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To examine the prevalence of symptoms of asthma and allergy in different farming groups in New Zealand. A postal questionnaire was sent to a random sample of 2,500 farmers throughout New Zealand. The response rate was 77% (1,706 of 2,203 eligibles). The 12-month period prevalence of current asthma was 11.8% overall, compared with 15% in the general population. Asthma prevalence was higher for horse breeders/groomers (16.5%), pig farmers (18.2%), poultry farmers (17.4%), and those working with oats (17.4%). Asthma was also significantly elevated among those working with cleaning powders (14.7%). Women were more likely to report current asthma than were men (OR 1.8, 95% CI 1.3–2.5). Hay fever was significantly higher in deer and crop farmers, and farmers working with horses and goats; eczema was higher for goat and deer farmers. The lower overall prevalence of asthma in farmers may be due to the healthy worker effect. Among farmers, the types of farming associated with an elevated prevalence of asthma and allergy in New Zealand are deer and goat farming, working with horses, poultry, pigs, and crop farming. Females reported more current asthma than males. Am. J. Ind. Med. 35:51–57, 1999. © 1999 Wiley-Liss, Inc.

Background Exposure to cotton is known to produce a specific occupational disease known as byssinosis. A large population of textile workers was investigated to determine whether such exposure was also associated with chronic bronchitis once other possible aetiological factors had been accounted for.Methods A total of 2991 workers were investigated for the presence of symptoms compatible with chronic bronchitis. An MRC adapted respiratory questionnaire and MRC definition of chronic bronchitis were used for diagnostic labelling. Current and lifetime exposure to dust was estimated by personal and work area sampling, and the use of records of retrospective dust levels previously measured over the preceding 10 years. Airborne endotoxin exposure was measured using a quantitative turbidometric assay. Lung function tests were performed to measure forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC). A control group of workers exposed to man-made fibre textiles was identified. The comparative prevalence of chronic bronchitis in the two populations was assessed, allowing for sex, age, smoking habit, and ethnic origin. Two case referent studies were also performed; cases of chronic bronchitis were separately matched with controls from the cotton and control populations to determine the effect of the symptomatic state on lung function.Results After controlling for smoking (pack years), workers in a cotton environment were significantly more likely to suffer from chronic bronchitis and this was most marked in workers over 45 years of age (odds ratio 2.51 (CI 1.3 to 4.9); p<0.01). Regression analysis of all possible influencing parameters showed that cumulative exposure to cotton dust was significantly associated with chronic bronchitis after the effects of age, sex, smoking, and ethnic group were accounted for (p<0.0005). In the intra-cotton population case control study a diagnosis of chronic bronchitis was associated with a small decrement in lung function compared with controls: percentage predicted FEV₁ in cases 81.4% (95% CI 78.3 to 84.6), controls 86.7% (84.9 to 88.5); FVC in cases 89.9% (95% CI 87.0 to 92.9), controls 94.6% (92.8 to 96.4). After controlling for cumulative past exposure and pack years of smoking the effect of the diagnostic state remained significant for both FEV₁ (p<0.01) and FVC (p<0.05).Conclusions Chronic bronchitis is more prevalent in cotton workers than in those working with man-made fibre and exposure is additive to the effect of smoking. The diagnosis of chronic bronchitis is associated with a small but significant decrement in lung function.

Our objectives were to measure the prevalence of work-related and nonwork-related respiratory symptoms in a group of New Zealand mussel openers who open green-lipped mussels, and to relate these to demographic factors, work history, smoking history, and pulmonary function measurements. A cross-sectional study of respiratory symptoms and lung function was performed on 224 New Zealand mussel openers (99.6% of the study population) at nine work sites. In addition, peak expiratory flow (PEF) change across-shift was measured at one work site in 19 workers. The mean age of all mussel openers was 33.4 years and the mean duration of mussel opening was 5.0 years; 25% were male, 54.7% were current smokers, and 13.9% were ex-smokers. The reported symptom prevalences were: any wheeze, 35%; work-related wheeze, 23%; any chest tightness, 30.5%; work-related chest tightness, 20.2% (work-related symptoms were defined as symptoms improving on rest days or worse at work). Seventy-two mussel openers (32.3%) answered positively to at least 1 of 4 questions concerning work-related symptoms. The mean predicted FEV1 (SD) for this group was 74.3% (14.5), and the mean predicted FVC (SD) was 79.2% (16.0). Nineteen workers completed serial PEF, and the mean percentage change was +1.5% at 7 hr, but 8 workers had falls ranging between 1.1–14% after either 1 or 7 hr of work. Duration of mussel opening of greater than 2 years, but less than 7 years (OR = 2.29; 95% CI, 1.07–4.91), and duration of mussel opening greater than 7 years (OR = 3.72; 95% CI, 1.52–9.11), were significant predictors of work-related respiratory symptoms. Female sex (OR = 1.73; 95% CI, 0.83–3.60) was also associated with the presence of work-related symptoms. No relationship was found with measured hygiene parameters or cleaning agents used. In conclusion, duration of work as a mussel opener was associated with the presence of work-related respiratory symptoms, after adjustment for age, sex, and smoking habit. There were marked abnormalities in mean FEV1 and FVC, although no consistent changes across working shift were noted. Am. J. Ind. Med. 34:163–168, 1998. © 1998 Wiley-Liss, Inc.

Our objectives were to measure the prevalence of work‐related and nonwork‐related respiratory symptoms in a group of New Zealand mussel openers who open green‐lipped mussels, and to relate these to demographic factors, work history, smoking history, and pulmonary function measurements. A cross‐sectional study of respiratory symptoms and lung function was performed on 224 New Zealand mussel openers (99.6% of the study population) at nine work sites. In addition, peak expiratory flow (PEF) change across‐shift was measured at one work site in 19 workers. The mean age of all mussel openers was 33.4 years and the mean duration of mussel opening was 5.0 years; 25% were male, 54.7% were current smokers, and 13.9% were ex‐smokers. The reported symptom prevalences were: any wheeze, 35%; work‐related wheeze, 23%; any chest tightness, 30.5%; work‐related chest tightness, 20.2% (work‐related symptoms were defined as symptoms improving on rest days or worse at work). Seventy‐two mussel openers (32.3%) answered positively to at least 1 of 4 questions concerning work‐related symptoms. The mean predicted FEV1(SD) for this group was 74.3% (14.5), and the mean predicted FVC (SD) was 79.2% (16.0). Nineteen workers completed serial PEF, and the mean percentage change was +1.5% at 7 hr, but 8 workers had falls ranging between 1.1–14% after either 1 or 7 hr of work. Duration of mussel opening of greater than 2 years, but less than 7 years (OR = 2.29; 95% CI, 1.07–4.91), and duration of mussel opening greater than 7 years (OR = 3.72; 95% CI, 1.52–9.11), were significant predictors of work‐related respiratory symptoms. Female sex (OR = 1.73; 95% CI, 0.83–3.60) was also associated with the presence of work‐related symptoms. No relationship was found with measured hygiene parameters or cleaning agents used. In conclusion, duration of work as a mussel opener was associated with the presence of work‐related respiratory symptoms, after adjustment for age, sex, and smoking habit. There were marked abnormalities in mean FEV1and FVC, although no consistent changes across working shift were noted. Am. J. Ind. Med. 34:163–168, 1998. © 1998 Wiley‐Liss, Inc.

Workers with asthma frequently complain asthma symptoms are worse at work. Work aggravated asthma (WAA) is asthma made worse by but not caused by workplace exposures. Work practices and exposures can affect asthmatics with mild, moderate or severe asthma.The aim of this study was to explore the personal perception and impact of WAA. A purposive sampling strategy was used to recruit subjects into this study. The sample was selected from a group of participants in a WAA cross sectional postal questionnaire study. For enrichment qualitative data was also used from the postal questionnaire. All subjects had self-reported WAA and were stratified according to asthma severity. Data were analysed using thematic analysis.Eighty five subjects provided qualitative data from the postal questionnaire, 6 subjects were interviewed with an in depth face to face interview and one subject an in depth telephone interview. No further interviews were conducted when data saturation point was met. Five main themes concerning the workers perception of WAA were identified. These were; the working environment, lack of understanding about asthma, mental health, social impact and financial impact. Workers believed that a variety of triggers within the workplace caused them to have asthma symptoms. High levels of stress impacted on quality of life and job satisfaction. Some workers were willing to leave the workplace or change career because of the emotional impact feeling stressed at work had on their lives. WAA had an impact on social and family life with individuals giving up socialising when they had asthma symptoms. Feelings of guilt for relying on a partner, children and family to care for them were common. The financial burden of buying inhalers, attending appointments and in some cases reducing working hours or changing to less well paid roles had an impact. There was a perception that employers and colleagues had a lack of understanding of asthma, in particular the variable nature of the disease.Asthma education programmes in workplaces could help employers and workers understand how to deal with a colleague with asthma and alleviate the stress those workers with WAA experience.

The term 'pneumoconiosis' is used to describe pulmonary diseases associated with dust inhalation. It is normally used in the context of coal-worker's pneumoconiosis, but many other dusts can cause the dext of coal-worker's pneumoconiosis, but many other dusts can cause the disease. This contribution focuses on the major causes of pneumoconiosis in the UK (coal-worker's pneumoconiosis and silicosis). The site of damage (if any) within the lung is a function of both the size and the toxicity of the inhaled particles. Generally, particles with a median diameter of 0.5-10 @mm can penetrate the alveoli, and those that are toxic to host cells (particularly macrophages) can cause permanent harm. Many mechanisms are likely to be particle specific; in general, however, release of pro-inflammatory cytokines (initially from alveolar macrophages) causes fibroblast formation and eventual fibrosis. The propensity of different types of particles to cause fibrosis varies widely; for example, silica dust is highly fibrogenic, whereas iron dust is not.

In order to compare and contrast the sampling response to cotton dust of two forms of dust sampling 85 work areas were identified over a 2-year period for investigation in eight Lancashire spinning mills. Three hundred and five work area dust samples were undertaken and 252 personal dust samples were performed. Operatives who spent a minimum of 80% of their working shift in the area in which work area sampling was also performed were selected for personal sampling. Work area dust exposures have recently shown an upward trend, with highest concentrations occurring in the ring spinning room (median 1.15 mg m−3, range 0.82–2.06). Personal dust samples showed a reduction in dust exposures as cotton processing progressed, from a high in the opening room (median value of 6.24 mg m−3, range 1.0–41.5) to a minimum of 1.02 mg m−3 (range 0.30–0.93) in the winding room. The ratio of measured personal sampling dust exposure to work area sampling exposure was used to compare the relative performance of the two techniques. This ratio was highest in the early processes. There was a 7.8-fold difference in measurement between the two techniques in the opening processes, falling to 4.9 in carding and 4.2 in the other card-room processes. However in ring spinning the ratio was only 1.4, suggesting a degTee of comparability in the methods at this stage of processing. The value rose to 2.5 for the last stage (winding). Respiratory disease is known to occur predominantly in the early stages of processing (opening and carding) where high dust concentrations are found using the personal technique. These data support the use of personal sampling for setting exposure limits to cotton dust in preference to the current recommended method using work area sampling techniques, which may significantly underestimate dust exposure in the high risk work areas and is outdated.