammatory cytokine cocktail (TNF-α, IL-1ß and IFN-γ). RESULTS: The pro-inflammatory cytokine cocktail induced islet dysfunction and potently increased the expression and production of IL-12 ligand and IL-12 receptor in human islets. In human islets, the receptor for IL-12 co-localised to the cell surface of insulin-producing cells. Both IL-12 ligand and IL-12 receptor are expressed in the homogeneous beta cell line INS-1. IL-12 induced changes in gene expression, including a dose-dependent upregulation of IFNγ (also known as IFNG), in INS-1 cells. A neutralising antibody to IL-12 directly inhibited IFNγ gene expression in human donor islets induced by either IL-12 or pro-inflammatory cytokine stimulation. Functionally, IL-12 impaired glucose-stimulated insulin secretion (GSIS) in INS-1 cells and human donor islets. A neutralising antibody to IL-12 reversed the beta cell dysfunction (uncoupling of GSIS or induction of caspase-3 activity) induced by pro-inflammatory cytokines. CONCLUSIONS/INTERPRETATION: These data identify beta cells as a local source of IL-12 ligand and suggest a direct role of IL-12 in mediating beta cell pathology.

Interaction between cytokines and inflammatory cells in islet dysfunction, insulin resistance and vascular disease.

Inflammation is an established pathogenic player in insulin resistance, islet demise and atherosclerosis. The complex interactions between cytokines, immune cells and affected tissues result in sustained inflammation in diabetes and atherosclerosis. 12- and 15-lipoxygenase (LO), such as 12/15-LO, produces a variety of metabolites through peroxidation of fatty acids and potentially contributes to the complex molecular crosstalk at the site of inflammation. 12- and 15-LO pathways are frequently activated in tissues affected by diabetes and atherosclerosis including adipose tissue (AT), islets and the vasculature. Moreover, mice with whole body and tissue-specific knockout of 12/15-LO are protected against insulin resistance, hyperglycaemia and atherosclerosis supporting functional contribution of 12- and 15-LO pathways in diabetes and atherosclerosis. Recently, it has emerged that there is a temporal regulation of the particular isoforms of 12- and 15-LO in human AT and islets during the development of type 1 and type 2 diabetes and obesity. Analyses of tissues affected by diabetes and atherosclerosis also implied the roles of interleukin (IL)-12 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-1 (NOX-1) in islets and IL-17A in atherosclerosis. Future studies should aim to test the efficacy of inhibitions of these mediators for treatment of diabetes and atherosclerosis.

Health surveillance for occupational respiratory disease.

BACKGROUND: Occupational lung diseases remain common, and health surveillance is one approach used to assist identification of early cases. AIMS: To identify areas of good practice within respiratory health surveillance and to formulate recommendations for practice. METHODS: Published literature was searched since 1990 using a semi-systematic methodology. RESULTS: A total of 561 documents were identified on Medline and Embase combined. Other search engines did not identify relevant documents that had not already been identified by these two main searches. Seventy-nine of these were assessed further and 36 documents were included for the full analysis. CONCLUSIONS: Respiratory health surveillance remains a disparate process, even within disease type. A standard validated questionnaire and associated guidance should be developed. Lung function testing was common and generally supported by the evidence. Cross-sectional interpretation of lung function in younger workers needs careful assessment in order to best identify early cases of disease. More informed interpretation of the forced expiratory volume in 1 s/forced vital capacity ratio, for example by using a lower limit of normal for each worker, and of longitudinal lung function information is advised. Immunological tests appear useful in small groups of workers exposed to common occupational allergens. Education, training and improved occupational health policies are likely to improve uptake of health surveillance, to ensure that those who fail health surveillance at any point are handled appropriately.

Smoking cessation in the workplace.

BACKGROUND: The workplace is an important setting for reaching potentially large numbers of smokers. AIMS: To review the evidence about smoking cessation in the workplace. METHODS: Literature review including a synthesis of findings from recent systematic reviews and meta-analyses of workplace smoking cessation programmes, a separate review of the qualitative evidence, case studies and an expert panel assessment. RESULTS: We found advantages, identified or confirmed from the mixed methods used in this work to holding smoking cessation programmes in the workplace. These included: (i) easy access to large numbers of worker populations for large workplaces, (ii) the potential improved recruitment to such programmes given this, (iii) the opportunity to access young men, traditionally difficult to achieve, (iv) access to occupational health and other staff who can assist with support and delivery and (v) ability for workers to attend relatively easily. Evidence on the importance of developing peer support at work was mixed. The simple provision or availability of programmes and interventions was unlikely to provide any beneficial behaviour change. Interventions should target workers that actively want to stop smoking, use elements that workers have identified as useful or focus on altering beliefs about smoking and the need to stop. CONCLUSIONS: Smoking cessation programmes at work can provide useful support for workers wishing to stop smoking. They are only likely to be effective if participants have moved beyond the contemplation stage regarding smoking cessation, so that stopping smoking is a personal priority.

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.

Sensitization and symptoms associated with soybean exposure in processing plants in South Africa.

BACKGROUND: Following the results of a previous study that highlighted the potential for significant levels of dust exposure in South African soybean processing plants, a clinical investigation was undertaken to study the respiratory health of workers in this industry. METHODS: Workers from three soybean-processing plants were studied with a respiratory questionnaire and estimation of atopy and specific soybean IgE. RESULTS: A total of 144 of the 181 (79.6% participation rate) plant employees completed the questionnaire and 136 (75.1%) gave blood samples for analysis of specific IgE. There was a significant association between work-related chest tightness (OR 4.0 [95% CI 1.3-12.6]), work-related nasal symptoms (OR 4.3 [95% CI 1.3-14.6]) and cough or chest tightness after handling soybean (OR 3.6 [95% CI 1.1-11.6]) and soybean sensitization. There was a significant association between current exposure to dust during soybean off-loading and "flu-like" illness (OR 2.7 [95% CI 1.0-7.2]), and cough or chest tightness after such work (OR 7.4 [95% CI 2.4-23.6]). The strongest predictor of work related nasal symptoms was sensitization to soybean, the latter strongly predicted by the presence of atopy (OR 34.7 [95% CI 6.6-182.5]). CONCLUSIONS: Exposure and sensitization to soybean were associated with the presence of work related symptoms, including flu-like symptoms, cough, chest tightness, and nasal symptoms. The aetiology of these symptoms and more particularly the best intervention strategies require more detailed investigation.

Self-reported work-related symptoms in hairdressers.

BACKGROUND: Detailed studies of current symptoms reported by hairdressers and of the training received to reduce the health risks associated with this work are uncommon. AIMS: To document current levels of self-reported health problems in hairdressers, compared to non-hairdressing controls. METHODS: An interviewer-led questionnaire recording demographic information, work history, health training levels and the presence of self-reported respiratory, skin, musculoskeletal and non-specific symptoms was administered. RESULTS: In total, 147 hairdressers, 86% of whom were female (median age 27 years) and 67 non-hairdressing controls, all female (median age 38 years) were recruited. Following adjustment for age, smoking and years worked, hairdressers reported significantly higher levels of musculoskeletal problems, including work-related shoulder pain (OR 11.6, 95% CI 2.4-55.4), work-related wrist and hand pain (2.8, 1.1-7.6), work-related upper back pain (3.8, 1.0-14.9), work-related lower back pain (4.9, 1.5-15.9) and work-related leg/foot pain (31.0, 3.8-267.4). The frequency of self-reported asthma was similar in both groups (hairdressers 16%, controls 17%) as was chest tightness and wheeze. Work-related cough was significantly more frequently reported in hairdressers than in controls (13.2, 1.3-131.5). While hairdresser training was commonplace, such training did not always appear to have resulted in awareness of potential workplace health risks. CONCLUSIONS: This study identified frequently reported musculoskeletal, skin and respiratory symptoms in hairdressers. This points to a need to develop training that not only deals with risk assessment but also informs hairdressers about the health risks of their work.

Medium-density fibreboard and occupational asthma. A case series.

BACKGROUND: Medium-density fibreboard (MDF) is a wood composite material, composed primarily of softwood, bonded with a synthetic formaldehyde-based resin. It is increasingly used, as it has various advantages over natural woods. METHODS: Enquiry of the national reporting scheme data and three case reports were used to further the evidence base linking this exposure to occupational asthma (OA). RESULTS: From 1991 to 2007, 21 cases of occupational sensitization to MDF were reported to the UK voluntary reporting scheme, Surveillance of Work Related Occupational Respiratory Disease (SWORD): 18 reported as occupational asthma (OA) and 3 as occupational rhinitis. All workers were male, with a mean age of 48 years, working in education, furniture manufacturing or joinery among other employments. CONCLUSIONS: Whilst reporting scheme data identified relatively small numbers of cases of OA likely to be due to MDF, the evidence base supporting this link is generally lacking. The three cases presented, where OA was attributed to MDF exposure, add to this evidence.

Impact of worker education on respiratory symptoms and sensitization in bakeries.

BACKGROUND: Flour exposure is known to cause significant respiratory problems. AIMS: To investigate the development of work-related sensitization, the period between first exposure and the development of symptoms (latent period) and the impact of workplace training programmes on respiratory health in plant bakers. METHODS: Two hundred and sixty-four bakers were investigated by assessing work-related respiratory symptoms and latent period before symptoms/sensitization, spirometry and testing for an array of workplace-specific IgE. RESULTS: There was a significant relationship between the presence of work-related respiratory symptoms and flour dust allergen-specific IgE. Latent periods varied widely: median for work-related nasal symptoms 36 months, cough 42 months and chest tightness 120 months. Latent periods were shorter for workers with evidence of flour sensitization (work-related wheeze: mean 13 months with sensitization, 97 months without, P < 0.05, work-related nasal symptoms, respectively; mean 19 months, 71 months, P < 0.01). Those warned of the health implications of flour dust had less work-related wheeze (warned; 1%, not warned 11%, P < 0.05). There was an excess of work-related symptoms and work-related-specific IgE combined in those who had not been warned of these health implications (12 versus 1%, P <0.01). CONCLUSIONS: Reporting of 'being warned' of potential health implications from breathing flour dust protected strongly against the reporting of important health end points. Latent periods for the development of work-related symptoms varied widely. Simple health messages, which may be overlooked in worker training programmes, can have significant benefits for worker health in the bakery population.

Work-related symptoms in nail salon technicians.

BACKGROUND: Nail salons are a rapidly expanding small business sector. Environmental health practitioners have raised concerns about potential health and safety issues. AIMS: To establish the extent of work-related health issues reported by nail salon technicians, their knowledge of health and safety regulations and of the products used. METHODS: Nail technicians completed a researcher-administered questionnaire, and responses were compared to those of non-exposed office-based control subjects. RESULTS: In all, 39 of 588 nail salons approached agreed to participate (7%), with all 71 (100%) of the available nail technicians within these salons completing study questionnaires. The majority of the nail technicians (99%) had received training that had included aspects of health and safety and most reported being aware of the Control of Substances Hazardous to Health regulations (59/70, 84%) and risk assessments (65/70, 93%). Compared to the control group, the nail technicians reported statistically significant increased levels of work-related neck (OR 5.0, 95% CI 1.6-15.6), shoulder (15.0, 3.1-71.8), wrist/hand (3.6, 1.2-10.7) and lower back problems (3.5, 1.0-12.5). Work-related nasal symptoms were also significantly more common in nail technicians (6.2, 1.3-30.7). CONCLUSIONS: This study demonstrated a higher prevalence of a range of musculoskeletal problems and respiratory symptoms reported by nail technicians compared to office-based controls. An ergonomic and exposure assessment of work practices in this industry is warranted to identify the working practices associated with these symptoms, in order to inform best practice, supplement industry and regulatory guidance and develop appropriate practical work-based training.

Respiratory symptoms in insect breeders.

BACKGROUND: A number of specialist food suppliers in the UK breed and distribute insects and insect larvae as food for exotic pets, such as reptiles, amphibians and invertebrates. AIMS: To investigate the extent of work-related (WR) symptoms and workplace-specific serum IgE in workers potentially exposed to a variety of biological contaminants, including insect and insect larvae allergens, endotoxin and cereal allergens at a UK specialist insect breeding facility. METHODS: We undertook a study of respiratory symptoms and exposures at the facility, with subsequent detailed clinical assessment of one worker. All 32 workers were assessed clinically using a respiratory questionnaire and lung function. Eighteen workers consented to provide serum for determination of specific IgE to workplace allergens. RESULTS: Thirty-four per cent (11/32) of insect workers reported WR respiratory symptoms. Sensitization, as judged by specific IgE, was found in 29% (4/14) of currently exposed workers. Total inhalable dust levels ranged from 1.2 to 17.9 mg/m(3) [mean 4.3 mg/m(3) (SD 4.4 mg/m(3)), median 2.0 mg/m(3)] and endotoxin levels of up to 29435 EU/m(3) were recorded. CONCLUSIONS: Exposure to organic dusts below the levels for which there are UK workplace exposure limits can result in respiratory symptoms and sensitization. The results should alert those responsible for the health of similarly exposed workers to the potential for respiratory ill-health and the need to provide a suitable health surveillance programme.

Comparison of various airflow measurements in symptomatic textile workers.

AIMS: To investigate the poorly understood relationship between work-related respiratory symptoms, airway reactivity, across working shift change in forced expiratory volume in 1 s (FEV(1)) and work-related changes in serial peak expiratory flow (sPEF) measures in a group of textile workers. METHODS: Fifty-three workers, 34 exposed to cotton dust and 19 to man-made fibre (MMF), were investigated using a standard respiratory questionnaire, sPEF, across-shift FEV(1) measurement and airway responsiveness. RESULTS: Thirty-four workers (64%) were male, and 9 workers (17%) had a >5% across-shift fall in FEV(1), and these falls were associated with the presence of work-related symptoms. Seven workers had a positive sPEF chart as judged by the software analysis (OASYS), although there was no relationship between work-related symptoms and sPEF. Six cotton workers (18%) and one MMF worker (5%) had airway hyperreactivity, which was associated strongly with work-related symptoms. Five of the 7 subjects with a positive sPEF had airway hyperreactivity compared with 12 of 46 with a negative sPEF. CONCLUSIONS: In this worker group, the presence of work-related respiratory symptoms was best associated with airway hyperresponsiveness and across-shift changes in FEV(1). While a positive sPEF chart was associated with increased airway responsiveness, it was not associated with work-related symptoms. sPEF measurements may not be the initial investigation of choice for such workers. As these findings also have relevance to developing evidence-based approaches to health surveillance, further work is needed to better define these relationships in other workers complaining of work-related respiratory symptoms.