bluuebunny/crossref_metadata_2025 huggingface dataset:
A meta-analysis of the relation between cumulative exposure to asbestos and relative risk of lung cancer.
Authors: Lash T L , Crouch E A , Green L C
Published: December 2008

OBJECTIVES: To obtain summary measures of the relation between cumulative exposure to asbestos and relative risk of lung cancer from published studies of exposed cohorts, and to explore the sources of heterogeneity in the dose-response coefficient with data available in these publications. METHODS: 15 cohorts in which the dose-response relation between cumulative exposure to asbestos and relative risk of lung cancer has been reported were identified. Linear dose-response models were applied, with intercepts either specific to the cohort or constrained by a random effects model; and with slopes specific to the cohort, constrained to be identical between cohorts (fixed effect), or constrained by a random effects model. Maximum likelihood techniques were used for the fitting procedures and to investigate sources of heterogeneity in the cohort specific dose-response relations. RESULTS: Estimates of the study specific dose-response coefficient (kappa 1.i) ranged from zero to 42 x 10(-3) ml/fibre-year (ml/f-y). Under the fixed effect model, a maximum likelihood estimate of the summary measure of the coefficient (k1) equal to 0.42 x 10(-3) (95% confidence interval (95% CI) 0.22 to 0.69 x 10(-3)) ml/f-y was obtained. Under the random effects model, implemented because there was substantial heterogeneity in the estimates of kappa 1.i and the zero dose intercepts (Ai), a maximum likelihood estimate of k1 equal to 2.6 x 10(-3) (95% CI 0.65 to 7.4 x 10(-3)) ml/f-y, and a maximum likelihood estimate of A equal to 1.36 (95% CI 1.05 to 1.76) were found. Industry category, dose measurements, tobacco habits, and standardisation procedures were identified as sources of heterogeneity. CONCLUSIONS: The appropriate summary measure of the relation between cumulative exposure to asbestos and relative risk of lung cancer depends on the context in which the measure will be applied and the prior beliefs of those applying the measure. In most situations, the summary measure of effect obtained under the random effects model is recommended. Under this model, potency, k1, is fourfold lower than that calculated by the United States Occupational Safety and Health Administration.
Cancer mortality among magazine printing workers.
Authors: Luce D , Landre M F , Clavel T , Limousin I , Dimerman S , Moulin J J
Published: December 2008

OBJECTIVE: After an inquiry from the employees of an offset printing plant, a historical cohort study was conducted to investigate cancer mortality among these workers. METHODS: The cohort comprised 262 men, who contributed 2771 person-years of observation. 16 deaths were identified during the follow up period (1980-91). Expected numbers of deaths were derived from age specific regional rates. Standardised mortality ratios (SMR) and 95% confidence intervals (95% CIs) were calculated. RESULTS: An increased cancer mortality was found after 10 years of employment (SMR 213, 95% CI 98 to 405, based on nine deaths), mainly due to a high mortality from lung cancer (SMR 381, 95% CI 104 to 975, four deaths), and from oesophageal cancer (SMR 1049, 95% CI 216 to 3065, three deaths). For workers with at least 20 years since the start of employment, the SMR was 262 (95% CI 105 to 540) for all cancer sites, 447 (95% CI 92 to 1306) for lung cancer, and 1094 (95% CI 132 to 3952) for oesophageal cancer. The increased cancer mortality was concentrated among pressmen. CONCLUSION: Although based on small numbers, the findings suggest an increased risk of cancer among these workers, which should be further investigated.
Effects of acute exposure to ultrahigh radiofrequency radiation on three antenna engineers.
Authors: Schilling C J
Published: December 2008

Three men were accidentally exposed to high levels of ultrahigh frequency radiofrequency radiation (785 MHz mean frequency) while working on a television mast. They experienced an immediate sensation of intense heating of the parts of the body in the electromagnetic field followed by a variety of symptoms and signs which included pain, headache, numbness, and parasthesiae, malaise, diarrhoea, and skin erythema. The most notable problem was that of acute then chronic headache involving the part of the head which was most exposed.
Structural nerve changes at wrist level in workers exposed to vibration.
Authors: Strömberg T , Dahlin L B , Brun A , Lundborg G
Published: December 2008

OBJECTIVES: To analyse the character of morphological changes occurring in a well defined peripheral nerve in humans exposed to vibration from hand held tools. METHODS: Biopsies of the dorsal interosseus nerve just proximal to the wrist were taken from 10 men exposed to vibration and from 12 male age matched necropsy controls. The nerve was resected for pain relief either as the sole procedure or in conjunction with carpal tunnel release. All specimens were sectioned and examined by light microscopy in standard sections, thin epon sections, and teasing preparations. RESULTS: The combined results of the analyses showed pathological changes in all 10 patients dominated by breakdown of myelin and by interstitial and perineurial fibrosis. All but one of the 12 controls were normal. CONCLUSION: These findings often show severe nerve injury previously not described at this level. They indicate that demyelination may be the primary lesion in neuropathy induced by vibration followed by fibrosis associated with incomplete regeneration or with organisation of oedema. Vibration can induce structural changes in peripheral nerves just proximal to the wrist and such changes may constitute a structural component in carpal tunnel syndrome among people exposed to vibration. This may help to explain the poor results achieved by carpal tunnel release in these patients.
Nerve injury induced by vibration: prevention of the effect of a conditioning lesion by D600, a Ca2+ channel blocker.
Authors: Widerberg A , Bergman S , Danielsen N , Lundborg G , Dahlin L B
Published: December 2008

OBJECTIVES: Exposing a hind leg of a rat to vibration induces an injury to the sciatic nerve--a so called conditioning lesion. After such injury induced by vibration the regenerative capacity of the nerve is improved and can be detected as an increased axonal outgrowth from a test crush lesion to the same nerve. The purpose was to study whether the effect of a conditioning lesion induced by vibration can be prevented by local treatment with a Ca2+ channel blocker D600. METHODS: D600 (methoxyverapamil) or Ringer's solution was locally applied to the sciatic nerve on one side through a silicone tube connected to a miniosmotic pump, which was implanted subcutaneously. During the same period the hind leg was exposed to vibration (80 Hz; 32 m/s2 root mean squared) for five hours daily for five consecutive days. The other hind leg was not vibrated. After the end of exposure to vibration the sciatic nerves were crushed bilaterally (test crush lesions) and three or six days later the regeneration distances of sensory axons were measured by the pinch reflex test. RESULTS: Nerves in the control animals (without implanted miniosmotic pumps and nerves on to which Ringer's solution was locally applied) that were exposed to vibration showed a significantly increased outgrowth length of sensory axons from the test crush lesion compared with the non-vibrated side. Such an effect of a conditioning lesion from the exposure to vibration was suppressed by local application of D600. CONCLUSIONS: Local administration of a Ca2+ channel blocker D600 can prevent the effect of a conditioning lesion-that is, the nerve injury induced by vibration can be inhibited by D600. This may have implications for the treatment of patients with neuropathy of the hand induced by vibration.
Occupational factors related to shoulder pain and disability.
Authors: Pope D P , Croft P R , Pritchard C M , Silman A J , Macfarlane G J
Published: December 2008

OBJECTIVES: To determine, in a population based study, the influence of occupational factors on the occurrence of shoulder pain and disability. METHODS: A random sample of patients was selected from the register of a general practice in the Greater Manchester area of the United Kingdom. Information was collected by a posted questionnaire with specific enquiries about symptoms in the shoulder region and related disability. A lifetime occupational history was obtained including physical exposures, working conditions, and psychosocial aspects of each workplace. Analysis has been conducted as a case-control study, comparing occupational exposures at the time of onset of symptoms in those with shoulder pain and disability with corresponding occupational exposures in those without shoulder pain and disability. RESULTS: An increased risk of shoulder pain and disability in men was associated with carrying weights on one shoulder (relative risk (RR) 5.5, 95% confidence interval (95% CI) 1.8 to 17), whereas those who reported working with hands above shoulder level, using wrists or arms in a repetitive way, or stretching down to reach below knee level had about twice the risk of shoulder pain and disability. Men working frequently in very cold or damp conditions had a fourfold and sixfold risk respectively of shoulder pain and disability. Reporting of shoulder pain and disability was also more common among men and women who reported that their work caused a lot of stress (RR 1.9, 95% CI 0.9 to 4.1) or was very monotonous (RR 2.7, 95% CI 1.3 to 5.4). The relations between physical exposures, working conditions, and psychosocial factors were independent. CONCLUSIONS: This population based study has shown that physical activities carried out at work, the physical conditions under which the work is conducted, psychosocial aspects of work, or the working environment are all independently related to the occurrence of shoulder symptoms and disability, emphasising the multifactorial nature of this condition.
Relapse and short sickness absence for back pain in the six months after return to work.
Authors: Infante-Rivard C , Lortie M
Published: December 2008

OBJECTIVES: To measure the incidence of back pain relapse (causing three consecutive days off work on medical advice) and of short sickness absence (less than three consecutive days), and to determine whether the incidence of such events was affected by overall pain and specific pain related to simple daily movements (functional capacity) assessed at discharge. METHODS: A cohort of workers with a first compensated episode of back pain was prospectively followed up from return to work after rehabilitative treatment. Follow up among 230 workers was carried out monthly by phone for a maximum of six months. Crude and adjusted rate ratios (RRs) along with 95% confidence intervals (95% CIs) were estimated with the Cox's proportional hazards model. RESULTS: Within six months of return to work, 29 workers (12.6%) had relapsed, and another 15 workers (6.5%) had a short sickness absence. 50% of relapses had occurred within 42 days of return to work whereas this figure was 28 days for short sickness absence. In a multivariate model that considered pain and clinical variables at discharge only a scale combining all pain variables (specific daily movements as well as the visual analog overall pain scale) contributed to relapse and short sickness absence as the outcome (RR (95% CI)) (1.53 (0.96-2.43)); the same was true in a model considering pain and workers' views on desired changes to work conditions (1.60; 1.08 to 2.36). CONCLUSIONS: Incidence of relapse or short sickness absence in the first six months after return to work was 19.1%. Of all measured prognostic variables (sociodemographic, clinical, workers' views, and pain), only overall pain and pain associated with carrying out simple daily movements were helpful in predicting relapse or short sickness absence.
Pulmonary toxicity of components of textile paint linked to the Ardystil syndrome: intratracheal administration in hamsters.
Authors: Clottens F L , Verbeken E K , Demedts M , Nemery B
Published: December 2008

OBJECTIVES: It was hypothesised from an epidemiological investigation that a formula change from Acramin FWR (a polyurea) to Acramin FWN (a polyamide-amine) had led to severe pulmonary disease in textile printing sprayers in SPAIN AND ALGERIA. To verify this, the pulmonary toxicity of the components of the paint systems involved was assessed in experimental animals. METHODS: Individual components and relevant mixtures, diluted in phosphate buttered saline, were given by intratracheal instillation of 2 ml/kg to hamsters. Pulmonary toxicity was assessed on days 3, 7, 14, 28, and 92 after a single intratracheal instillation, by histology and by measuring wet and dry lung weight, protein concentration, the activities of lactate dehydrogenase, alkaline phosphatase, beta-N-acetyl-glucosaminidase, and gamma-glutamyltransferase, inflammatory cell number and distribution in bronchoalveolar lavage fluid (BALF), and hydroxyproline content in dried lung tissue. RESULTS: Based on the doses that killed 50% of the animals (LD50s), the various components were found to be 10 to 1250 times more toxic when given intratracheally than when given orally (according to reported oral LD50s in rats). Acramin FWN, Acramin FWR, Acrafix FHN, or their mixtures caused lung damage. Protein concentration, enzyme activities, total cell number, and percentage of polymorphonuclear neutrophils were increased in BALF during the first week after intratracheal instillation. Lung weights remained high for at least a month. Histology showed inflammatory cell infiltration and subsequent fibrosis with collagen deposition. This finding was confirmed by an increased hydroxyproline content in dried lung tissue. Acramoll W did not show toxic effects. CONCLUSIONS: The study suggests that there is no major difference, in hamsters, between the acute intratracheal toxicity of Acramin FWR and that of Acramin FWN. Consequently, there is no simple toxicological explanation for the epidemiological hypothesis. However, the pulmonary toxicity of these non-irritant polymeric compounds is surprisingly high. The Ardystil disaster and these results should serve as a strong warning that conventional toxicity testing of chemicals does not necessarily protect workers against respiratory toxicity.
Mortality of doctors in different specialties: findings from a cohort of 20000 NHS hospital consultants.
Authors: Carpenter L M , Swerdlow A J , Fear N T
Published: December 2008

OBJECTIVES: To examine patterns of cause specific mortality in NHS hospital consultants according to their specialty and to assess these in the context of potential occupational exposures. METHODS: A historical cohort assembled from Department of Health records with follow up through the NHS Central Register involving 18,358 male and 2168 female NHS hospital consultants employed in England and Wales between 1962 and 1979. Main outcome measures examined were cause specific mortality during 1962-92 in all consultants combined, and separately for 17 specialty groups, with age, sex, and calendar year adjusted standardised mortality ratios (SMRs) for comparison with national rates, and rate ratios (RRs) for comparison with rates in all consultants combined. RESULTS: The 2798 deaths at ages 25 to 74 reported during the 30 year study period were less than half the number expected on the basis of national rates (SMR 48, 95% confidence interval (95% CI) 46 to 49). Low mortality was evident for cardiovascular disease, lung cancer, other diseases related to smoking, and particularly for diabetes (SMR 14, 95% CI 6 to 29). Death rates from accidental poisoning were significantly raised among male consultants (SMR 227, 95% CI 135 to 359), the excess being most apparent in obstetricians and gynaecologists (SMR 934); almost all deaths from accidental poisoning involved prescription drugs. A significantly raised death rate from injury and poisoning among female consultants was due largely to a twofold excess of suicide (SMR 215, 95% CI 93 to 423), the rate for this cause being significantly raised in anaesthetists (SMR 405). Compared with all consultants, significantly raised mortality was found in psychiatrists for all causes combined (RR 1.12), ischaemic heart disease (RR 1.18), and injury and poisoning (RR 1.46); in anaesthetists for cirrhosis (RR 2.22); and in radiologists and radiotherapists for respiratory disease (RR 1.68). There were significant excesses of colon cancer in psychiatrists (RR 1.67, compared with all consultants) and ear, nose, and throat surgeons (RR 2.25); melanoma in anaesthetists (RR 3.33); bladder cancer in general surgeons (RR 2.40); and laryngeal cancer in ophthalmologists (RR 7.63). CONCLUSIONS: Lower rates of smoking will have contributed substantially to the low overall death rates found in consultants, but other beneficial health related behaviours, and better access to health care, may have also played a part. The increased risks of accidental poisoning in male consultants, and of suicide in female consultants are of concern, and better preventive measures are needed. The few significant excesses of specific cancers found in certain specialties have no obvious explanation other than chance. A significant excess mortality from cirrhosis in anaesthetists might reflect an occupational hazard and may warrant further investigation.
Lung cancer in relation to employment in the electrical utility industry and exposure to magnetic fields.
Authors: Savitz D A , Dufort V , Armstrong B , Thériault G
Published: December 2008

OBJECTIVES: A recent study found that lung cancer may be associated with exposures encountered in the electrical utility industry. To further evaluate this possibility, data were collected and analysed from five large electrical utility companies in the United States. METHODS: A cohort of 138905 male workers employed between 1950 and 1986 was followed up for mortality to the end of 1988, with 20733 deaths identified of which 1692 were due to lung cancer. Mortality from lung cancer was examined in relation to the duration of employment in specific jobs thought to have high exposure to 60 Hz magnetic fields and to an index of cumulative exposure to magnetic fields based on personal measurements. Exposure to pulsed electromagnetic fields (PEMFs) as estimated from another study was also considered. Poisson regression generated rate ratios for categories of exposure based on comparisons within the cohort adjusted for age, calendar year, race, socioeconomic status, work status, and estimated exposure to asbestos. RESULTS: Mortality rose modestly with duration of work as an electrician or power plant operator reaching rate ratios of 1.4 with > or = 20 years in those jobs but not with duration of work as a lineman or a combination of jobs thought to have high exposures to 60 Hz magnetic fields or PEMFs. Cumulative indices of exposure to 60 Hz magnetic fields and PEMFs were both associated with rate ratios of 1.2-1.3 in the highest intervals. CONCLUSIONS: These data suggest that lung cancer is not strongly associated with duration of employment in specific jobs associated with high potential exposure to 60 Hz magnetic fields or to PEMFs. Small associations of lung cancer with indices of both 60 Hz magnetic fields and PEMFs leave open the possibility that larger associations have been diluted through exposure misclassification. Refined exposure assessment, especially to PEMFs, would be required to evaluate that possibility.
Routes of asbestos exposure and the development of mesothelioma in an English region.
Authors: Howel D , Arblaster L , Swinburne L , Schweiger M , Renvoize E , Hatton P
Published: December 2008

OBJECTIVES: To investigate the contribution of exposure to asbestos through different routes in the development of mesothelioma. METHODS: Case-control study. 185 confirmed cases of mesothelioma and 160 controls were identified, when death had occurred between 1979 and 1991 in four health districts in Yorkshire. The surviving relatives were interviewed to ascertain lifetime exposure to asbestos. Adjusted odds ratios (ORs) of exposure to asbestos (through occupational, paraoccupational, and residential routes) were calculated for cases and were compared with controls. RESULTS: Likely or possible occupational exposure to asbestos was more common in cases than in controls (OR 5.6, 95% confidence interval (95% CI) 3.1 to 10.1). After excluding those with likely or possible occupational exposure, likely or possible paraoccupational exposure was more common in cases than controls (OR 5.8, 95% CI 1.8 to 19.2). Only six cases of mesothelioma were identified as being solely exposed to asbestos through their residence, compared with nine controls. The OR for residential exposure to asbestos varied between 1.5 and 6.6, depending on which potential industrial sources were included, but the 95% CIs were so wide that slightly reduced or greatly increased odds comparing cases with controls could not be excluded. CONCLUSION: Study results support previous evidence that occupational and paraoccupational exposure to asbestos is associated with developing mesothelioma. Despite a rigorous search, purely residential exposure seemed to account for only 3% of identified cases. No firm conclusion can be drawn about the risks from residential exposure alone, as many of the study subjects could also have been occupationally or paraoccupationally exposed to asbestos.
Urinary neutral endopeptidase in workers exposed to cadmium: interaction with cigarette smoking.
Authors: Nortier J , Bernard A , Roels H , Deschodt-Lanckman M , Gueuning C , Lauwerys R
Published: December 2008

OBJECTIVES: Structural impairment of the renal proximal tubular epithelium induced by cadmium (Cd) was investigated by measuring the concentration of neutral endopeptidase 24.11 (NEP), an ectoenzyme of the apical brush border, in the urine of 106 male workers employed in a Cd smelter (among whom 52 were occupationally exposed to Cd), and by comparing it with other tubular markers (low molecular weight proteins, lysosomal enzymes). METHODS: NEP (EC 3.4.24.11), beta-N-acetyl-glucosaminidase (NAG) (EC 3.2.1.30), and NAG-B isoenzyme activities were measured by fluorimetric assays, whereas the concentrations of retinol binding protein (RBP), beta 2-microglobulin (beta 2M), and Clara cell protein (CC16) were measured by automated latex agglutination techniques. RESULTS: An increased urinary excretion of NEP as well as microproteins was found only in subjects excreting more than 5 micrograms Cd/g creatinine. In this group, NEP concentrations were significantly higher in the subjects who smoked. This significant interaction could not be found for any other marker tested. CONCLUSIONS: The data suggest that NEP enzymuria is high even at low exposures to Cd (with a threshold of urinary cadmium excretion (U-Cd) at 5 micrograms/g creatinine), indicating early structural alterations. Moreover, its particular sensitivity to smoking could be useful in the detection of new population clusters potentially more susceptible to development of nephrotoxic insult.
Minimal immunological effects on workers with prolonged low exposure to inorganic mercury.
Authors: Soleo L , Vacca A , Vimercati L , Bruno S , Di Loreto M , Zocchetti C , Di Stefano R , Candilio G , Lasorsa G , Franco G , Foa V
Published: December 2008

OBJECTIVES: This study was carried out to investigate possible immunological changes in workers with prolonged low exposure to inorganic mercury in a fluorescent light bulb factory. METHODS: 29 immunological variables were examined in 34 workers with prolonged low level exposure to inorganic mercury (exposed workers) and 35 unexposed workers as the controls. The selected indicator of mercury exposure was concentration of mercury in the urine (U-Hg), which declined progressively from 36.0 micrograms/l in 1978 to 6.0 micrograms/l in the study year 1994. RESULTS: None of the exposed workers had ever shown signs of either acute or chronic inorganic mercury toxicity or had shown any form of hypersensitivity. The only changes found in the exposed workers, compared with the controls, were a reduction of the cells that express cluster differentiation (CD25,(T activation antigen (Tac antigen))) and concentrations of tumour necrosis factor-alpha (TNF-alpha) in serum. However, the decrease of cells that express CD25 was unrelated to occupational exposure and was, in all likelihood a chance finding. Conversely, the decline in serum TNF-alpha was closely associated with occupational exposure. However, no dose-response relation was found between U-Hg and TNF-alpha concentrations; nor were TNF-alpha concentrations affected by cumulative occupational exposure to inorganic mercury in over 20 years. CONCLUSIONS: Tentatively, we suggest that reduced serum TNF-alpha concentrations might be indicative of an in vivo functional defect of the monocyte macrophage system in this particular group of workers even though they were clinically asymptomatic.
Surveillance of nasal and bladder cancer to locate sources of exposure to occupational carcinogens.
Authors: Teschke K , Morgan M S , Checkoway H , Franklin G , Spinelli J J , van Belle G , Weiss N S
Published: December 2008

OBJECTIVE: To locate sources of occupational exposure to nasal and bladder carcinogens for surveillance follow up in British Columbia, Canada. METHODS: Incident cases of nasal cancer (n = 48), bladder cancer (n = 105), and population based controls (n = 159) matched for sex and age, were interviewed about their jobs, exposures, and smoking histories. Odds ratios (ORs) were calculated for 57 occupational groups with stratified exact methods to control for age, sex, and smoking. RESULTS: Occupational groups at increased risk of nasal cancer included: textile workers (six cases, OR 7.6); miners, drillers, and blasters (six cases, OR 3.5); welders (two cases, OR 3.5); pulp and paper workers (three cases, OR 3.1); and plumbers and pipefitters (two cases, OR 3.0). Nasal cancer ORs were not increased in occupations exposed to wood dust, possibly due to low exposures in local wood industries. Strongly increased risks of bladder cancer were found for sheet metal workers (four cases, OR 5.3), miners (19 cases, OR 4.5), gardeners (six cases, OR 3.7), and hairdressers (three cases, OR 3.2). Among occupations originally considered at risk, the following had increased risks of bladder cancer: painters (four cases, OR 2.8); laundry workers (five cases, OR 2.3); chemical and petroleum workers (15 cases, OR 1.8); machinists (eight cases, OR 1.6); and textile workers (three cases, OR 1.5). CONCLUSIONS: Occupational groups with increased risks and three or more cases with similar duties were selected for surveillance follow up. For nasal cancer, these included textile workers (five were garment makers) and pulp and paper workers (three performed maintenance tasks likely to entail stainless steel welding). For bladder cancer, these included miners (12 worked underground), machinists (five worked in traditional machining), hairdressers (three had applied hair dyes), and laundry workers (three were drycleaners).
Self reported respiratory symptoms and diseases among hairdressers.
Authors: Leino T , Tammilehto L , Luukkonen R , Nordman H
Published: December 2008

OBJECTIVES: Hairdressers are exposed to many irritative and allergenic substances capable of causing occupational respiratory symptoms and diseases. The self reported prevalence of respiratory symptoms and diseases was studied, and the risks among hairdressers compared with saleswomen was estimated. METHODS: A cross sectional prevalence study of respiratory symptoms and diseases was carried out among hairdressers and supermarket saleswomen, with a computer assisted telephone interview method (CATI). The study population comprised all the female hairdressers and supermarket saleswomen aged 15-54 years in the Helsinki metropolitan area, Finland. Disproportionate random samples of female hairdressers and sales-women were drawn from the trade union membership registers. The interviews were carried out between February and April 1994. A response rate of 80.5% (355/440) was obtained for hairdressers and 82.2% (583/709) for saleswomen. Atopy, smoking, chronic illnesses, type of work, working hours, working conditions, personal and professional use of hair products, and the use of personal protective devices were assessed. The outcome variables were self reported symptoms of the upper and lower respiratory tract. These were used to define chronic bronchitis, and asthma, laryngitis, and allergic rhinitis diagnosed by a physician. RESULTS: There was a considerable difference in the prevalence of chronic bronchitis; 6.8% in hairdressers versus 1.9% in saleswomen. The odds ratio (OR) adjusted for age, smoking, and atopy for chronic bronchitis indicated an increased risk of chronic bronchitis (OR 4.8, 95% confidence interval (95% CI) 2.2 to 10.1). No association was found between work as a hairdresser and asthma, laryngitis, and allergic rhinitis. Also the prevalence of rhinitis, rhinitis with eye symptoms, cough with phlegm, dyspnoea, and dyspnoea accompanied by cough was increased among hairdressers. The corresponding adjusted risk ORs were 1.7 (95% CI 1.3 to 2.3) for rhinitis, 1.9 (95% CI 1.4 to 2.6) for rhinitis with eye symptoms, 1.4 (CI 1.1 to 1.9) for cough with phlegm, 1.5 (95% CI 1.0 to 2.2) for dyspnoea, and 1.6 (95% CI 1.0 to 2.7) for dyspnoea with cough. CONCLUSIONS: Our results indicate an increased prevalence of upper and lower respiratory symptoms among hairdressers. Allergenic and irritative chemicals in hairdressing are likely candidates explaining the difference found between the hairdressers and controls. Work related reasons should be considered when a hairdresser presents with airway symptoms. Preventive actions are needed to improve the working conditions and personal protection.
Occupational exposure to dust: inflammation and ischaemic heart disease.
Authors: Sjögren B
Published: December 2008

OBJECTIVES: To review the possible association between occupational exposure to dust and ischaemic heart disease (IHD). METHODS: A literature search was performed of relevant studies regarding IHD in specific exposures to dust. The chosen exposures were arsenic, asbestos, beryllium, lead, polycyclic aromatic hydrocarbons, and quartz. The chosen occupations were farmers, paper and paper pulp workers, sawyers, and welders. DISCUSSION: A theory was launched in 1995 that urban particulate air pollution may provoke alveolar inflammation, with release of mediators capable of increasing blood coagulability in susceptible people and cause cardiovascular deaths. The present review expands this hypothesis and links occupational exposure to inhaled particles with the occurrence of ischaemic heart disease. CONCLUSION: This hypothesis should be tested by comparing the concentrations of fibrinogen in workers exposed and nonexposed to particles with control for other possible confounders such as smoking habits.
Effects of low level exposure to lead on neurophysiological functions among lead battery workers.
Authors: Kovala T , Matikainen E , Mannelin T , Erkkilä J , Riihimäki V , Hänninen H , Aitio A
Published: December 2008

OBJECTIVES: Assessment of neurophysiological functions in workers with low level exposure to lead and evaluation of the efficacy of bone lead measurements in the prediction of effects of lead. METHODS: Exposure to lead of 60 workers from a lead battery battery factory was estimated from historical blood lead measurements and analysis of lead in the tibial and calcaneal bones with x ray fluorescence. Peripheral and central nervous system functions were assessed by measuring conduction velocities, sensory distal latencies, sensory amplitudes, and vibration thresholds as well as by quantitative measurement of the absolute and relative powers and mean frequencies of different electroencephalograph (EEG) channels. RESULTS: Sensory amplitudes, and to a smaller degree sensory or motor conduction velocities, showed a negative correlation with long term exposure to lead, most clearly with integrated blood lead concentration and exposure time. Vibration thresholds measured in the arm were related to recent exposure to lead, those measured in the leg to long term exposure. The alpha and beta activities of the EEG were more abundant in subjects with higher long term exposure to lead. Calcaneal lead content reflected short term exposure, tibial lead content reflected long term exposure. Blood lead history showed a closer relation with effects of lead than the tibial or calcaneal lead concentrations. CONCLUSIONS: Vibratory thresholds, quantitative EEG, and to a smaller extent the sensory amplitude, provide sensitive measures of effects of lead in occupationally exposed adults. Most accurate estimates of health risks induced by lead can be obtained from a good history of blood lead measurements. If such a history of blood lead concentrations is not available, analysis of bone lead may be used for the assessment of health risks.
Medical insurance claims associated with international business travel.
Authors: Liese B , Mundt K A , Dell L D , Nagy L , Demure B
Published: December 2008

OBJECTIVES: Preliminary investigations of whether 10,884 staff and consultants of the World Bank experience disease due to work related travel. Medical insurance claims filed by 4738 travellers during 1993 were compared with claims of non-travellers. METHODS: Specific diagnoses obtained from claims were analysed overall (one or more v no missions) and by frequency of international mission (1, 2-3, or > or = 4). Standardised rate of claims ratios (SSRs) for each diagnostic category were obtained by dividing the age adjusted rate of claims for travellers by the age adjusted rate of claims for non-travellers, and were calculated for men and women travellers separately. RESULTS: Overall, rates of insurance claims were 80% higher for men and 18% higher for women travellers than their non-travelling counterparts. Several associations with frequency of travel were found. SRRs for infectious disease were 1.28, 1.54, and 1.97 among men who had completed one, two or three, and four or more missions, and 1.16, 1.28, and 1.61, respectively, among women. The greatest excess related to travel was found for psychological disorders. For men SRRs were 2.11, 3.13, and 3.06 and for women, SRRs were 1.47, 1.96, and 2.59. CONCLUSIONS: International business travel may pose health risks beyond exposure to infectious diseases. Because travellers file medical claims at a greater rate than non-travellers, and for many categories of disease, the rate of claims increases with frequency of travel. The reasons for higher rates of claims among travellers are not well understood. Additional research on psychosocial factors, health practices, time zones crossed, and temporal relation between travel and onset of disease is planned.
Daily time series for cardiovascular hospital admissions and previous day's air pollution in London, UK.
Authors: Poloniecki J D , Atkinson R W , de Leon A P , Anderson H R
Published: December 2008

OBJECTIVE: To test for a significant association between air pollution and emergency hospital admissions for circulatory diseases (international classification of diseases-9 390-459) in London, England, that would be consistent with a causal effect of pollution on the previous day. METHODS: Long term concurrent trends, temperature, humidity, day of the week, influenza epidemic of 1989, and cyclical covariations with periodicity > 20 days in daily measures of pollution and admissions for 1987-94 were allowed for. RESULTS: There were 373556 admissions. No association was found between O3 and circulatory diseases. Four other pollutants were associated with acute myocardial infarction and circulatory diseases combined. P values and attributable cases (95% confidence intervals) for acute myocardial infarction were: black smoke P = 0.003, 2.5% (0.8% to 4.3%); NO2 P = 0.002, 2.7% (0.8% to 4.6%); CO P = 0.001, 2.1% (0.7% to 3.5%); and SO2 P = 0.0006, 1.7% (0.7% to 2.6%). There were also associations between black smoke and angina (P = 0.02), NO2 and arrhythmia (P = 0.04), and CO and other circulatory diseases (P = 0.004), but none with heart failure. Acute myocardial infarction was the only diagnosis for which there were significant associations with and without adjustment for cyclical terms. The associations with acute myocardial infarction were significant only in the cool season. CONCLUSION: Population data were consistent with 1 in 50 heart attacks currently presenting at London hospitals being triggered by outdoor air pollution. Further research is now needed to investigate whether background concentrations of black smoke, NO2, CO, and SO2 are a preventable cause of myocardial infarction. These results, if applied to all myocardial infarctions in the United Kingdom, indicate a potential saving of 6000 heart attacks a year.
Risk of spontaneous abortion in women occupationally exposed to anaesthetic gases: a meta-analysis.
Authors: Boivin J F
Published: December 2008

OBJECTIVES: To determine the association between maternal occupational exposure to anaesthetic gases and risk of spontaneous abortion. METHODS: A meta-analysis was performed of published epidemiological studies identified from literature reviews, unsystematic perusal of reference lists of relevant publications, and two Medline searches (1984-92, keywords: anaesthetic gases; anaesthetics; anaesthetics, local; operating rooms; operating room nursing; pregnancy; abortion; 1985-92, keywords: anaesthetics; adverse effects; occupational exposure; anaesthesia, inhalation; operating room nursing; pregnancy; abortion). All peer reviewed studies were retained. Student theses were excluded, as were conference abstracts, unpublished material, and two studies in which data on paternal and maternal occupational exposures were pooled. The relative risk of spontaneous abortion was estimated. RESULTS: One study found no increase in risk of abortion when gases were scavenged or when the exposure to unscavenged gases was low. None of the studies included ambient gas sampling. 24 comparisons between exposed and unexposed women, obtained from 19 reports, were included. The overall relative risk was 1.48 (95% confidence interval (95% CI), 1.4 to 1.58). To test whether this result was influenced by the quality of the studies, the validity of the reviewed papers was rated on the basis of three criteria: appropriateness of the unexposed comparison group, control for non-occupational confounding variables, and response rate. The estimate of risk increased to 1.9 (95% CI, 1.72 to 2.09) when analysis was restricted to the six comparisons which were rated the most rigorous. CONCLUSIONS: Epidemiological studies based on data obtained in the prescavenging era indicate an increased risk of spontaneous abortion. The estimated increased risk was not diminished but rather increased by exclusion of the more methodologically flawed studies.
Electron microscopic microanalysis of bronchoalveolar lavage: a way to identify exposure to silica and silicate dust.
Authors: Monsó E , Carreres A , Tura J M , Ruiz J , Fiz J , Xaus C , Llatjós M , Morera J
Published: December 2008

OBJECTIVES: The diagnostic implications of finding non-fibrous inorganic particles in bronchoalveolar lavage (BAL) fluid has not been fully assessed. The aim of this study has been to measure the silica and non-fibrous silicates in BAL fluid from populations with different exposures to inorganic dust, and to find whether such measurement is useful for diagnostic purposes. MATERIALS AND METHODS: BAL samples from 19 subjects with only environmental exposure to inorganic dust (group A, mean (SD) age 50.7 (15.2)), 23 subjects with normal chest x ray films exposed to silica or silicates at work (group B, mean (SD) age 52.0 (12.4)), and 15 subjects with a previous diagnosis of silicosis (group C, mean (SD) age 68.0 (6.5)) were studied. Absolute and relative cell counts were found, and the samples were prepared for microanalysis by electron microscopy (EM). Firstly, semiquantitative x ray microanalysis was performed to find the level of silicon (Si) (peak/background Si) and this was followed by microanalysis of individual particles by EM. Variables related to the level of Si detected were assessed with multivariate analysis. RESULTS: Detected levels were higher in group B (2.09, 95% confidence interval (95% CI) 1.56 to 2.82) and C (1.50, 95% CI 1.07 to 2.12) than in group A (0.87, 95% CI 0.66 to 1.16) (P < 0.05, Dunett t test). A first multivariate analysis showed that exposure to silica or silicates was the only determinant of the level of Si expressed as log peak/background Si, when adjusted for age, sex, smoking habit, and cell count. A second multivariate analysis with microanalysis of individual particles as an independent variable showed the silica count to be the main predictor of detected concentration of Si. Silica and non-aluminium silicates together explain 55.5% (R2) of the variation in detected levels of Si. CONCLUSIONS: Detected levels of Si in BAL fluid depend on silica count and are higher in subjects with exposure to inorganic dust at work, but will not discriminate between exposed subjects with and without silicosis. Because semiquantitative x ray microanalysis does not accurately define exposure to non-silica inorganic particles, this measurement must be followed by EM microanalysis of individual particles in most cases, especially when exposure to silicates or metal dust is suspected.
Haemodynamic changes in ipsilateral and contralateral fingers caused by acute exposures to hand transmitted vibration.
Authors: Bovenzi M , Griffin M J
Published: December 2008

OBJECTIVES: To investigate changes in digital circulation during and after exposure to hand transmitted vibration. By studying two frequencies and two magnitudes of vibration, to investigate the extent to which haemodynamic changes depend on the vibration frequency, the vibration acceleration, and the vibration velocity. METHODS: Finger skin temperature (FST), finger blood flow (FBF), and finger systolic pressure were measured in the fingers of both hands in eight healthy men. Indices of digital vasomotor tone-such as critical closing pressure and vascular resistance-were estimated by pressure-flow curves obtained with different hand heights. With a static load of 10 N, the right hand was exposed for 30 minutes to each of the following root mean squared (rms) acceleration magnitudes and frequencies of vertical vibration: 22 m.s-2 at 31.5 Hz, 22 m.s-2 at 125 Hz, and 87 m.s-2 at 125 Hz. A control condition consisted of exposure to the static load only. The measures of digital circulation and vasomotor tone were taken before exposure to the vibration and the static load, and at 0, 20, 40, and 60 minutes after the end of each exposure. RESULTS: Exposure to static load caused no significant changes in FST, FBF, or indices of vasomotor tone in either the vibrated right middle finger or the non-vibrated left middle finger. In both fingers, exposure to vibration of 125 Hz and 22 m.s-2 produced a greater reduction in FBF and a greater increase in vasomotor tone than did vibration of 31.5 Hz and 22 m.s-2. In the vibrated right finger, exposure to vibration of 125 Hz and 87 m.s-2 provoked an immediate vasodilation which was followed by vasoconstriction during recovery. The non-vibrated left finger showed a significant increase in vasomotor tone throughout the 60 minute period after the end of vibration exposure. CONCLUSIONS: The digital circulatory response to acute vibration depends upon the magnitude and frequency of the vibration stimulus. Vasomotor mechanisms, mediated both centrally and locally, are involved in the reaction of digital vessels to acute vibration. The pattern of the haemodynamic changes in the fingers exposed to the vibration frequencies used in this study do not seem to support the frequency weighting assumed in the current international standard ISO 5349.
Risks of leukaemia among residents close to high voltage transmission electric lines.
Authors: Thériault G , Li C Y
Published: December 2008

OBJECTIVES: To reassess the risk of leukaemia associated with residential exposure near high voltage transmission electric lines of 49 kV and above in view of the recent publications. METHODS: Through a review of papers considering the risk of leukaemia among people living near high voltage transmission lines, the combined risks of leukaemia were calculated for distances < or = 50 m and < or = 25 m and for exposures at 2 mG, 3 mG, 4 mG, and 10 mG. RESULTS: The combined analysis of the contributive studies indicated an estimate of risk (odds ratio (OR)) for exposure > or = 2 mG of 1.3, 95% confidence interval (95%CI) 1.0 to 1.7. The ORs increased with exposures at 3 mG, 4 mG, and 10 mG. The risks were also increased for distances of 50 and 25 m from the lines. CONCLUSIONS: This meta-analysis tends to confirm the presence of an association between exposure to magnetic fields and leukaemia among people who reside in the vicinity of high voltage transmission electric lines of > or = 49 kV. There is consistency across studies. Measures of exposure used in the studies were either distance from the lines or calculated fields estimated from pertinent line features. The results apply to adults as well as to children.
Risk of congenital anomalies in children of parents occupationally exposed to low level ionising radiation.
Authors: Green L M , Dodds L , Miller A B , Tomkins D J , Li J , Escobar M
Published: December 2008

OBJECTIVES: To evaluate the risk of having a child with a congenital anomaly in relation to occupational exposure to low level ionising radiation in the pre-conception period. METHODS: A case-control study based on the Canadian congenital anomalies registry used record linkage techniques to identify congenital anomalies among male and female workers in Canada's largest electric company. Cases were defined as parents of a child with a congenital anomaly born between April 1979 and December 1986 who had a congenital anomaly diagnosed within the first year of life. Controls were an individually matched sample of parents of a liveborn child without an anomaly. Risk of congenital anomaly was assessed in relation to parental exposure to ionising radiation acquired through work within a nuclear generating station of an electric power company. Exposure was assessed according to employment, whether or not the worker was monitored for radiation exposure, and quantitative estimates of radiation dose. RESULTS: Employment within the electric power industry was not associated with an increased risk of congenital anomalies in the offspring of mothers or fathers. Risk estimates for workers monitored (those who are likely to be exposed to ionising radiation) were 1.75 (95% confidence interval (95% CI) 0.86 to 3.55) for mothers and 0.84 (95% CI 0.68 to 1.05) for fathers. Exposure for fathers before conception, defined cumulatively and for six months before conception, was not associated with increased risk of anomalies in their offspring. There were no significant increases in risk found between type of anomaly and any measure of exposure, although the statistical power in these groups was limited. The study had insufficient numbers to evaluate the effects of ionising radiation in mothers as only three mothers had recorded doses > 0 mSv. CONCLUSIONS: Overall, workers in a nuclear power industry, and specifically those exposed before conception to low levels of ionising radiation, do not appear to be at an increased risk of having a liveborn child with a congenital anomaly.