Effects of Juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics

Rising feed costs and recurring feed shortages necessitate the investigation into alternative and underutilized feed resources. Nutritional characteristics of species are either unknown or limited to leaves and ground material from small stems. Therefore, the objective was to quantify nutritional characteristics, 48-h true IVDMD (tIVDMD), microbial gas production, and secondary compound characteristics of entire woody plant material of 4 species-, , , and -at immature and mature stages of growth. Immature plants had greater CP concentrations and lower NDF concentrations ( < 0.001) than mature plants regardless of species. Mature plants also had greater ( < 0.001) concentrations of ADF compared with immature plants with the exception of . In general, immature , , and had greater ( < 0.02) tIVDMD and total 48-h and asymptotic gas production than mature plants. Immature and plants were more digested (tIVDMD; < 0.001) than immature and , but tIVDMD did not differ in mature plant material across species. Condensed tannins (CT) were greater ( < 0.001) in immature and than mature plants; differences in CT concentrations among immature species were also detected ( < 0.04). Volatile oil yields were similar across maturity and species with 1 exception: immature yielded more ( < 0.02) volatile oil than mature material. Volatile oil composition across species varied and contained a range of 65 to 70 terpene compounds. The dominant terpenes across species were generally greater ( < 0.05) in immature vs. mature plant material with the exception of . Labdane acids were negligible in , , and and greater in ( < 0.001). Ground material from mature juniper species, although inferior in nutritional quality compared with immature plants, is comparable to traditional low-quality roughage ingredients. Given that has been successfully fed in lamb feedlot diets, the similarities of , and suggest that all three species have potential to be effective roughage ingredients.

Modifiable and non-modifiable risk factors for poor semen quality: a case-referent study

STUDY QUESTION

Are common lifestyle factors associated with low-motile sperm concentration (MSC)?

SUMMARY ANSWER

Common lifestyle choices make little contribution to the risk of low MSC.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Reviews of male subfertility often highlight how aspects of men's adult lifestyle can significantly increase their risk of subfertility but the strength of supporting evidence is weak. In this study, although low MSC was associated with a history of testicular surgery, being in manual work, not wearing loose underwear and black ethnicity, no relation was found to consumption of alcohol, use of tobacco or recreational drugs or high body mass index (BMI). These results suggest that delaying assisted conception to make changes to lifestyle is unlikely to enhance conception.

DESIGN

Unmatched case-referent study with 939 cases and 1310 referents. Cases had a low-MSC relative to the time since last ejaculation (<12 × 10(6) for 3 days of abstinence). Exposures included self-reported exposures to alcohol, tobacco, recreational drugs as well as occupational and other factors.

PARTICIPANTS AND SETTING

Eligible men, aged 18 or above, were part of a couple who had been attempting conception without success following at least 12 months of unprotected intercourse and also had no knowledge of any semen analysis. They were recruited from 14 fertility clinics across the UK during a 37-month period from 1 January 1999.

MAIN RESULTS AND THE ROLE OF CHANCE

Risk factors for low MSC, after adjustment for centre and confounding factors, included a history of testicular surgery [odds ratio = 2.39, 95% confidence interval (CI): 1.75, 3.28], being in manual work [odds ratio (OR) = 1.28, 95% CI: 1.07, 1.53] or not working (OR = 1.78, 95% CI: 1.22, 2.59) and having black ethnicity (OR = 1.99, 95% CI: 1.10, 3.63). Conversely, men who wore boxer shorts (OR = 0.76, 95% CI: 0.64, 0.92) or who had a previous conception (OR = 0.71, 95% CI: 0.60, 0.85) were less likely to be a case. No significant association was found with smoking and alcohol consumption, the use of recreational drugs, a high BMI or having a history of mumps or fever.

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

Data were collected blind to outcome, and exposure information should not have been subject to reporting bias. Among men attending the various clinics less than half met the study eligibility criteria and among those who did, two out of five were not recruited. It is not known whether any of those who refused to take part did so because they had a lifestyle they did not want subjected to investigation. Although the power of the study was sufficient to draw conclusions about common lifestyle choices, it cannot comment on exposures that are perhaps rare and poorly reported: the finding that use of street drugs was unrelated to low MSC cannot be assumed to apply to all such drugs and all patterns of use. The case definition did not consider sperm morphology or sperm DNA integrity.

GENERALIZABILITY TO OTHER POPULATIONS

All participating clinics saw patients at no cost (under the UK National Health Service) and the study population may differ from those in countries without such provision. Even within the UK, low-income couples may choose not to undertake any investigation believing that they would subsequently be unable to afford treatment.

The virtues of a deliberately mis-specified disease model in demonstrating a gene-environment interaction

OBJECTIVES

This study seeks to assess the impact of measurement errors in cumulative exposure on estimates of a gene-environment interaction in a nested case-control study in occupational epidemiology. In the approach considered here, exposure intensity is assessed at the group level and the exposure duration individually (both with error). Genetic susceptibility is assumed to be known exactly. Differences in "gene" are assumed to affect disease risk only in exposed subjects.

METHODS

Three data analysis strategies were considered: one using a correctly specified disease model (exposure and exposure-gene interaction), and two using mis-specified disease models, one with "gene" as the only risk factor ("gene-only" model) and the other with main effects of both gene and exposure along with their interaction ("full" model).

RESULTS

In simulations, estimates of the gene-environment interaction based on the correctly specified disease model were greatly attenuated and power was diminished appreciably even when errors in exposure were modest. Significant associations were detected more frequently in the gene-only model when errors in exposure were large. When the "full" mis-specified model was fitted to the simulated data, it yielded erratic estimates. This is illustrated in an analysis of the interaction of cumulative exposure to organophosphate pesticides and paraoxonase gene on the risk of chronic neuropsychological effects among farmers who dip sheep.

CONCLUSION

If "gene" contributes to disease risk only in the presence of exposure, the existence of the gene-environment interaction can be efficiently inferred from a deliberately mis-specified "gene-only" disease model in nested case-control studies.

GST CYP and PON1 polymorphisms in farmers attributing ill health to organophosphate-containing sheep dip

Previously we reported that in sheep dippers exposed to organophosphates the frequency of paraoxonase (PON1) polymorphisms differed between those with or without self-reported ill health. We have now examined whether polymorphisms in other genes involved in xenobiotic metabolism alter disease risk in this population. There were elevated but non-significant risks associated with the CYP2D6 WT genotype (odds ratio (OR) 1.47, 95% CI 0.83-2.60), or a GSTP1*B or *C allele (OR 1.37, 95% CI 0.88-2.01) or being GSTM1*2/GSTT1*2 homozygous (OR 1.61, 95% CI 0.74-3.48). Similar results were generally obtained after the exclusion of subjects to obtain a more homogenous case-referent population: for double null GSTM1 and GSTT1 homozygotes the OR was 2.06 (95% CI 0.85-2.04). In those also likely to have been exposed to diazinon, risks associated with a GSTP1*B or *C allele (OR 1.82, 95% CI 0.92-3.63) or a GSTM1*2/GSTT1*2 homozygous (OR 2.60, 95% CI 0.72-10.42) were elevated but not to a significant extent. Risk associated with PON1 genotype and phenotype varied with CYP2D6 and GSTP1 genotype but not consistently with a priori hypotheses. Further work is necessary to delineate more clearly pathways of organophosphate activation and non-PON1 pathways of detoxification and to confirm whether CYP and GST polymorphisms alter disease risk in populations exposed to organophosphates.

Incidence by occupation and industry of acute work related respiratory diseases in the UK, 1992-2001

AIMS

To summarise incidence rates and epidemiological characteristics of new cases of work related respiratory disease reported by specialist physicians in thoracic and occupational medicine, with particular reference to occupation, industry, and causal agents for asthma, inhalation accidents, and allergic alveolitis.

METHODS

Cases reported 1992-2001 to the SWORD and OPRA national surveillance schemes, in which almost all UK chest and occupational physicians participate, were analysed by age, sex, cause, occupation, and industry, with incidence rates calculated against appropriate denominators.

RESULTS

Excluding diseases of long latency, infrequently seen by occupational physicians, the distribution of diagnoses in the two specialties was similar, but with rates generally much higher in occupational than chest physicians. Occupational asthma was responsible for about 25% of cases overall, affecting mainly craft related occupations and machinists, and most often attributed to isocyanates, metals, grains, wood dusts, solders, and welding fume. These same occupations were those at highest risk from inhalation injuries, most frequently caused by irritant gases, vapours, and fume. Among medical technicians and nurses, however, glutaraldehyde and latex were the main causes of occupational asthma. Allergic alveolitis was seldom reported, with almost all cases in agriculture, forestry, and fishing.

CONCLUSION

During the 10 year period studied, there were few changes in level of reported incidence, apart from some decline in occupational asthma and inhalation injuries. These results and their implications should be distinguished from much higher estimates of asthma made worse by work derived from population surveys, based on prevalence rather than incidence, and self-reported symptoms rather than diagnoses made by specialist physicians. Even so, the reported incidence of new cases of acute respiratory illness caused by work remains substantial.

Paraoxonase polymorphisms and self-reported chronic ill-health in farmers dipping sheep

BACKGROUND

Serum paraoxonase (PON1) provides protection against organophosphate induced toxicity. Recently we reported that the frequency of paraoxonase polymorphisms in sheep dippers with self-reported chronic ill-health differed from that in dippers with a similar dipping history but no ill-health. As these analyses may have included subjects with conditions unrelated to organophosphate exposure, the aim of this study was to examine whether the risk associated with PON1 polymorphisms varied using a more homogenous case and referent population.

METHODS

Each subject completed a detailed symptom questionnaire and their general practitioner was asked whether there was any history of neurological disease that could be confused with the effects of organophosphate poisoning. Subjects were then excluded both on clinical grounds and where identified as atypical on discriminant analysis.

RESULTS

Risk associated with the PON1 192 and 55 genotypes altered little with these changes in the population.

CONCLUSIONS

These findings are consistent with the hypothesis that organophosphates contribute to the self-reported ill-health of sheep dippers.

The incidence of work-related disease reported by occupational physicians, 1996-2001

In the course of six calendar years, 1996-2001, 5491 new cases of work-related disease were reported by a 1-in-12 random sample of occupational physicians throughout the UK. This represented an estimated total of almost 66 000, or 11 000 cases per annum. These cases have now been analysed by sex, occupation (nine categories) and industry (eight categories), and annual average incidence rates calculated in five main disease groups against a similarly classified denominator of 3.2 million employees served by the same physicians. The overall average annual estimated rate (342 per million) was eight times higher than that reported by clinical specialists, calculated in a similar manner against the entire employed population of the UK (28 million), but 17 times higher for musculoskeletal disease. For men employed in mines and quarries, and both men and women in metallic and automotive manufacture, rates for most types of disease were very high. Occupations with the highest rates were craftsmen and female associate professionals. In all these occupational and industrial groups with high rates, musculoskeletal complaints were the main cause, and skin, respiratory or stress diseases were next in importance. In each type of disease, there was a wide range in incidence rates, suggesting important differences in risk by occupation or industry.

Prognosis and work absence due to occupational contact dermatitis

The consequences of a diagnosis of occupational contact dermatitis (OCD) were investigated using cases available from the voluntary surveillance scheme, EPIDERM. Cases of OCD reported from November 1994 to September 1995 were identified and sampled to give at least 100 cases of allergic, irritant and mixed OCD reported by consultant dermatologists (344 cases) and occupational physicians (377 cases). A questionnaire was sent to the reporting physician to elicit further information. 512 completed questionnaires were returned, of which 510 were eligible for analysis. Among cases reported by dermatologists (n = 286) and occupational physicians (n = 224), 7% (6.3%) had been unemployed and 16.8% (20.1%) had taken sick leave. 3 factors independently predicted time off work in a logistic regression analysis: age OR = 1.25 (95% CI, 1.05-1.49), allergic dermatitis OR = 1.77 (95% CI, 1.13-2.79) and medicolegal assessment OR = 4.42 (95% CI, 2.20-8.89). Overall, 15.7% did not improve clinically between the first and last visit. Those who did not improve had been exposed to the agent for longer (mean 7.6 years) than those who did (5.3 years) (p = 0.09). In patients <or= 45 years, those reported to be atopic failed to improve (25.4%) more often than those not atopic (13.4%) (p = 0.04). The substantial numbers (21%) with time off work and with persistent dermatitis suggest that OCD continues to have a significant impact on workers and their employers.

Surveillance for work-related hearing loss in the UK: OSSA and OPRA 1997-2000

Surveillance data on occupational audiological disorders have been collected by the Occupational Surveillance Scheme for Audiological Physicians (OSSA) since October 1997 and by the Occupational Physicians Reporting Activity (OPRA) from January 1996. During the 3 years ending in September 2000, a total of 1620 new cases were received from consultant audiological physicians; 988 new cases were estimated from reports by occupational physicians in the period from October 1997 to September 2000. The annual incidence of occupational noise-induced hearing loss (NIHL) was 1.94 and 1.23 per 100 000 workers for the OSSA and OPRA schemes, respectively. The median age at diagnosis with NIHL was 59 years in OSSA reports and 50 years in OPRA; nearly all cases were seen in men (95.6 and 92.5% male cases for OSSA and OPRA, respectively). High incidence rates based on OSSA reports were seen in foundry labourers (64.0 per 100 000 employed), coal gas and coke oven furnace workers (54.6), workers in transport and communication (43.1), metal workers (31.3), and members of the armed forces (28.3). Data from occupational physicians point to high rates in sawyers and woodworking machinists, metal furnace workers, coach and carriage builders, maintenance fitters, and engineering labourers. Among workers aged < or =45 years, those in manufacturing and the armed forces were prominent. The long latency of occupational hearing loss makes surveillance difficult, but consistent patterns in occupational risk suggest targets for preventive efforts.

Polymorphisms in the NAD(P)H: quinone oxidoreductase gene and small cell lung cancer risk in a UK population

NAD(P)H: quinone oxidoreductase (NQO1) protects the cell against cytotoxicity by reducing the concentration of free quinone available for single electron reduction. The NQO1 gene is polymorphic and the variant protein exhibits just 2% of the enzymatic activity of the wildtype protein. In this study, we investigated NQO1 genotype in relation to lung cancer risk in patients attending a Manchester bronchoscopy clinic. The cases were patients with a current, or history of, malignant tumour of the lung, trachea or bronchus. The control group were all other patients attending the clinic who had never been diagnosed with a tumour. DNA extraction from bronchial lavage or blood samples and genotyping was successfully carried out for 82 of the cases and 145 controls. Patients carrying at least one variant allele were found to have almost a 4-fold increased risk of developing small cell lung cancer (adjusted OR=3.80, 95% C.I. 1.19-12.1). No association between NQO1 genotypes and non-small cell lung cancer risk was found. Furthermore, the excess small cell lung cancer risk associated with non-wildtype NQO1 genotypes was only apparent in heavy smokers where there was a >10-fold increased risk (adjusted OR=12.5, 95% C.I. 2.1-75.5). These results suggest that the NQO1 protein may be involved in the detoxification of those carcinogens associated with the development of small cell lung cancer. Individuals with reduced enzyme activity, due to a polymorphism in this gene, may therefore have an increased risk of developing this disease.

The reported incidence of work-related musculoskeletal disease in the UK: MOSS 1997-2000

Consultant rheumatologists participate in surveillance of work-related musculoskeletal conditions under the Musculoskeletal Occupational Surveillance Scheme (MOSS), which has been in operation since 1997. During the first 3 years of the scheme, an estimated total of 8070 cases and 8442 diagnoses were obtained, an average of slightly less than 2700 estimated cases each year. Disorders of the upper limb accounted for approximately 66% (5502) of the total, with hand/wrist/arm conditions (3693 cases) comprising the majority of these. Conditions of the lumbar spine and trunk (13% of cases), the cervical spine (12%) and the shoulder (12%) were also frequently reported. Pain with ill-defined pathology was reported in 35% of cases with hand and forearm disorders. Overall, 82% of cases were related to repetitive rather than single injury. The largest numbers of cases were seen in workers in craft occupations (1659) and in clerical and secretarial workers (1524). High rates of musculoskeletal conditions, particularly of upper limb disorders, are notable in mining. In most occupations, and overall, women were at greater risk than men.

Association of occupational physical demands and psychosocial working environment with disabling shoulder pain

OBJECTIVE

To estimate the individual and combined associations of physical and psychosocial working environment with disabling shoulder pain and to identify groups at "high risk" for shoulder pain.

METHODS

A cross sectional survey was conducted at five manual occupational settings in south Manchester, United Kingdom (n=775, 83%).

RESULTS

Both the duration of occupational physical demands (working postures, manual handling activities, and repetitive arm movements) and psychosocial working environment (psychological demands and lack of opportunity to learn new skills) were found to be significantly associated with shoulder pain. Three occupational factors identified a high risk group for shoulder pain: duration of lifting with one hand (prevalence rate ratio (PRR) (highest third) 2.0, 95% confidence interval (CI) 1.4 to 2.8), duration of working above shoulder level (PRR (highest third) 2.2, 95% CI 1.5 to 3.3), and whether employees found their work stressful (PRR (highest third) 1.4, 95% CI 1.0 to 2.1). In addition, a measure of psychological distress (General Health Questionnaire (GHQ) score) was found to identify a group at high risk for shoulder pain (PRR (highest third) 1.9, 95% CI 1.3 to 2.9). In employees exposed to three or more of these factors, 79% (23/29) reported shoulder pain compared with only 16% (56/353) of those not exposed to any.

CONCLUSION

This study has identified a variety of occupational physical demands and psychosocial factors associated with shoulder pain. It has also identified groups of employees at a "high risk" for shoulder pain by their exposure to both physical and psychosocial factors.

Short term influence of mechanical factors on regional musculoskeletal pain: a study of new workers from 12 occupational groups

OBJECTIVES

To determine the influence of short term exposure to mechanical factors on regional musculoskeletal pain.

METHODS

Full time newly employed workers were recruited from 12 occupational groups and information collected by questionnaire. Subjects indicated on a blank body manikin any low back, shoulder, wrist or forearm or both, or knee pain which had occurred during the past month and had lasted more than 1 day. Data were also collected with a previously validated questionnaire on working postures, manual handling activities, and repetitive movements of the upper limb. The relations between mechanical factors and each area of pain were calculated as odds ratios (ORs) with 95% confidence intervals (95% CIs). Adjustment was made for age and sex.

RESULTS

1081 subjects (median age 23; interquartile range 20--27) were recruited to the study (a participation rate of 91%). 261 (24%) reported low back pain, 221 (20%) shoulder pain, 93 (9%) wrist or forearm pain, and 222 (21%) knee pain. Several specific manual handling activities were found to be associated with low back, shoulder, and knee pain. Carrying weights of more than 50 lbs (23 kg) on one shoulder was the factor which was most strongly associated with low back pain (OR 2.4 (95% CI 1.5 to 3.8)), shoulder pain (OR 3.1 (95% CI 1.9 to 4.8)), and knee pain (OR 3.5 (95% CI 2.2 to 5.5)), whereas forearm pain was most strongly associated with repetitive movements of the wrists (OR 1.8 (95% CI 1.04 to 3.1)). By contrast very few postures were associated with regional pain, although bending forwards in an uncomfortable position for at least 15 minutes was associated with shoulder pain (OR 1.6 (95% CI 1.2 to 2.2)) and kneeling for at least 15 minutes was associated with knee pain (OR 1.8 (95% CI 1.2 to 2.6)). Exposure to mechanical factors was most strongly associated with pain at multiple sites rather than with pains in individual regions.

CONCLUSIONS

Even among workers with only short term exposure to mechanical factors, musculoskeletal pain is increased.

The influence of work related psychosocial factors and psychological distress on regional musculoskeletal pain: a study of newly employed workers

OBJECTIVE

To determine the influence of short term work related psychosocial factors (work demands, job control, and social support) and psychological distress on regional pain syndromes.

METHODS

Newly employed workers were recruited from 12 occupational groups and information collected by questionnaire. Subjects indicated on a blank body manikin any low back, shoulder, wrist/forearm, or knee pain that had occurred during the past month and lasted more than one day. Data were also collected on work related psychosocial factors and on levels of psychological distress [using the General Health Questionnaire (GHQ)]. The relationships between psychosocial factors and psychological distress and each area of pain were calculated as odds ratios with 95% confidence intervals. Adjustment was made for age, sex, and occupational group.

RESULTS

1081 subjects (median age 23; interquartile range 20-27) were recruited to the study shortly after commencing employment: 261 (24%) reported low back pain, 221 (20%) reported shoulder pain, 93 (9%) reported wrist/forearm pain, and 222 (21%) reported knee pain. High levels of psychological distress were associated with increased likelihood of pain, with a trend observed between scores on the GHQ and the odds of pain in each of the 4 sites. Those who perceived their work as stressful most of the time were more likely to report back (OR 1.8, 95% CI 1.01-3.1) or shoulder pain (OR 1.9, 95% CI 1.02-3.4) than those who considered their work seldom stressful. Pace of work or job autonomy was less markedly related to pain at individual sites. Strong relationships were observed between psychological distress, job demands (stressful work, hectic work), low job control, and pain at multiple sites.

CONCLUSION

The study has shown that adverse work related psychosocial factors, in particular aspects of job demand and control, influence the reporting of regional musculoskeletal pain. This occurs even after only short term exposure. The odds of reporting these adverse exposures are increased when pain is reported at multiple sites.

SWORD '99: surveillance of work-related and occupational respiratory disease in the UK

Systematic reports from chest and occupational physicians under the SWORD and OPRA (Occupational Physicians Reporting Activity) surveillance schemes continue to provide a picture of the incidence of occupational respiratory disease in the UK. An estimated total of 4393 incident cases (comprising 4530 diagnoses) were reported during the 1999 calendar year, an increase of 1427 cases over the previous year. Benign pleural disease was the single most frequently reported condition (28% of all diagnoses reported). Occupational asthma cases (1168; 26%) remained high, as did mesothelioma (1032; 23%). Analysis of trends over the past 8 years shows an increase in mesothelioma cases, but little change in asthma. The annual incidence per 100,000 employed people, 1996-1999, for mesothelioma, lung cancer and pneumoconiosis was high amongst construction workers (28.7), miners and quarrymen (26.5), woodworkers (18.9) and gas, coal and chemical workers (15.2). Trends in mesothelioma incidence by birth cohort continue to show an increase in construction workers and a continuing decline in shipyard and insulation workers. The relative proportion of pneumoconiosis cases attributed to coal mining has fallen steadily in workers born since approximately 1920 and most cases are now in men who have been employed in quarrying and rock drilling.

Surveillance of work-related diseases by occupational physicians in the UK: OPRA 1996-1999

The Occupational Physicians' Reporting Activity (OPRA) surveillance scheme for occupational physicians has now been in place for 4 years. During this period, an estimated 43,764 new cases of work-related disease have been reported. Musculoskeletal conditions make up nearly half (49%) of all cases; mental ill-health and skin disease account for 20% each, with respiratory conditions (8%) and hearing loss (5%) seen in lower proportions. Overall, eight of 42 diagnoses made up four-fifths of the new cases reported by occupational physicians. These were hand and arm disorders (8052 estimated cases), contact dermatitis (7104), disorders of the lumbar spine (6000), anxiety and depression (4788), work-related stress (3336), hearing loss (2100), elbow disorders (2040), and asthma (1680). Dermatitis and hearing loss were most frequent in manufacturing industries, lower back complaints in health care, and upper limb disorders in automotive manufacture. Psychiatric illnesses presented a different pattern, mainly affecting those in health, education and social service.

Occupational contact dermatitis in the UK: a surveillance report from EPIDERM and OPRA

Since February 1993 the EPIDERM surveillance scheme has collected data on occupational skin disease from consultant dermatologists in the UK. Reporting by occupational physicians to the scheme began in May 1994 and was superseded in January 1996 by the Occupational Physicians Reporting Activity (OPRA). The schemes currently receive reports on incident cases from 244 dermatologists and 790 occupational physicians. An estimated total of 9937 cases of contact dermatitis reported by dermatologists was calculated from surveillance data; 8129 contact dermatitis cases were estimated from reports by occupational physicians. The annual incidence of occupational contact dermatitis from dermatologist reports was 6.4 cases per 100,000 workers and 6.5 per 100,000 from reports by occupational physicians, an overall rate of 12.9 cases per 100,000 workers. Manufacturing industries account for the greatest number of cases seen by both sets of reporting physicians, with health care employment second. Reports from dermatologists also indicate high rates of dermatitis in the personal service industries (mainly hairdressers and barbers) and in agriculture. With the exception of an increase in cases seen in nurses in both schemes, the numbers and proportions of cases of contact dermatitis within occupations have remained fairly constant over the 6-year reporting period. Agents accounting for the highest number of allergic contact dermatitis cases were rubber (23.4% of allergic cases reported by dermatologists), nickel (18.2), epoxies and other resins (15.6), aromatic amines (8.6), chromium and chromates (8.1), fragrances and cosmetics (8.0), and preservatives (7.3). Soaps (22.0% of cases), wet work (19.8), petroleum products (8.7), solvents (8.0), and cutting oils and coolants (7.8) were the most frequently cited agents in cases of irritant dermatitis. The national scope of the data, together with the parallel structure by which both dermatologists and occupational physicians report incident cases, is useful in determining the extent of skin hazards in UK industry and may help in better targeting efforts to reduce the burden of skin disease at work.

SWORD '98: surveillance of work-related and occupational respiratory disease in the UK

The SWORD surveillance scheme, now 10 years old, uses systematic reporting from physicians to provide a picture of the incidence of occupational respiratory disease in the United Kingdom. An estimated total of 2966 incident cases was derived from reports by chest and occupational physicians during the 1998 calendar year. Occupational asthma continues to be the most-reported respiratory condition, with an estimated 822 cases (27% of total cases). The proportion of cases of mesothelioma (23%), benign pleural disease (21%) pneumoconiosis (7%) and inhalation injuries (6%) remain similar to those estimated in past years, although fewer cases overall were reported. The most commonly identified agents causing asthma in 1998 were enzymes, isocyanates, laboratory animals and insects, colophony and fluxes, flour, latex, and glutaraldehyde. An increased incidence of respiratory diseases of short latency was seen in mining, whilst cases in chemical, mineral products and motor vehicle manufacture remained high; lower rates were noted in wood products and textile manufacture when compared with 1997 figures. Inhalation accidents over the past 3 years were reviewed; gaseous agents and combustion products accounted for nearly half of cases. High rates for inhalation injuries were seen in coal miners, fuel production, motor vehicle manufacturing, water purification, and chemical manufacturing.

Crystalline silica and risk of lung cancer in the potteries

OBJECTIVE

To evaluate crystalline silica as a human carcinogen.

METHODS

A cohort of 5115 men, born 1916-45 and employed in the pottery, refractory, and sandstone industries of Stoke-on-Trent was identified from occupations subject to health surveillance by the local Silicosis Medical Board (now the Department of Social Security). Detailed occupational and smoking histories, and records of small parenchymal opacities on periodic radiographs were extracted from medical records. An exposure matrix was derived from some 1400 personal or static dust samples and tested against the presence of small parenchymal opacities in a subcohort of 1080 men employed for at least 10 years, who had started working in the industry before 1960.

RESULTS

Standardised mortality ratios (SMRs) calculated against mortalities for Stoke-on-Trent, with 95% confidence intervals (95% CIs), were raised for all causes (1.15 (1.05 to 1.26)), lung cancer (1.28 (0.99 to 1.62)) and non-malignant respiratory disease (2.04 (1.55 to 2.65)). Average concentration and duration of exposure to silica were, taken together, significantly related to the presence of small opacities (> or = 1/0). In a nested case-referent analysis of 52 cases of lung cancer and 197 matched referents, conditional logistic regression gave a significantly increased odds ratio (OR) for average silica concentration (micrograms/m3.100), after adjustment for smoking, of 1.66 (1.14 to 2.41) but not for duration of exposure nor, in consequence, for cumulative exposure.

CONCLUSION

The association between risk of lung cancer and quantitative estimates of silica exposure supports the SMR analysis and implies that crystalline silica may well be a human carcinogen.

Validity of a self-completed questionnaire measuring the physical demands of work

OBJECTIVES

This study determined the accuracy of workers in quantifying occupational physical demands on a self-administered questionnaire.

METHODS

First, a self-administered questionnaire on work postures, manual materials-handling, and repetitive upper-limb movements was validated using direct simultaneous observations for 123 randomly selected employees from 6 occupational settings. Second, weight estimation accuracy was assessed on visual analogue scales for 6 manual materials-handling activities using 20 randomly selected employees from 1 occupational setting.

RESULTS

At a dichotomous level (ever-never), the accuracy of most of the self-reported physical demands was good (sensitivity 60-100%; specificity 56-100%). A more-detailed analysis of the dimensions studied (frequency, duration and amplitude) also showed that the accuracy of the self-reported estimates was satisfactory. Full agreement between the estimated and observed frequency was >60% for most of the manual materials-handling activities. In addition the average difference between the estimated and observed duration of the physical demands was found to be small. Finally the average difference between the self-reported and actual weights of various loads was found to be modest.

CONCLUSIONS

The self-reported questionnaire used in this study would provide a useful instrument for estimating occupational physical demands and the frequency, duration, and amplitude of these demands in future epidemiologic studies associated with musculoskeletal pain.

Occupationally acquired infectious disease in the United Kingdom: 1996 to 1997

The incidence of occupationally acquired infectious diseases, has, up to now, been unknown. A reporting scheme for consultants in communicable disease control (CCDCs) (and their equivalents) throughout the United Kingdom was set up in October 1996 to estimate its extent. Monthly reporting cards were sent to CCDCs asking for brief details of all new cases of occupationally acquired infectious disease seen by them. Between October 1996 and September 1997, 1037 new cases were notified by CCDCs. The highest rates were among employees in food production and catering, farming, and among care workers, particularly in residential homes. During the same period an estimated 257 cases were reported in comparable surveillance schemes by chest physicians, occupational physicians and dermatologists. These figures probably underestimate the number of infections acquired in association with work substantially, and highlight diarrhoeal disease as the commonest problem.

Injuries after falls at work in the United Kingdom and Sweden with special reference to fractures in women over 45

OBJECTIVES

To describe the relation with age of risk of reported injury after a fall among women at work in two countries, the United Kingdom and Sweden, with particular emphasis on fractures, and to interpret these data.

METHODS

Rates of accidents compiled under the national reporting regulations of each country during a two year period were described by age, sex, cause (fall on the level, fall from a height, other), and occurrence of fracture, with emphasis on the relative risk (RR) in workers aged 45 years and over compared with those aged under 45. For fractures (major fractures only in the United Kingdom) among women, RRs were calculated for all occupations, with the three digit occupational classification schemes of each country. Summary RRs for older versus younger women, directly standardised for occupation, were derived.

RESULTS

Among women, RRs for injury after a fall on the level and fall from a height were 2.77 and 1.77 respectively in Sweden and 2.28 and 1.54 in the United Kingdom. When restricted to fractures, the RRs became 4.75 and 3.66 respectively in Sweden and 3.35 and 1.97 in the United Kingdom. Standardisation for occupation gave RRs for fractures of 4.87 and 3.75 in Sweden and 3.43 and 2.16 in the United Kingdom. Almost all occupational groups with enough fractures for analysis showed an excess of fractures related to falls among older women. A different age pattern was seen for all injuries or fracture after other types of accidents and for all types of accident in men.

CONCLUSION

It is argued that, for fractures at least, the results for women are unlikely to be due to reporting bias and unlikely to be explained by a greater exposure to workplace hazards among older women. Whether there is an increased risk of falling, as distinct from sustaining a fracture, is not clear. The generality of the increased risk suggest that efforts should be made to minimise hazards in all occupational sectors, particularly those using many women.

Shiftwork and mortality from ischaemic heart disease

OBJECTIVES

To investigate the relation between shift work and death from ischaemic heart disease (IHD).

METHODS

A nested case-control approach was used. The cohort comprised male manual workers who joined an industrial company aged 50 years or under between 1 January 1950 and 31 December 1992 and worked there for at least one month. Cases were 467 cohort members who died during the same period aged 75 years or under, with ischaemic heart disease (IHD) (international classification of diseases (ICD) 410-414) coded from the death certificate. For each case a control worker was chosen, who joined the company at the same age and in the same period but who survived the case. Work status (shift work or day work) was assigned to cases for their entire employment and to controls for that part of their employment which preceded the matching case's death. The main source of information was historical personnel records containing pay codes which differed for day work and shift work. Information on weight, height, blood pressure, and smoking from a pre-employment medical was available.

RESULTS

Two thirds of subjects had been employed for at least one month as shift workers and there was evidence that they had slightly better health at recruitment than day workers. The odds ratio for shift workers during the period starting 10 years after shift work began, and after adjustment for height, body mass index, blood pressure, smoking, duration of employment, and job status (skilled or unskilled) was 0.90 (90% confidence interval (90% CI): 0.68-1.21). There was no relation between risk of IHD death, and duration of shift work, but there was evidence of a reduced risk when actively employed as a shift worker, together with an increased risk in the first five years after leaving shift work to do day work.

CONCLUSIONS

Shift work did not increase the risk of death from ischaemic heart disease in this study. Those workers with poorer cardiovascular health may be under represented in groups with longer shift work experience because of health related selection out of shift work.

A study of lung function and chest radiographs in men exposed to zirconium compounds

Men working with zirconium compounds at one site in the North of England have been monitored since 1975 to evaluate effects on the lung of exposure (mainly < 10 mg/m3) over many years. Chest radiographs (in 1975, 1978, and 1982) and lung function measurements (from 1975-1988) were carried out on all men (178) known to have worked with the compounds and an estimate of cumulative exposure was computed from job title and likely exposures in each era. No evidence was found that zirconium exposure resulted in abnormal chest radiographs or impaired pulmonary function.

Occupational exposure to hydrocarbons and chronic pancreatitis: a case-referent study

OBJECTIVES

To investigate the hypothesis that hydrocarbon exposure is a risk factor for chronic pancreatitis.

METHODS

102 cases of chronic pancreatitis and 204 age and sex matched referents were interviewed about their occupational histories, alcohol and cigarette consumption, and diet. Exposure to hydrocarbons was inferred from interview responses by four assessors who were blind to disease state, and these data were then summarised by a cumulative hydrocarbon exposure (CHE) score.

RESULTS

After adjustment for alcohol, cigarettes, dietary antioxidants, and social class, odds ratios for low CHE scores were 1.20 (90% CI: 0.62-2.35) and 2.67 (90% CI: 1.22-5.87) for high scores. A test for trend with level of exposure among only those who had exposure scores > 0 gave p = 0.09. Analysis by type of hydrocarbon was limited to four exposures for each of which there were at least 20 exposed patients. The adjusted OR for paint solvents (any level) was 0.96 (90% CI: 0.48-1.93); for diesel exhaust fumes OR = 2.66 (90% CI: 1.05-6.73); for petrochemicals OR = 1.82 (90% CI: 0.80-4.11); and for chlorinated solvents OR = 1.49 (90% CI: 0.58-3.81).

CONCLUSIONS

These results support the original hypothesis. Further studies are needed to confirm or refute the findings here and to clarify the types of hydrocarbon involved.

Sick building syndrome in a Canadian office complex

A comprehensive questionnaire survey with limited environmental measurements was undertaken in a large sealed office complex where health complaints had been made by employees since the complex was first occupied. Most respondents suffered from upper respiratory tract irritation, eye and skin irritation, and many less specific complaints. Symptoms started shortly after first employment, were troublesome only at work, and persisted at other work locations within the complex. Employees who worked in cubicles tended to complain more than those who worked in open areas or closed offices; however, evidence of less than optimal ventilation, temperature, and humidity correlated poorly with symptom prevalence. The building was designed and ventilated for open-plan use; later partition into offices and cubicles appeared to aggravate the situation. Although concern about pregnancy outcome was expressed by women who conceived while employed at the complex, rates of spontaneous abortion and fetal defect were close to expectation.

Fathers' occupation and pregnancy outcome

Findings from a survey of 56,067 women in Montreal on maternal occupation and pregnancy outcome have been reported. Paternal occupation recorded in the same survey was analysed for spontaneous abortion in 24 occupational groups retaining the six main sectors of maternal occupation and allowing, by means of logistic regression, for seven potentially confounding variables. In only one of the 24 fathers' occupational groups was there a statistically significant excess of spontaneous abortions--mechanics, repairers, and certain assemblers (O/E = 1.10, 90% CI = 1.02-1.20); subdivision of this group suggested that this excess was mainly attributable to the large group of motor vehicle mechanics (O/E = 1.17). No significant excess of known chromosomally determined defects was found in any of the 24 occupational groups. An association of developmental defects was found with food and beverage processing (18 defects observed compared with 8.02 expected; p less than 0.05); however, there was no specificity in type of food, beverage, or congenital defect, and no obvious explanatory mechanism.

Congenital defects and work in pregnancy

The risk of congenital defect was examined in 47,913 pregnancies of women employed for 15 hours a week or more at time of conception. The rate of defects of all types per 1000 births in this series was 25.0; 1.8 from defects classified as chromosomal (group A), 10.8 as developmental (group B), and 12.5 as musculoskeletal (group C). Some evidence of an excess in the risk ratio (p less than 0.05) was found in the services sector and in four occupations--agriculture and horticulture (2.61), telephone and postal clerks (1.74), a miscellaneous group of service jobs (1.68), and receptionists and information clerks (1.47); excesses of lower statistical significance (p less than 0.1) were found in those engaged in plastics and rubber manufacture (2.02) and in child minders (1.84). There were two cases of tracheo-oesophageal fistula--a rare defect--among eight defects (1.32 expected) in agriculture and horticulture. Overall, the distribution of risk ratios in the 60 occupations examined was not significantly heterogeneous. Analysis of chemical exposure profiles for each occupational group showed no evidence of any increased risk, perhaps due to lack of sensitivity and discrimination in this method of exposure estimation. In 152 pregnancies of doctors and nurses who had administered antineoplastic drugs in the first month eight defects, miscellaneous in type, were observed compared with 4.05 expected (p = 0.05). Special study of musculoskeletal defects and work demands showed some evidence of an association with a long working week (greater than or equal to 46 hours) but no other ergonomic factor. With these few exceptions the survey failed to identify appreciable risk of congenital defect related to occupation.

The role of official tax-supported agencies in home care. A personal perspective

This article examines the role of the tax-supported, official public health agency and compares it with the private, nonprofit agency as both participate in making home health care available.

Fetal death and work in pregnancy

The relation between spontaneous abortion (n = 5010), stillbirth without congenital defect (n = 210), and working conditions was analysed in 22,613 previous pregnancies of 56,067 women interviewed, 1982-4, immediately after termination of their most recent (current) pregnancy. The 22,613 previous pregnancies were those in which at time of conception the women were employed 30 or more hours a week. Ratios of observed (O) to expected (E) fetal deaths after allowance by logistic regression for seven non-occupational confounding variables were calculated at four stages of pregnancy in 60 occupational groups and six main sectors for women whose work entailed various physical demands, environmental conditions, and exposure to chemicals. The O/E ratios for abortion were raised in the sales sector (1.13, p less than 0.05) and services sector (1.11, p less than 0.01) and for stillbirth in the sales sector (1.50, p less than 0.1). Substantially increased O/E ratios for late but not early abortion were found in operating room nurses (2.92, p less than 0.05), radiology technicians (3.82, p less than 0.01), and employees in agriculture and horticulture (2.40, p less than 0.05); in all categories the O/E ratio for stillbirth were also raised but only significantly (5.55, p less than 0.01) in the latter group. The O/E ratio for stillbirth was also raised in leather manufacture (3.09, p less than 0.01). In both individual and grouped analysis (the latter undertaken to minimise the possible effect of recall bias) significantly increased O/E ratios for abortion were found in women exposed to various high levels of physical stress, particularly weight lifting, other physical effort, and standing (p less than 0.01). Increased ratios for stillbirth at this level of significance (p less than 0.01) were found for other physical effort and vibration. Noteworthy chemical exposure was identified only in the health, services, and manufacturing sectors; the O/E ratio for stillbirth approached two in women exposed to solvents, almost all in manufacturing (p less than 0.01). In the latter sector exposed to solvents was also associated with an approximately 20% increase in abortion ratio at similar probability level.

Prematurity and work in pregnancy

The frequency of low birth weight (less than or equal to 2500 g) and of preterm birth (less than 37 weeks) was studied in 22,761 single live births in relation to maternal employment, taking account of 11 nonoccupational confounding factors. There was some increase of low statistical significance in both types of prematurity in service and manufacturing sectors of industry. A substantial excess of preterm births was seen in women employed in food and beverage service (O/E = 1.29, p = 0.03) and psychiatric nursing (O/E = 2.47, p less than 0.01) and of low birth weight in food and beverage service (O/E = 1.30, p = 0.02), in chambermaids and cleaners (O/E = 1.42, p = 0.03), and in those employed in the manufacture of metal and electrical and certain other goods (O/E = 1.57, p less than 0.01). Heavy lifting and long hours of work were consistently related to both outcomes, changing shift work less consistently. Noise was associated with low birth weight in the health and manufacturing sectors. The findings of this study are unlikely to have resulted from subject or observer bias but the role of unidentified factors related to selection for work are difficult to assess.

Visual display units and pregnancy: evidence from the Montreal survey

Data on 56,012 current and 48,608 previous pregnancies were obtained by interview in 11 Montreal hospitals, 1982 to 1984, after delivery or spontaneous abortion. In 17,632 pregnancies in occupations with substantial use of visual display units (VDUs), users and nonusers had similar rates of congenital defects in both current and previous pregnancies and of abortions in previous pregnancies. In current pregnancies there was an excess of abortions in users which could have been due to biased recall. In a further analysis of all 42 occupational groups ranked according to percentage use of VDUs, the risk of spontaneous abortion in both current and previous pregnancies was the same irrespective of the amount of VDU use. Thus, the study does not support the suggestion that work with a VDU in pregnancy increases the risk of congenital defect or spontaneous abortion.

Spontaneous abortion and occupation

Occupational factors in spontaneous abortion were studied in the current and previous pregnancies of 56,012 women interviewed in 11 Montreal maternity departments, 1982 to 1984. Ratios of observed to expected abortions (RR), after allowance for nonoccupational confounders, were significantly increased (P less than .05) among nursing assistants and attendants (RR 1.24 in current and 1.13 in previous pregnancies), food and beverage servers (RR 1.31 in current and 1.11 in previous pregnancies) and sales persons (RR 1.18 in current and 1.12 in previous pregnancies). Women whose work entailed heavy lifting, other physical effort, long hours, exposure to noise, and exposure to cold had also significantly increased risk ratios. However, when occupational groups were ranked according to work demands, thus avoiding potential bias from prior knowledge of outcome, increased risks were associated consistently only with heavy lifting and other physical effort.