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Biomedical subjects

D Coggon

Publications and source records attributed to D Coggon.

At least 127 records · Page 7Linked to original sources

Patterns of joint involvement in osteoarthritis of the hand: the Chingford Study.

OBJECTIVE: The hand is the major site of joint involvement in osteoarthritis (OA), but the clustering of this condition at different joint sites within the hand as part of an entity known as generalized OA remains contentious. We examine this issue in a population sample of 967 peri and postmenopausal women. METHODS: The pattern of radiographic involvement of hand joints was examined using the Kellgren and Lawrence system in a sample of women aged 45-64 years, selected from the general population in Chingford, East London. Log linear modelling techniques were used to examine clustering of OA in different joint sites and to examine whether this clustering remained significant after age adjustment. RESULTS: There was clear evidence of clustering in joint involvement: Thus 20 women had 4 or more affected joints compared with only 2 expected (chi 2 = 72.0, 4df, p < 0.001). The risk of multiple distal interphalangeal (DIP) joint involvement, after age adjustment, in a woman with a single affected DIP joint was significantly increased (OR 10.0, 95% CI 7.3-13.7) and was substantially greater than the corresponding risk for proximal interphalangeal joint (OR 3.1, 95% CI 1.4-6.8) involvement. Symmetry was the strongest determinant of pattern with an OR 38.8 (95% CI 14.5-103.5) for corresponding DIP joint involvement in the contralateral hand. CONCLUSION: These data provide clear evidence for a polyarticular subset of hand OA in women. There are 3 major determinants of the pattern of polyarticular involvement; symmetry, clustering by row and clustering by ray, in descending order of importance.

Female↗

Soft tissue sarcoma and non-Hodgkin's lymphoma in workers exposed to phenoxy herbicides, chlorophenols, and dioxins: two nested case-control studies.

We examined the effect of exposure to chemicals present in the production and spraying of phenoxy herbicides or chlorophenols in two nested case-control studies of soft tissue sarcoma and non-Hodgkin's lymphoma. Eleven sarcoma and 32 lymphoma cases occurring within an international cohort were matched for age, sex, and country of residence with 55 and 158 controls, respectively. Exposures to 21 chemicals or mixtures were estimated by three industrial hygienists who were blind to the subject's case-control status. Excess risk of soft tissue sarcoma was associated with exposure to any phenoxy herbicide [odds ratio (OR) = 10.3; 95% confidence interval (CI) = 1.2-91] and to each of the three major classes of phenoxy herbicides (2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, and 4-chloro-2-methylphenoxyacetic acid), to any polychlorinated dibenzodioxin or furan (OR = 5.6; 95% CI = 1.1-28), and to 2,3,7,8-tetrachlorodibenzo-p-dioxin (OR = 5.2; 95% CI = 0.85-32). Sarcoma risk was not associated with exposure to raw materials or other process chemicals. In the non-Hodgkin's lymphoma study, associations were generally weaker than those found in the study on sarcoma. These findings indicate that workers exposed to phenoxy herbicides and their contaminants are at a higher risk of soft tissue sarcoma.

Case-Control Studies↗

Lobar pneumonia: an occupational disease in welders.

We have used data from three analyses of occupational mortality for England and Wales to investigate a suspected hazard of pneumonia in welders. Mortality from the disease was consistently raised in welders aged 15-64, with standardised mortality ratios of 184 (95% CI 150-224) in 1959-63 and 157 (121-200) in 1970-72. Analysis of data for 1979-80 and 1982-90 showed that the increased risk is attributable mainly to an excess of pneumococcal and unspecified lobar pneumonia (proportional mortality ratio 255, 95% CI 192-332). No excess occurred in men above retirement age (65). A possible explanation of these findings is that welding fume reversibly increases the susceptibility of the lung to pneumonic infection. The observation of a similar mortality pattern in moulders and coremakers points to the metallic component of the fume as a possible culprit, but ozone or oxides of nitrogen could also be implicated. There are grounds for lobar pneumonia to be considered an occupational disease in welders.

Adolescent↗

Inflammatory bowel disease and domestic hygiene in infancy.

To test the hypothesis that Crohn's disease is caused by delayed exposure to enteric infections, we did a case-control study. We compared 133 patients who have Crohn's disease and 231 with ulcerative colitis who have controls selected from the general population and matched for age and sex. Crohn's disease was more common in subjects whose first houses had a hot-water tap (odds ratio 5.0, 95% CI 1.4-17.3) and separate bathroom (3.3, 1.3-8.3). Ulcerative colitis showed no clear relation to household amenities in infancy. These findings may explain why the incidence of Crohn's disease has increased in developed countries over the past 50 years.

Adolescent↗

Is there an epidemic of cancer?

Trends in cancer mortality in England and Wales are dominated by a slowly evolving epidemic of lung cancer attributable to smoking. When the substantial effects of tobacco are discounted there is no evidence that the overall incidence of cancer is rising, but striking trends are apparent for several specific tumours. These may offer important clues to aetiology.

Age Factors↗

Determinants of safe behaviour in farmers when working with pesticides.

Despite stringent regulation, accidents occur in the use of pesticides. To explore the factors which might influence farmers' approaches to safety when handling chemicals, we interviewed 84 agricultural workers from south-west Hampshire who reported having worked with pesticides in the previous 12 months. Most of those interviewed claimed that they always followed manufacturers' instructions regarding indications for use, method of application, mixing of chemicals, cleaning up and washing hands, but compliance was lower for recommendations about personal protective equipment and disposal of containers. Only 38% of subjects said that they always read all of the manufacturer's label when using a product for the first time. The main determinant of safe behaviour was the person's approach to safety in other situations, but formal training in the use of pesticides was also associated with more frequent use of personal protective equipment. Possession of a certificate of competence in pesticide use appeared to have less influence on working methods. Future efforts should be directed at changing farmers' handling of pesticides.

Adult↗

Cutaneous warts in butchers.

Several studies have indicated a high prevalence of hand warts in meat handlers, although the reasons for this are not clear. The high prevalence may be partly due to HPV7, a virus found almost exclusively in meat handlers, but the source of HPV7 is not known. We have carried out a cross-sectional survey of hand warts in male meat workers and controls from other occupational groups, to investigate the reasons for the high prevalence of warts, and particularly of HPV7, in butchers. We studied 240 abattoir workers, 246 retail and wholesale butchers, 308 engineering fitters and 292 office workers. Each subject was interviewed using a standard questionnaire, and his hands were examined by a dermatologist. Scrapings from the warts were tested for HPV1, HPV2 and HPV7 by a polymerase chain reaction method. The prevalence of hand warts was 33.3% in the abattoir workers, 34.1% in the butchers, 19.5% in the engineers and 14.7% in the office workers. Scrapings were taken from 247 of 267 subjects with warts, and HPV DNA was detected in 151 samples. The most common viruses were HPV2 (94 men) and HPV7 (76 men). The excess of warts in meat workers was largely due to HPV7, which was found in only two of the office workers, and was not found in any of the engineers. Logistic regression analysis showed no association between the prevalence of hand warts (or HPV2 and HPV7 specifically) and hand trauma, cold and wet working conditions, smoking, atopy, or handling any particular kind of meat. We suggest that some constituent of animal flesh predisposes to replication of HPV7 in keratinized epithelium.

Abattoirs↗

Butchers' warts: no evidence for person to person transmission of HPV7.

The distribution of warts due to HPV7 in workers in six abattoirs and 103 retail and wholesale butcheries has been studied to determine whether the high prevalence of HPV7 in the meat trade is the result of enhanced person to person transmission, or whether it is a ubiquitous virus which is activated by an unknown factor in meat. Warts were detected in 164 of 486 men. Scrapings were taken from 156 men, and HPV DNA was found in 112 samples, 74 of which contained HPV7. HPV7 was found in 36 workplaces, and there was no evidence of clustering of cases, as would be expected if person to person transmission was occurring in the workplace. This suggests that HPV7 is widely distributed in the community, but only causes clinical disease under specific conditions. We suggest that some unknown factor in meat enhances viral replication.

Abattoirs↗

Occupational activity and osteoarthritis of the knee.

OBJECTIVES: To test the hypothesis that specific occupational physical activities are risk factors for knee osteoarthritis (OA). METHODS: A population-based case-control study of knee osteoarthritis was carried out in which 109 men and women with painful, radiographically confirmed knee OA were compared with 218 age and sex matched controls who had not suffered knee pain and had normal radiographs. Information collected included a lifetime occupational history and details of specific workplace physical activities. RESULTS: After adjustment for obesity and Heberden's nodes, the risk of knee OA was significantly elevated in subjects whose main job entailed more than 30 minutes per day squatting (OR 6.9, 95% CI 1.8-26.4) or kneeling (OR 3.4, 95% CI 1.3-9.1), or climbing more than ten flights of stairs per day (OR 2.7, 95% CI 1.2-6.1). The increase in risk associated with kneeling or squatting appeared to be more marked in subjects whose jobs entailed heavy lifting, but the size of the study did not permit precise delineation of any such interaction. CONCLUSIONS: These data suggest that prolonged or repeated knee bending is a risk factor for knee OA, and that risk may be higher in jobs which entail both knee bending and mechanical loading.

Activities of Daily Living↗

Defining osteoarthritis of the hand for epidemiological studies: the Chingford Study.

OBJECTIVES: To explore the relative merits of clinical and radiological examination in defining hand osteoarthritis (OA) for epidemiological purposes. METHODS: A total of 976 women aged 45-64 years were selected from the general population and underwent a structured interview, clinical examination of the hand joints and radiography of the hands and knees. The inter-relationship of the clinical and radiological findings was examined, and also the association of each with hand symptoms and the presence of knee OA. RESULTS: Clinical and radiographic signs of hand OA generally correlated with each other, and each was associated with hand symptoms to a similar degree. When analysed in combination, they were only marginally better at predicting symptoms than when tested individually. However, when they were examined in relation to radiographic features of knee OA, there was a significantly stronger association with radiographic features of hand OA than with clinical features. CONCLUSIONS: Hand radiology provides a better overall assessment of osteoarthritis than physical examination of the interphalangeal joints or carpo-metacarpal joint; in situations where radiology is not available clinical examination is a viable substitute.

England↗

Epidemiological studies of styrene-exposed populations.

The potential human carcinogenicity of styrene has been investigated mainly by epidemiological studies of occupationally exposed populations. Several cohort studies have suggested that workers exposed to styrene in the chemical industry have increased mortality from lymphatic and hematopoietic cancer. However, this finding has not been consistent and has not been reproduced in studies of reinforced plastics manufacturers, whose exposures to styrene are generally higher. The explanation for the observed associations may therefore be confounding by concomitant exposures to other chemicals such as benzene and butadiene, which are not used in the reinforced plastics industry. Despite their large size, the published studies of mortality and cancer incidence lack the statistical power to rule out an important hazard from long-term exposure to high (> 50 ppm) airborne concentrations of styrene. However, they indicate that any risk of cancer from lower levels of exposure is likely to be small.

Humans↗

Cancer mortality in a historical cohort study of workers exposed to styrene.

OBJECTIVES: The goal of this study was to determine whether exposure to styrene is associated with an increased risk for neoplasms of the lymphatic and hematopoietic tissues. METHODS: A historical cohort study was conducted in Denmark, Finland, Italy, Norway, Sweden, and the United Kingdom. It involved 40,688 workers ever employed in the reinforced plastics industry, where high exposure to styrene occurs. Exposure to styrene was reconstructed through job histories and environmental and biological monitoring data. Cause-specific national death rates were used as the reference. Poisson regression was applied for internal comparisons. RESULTS: Among the exposed workers, no excess was observed for mortality from all neoplasms. Mortality from neoplasms of the lymphatic and hematopoietic tissues increased with time since first exposure and average level of exposure to styrene, but was not consistently associated with duration of exposure or with cumulative exposure. CONCLUSIONS: These findings leave open the possibility of an excess risk of neoplasms of the lymphatic and hematopoietic tissues among workers exposed to styrene.

Cohort Studies↗

Chemical exposure in manufacture of phenoxy herbicides and chlorophenols and in spraying of phenoxy herbicides.

Exposure patterns are reported for manufacturing and sprayer cohorts incorporated in the "IARC International Register of Workers exposed to Phenoxy Herbicides and Contaminants." Information was based on company questionnaires, company reports, plant visits, and serum 2, 3, 7, 8-TCDD measurements. In addition to phenoxy herbicides and chlorophenols, workers in manufacturing plants may have been exposed to raw materials, process chemicals, other agents synthesized or formulated, and impurities of all these agents. Sprayers also had a complex exposure pattern, including phenoxy herbicides and some other pesticides, their carriers and additives, and residues of chemicals formed during manufacture. Occurrence of agents, including dioxins, varied between countries. Biological monitoring and industrial hygiene data were rarely available, most since the late 1970s. Exposure of workers depended mainly on the jobs they performed, but several factors influenced level of exposure. A quantitative exposure classification is not feasible in this study. Semiquantitative exposure estimates may be derived through a critical interpretation of biological monitoring and industrial hygiene data together with individual work histories.

2-Methyl-4-chlorophenoxyacetic Acid↗

Sunlight exposure, antioxidant status, and cataract in Hong Kong fishermen.

STUDY OBJECTIVES: The aim was to test whether cataract is associated with higher lifetime exposure to sunlight, and whether antioxidants protect against cataract. DESIGN: This was a cross sectional survey of eye disease, with assessment of antioxidant status in a subgroup. SETTING: Hong Kong fishing communities in 1989. PARTICIPANTS: 685 men and women aged 55 to 74 years old were included in the study, of whom 367 (54%) attended hospital for detailed examination. MEASUREMENTS AND MAIN RESULTS: At a mobile clinic visual acuity and lens opacities were assessed, and using a questionnaire, occupational history and lifetime exposure to sunlight. At hospital ophthalmic measurements were repeated and blood was taken for measurement of plasma vitamin C, vitamin E, and total carotenoids, and red cell activities of glucose-6-phosphate dehydrogenase, glutathione peroxidase, superoxide dismutase, and catalase. Higher grades of cataract (particularly nuclear cataract) tended to be more common in subjects with the most sun exposure, although not to the point of statistical significance. In contrast to earlier studies, no association was found with antioxidant status. CONCLUSIONS: The findings give some support to the hypothesis that sunlight causes cataract. The absence of a relation to antioxidant status may be because blood levels of antioxidants at one point in time do not adequately reflect a subject's past metabolic state, and particularly the past activity of antioxidants in the lens.

Aged↗

Education, reading, and familial tendency as risk factors for myopia in Hong Kong fishermen.

STUDY OBJECTIVE: The aim was to assess the influence of childhood reading on the development of myopia after allowance for familial differences in susceptibility. DESIGN: The study was a cross sectional survey. SETTING: Four fishing harbours in Hong Kong in 1989. SUBJECTS: Participants were 408 men and women aged 15-39 years old from 159 families. MAIN RESULTS: Histories of school attendance and reading habits in childhood were obtained at interview. Myopia was assessed by retinoscopy. Associations between myopia (defined as a refractive error of at least -1.0D in one or both eyes) and indices of reading in childhood were explored. Myopia was more common in subjects who had attended school (odds ratio = 1.7, 95% CI 1.0-3.0), with the highest risks in those who had started school at the earliest ages and who had spent the most time reading and writing while at primary school. Allowance for familial tendency to myopia produced no diminution in the risks associated with reading. CONCLUSIONS: These data support the hypothesis that reading in childhood is a cause of short sight.

Adolescent↗