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Biomedical subjects

D Fishwick

Publications and source records attributed to D Fishwick.

At least 37 records · Page 2Linked to original sources
PubMed1999

Asthma and allergy in New Zealand farmers.

AIMS: To examine the prevalence of symptoms of asthma and allergy in different farming groups in New Zealand. METHODS: A postal questionnaire was sent to a random sample of 2,500 farmers throughout New Zealand. RESULTS: 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. CONCLUSIONS: 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.

Adolescent↗
PubMed1999

Two year follow up of pulmonary function values among welders in New Zealand.

OBJECTIVES: To examine whether welding is a risk factor for an accelerated decline in pulmonary function. METHODS: 2 Year follow up of pulmonary function and respiratory symptoms among 54 welders and 38 non-welders in eight New Zealand welding sites. RESULTS: There were no significant differences in age, height, smoking habits, ethnicity, or total time in industrial work between welders and non-welders. No overall differences were noted in the changes of pulmonary function variables between the two study groups. However, when the comparison was restricted to smokers, welders had a significantly greater (p = 0.02) annual decline (88.8 ml) in FEV1 than non-welders, who had a slight non-significant annual increase (34.2 ml). Also, welders without respiratory protection or local exhaust ventilation while welding had a greater annual decline both in forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) than welders with protection (p = 0.001 and 0.04, respectively). Among welders a significant association was found between the acute across shift change and the annual decline in FEV1. Chronic bronchitis was more common among welders (24%) than non-welders (5%). Only one welder (2%) but eight non-welders (21%) reported having asthma. CONCLUSIONS: Welders who smoked and welders working without local exhaust ventilation or respiratory protection have an increased risk of accelerated decline in FEV1.

Adult↗
PubMed1998

Work-related respiratory symptoms and lung function in New Zealand mussel openers.

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-section 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 of cleaning agents used. In conclusions, duration of work as a mussel opener was associated with the present of work-related respiratory symptoms, after adjustment of age, sex, and smoking habit. There were marked abnormalities in mean FEV1 and FVC, although no consistent changes across working shift were noted.

Adult↗
PubMed1998

A comparison of performance of two personal sampling heads for cotton dust.

Cotton dust sampling for monitoring worker exposure was traditionally performed by work area sampling. A change to an exposure limit based on personal sampling has recently been agreed. The choice of sampling head for personal monitoring exposure was hampered by the use of two different sampling heads in the major epidemiological studies of textile workers which had incorporated personal sampling techniques. The purpose of this study was to compare the results of exposure measurements using these two sampling heads. This study has examined the performance of the two sampling heads, by performing dual sampling on cotton operatives during normal working activities. Each operative included wore two samplers randomly allocated to left or right side. A minimum of 200 minutes of sampling was accepted and the relative concentrations calculated. The IOM total dust sampler produced repeatedly higher measurements than the Manchester head. The ratio overall was 1.33 (95% C.I. 1.20-1.49). The performance was similar across the ranges of dust exposure from low (< 1 mg/m3-ratio 1.28), medium (1-3 mg/m3-ratio 1.43) to high exposure (> 3 mg/m3-ratio 1.24). The two heads give reproducibly proportionate dust measurements with approximately 30% greater results obtained with the IOM total dust sampler. Either dust sampling head could be used for worker monitoring and the results adjusted accordingly for reference to the Maximum Exposure Limit.

Dust↗
PubMed1998

Respiratory symptoms among glass bottle workers--cough and airways irritancy syndrome?

Glass bottle workers have been shown to experience an excess of respiratory symptoms. This work describes in detail the symptoms reported by a cohort of 69 symptomatic glass bottle workers. Symptoms, employment history and clinical investigations including radiology, spirometry and serial peak expiratory flow rate records were retrospectively analyzed from clinical records. The results showed a consistent syndrome of work-related eye, nose and throat irritation followed after a variable period by shortness of breath. The latent interval between starting work and first developing symptoms was typically 4 years (median = 4 yrs; range = 0-28). The interval preceding the development of dysponea was longer and much more variable (median = 16 yrs; range = 3-40). Spirometry was not markedly abnormal in the group but 57% of workers had abnormal serial peak expiratory flow rate charts. Workers in this industry experience upper and lower respiratory tract symptoms consistent with irritant exposure. The long-term functional significance of these symptoms should be formally investigated.

Adult↗
PubMed1998

Chronic bronchitis, work related respiratory symptoms, and pulmonary function in welders in New Zealand.

OBJECTIVES: A cross sectional study of respiratory symptoms and lung function in welders was performed at eight New Zealand welding sites: 62 current welders and 75 non-welders participated. METHODS: A questionnaire was administered to record demographic data, smoking habit, and current respiratory symptoms. Current and previous welding exposures were recorded to calculate a total lifetime welding fume exposure index. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) were measured before the start of the shift. RESULTS: There were no significant differences in ethnicity, smoking habits, or years of work experience between welders and non-welders. Symptoms of chronic bronchitis were more common in current welders (11.3%) than in non-welders (5.0%). Of those workers with a cumulative exposure index to welding fume > or = 10 years, 16.7% reported symptoms of chronic bronchitis compared with 4.7% of those with a cumulative exposure index < 4 years (odds ratio (OR) 4.1, 95% confidence interval (95% CI) 0.90 to 17.6). Workers with chronic bronchitis had significantly lower measures of baseline PEF (p = 0.008) and FEV/FVC ratio (p = 0.001) than workers without chronic bronchitis. Multivariate analysis showed that current smoking (OR 9.3, 1.0 to 86.9) and total exposure index to welding fumes > 10 years (OR 9.5, 1.3 to 71.9) were independent risk factors for chronic bronchitis. The report of any work related respiratory symptom was more prevalent in welders (30.7%) than non-welders (15.0%) and workers with these symptoms had significantly lower FEV, (p = 0.004) and FVC (p = 0.04) values. Multivariate analysis identified a high proportion of time spent welding in confined spaces as the main risk factor for reporting these symptoms (OR 2.8, 1.0 to 8.3). CONCLUSION: This study has documented a high prevalence of symptoms of chronic bronchitis and other work related respiratory symptoms in current welders. Also, workers with chronic bronchitis had reduced PEF and FEV/FVC compared with those without chronic bronchitis. These symptoms related both to cigarette smoking and a measure of lifetime exposure to welding fume.

Adolescent↗
PubMed1997

Respiratory questionnaire responses: how they change with time.

AIM: Responses to respiratory questionnaires are often used to identify individuals with asthma symptoms and may also be used to identify asymptomatic individuals. This study investigates the repeat responses over four years to such a questionnaire in a population of adult New Zealanders. METHODS: Seven hundred and twenty three asthmatics were sent two almost identical questionnaires in three areas of New Zealand, separated by approximately four years. All of them had answered yes to at least one of the three questions under study in the first survey. RESULTS: Following the second asthma questionnaire only 487 (67.4%) answered yes to at least one of the survey questions. Similarly, 51.1% of those who had reported having nocturnal shortness of breath in the first survey did so in the second survey, 69.9% of those who reported having had an asthma attack in the first survey did so in the second survey, and finally 74.8% of those who reported using asthma medication in the first survey did so in the second survey. CONCLUSION: Even in a previously identified symptomatic asthmatic group, a large proportion did not report respiratory symptoms and asthma medication use four years later. This implies that the true prevalence pool of susceptibles is likely to be far greater than is identified in surveys of the 12-month period prevalence of asthma symptoms. This has implications not only for the design of epidemiological studies (e.g., it poses problems for the selection of a control group of non-asthmatics in prevalence case-control studies), but also for the planning of health services and educational programmes for people with asthma.

Adult↗
PubMed1997

Under the volcano: fire, ash and asthma?

AIMS: To investigate the prevalence of respiratory symptoms in known asthmatics, following exposure to airborne volcanic ash particles caused by the eruptions of Mount Ruapehu, New Zealand, commencing September 1995. METHOD: A one page postal questionnaire was sent to 1392 previously identified asthmatics 2 months after the first major eruption. RESULTS: Two hundred and thirty seven subjects had moved from the area, died or gone overseas since the original contact 4 years previously; therefore the target population was 1155 subjects of whom 361 lived in the exposed area and 794 in the nonexposed areas. The response rates were 246 (68.1%) in the exposed group and 477 (60.1%) in the nonexposed group making a total of 723 individuals. The prevalence of nocturnal shortness of breath in the last two months was 29.3% in the exposed group and 24.7% in the nonexposed (OR = 1.26, 95% CI; 0.83-1.78). Similarly 30.9% of the exposed group had an asthma attack in the last 2 months compared to 31.9% of the nonexposed group (OR = 0.96, 95% CI; 0.69-1.33). Finally, 48.4% of the exposed group used asthma medication in the 2 months following the eruption in comparison to 53% of the nonexposed group (OR = 0.83, 95%, CI; 0.61-1.12). CONCLUSIONS: The study showed no association between living in an area exposed to volcanic ash particles and either asthma symptoms or the use of asthma medication. There was a small but nonsignificant increase in nocturnal shortness of breath in the exposed group.

Acute Disease↗
PubMed1997

Occupational asthma in New Zealanders: a population based study.

OBJECTIVES: To examine the effect of occupation on respiratory symptoms in a randomly selected adult population aged 20-44 years. METHODS: It is based on the phase II sampling of the New Zealand part of the European Community respiratory health survey. 1609 people (63.9% response rate) completed a detailed respiratory questionnaire. Of those responding, 1174 (73%) underwent skin tests and 1126 (70%) attended to undergo methacholine bronchial challenge. Current occupation was recorded and a previous occupation was also recorded if it had led to respiratory problems. 21 occupational groups were used for analysis for the five definitions of asthma wheezing in the previous 12 months; symptoms related to asthma; bronchial hyperresponsiveness (BHR); BHR with wheezing in the previous 12 months; and BHR with symptoms related to asthma. RESULTS: Prevalence odds ratios (ORs) were significantly increased for farmers and farm workers (OR 4.16, 95% confidence interval (95% CI) 1.33 to 13.1 for the combination of wheezing and BHR). Increased risks of prevalence of asthma were also found for laboratory technicians, food processors (other than bakers), chemical workers, and plastic and rubber workers. Workers had also been divided into high and low risk exposure categories according to relevant publications. The prevalence of wheezing was greater in the high risk group (OR 1.57, 95% CI 0.83 to 2.95) than in the low risk group. Atopy was associated with asthma, but the prevalence of atopy did not differ significantly between occupational exposure groups. The attributable risk of wheezing that occurred after the age of 15 years and that was estimated to be due to occupational exposure (based on the defined high risk group) was 1.9%, but this increased to 3.1% when farmers and food processors (other than bakers) were also included in the high risk group. CONCLUSIONS: This population based study has identified certain occupations significantly associated with combinations of asthmatic symptoms and BHR.

Adult↗
PubMed1997

Chronic bronchitis in textile workers.

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.

Adult↗
PubMed1997

Chronic bronchitis, shortness of breath, and airway obstruction by occupation in New Zealand.

The objectives of this study were to measure the population prevalence of symptoms of chronic obstructive lung disease and mild airway obstruction and to compare these between occupational groups. There were 1,609 subjects (63.9% response rate) who completed a respiratory questionnaire. Of these, 1,132 (70.4%) underwent pulmonary function testing (FEV1 and FVC). Twenty-one categories of current occupation were used for analysis. Four definitions of chronic obstructive pulmonary disease (COPD) were used: (1) chronic bronchitis, (2) chronic bronchitis with airway obstruction, (3) shortness of breath, and (4) shortness of breath with airway obstruction. For chronic bronchitis, adjusted prevalence odds ratios were significantly elevated for food processors other than bakers (OR = 2.83; 95% CI, 1.27 to 6.29) and chemical processors (OR = 18.84; 3.71 to 95.64). The combination of chronic bronchitis and mild airway obstruction (FEV1/FVC < 0.75) was associated with bakers (OR = 25.5; 3.86 to 168.53) and spray painters (OR = 14.40; 2.85-72.69). Shortness of breath was associated with hairdressers (OR = 2.75; 0.80 to 9.42) and bakers (OR = 6.72; 0.57 to 79.66), and nursing was associated with lower levels of shortness of breath (OR = 0.42; 0.16 to 1.15). Working ever with vapors, gases, dust, or fumes was significantly associated with chronic bronchitis and airway obstruction (OR = 3.13; 1.07 to 9.12). This population-based study has identified certain occupations with increased prevalence of chronic bronchitis and COPD.

Adult↗
PubMed1997

Respiratory symptoms, across-shift lung function changes and lifetime exposures of welders in New Zealand.

OBJECTIVES: The possibility was investigated that exposure to welding fumes causes an acute decrease in pulmonary function. METHODS: Changes in the pulmonary function of 62 current welders and 75 nonwelders at the same sites and the relationship with work-related symptoms were recorded. RESULTS: Work-related cough was reported by 22.6% of the current welders and 6.7% of the nonwelders [odds ratio (OR) 4.1, 95% confidence interval (95% CI) 1.5-11.5], and the respective figures for at least 1 work-related symptom were 30.7% and 16.0% (OR 2.3, 95% CI 1.0-5.2). The groups' preshift lung function did not differ. The mean percentage change from the base-line value of the forced expiratory volume in 1 s (FEV1.0) after 15 minutes of work was -2.8% (range -29.3% to +20.9%) for the current welders and +1.0% (range -20.7% to +22.6%) for the nonwelders (P = 0.01). A multivariate analysis identified current welding as the most significant risk factor for a decrease of at least 5% in FEV1.0 after 15 minutes, the risk being greater for those with no local exhaust ventilation (OR 22.4, 95% CI 4.5-113.4) than for those with personal protection only (OR 16.0, 95% CI 2.1-122.9) and those with local exhaust ventilation (OR 2.8, 95% CI 0.2-41.2) or passive exposure only (OR 2.0, 95% CI 0.5-8.8). CONCLUSIONS: An acute decrease in FEV1.0 in relation to work is more prevalent among welders than among nonwelders, and is more common among welders without local exhaust ventilation than among those with it.

Adult↗
PubMed1996

Lung function in Lancashire cotton and man made fibre spinning mill operatives.

OBJECTIVES: This survey was conducted to investigate current lung function levels in operatives working with cotton and man made fibres. Dust concentrations, smoking history, and occupational details were recorded so that factors influencing lung function could be identified. METHODS: A cross sectional study of respiratory symptoms and lung function was made in 1057 textile spinning operatives of white caucasian extraction. This represented 96.9% of the total available working population to be studied. Most (713) worked currently with cotton. The remainder worked with man made fibre. Lung function was assessed by measuring forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Exposure to cotton dust was measured in the work area and personal breathing zones, and retrospective exposure to cotton dust over a working life was estimated with accurate work history and best available hygiene data. RESULTS: 3.5% of all operatives had byssinosis, 55 (5.3%) chronic bronchitis, 36 (3.5%) work related persistent cough, 55 (5.3%) non-byssinotic work related chest tightness, and 56 (5.3%) work related wheeze. A total of 212 static work area dust samples (range 0.04-3.23 mg/m3) and 213 personal breathing zone samples (range 0.14-24.95 mg/m3) were collected. Percentage of predicted FEV1 was reduced in current smokers (mean 89.5, 95% confidence interval (95% CI) 88-91) in comparison with non-smokers (93.1, 90.5-94.1) and FVC was reduced in operatives currently working with man made fibre (95.3, 93.8-96.9) in comparison with cotton (97.8, 96.6-99.0). Regression analysis identified smoking (P < 0.01), increasing age (P < 0.01), increasing time worked in the waste room (P < 0.01), and male sex (P < 0.05) as being associated with a lower FEV1 and FVC. Current and retrospective cotton dust exposures did not appear as predictor variables in the regression analysis although in a univariate analysis, FEV1 was reduced in those operatives exposed to high dust concentrations assessed by personal and work area sampling. DISCUSSION: This study has documented loss of lung function in association with exposure to cotton dust. Those operatives with work related symptoms had significantly lower FEV1 and FVC than asymptomatic workers. Although lung function seemed to be affected by high dust exposures when operatives were stratified into high and low exposure groups, regression analysis did not identify current dust concentrations as an independent factor influencing loss. Smoking habit was found to explain most of the measured change in FEV1 and FVC. It is likely that smoking and dust exposure interact to cause loss of lung function in cotton textile workers.

Adult↗