bluuebunny/crossref_metadata_2025 huggingface dataset:
Allergy to laboratory animals: a follow up study of its incidence and of the influence of atopy and pre-existing sensitisation on its development.
Authors: Botham P A , Lamb C T , Teasdale E L , Bonner S M , Tomenson J A
Published: December 2008

OBJECTIVES--To investigate the incidence of allergy to laboratory animals (ALA) during the first two years of employment, and to study the effect on ALA of atopy and sensitisation. METHODS--A follow up prospective study of ALA at the Zeneca (formerly ICI) Research Laboratories. RESULTS--The incidence of the disease during the first year of employment has remained at about 10% since the mid-1980s. This compares with an incidence of 37% in the early 1980s. The reduction in incidence and its maintenance at a lower level is thought to be due to the introduction and management of improved engineering controls, working practices, and educational programmes designed to reduce exposure to allergens from laboratory animals. The underlying incidence of immunological sensitisation to animals (the presence of immunoglobulin E (IgE) antibodies to animal allergens) is much higher (40% after one and 53% after two years of exposure). Both atopic diathesis and presensitisation to laboratory animals increased the likelihood that a person would develop ALA. CONCLUSION--Neither factor predicted the disease accurately so their use should be restricted to the identification of people who may be more susceptible to the development of ALA (and thus who may need to pay particular attention to the use of personal protective equipment) rather than to their exclusion.
Differential release of superoxide anions by macrophages treated with long and short fibre amosite asbestos is a consequence of differential affinity for opsonin.
Authors: Hill I M , Beswick P H , Donaldson K
Published: December 2008

OBJECTIVE--To investigate the ability of short and long fibre samples of amosite asbestos to stimulate superoxide production in isolated rat alveolar macrophages, and to determine how opsonisation with rat immunoglobulin might modify this response. METHODS--Macrophages were isolated from rat lung by bronchoalveolar lavage and challenged with both opsonised and non-opsonised long and short fibres of amosite asbestos. Release of superoxide anions was measured by the spectrophotometric reduction of cytochrome c, in the presence and absence of superoxide dismutase. RESULTS--Both long and short fibre samples of amosite asbestos without opsonisation were ineffective in stimulating isolated rat alveolar macrophages to release superoxide anions in vitro. After opsonisation with immunoglobulin, however, a dramatic enhancement of release of superoxide anion was seen with long fibres, but not short, which confirms the importance of fibre length in mediating biological effects. The increased biological activity of the long fibre sample is explained by increased binding of the opsonin to the fibre surface as, at equal mass, the long fibres bound threefold more immunoglobulin than the short fibres. CONCLUSION--Opsonisation is an important factor in modulation of the biological activity of fibres at the cellular level. Differences in binding of opsonin to samples of fibre previously considered to be identical apart from length, suggest that surface reactivity needs to be taken into account when fibres are compared. Binding of biological molecules, in vivo, may thus be an important modifying factor in the pathological processes initiated by fibres.
Cancer incidence in Swedish sterilant workers exposed to ethylene oxide.
Authors: Hagmar L , Mikoczy Z , Welinder H
Published: December 2008

OBJECTIVES--To assess the risk of cancer, especially leukaemia, in a cohort of sterilant workers exposed to ethylene oxide (EtO). METHODS--A cohort of 2170 workers employed for at least one year in two plants that produce disposable medical equipment sterilised with EtO has previously been established. The results of an update with four more years of observation are presented. The cancer incidence was assessed for the periods 1976 to 1990 and 1972 to 1990 and cause specific standardised incidence ratios (SIRs) were calculated. Individual cumulative exposure to EtO, expressed as ppm-years, was estimated and used in exposure-response analyses. RESULTS--Six lymphohaematopoietic tumours were observed (SIR 1.78, 95% confidence interval (95% CI) 0.65-3.88), of which two were leukaemias (SIR 2.44; 95% CI 0.30-8.81). When those with cumulative exposures to EtO below the median value (0.13 ppm-years) were excluded, and a minimum of 10 years induction latency period was applied, the incidence ratio for leukaemia increased further (SIR 7.14, 95% CI 0.87-25.8), but was still not significantly enhanced. CONCLUSIONS--The risk estimate for leukaemia increased, but non-significantly, with time since start of exposure, and with cumulative exposures to EtO above the median value. The subjects with leukaemia had, however, only slightly higher cumulative exposure estimates for EtO than the average cohort member. Nevertheless, the present results may add some minor evidence for an association between EtO and an increased risk of leukaemia.
Mortality of inhabitants in an area polluted by cadmium: 15 year follow up.
Authors: Nishijo M , Nakagawa H , Morikawa Y , Tabata M , Senma M , Miura K , Takahara H , Kawano S , Nishi M , Mizukoshi K
Published: December 2008

OBJECTIVE--To assess the influence of environmental exposure to cadmium (Cd) on long term outcome of inhabitants living in an area polluted by Cd. METHODS--A follow up study for 15 years (from 1974-5 to 1991) was carried out on 2408 inhabitants (amounting to 95% of the target population, 1079 men and 1329 women) of the Kakehashi River basin in Ishikawa Prefecture, Japan. These inhabitants had been the subjects of the health impact survey in 1974-5 to evaluate (by measurement of urinary retinol binding protein (RBP)) renal dysfunction induced by Cd. Analysis of mortality was performed by dividing subjects into a urinary RBP positive (> or = 4 mg/l) group and RBP negative (< 4 mg/l) group. RESULTS--After adjustment for age with Cox's proportional hazard model, RBP > or = 4 mg/l showed a significant relation to mortality in both sexes. At this time, the mortality risk ratio of the RBP positive to negative group was 1.71 in the men and 1.42 in the women. When the SMRs according to causes of deaths in the RBP positive group were compared with those of the RBP negative group or the overall Japanese population increases of SMR for cardiovascular diseases, especially heart failure, and renal diseases were found in both sexes. CONCLUSION--These results suggest that the prognosis of the exposed inhabitants with renal tubular dysfunction is unfavourable, and these increases of mortality are due to heart failure and renal diseases.
Significance of dermal and respiratory uptake in creosote workers: exposure to polycyclic aromatic hydrocarbons and urinary excretion of 1-hydroxypyrene.
Authors: Elovaara E , Heikkilä P , Pyy L , Mutanen P , Riihimäki V
Published: December 2008

OBJECTIVES--To evaluate workers' exposure in a creosote impregnation plant by means of ambient and biological monitoring. METHODS--Naphthalene (vapour phase) and 10 large molecular polycyclic aromatic hydrocarbons (PAHs) (particulate phase) were measured in the breathing zone air during an entire working week. 1-Hydroxypyrene (1-HP) was measured in 24 hour urine as a metabolite of the pyrene found in neat (dermal exposure) and airborne creosote. RESULTS--Naphthalene (0.4-4.2 mg/m3) showed 1000 times higher concentrations in air than did the particulate PAHs. In total, the geometric mean (range) of three to six ring PAHs was 4.8 (1.2-13.7) micrograms/m3; pyrene 0.86 (0.23-2.1) micrograms/m3, and benzo(a)pyrene 0.012 (0.01-0.05) micrograms/m3. There was no correlation between pyrene and gaseous naphthalene. The correlations between pyrene and the other nine particulate PAHs were strong, and gave a PAH profile that was similar in all air samples: r = 0.83 (three to six ring PAHs); r = 0.81 (three ring PAHs); r = 0.78 (four to six ring PAHs). Dermal exposure was probably very high in all workers, because the daily output of urinary 1-HP exceeded the daily uptake of inhaled pyrene by < or = 50-fold. Urinary 1-HP concentrations were very high, even on Monday mornings, when they were at their lowest (4-22 mumol/mol creatinine). 1-HP seldom showed any net increase over a workshift (except on Monday) due to its high concentrations (16 to 120 mumol/mol creatinine) in the morning samples. 1-HP was always lower at the end of the shift (19 to 85 mumol/mol creatinine) than in the evening (27 to 122), and the mean (SD) change over the working week (47 (18)) was greater than the change over Monday (35 (32)). The timing of 1-HP sampling is therefore very important. CONCLUSIONS--Urinary 1-HP proved to be a good biomarker of exposure to three to six ring PAHs but not to airborne naphthalene. Hence, biomonitoring based on 1-HP has to be completed with exposure assessment for naphthalene as a marker for creosote volatiles that mainly enter the body through the lungs.
Bilateral median and ulnar neuropathy at the wrist in a parquet floorer.
Authors: dell'Omo M , Muzi G , Cantisani T A , Ercolani S , Accattoli M P , Abbritti G
Published: December 2008

Many cases of work related compression neuropathy of the ulnar and median nerves at the wrist have been described. This report presents a case of bilateral distal neuropathy of the median and ulnar nerves in a parquet floorer, who laid wooden block flooring by hand and used the palms and volar surface of both hands to hit the blocks into place. He also used an electric sander and polisher. Bilateral numbness and paraesthesias in all fingers had been present for about one year. Clinical examination was normal; the neurological assessment indicated slight impairment in response to tactile, heat, and pain stimuli in all 10 fingers. Electroneurography showed increased distal motor latencies of median and ulnar nerves at both wrists, although the lower limbs were normal. The results of blood, urine, and instrumental tests excluded systemic disease or local factors that could cause compression neuropathy. After stopping work for three months, the clinical picture and electroneurographic results improved. These data support the hypothesis that the damage to the median and ulnar nerves had been caused by the patient's way of working, which provoked repeated bilateral microtrauma to his wrists. To diagnose work related multiple neuropathy can be difficult and an accurate work history is necessary. Preventive measures and diligent health care are required for this category of worker.
Mortality and cancer morbidity in workers from an aluminium smelter with prebaked carbon anodes--Part III: Mortality from circulatory and respiratory diseases.
Authors: Rønneberg A
Published: December 2008

OBJECTIVE--To investigate associations between exposure to pot emissions (fluorides, sulphur dioxide) and mortality from chronic obstructive lung disease, coal tar pitch volatiles and mortality from diseases related to atherosclerosis, and carbon monoxide and mortality from ischaemic heart disease. METHODS--Mortality between 1962 to 1991 was investigated in a cohort of 1085 men hired by a Norwegian aluminium smelter between 1922 and 1975. Associations between cumulative exposure and mortality were investigated through SMR analysis based on national mortality rates; temporal relations were explored by considering exposures only within specific time windows. Circulatory mortality was also investigated by Poisson regression analysis. RESULTS--There were 501 deaths v 471.3 expected in the cohort. The excess was confined to short term workers and did not seem to be associated with exposures in the smelter. Analysis of mortality among the 661 men with at least three years employment showed associations between cumulative exposure to tar 40 years before observation and atherosclerotic mortality (P = 0.03), and between exposure to pot emissions 20-39 years before observation and mortality from chronic obstructive lung disease (P = 0.06). No association was found between exposure to carbon monoxide and mortality from ischaemic heart disease, but cerebrovascular mortality was associated with exposure to pot emissions (P = 0.02). Results for atherosclerotic and cerebrovascular diseases were confirmed through Poisson regression analysis. CONCLUSIONS--The data support previous findings of increased mortality from ischaemic heart disease in workers exposed to tar, and some support is also provided for earlier reports of increased respiratory mortality in potroom workers.
Byssinosis in Guangzhou, China.
Authors: Jiang C Q , Lam T H , Kong C , Cui C A , Huang H K , Chen D C , He J M , Xian P Z , Chen Y H
Published: December 2008

OBJECTIVES--To study the prevalence of byssinosis and other respiratory abnormalities in workers exposed to cotton dust in Guangzhou in two factories that processed purely cotton. METHODS--All the 1320 workers exposed were included. The controls were 1306 workers with no history of occupational dust exposure. Total dust and inhalable dust were measured by Chinese total dust sampler and American vertical elutriator respectively. A World Health Organisation questionnaire was used. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured by a Vitalograph spirometer. RESULTS--The median inhalable dust concentrations ranged from 0.41 to 1.51 mg/m3 and median total dust concentrations from 3.04 to 12.32 mg/m3. The prevalence of respiratory abnormalities in the cotton workers were (a) typical Monday symptoms 9.0%; (b) FEV1 fall by > or = 5% after a shift 16.8%; (c) FEV1 fall by > or = 10% after a shift 4.2%; (d) FEV1 < 80% predicted 6.1%; (e) FEV1/FVC < 75% 4.0%; (f) cough or phlegm 18.2%; (g) chronic bronchitis 10.9%; and (h) byssinosis, defined by (a) plus (b) 1.7%. With the exception of (d), most of the prevalences increased with increasing age, duration of exposure, and cumulative inhalable dust exposure. No increasing trends of respiratory abnormalities were found for current total dust, inhalable dust, and cumulative total dust concentrations. Compared with controls, after adjustment for sex and smoking, with the exception of (d), all the pooled relative risks of respiratory abnormalities were raised for cotton exposure. CONCLUSION--It is concluded that cumulative inhalable cotton is likely to be the cause of byssinotic symptoms, acute lung function decrements, cough, or phlegm, and chronic bronchitis.
Cause of occupational disease.
Authors: Muir D C
Published: December 2008

The concept of causality is reviewed with special emphasis on occupational diseases. Separate approaches from the philosophical, scientific, and legal points of view are identified. There is controversy over the methodology of logical causality; inductive and deductive methods are described and reference is made to the verification or refutation approach. Application of the methods to epidemiology are reviewed. It is likely that many diseases have multiple causes and that only a component of occupational causality can be identified in each patient. Methods of assigning such a component are discussed. The difficulties of developing an equitable compensation policy in such circumstances are reviewed. The possible benefits of proportional compensation are noted.
Exposure to styrene and chronic health effects: mortality and incidence of solid cancers in the Danish reinforced plastics industry.
Authors: Kolstad H A , Juel K , Olsen J , Lynge E
Published: December 2008

OBJECTIVES--To study the occurrence of non-malignant diseases and solid cancers in workers exposed to styrene in the Danish reinforced plastics industry. METHODS--All 36,610 workers of 386 reinforced plastics companies and 14,293 workers not exposed to styrene from similar industries were followed up from 1970 to 1990. This industry is characterised by simple exposure conditions, exposure to high concentrations of styrene, and a high proportion of small companies, and the exposure assessment was based on experts' classification on a company level. The mortality from non-malignant causes and the incidence of solid cancers were compared with the national rates. Poisson models were used for internal comparisons. RESULTS--A total of 3031 deaths and 1134 newly diagnosed cases of solid cancer were reported in the workers in the reinforced plastics industry. In companies where 50% or more of the workers produced reinforced plastics an increased mortality rate ratio (MRR) for degenerative disorders of the nervous system (multiple sclerosis, parkinsonism, and motor neurone disease; MRR 1.8, 16 cases, 95% confidence interval (95% CI) 0.9-3.8) and an increased incidence rate ratio (IRR) for pancreatic cancer (IRR 2.2, 17 cases, 95% CI 1.1-4.5) was found. For both disease categories increased occurrence was also found among long term workers, workers of the 1960s (the period with the highest exposure to styrene), and workers with a latent period of more than 10 years after the start of employment. No other non-malignant diseases or solid cancers showed these patterns. CONCLUSION--The findings have to be interpreted with caution, due to the company based exposure assessment, but the possible association between exposures in the reinforced plastics industry, mainly styrene, and degenerative disorders of the nervous system and pancreatic cancer, deserves attention.
Longitudinal study of the health of cotton workers.
Authors: Li D , Zhong Y N , Rylander R , Ma Q Y , Zhou X Y
Published: December 2008

OBJECTIVES--To follow up a group of newly employed workers in a cotton mill, and to report changes in symptoms over time. METHODS--A group of 110 mill workers at a cotton mill in Shijiazhuang, China, was investigated by questionnaire, skin testing, and spirometric measurements of airway responsiveness through forced expiratory volume in one second (FEV1). The workers were examined before starting work, at 10 weeks, and at one year. RESULTS--Decreases in FEV1 over shifts were small at 10 weeks and one year, and slightly higher among people with skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholine was increased at 10 weeks. It remained about the same after one year, except in the workers positive for the skin test, in whom it was further increased. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year; nasal irritation remained unchanged and dry cough decreased between 10 weeks and one year. CONCLUSION--The results suggest that the airway inflammation caused by cotton dust increases with increasing exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.
Pleural malignant mesothelioma and non-occupational exposure to asbestos in Casale Monferrato, Italy.
Authors: Magnani C , Terracini B , Ivaldi C , Botta M , Mancini A , Andrion A
Published: December 2008

OBJECTIVES--To assess and quantify the occurrence of pleural malignant mesotheliomas in people who neither experienced occupational exposure to asbestos nor were married to (or known to live with) workers exposed to asbestos in the workplace. The study was conducted in the area of the local health authority of Casale Monferrato, in north western Italy, where a large factory that produced asbestos cement was active up to 1985. No other major activities related to asbestos have ever been present in the area. METHODS--A retrospective survey covering the period 1980 to 1991 identified 126 incident pleural malignant mesotheliomas histologically diagnosed among residents in the local health authority (population at the 1981 census 98,000). Submission of 83 of 95 cases diagnosed during 1980-9 for revision by a panel of five expert pathologists led to the exclusion of 21. The 31 cases diagnosed in 1990-1 were not submitted for revision. For 64 of the 105 retained cases, information derived from different sources (rosters of the employees in the asbestos cement factory dated back to 1907, list of their spouses, clinical records) did not suggest occupational or paraoccupational exposure to asbestos. RESULTS--Incidence excludes cases for which there was some suggestion of occupational or paraoccupational exposure to asbestos. Incidence of histologically confirmed malignant mesothelioma among residents in the local health authority (annual x 100,000; age adjusted) was 4.2 in men and 2.3 in women (based on 26 and 18 cases respectively). In both sexes, rates in 1985-9 were higher than in the previous quinquennium. Corresponding estimates for 1990-1 (based on unrevised diagnoses) suggest similar rates in men and women. CONCLUSION--Rate ratios which are four to six times those measured by conventional Italian cancer registries can hardly be totally explained by bias produced by lack of recognition of occupational or paraoccupational exposure. The problem of proving this type of negative data is common to other circumstances of alleged cancer clusters of environmental (non occupational) origin.
Decline in annual lung function in workers exposed to asbestos with and without pre-existing fibrotic changes on chest radiography.
Authors: Nakadate T
Published: December 2008

OBJECTIVES--To examine whether or not workers with pre-existing mild pulmonary fibrosis have accelerated decline in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC), under low level exposure to chrysotile asbestos. METHODS--All male workers in two asbestos manufacturing factories were followed up annually for six years to compare their declines in FEV1 and FVC. The values of FEV1 and FVC were divided by the square of the person's height to adjust for body size differences (FEV1/Ht2 and FVC/Ht2, respectively). Annual change was calculated for each subject as a slope of the simple linear regression with FEV1/Ht2 or FVC/Ht2 regressed according to age. Analysis was conducted on 242 middle aged workers who had normal routine spirometry values, normal chest radiographs or mild pneumoconiosis up to 1/2 grade, without changes either in smoking habit or severity of pneumoconiosis during the study period, and with acceptable spirograms in three or more surveys. The occupational environment, in terms of chrysotile asbestos, had been well controlled below the threshold limit value of Japan at that time--namely, 2 fibres/micromilligrams. RESULTS-There was no significant effect from the interaction between pre-existing mild pulmonary fibrosis and low level of exposure to chrysotile asbestos on the accelerated annual decline of FEV1/Ht2, or FVC/Ht2. Fibrosis significantly contributed to annual changes in FEV1/Ht2, even after adjustment for mean FEV1 and smoking. The point estimate of the contribution was - 4.9 ml/m2/y. No significant independent contribution of exposure was found in decline of either FEV1/Ht2 or FVC/Ht2. CONCLUSIONS--Pre-existing pulmonary fibrosis is an independent risk factor for accelerated annual decline of FEV1, even when mild and stable. Additional decline due to exposure to chrysotile asbestos is less probable if it is well controlled under the current threshold limit value.
Epidemiological evaluation of release of monocyte TNF-alpha as an exposure and effect marker in pneumoconiosis: a five year follow up study of coal workers.
Authors: Schins R P , Borm P J
Published: December 2008

OBJECTIVES--To determine (a) reproducibility with previous cross sectional findings, and (b) the predictive value of initial release of tumour necrosis factor-alpha (TNF-alpha) towards later progression of coalworkers' pneumoconiosis (CWP). METHODS--Release of monocyte TNF-alpha after in vitro stimulation with coal mine dust, silica, and endotoxin was measured in 104 retired miners and was related to stage of CWP (chest radiograph) and cumulative exposure. A subgroup of 46 miners was screened by high resolution computed tomography (HRCT). Prospective analysis of TNF-alpha (40 out of 104 miners involved in the previous TNF-alpha study) was done by relating initial TNF-alpha to five year progression of CWP measured by comparison of paired chest radiographs. RESULTS--As observed previously, dust stimulated release of TNF-alpha was increased in miners, especially in the early stages of pneumoconiosis. Cumulative exposure was related to pneumoconiotic stage but not to release of TNF-alpha. This excluded TNF-alpha as an exposure marker. Initial concentrations (1987) of TNF-alpha were related to later progression of CWP. Miners who showed abnormally high dust stimulated release of TNF-alpha had an increased risk of progression in CWP (relative risk 8.1). CONCLUSIONS--These results show (a) the significant involvement of TNF-alpha in pneumoconiosis in humans induced by coal dust and (b) that this routine test possibly constitutes a powerful tool to estimate individual prognosis of pneumoconiotic disease, even after the end of occupational exposure.
Survey of the respiratory health of the workers of a talc producing factory.
Authors: Wild P , Réfrégier M , Auburtin G , Carton B , Moulin J J
Published: December 2008

OBJECTIVES--To assess the effect of an occupational exposure to talc dust on respiratory health. METHODS--166 talc millers from a French factory underwent spirometry and filled in a standardised respiratory questionnaire during their annual medical visit in 1989. A full sized chest radiograph taken in 1987 for the subjects hired before 1982 was also available, for the others a radiograph taken when hired was used. Radiography was repeated in 1992 for all subjects still active at this date (n = 139). The occupational exposure to talc dust was characterised for each workplace with 1440 personal samples collected since 1986 and by semiquantitative estimates of the historical exposure. RESULTS--The geometric mean (range) of estimated exposure was 1.87 (0.5 to 50) mg/m3 and the estimated cumulative exposure at the date of spirometry was > 150 y mg/m3 for 41 subjects. After adjustment for smoking in a linear model the standardised residual values of both forced vital capacity and forced expiratory volume in one second decreased significantly with increasing exposure. The prevalence of dyspnoea also increased after adjustment for smoking categories and age in a logistic regression. The prevalence of small radiological opacities was significantly related to age and to the exposure after adjustment for age and smoking categories. The incidence of new opacities between the two radiographs (11 new opacities with a profusion higher than 0/1) was significantly related to smoking (10 out of 11 are smokers) but not to the exposure. CONCLUSION--This study shows an effect of high levels of talc dust both on functional variables and on the prevalence of small radiological images, but provides no clear evidence about the possible effect of present levels of exposure.
Empirical evaluation of the influence of control selection schemes on relative risk estimation: the Welsh nickel workers study.
Authors: Morabia A , Ten Have T , Landis J R
Published: December 2008

OBJECTIVE--To perform an empirical evaluation of the theory that relative incidence rate (RIR) and relative risk (RR) can be directly estimated from case-control studies that have different sampling schemes of controls. METHODS--With data from the South Wales nickel refinery workers (SWNRW) study, a nested case-control study of the relation of nickel exposure to respiratory cancers, was conducted within each of four fixed subcohorts that differed for stability of exposure, incidence rates and RIR. Odds ratios (ORs) and confidence intervals (CIs) were estimated either with all available controls or with randomly sampled subsets of controls. RESULTS--Respiratory cancers were not rare as risk of nasal and lung cancer in workers unexposed to nickel varied from 15% to 26% over the full risk period. The RIR was adequately estimated by the OR when controls were identified concurrently to case occurrence throughout the risk period. The RR was well approximated with the OR when controls were a sample of the study base. CONCLUSIONS--These results add empirical support to the theory that the RIR or the RR can be validly estimated in case-control studies. Overall, this theory is relatively tolerant of large departures from the stability assumptions of exposure and of incidence.
Risk of thyroid nodules in subjects occupationally exposed to radiation: a cross sectional study.
Authors: Antonelli A , Silvano G , Bianchi F , Gambuzza C , Tana L , Salvioni G , Baldi V , Gasperini L , Baschieri L
Published: December 2008

OBJECTIVES--To examine, by ultrasonography the prevalence of thyroid nodules in a cross sectional study of male medical workers occupationally exposed to chi radiation at the Pisa hospital, in comparison with controls matched for age and sex. METHODS--50 male medical workers exposed to radiation were randomly matched for age (+/- 2 years) with 100 male workers not occupationally exposed to ionising radiation who lived in a slightly iodine deficient area of Tuscany (Lunigiana) (control group 1), and with 100 male workers not exposed to radiation who lived in the same area (Pisa) (control group 2). RESULTS--Of the occupationally exposed subjects, thyroid nodules were detected in 19/50 (38.0%). Among controls, thyroid nodules were detected in 19/100 subjects of control group 1 and in 13/100 of control group 2. Comparison of exposed and control groups, stratified into 30-39, 40-49, and 50-59 year old age subgroups, showed a higher significant relative risk for thyroid nodules in the exposed subjects. CONCLUSION--The results suggest that occupational exposure to radiation may be a risk factor for thyroid nodules.
Need for vaccination of sewer workers against leptospirosis and hepatitis A.
Authors: De Serres G , Levesque B , Higgins R , Major M , Laliberté D , Boulianne N , Duval B
Published: December 2008

OBJECTIVES--This study compared the prevalence of Leptospira interrogans and hepatitis A virus (HAV) antibodies in serum samples from sewer workers and controls. METHODS--A blood sample was obtained from 76 of the 101 municipal sewer workers (75%) of Quebec City and from two controls matched to each for age and sex. Testing was done for antibodies against serovars of Leptospira icterohaemorragiae, bratislava, hardjo, grippotyphosa, and kennewicki (pomona) and hepatitis A. RESULTS--Sewer workers had a greater prevalence of antibodies against leptospirosis than controls (12% v 2%, P = 0.003). In contrast, antibodies to HAV were not significantly more prevalent among workers than among controls (54% v 49%, P = 0.51). Prevalence of HAV antibodies increased significantly with age both among workers and controls (chi 2 for trend, P < 0.001). In contrast with younger workers, prevalence of HAV antibodies was greater among workers > or = 40 years than among their controls (81% v 65%, P = 0.04). CONCLUSION--Leptospirosis continues to be a problem to sewer workers but hepatitis A is apparently no longer a risk. The likely explanation is that leptospira are still abundant in the sewage system in contrast with HAV, which is only rarely to be found in sewage as a result of the generalised decrease in incidence of hepatitis A in the past three decades. The decision to vaccinate sewer workers against hepatitis A should take into account that it is impossible to avoid all contact with sewage fluid and, despite the fact that the actual incidence of hepatitis A is low, there is a real possibility of sporadic exposure during a future outbreak.
Mortality of white South African gold miners.
Authors: Reid P J , Sluis-Cremer G K
Published: December 2008

OBJECTIVES--This two part study aimed to determine whether there was an excess mortality generally or for some diseases among middle aged white South African gold miners on the Witwatersrand and whether the underground dust exposure of these miners contributed to the development of lung cancer, chronic obstructive pulmonary disease (COPD), or ischaemic heart disease (IHD). METHODS--A cohort of 4925 white miners in South Africa, born between 1 January 1916 and 31 December 1930 who were alive and working in the vicinity of Johannesburg on 1 January 1970, then aged between 39 and 54, was followed up for 20 years by which time 2032 had died. Most were gold miners (about 87% had worked 85% or more of their shifts in gold mines). Standardised mortality ratios (SMRs) were calculated as percentages of the number of deaths observed in the cohort for a condition as stated on the death certificate divided by the number expected on the basis of concurrent mortality in the reference population (the total age specific white male population of South Africa). A case-control analysis was performed for three diseases (lung cancer, COPD, and IHD), the results of which are presented for those miners in the cohort who had spent at least 85% of their service on gold mines and had worked at least 15% of their shifts underground. RESULTS--The SMR for all causes of death was 129.6%, raised because of excess mortality due to the following causes: lung cancer (SMR = 139.8%), IHD (124.1%), COPD (189%) and cirrhosis of the liver (155.3%). Smoking was confirmed to be the main risk factor for lung cancer and COPD although cumulative dust exposure was found to increase the risk of COPD in conjunction with smoking. No significant risk of lung cancer resulted from exposure to dust. High blood pressure and smoking were found to increase the risk of IHD, but no association between IHD and the quetelet index (weight/height2) was found. CONCLUSIONS--The most significant and unexpected finding was the 30% increase in the SMR for all causes. Very little of this increase could be attributed to mining and the main factor for this was probably the adoption of an unhealthy lifestyle by these men (compared with other South African white men) particularly smoking (86% were smokers) and alcohol consumption.
A case cohort study of suicide in relation to exposure to electric and magnetic fields among electrical utility workers.
Authors: Baris D , Armstrong B G , Deadman J , Thériault G
Published: December 2008

OBJECTIVES--This case cohort study examines whether there is an association between exposure to electric and magnetic fields and suicide in a population of 21,744 male electrical utility workers from the Canadian Province of Québec. METHODS--49 deaths from suicide were identified between 1970 and 1988 and a subcohort was selected comprising a 1% random sample from this cohort as a basis for risk estimation. Cumulative and current exposures to electric fields, magnetic fields, and pulsed electromagnetic fields (as recorded by the POSITRON meter) were estimated for the subcohort and cases through a job exposure matrix. Two versions of each of these six indices were calculated, one based on the arithmetic mean (AM), and one on the geometric mean (GM) of field strengths. RESULTS--For cumulative exposure, rate ratios (RR) for all three fields showed mostly small non-significant increases in the medium and high exposure groups. The most increased risk was found in the medium exposure group for the GM of the electric field (RR = 2.76, 95% CI 1.15-6.62). The results did not differ after adjustment for socioeconomic state, alcohol use, marital state, and mental disorders. There was a little evidence for an association of risk with exposure immediately before the suicide. CONCLUSION--Some evidence for an association between suicide and cumulative exposure to the GM of the electric fields was found. This specific index was not initially identified as the most relevant index, but rather emerged afterwards as showing the most positive association with suicide among the 10 indices studied. Thus the evidence from this study for a causal association between exposure to electric fields and suicide is weak. Small sample size (deaths from suicide) and inability to control for all potential confounding factors were the main limitations of this study.
Blood antioxidant enzymes as markers of exposure or effect in coal miners.
Authors: Perrin-Nadif R , Auburtin G , Dusch M , Porcher J M , Mur J M
Published: December 2008

OBJECTIVE--To investigate if blood Cu++/Zn++ superoxide dismutase, glutathione peroxidase, catalase, and total plasma antioxidant activities could be markers of biological activity resulting from exposure to respirable coal mine dust in active miners, and of pneumoconiosis in retired miners. METHODS--Blood samples were randomly obtained from active surface workers (n = 30) and underground miners (n = 34), and from retired miners without (n = 21), and with (n = 33) pneumoconiosis. Antioxidant enzyme activities and total plasma antioxidants were measured in erythrocytes and plasma. Non-parametric tests were completed by analyses of covariance to compare antioxidants between groups, taking into account potential confounding factors (age, smoking history (pack-years)). RESULTS--Erythrocyte Cu++/Zn++ superoxide dismutase activity was significantly higher in the group of underground miners than the group of surface workers. The differences in total plasma antioxidants and plasma glutathione peroxidase activity between both groups were related to age. Glutathione peroxidase activity increased in the plasma of retired miners with pneumoconiosis, compared with retired miners without pneumoconiosis. No differences were found either in erythrocyte antioxidant enzyme activities or in total plasma antioxidants between the groups of retired miners without and with pneumoconiosis. CONCLUSIONS--In this study, erythrocyte Cu++/Zn++ superoxide dismutase activity may be considered as a marker of effect of respirable coal mine dust in exposed workers. This result is in agreement with the hypothesis that reactive oxygen species are involved in cell injury induced by coal mine dust, and may be predictive of the degree of inflammation and pneumoconiosis induced by coal mine dust. The increase in glutathione peroxidase activity in the plasma of retired miners with pneumoconiosis may be the result of a response to the increasing hydrogen peroxide (H2O2) production due to the disease process.
Bladder cancer and occupation: a case-control study in northern Italy.
Authors: Porru S , Aulenti V , Donato F , Boffetta P , Fazioli R , Cosciani Cunico S , Alessio L
Published: December 2008

OBJECTIVES--A hospital based case-control study was conducted between 1992 and 1993 in the province of Brescia, a highly industrialised area in northern Italy, to evaluate occupational risk factors of bladder cancer. METHODS--The study evaluated 355 histologically confirmed cases of bladder cancer (275 men, 80 women) and 579 controls affected by urological non-neoplastic diseases (397 men, 182 women). Lifetime occupational history, smoking and drinking habits, and sociodemographic characteristics were recorded by means of a structured questionnaire. Odds ratios (ORs) were computed with adjustment for age, smoking, alcohol and coffee consumption, education, and place of residence. RESULTS--A significant (P < 0.05) increase of risk of bladder cancer were found in men for labourers in the construction industry (OR 2.1, 95% confidence interval (95% CI) 1.1-3.9) and for recreational and cultural services (OR 5.0, 95% CI 1.3-18.9). Increased risks, although not significant, were found for various other occupations and industries such as machinery mechanics, metal processers and polishers, blacksmiths, gunsmiths, painters; for transport workers, an increased risk with increasing duration of employment was found. CONCLUSIONS--Occupational exposures seem to contribute to bladder cancer risk in the area under study.
Acute effects of vibration on peripheral blood flow in healthy subjects.
Authors: Egan C E , Espie B H , McGrann S , McKenna K M , Allen J A
Published: December 2008

OBJECTIVES: The main objective was to study the acute vascular effects in the hands of normal healthy subjects of a complex vibration spectrum similar to that generated by many industrial hand held tools. The effects of repeated bouts of vibrations and alterations in the intensity of vibration were also studied. METHODS: Blood flow was measured by venous occlusion plethysmography with strain gauges. Vibration across a frequency range of 0.4 to > 4000 Hz was generated by a pneumatic chisel and applied to the right hand. Blood flow was measured in both middle fingers, both big toes, or both forearms before, during, and after a two minute period of vibration. Systolic pressure of a finger and heart rate were also measured. RESULTS: Vibration was associated with a significant bilateral reduction in finger and toe blood flow (P < 0.01 and P < 0.03) and a significant increase in heart rate (P < 0.05) but had no effect on forearm blood flow. The finger response was not abolished by repeated bouts of the vibration but was initially most notable during the first minute of vibration. Increasing the intensity of vibration delayed recovery. CONCLUSIONS: Hand vibration causes a generalised increase in sympathetic tone in the heart and extremities. This may be a factor in the development of vasospastic disease in habitual users of hand held industrial vibrating tools.
Mortality study of nickel platers with special reference to cancers of the stomach and lung, 1945-93.
Authors: Pang D , Burges D C , Sorahan T
Published: December 2008

OBJECTIVES: To re-examine mortality patterns in a cohort of nickel platers with no history of chromium plating. METHODS: All 284 men first employed by the company in 1945-75 with a minimum employment of three months in the nickel plating department were identified. Workers who had worked in the chromium plating or nickel/chromium plating departments were excluded. Standardised mortality ratios (SMRs), P values, and 95% confidence intervals were calculated. Poisson regression was used to carry out statistical modelling of mortalities within the cohort (internal standard). Four variables were considered to have the potential to influence mortality within the cohort: attained age (age at follow up or age at death), year of starting nickel work, period of follow up (measured from the first period of work with nickel exposure), and duration of exposure to nickel. RESULTS: The only significant difference between observed and expected numbers, when investigated by site of cancer and by broad non-cancer groupings, was that for stomach cancer (observed eight, expected 2.49, SMR 322). CONCLUSIONS: The study provides only weak evidence that nickel plating is associated with an excess risk of stomach cancer. This cohort of nickel platers does not seem to have experienced any discernible risk of occupational lung cancer. Other studies of nickel platers rather than nickel/chromium platers would be useful.
Current approaches to neurobehavioural testing in occupational health.
Authors: Spurgeon A
Published: December 2008

In recent years neurobehavioural tests have been used increasingly in occupational settings to identify changes in cognitive function associated with exposure to neurotoxicants. Potential applications of these methods in occupational health include research, diagnosis, and screening. Applications in cross sectional research studies, involving the comparison of the performance of exposed and control groups, are well established. However, the use of such methods requires attention to factors other than exposure which may influence test performance. The validity of adapting existing test batteries for diagnosis or screening is questionable. Well developed techniques exist for diagnosis but this requires lengthy and skilled test administration and interpretation and cannot be accomplished with research batteries. The application of neurobehavioural methods for screening currently presents several difficulties. Current problems and future directions in this field are discussed.
Self reported rate of occupational asthma in Sweden 1990-2.
Authors: Torén K
Published: December 2008

OBJECTIVES: To estimate the annual rates of self reported occupational asthma in different occupational groups in Sweden. METHODS: All claims of occupational asthma 1990-2 in the Swedish register of reported occupational diseases were classified according to occupation. The number of people employed in each occupational group in the general population was obtained from the 1990 national census. Reporting rates (cases/million/ year) were calculated for each occupation with more than five reported cases, according to sex and age (20 to 64 years, and 20 to 44 years). RESULTS: 1010 cases were reported giving an annual crude reporting rate of 80/million (95% confidence interval (95% CI) 70 to 90). For men, the crude reporting rate was 91/million (95% CI 84 to 98), and for women 70/million (95% CI 80 to 106). The highest reporting rates were among male bakers-(775/million), furnacemen (702/million), male welders (647/million), female chemical and plastic production workers (629/million), and female poultry and dairy farm workers (602/million). CONCLUSIONS: A surveillance system based on self reporting is influenced by considerable bias, especially reporting bias. However, results for the specific occupations with high rates were similar to those found with other surveillance systems. This indicates that our system is a useful one.
Concentration of blood lead and ethnicity in the United Kingdom.
Authors: Kolev S T , House I , Bell G , Shaw D , Murray V
Published: December 2008

The relation between concentration of blood lead and ethnic background in 779 children was examined with the analytical results from the trace element service at the Medical Toxicology Unit (MTU), Guy's and St Thomas's Hospital Trust for the period 1980-94. The ethnic identity was determined with the first and the second names of the investigated subjects. Of the patients of European origin (European) studied 72.8% v only 50.6% of the children with origins in the Indian subcontinent (Asian) had a concentration of blood lead < 100 micrograms/l. The percentage of subgroups with concentrations above the upper acceptable limit of 200 micrograms/l was significantly higher in Asian subjects (European 5% v Asian 26.5%), with the most pronounced difference in those with concentrations of blood lead of 500 micrograms/l (European 0.8% v Asian 10.5%). This study shows that a correlation exists between Asian ethnic background and concentration of blood lead in children. Factors such as cultural habits-for example, use of traditional remedies, cosmetics, diet- and socioeconomic status, may have contributed to this results.