[Immediate and delayed outcomes after electrical injury. A guide for clinicians]. / Elolyckor kan ge skador som visar sig efter lång tid - Det akuta omhändertagandet kan vara avgörande på sikt.

Immediate and delayed outcomes after electrical injury. A guide for clinicians In Sweden about 300 electrical injuries are recorded each year at the Swedish National Electrical Safety Board. Most of our knowledge of the health consequences of these arise from clinical case series. Severe electrical injuries have direct thermal effects and may result in ventricular fibrillation, skin burns, as well as muscular and nerve affection. Long-term consequences include pain, vascular symptoms, cognitive and neurological symptoms and signs. These sequelae may occur even though the initial symptoms were relatively modest. Mechanisms are better understood for the immediate symptoms, compared to long-term and delayed non-thermal medical consequences. Attention to and treatment of patients with electrical injury needs to be improved to minimize long-term consequences. Good medical care in the acute phase and early multidisciplinary follow-up of severe cases will likely reduce associated morbidity. Each electrical injury should result in an inquiry to identify the cause of the accident in order to suggest actions to prevent new incidents.

Inflammatory markers and exposure to airborne particles among workers in a Swedish pulp and paper mill.

PURPOSE: To study the relationship between exposure to airborne particles in a pulp and paper mill and markers of inflammation and coagulation in blood. METHODS: Personal sampling of inhalable dust was performed for 72 subjects working in a Swedish pulp and paper mill. Stationary measurements were used to study concentrations of total dust, respirable dust, PM10 and PM2.5, the particle surface area and the particle number concentrations. Markers of inflammation, interleukins (IL-1b, IL-6, IL-8, and IL-10), C-reactive protein (CRP), serum amyloid A (SAA), and fibrinogen and markers of coagulation factor VIII, von Willebrand, plasminogen activator inhibitor, and D-dimer were measured in plasma or serum. Sampling was performed on the last day of the work free period of 5 days, before and after the shift the first day of work and after the shifts the second and third day. In a mixed model analysis, the relationship between particulate exposures and inflammatory markers was determined. Sex, age, smoking, and BMI were included as covariates. RESULTS: The average 8-h time-weighted average (TWA) air concentration levels of inhalable dust were 0.30 mg/m(3), range 0.005-3.3 mg/m(3). The proxies for average 8-h TWAs of respirable dust were 0.045 mg/m(3). Significant and consistent positive relations were found between several exposure metrics (PM 10, total and inhalable dust) and CRP, SAA and fibrinogen taken post-shift, suggesting a dose-effect relationship. CONCLUSION: This study supports a relationship between occupational particle exposure and established inflammatory markers, which may indicate an increased risk of cardiovascular disease.

Urinary 2,5-hexanedione excretion in cryptogenic polyneuropathy compared to the general Swedish population.

BACKGROUND: 2,5-hexanedione (2,5-HD) is the main neurotoxic metabolite of methyl-n-butyl ketone (MBK) and n-hexane, and known to cause polyneuropathy. The aim of our study was to compare the urinary levels of 2,5-HD between cases with cryptogenic polyneuropathy and the general Swedish population, and to elucidate the role of certain external factors. METHODS: Morning urine samples were collected from 114 cases with cryptogenic polyneuropathy (77 men and 37 women) and 227 referents (110 men and 117 women) randomly selected from the population registry. None had any current occupational exposure to n-hexane or MBK. The urine samples were analysed by a gas chromatographic method based on acidic hydrolysis. RESULTS: Cases had statistically higher urinary levels of 2,5-HD (0.48 mg/L) than the general population (0.41 mg/L) and men higher excretion than women (0.48 mg/L and 0.38 mg/L, respectively). There was no difference in 2,5-HD levels between current smokers and non-smokers. Occupational exposure to xylene, alcohol consumption and ever exposed to general anaesthesia were associated with lower excretion in men while for occupational exposure to nitrous oxide in women higher excretion was seen. Higher excretion of 2,5 HD was inversely related to increasing age. CONCLUSIONS: Significantly higher levels of urinary 2,5-HD were seen in men and cryptogenic polyneuropathy cases seemingly unexposed to n-hexane. Hypothetically, this might be due to either differences in metabolic patterns or some concealed exposure. The difference in means between cases and the general population is small and can therefore not allow any firm conclusions of the causality, however.

Cancer incidence among Swedish pulp and paper mill workers: a cohort study of sulphate and sulphite mills.

PURPOSE: Associations between various malignancies and work in the pulp and paper industry have been reported but mostly in analyses of mortality rather than incidence. We aimed to study cancer incidence by main mill pulping process, department and gender in a Swedish cohort of pulp and paper mill workers. METHODS: The cohort (18,113 males and 2,292 females, enrolled from 1939 to 1999 with >1 year of employment) was followed up for cancer incidence from 1958 to 2001. Information on the workers' department and employment was obtained from the mills' personnel files, and standardized incidence ratios (SIRs) were calculated using the Swedish population as reference. RESULTS: Overall cancer incidence, in total 2,488 cases, was not increased by work in any department. However, risks of pleural mesothelioma were increased among males employed in sulphate pulping (SIR, 8.38; 95 % CI, 3.37-17) and maintenance (SIR, 6.35; 95 % CI, 3.47-11), with no corresponding increase of lung cancer. Testicular cancer risks were increased among males employed in sulphate pulping (SIR, 4.14; 95 % CI, 1.99-7.61) and sulphite pulping (SIR, 2.59; 95 % CI, 0.95-5.64). Female paper production workers showed increased risk of skin tumours other than malignant melanoma (SIR, 2.92; 95 % CI, 1.18-6.02). CONCLUSIONS: Incidence of pleural mesothelioma was increased in the cohort, showing that asbestos exposure still has severe health consequences, and highlighting the exigency of strict asbestos regulations and elimination. Testicular cancer was increased among pulping department workers. Shift work and endocrine disruptors could be of interest in this context.

Polymorphisms of GSTT1, GSTM1, and EPHX genotypes in patients with cryptogenic polyneuropathy: a case-control study.

The aim of this study was to analyze whether polymorphisms for the null alleles of Glutathione S-Transferase Mu-1 (GSTM1), Glutathione S-Transferase Theta-1 (GSTT1), and a low-activity genetic variation of epoxide hydrolase exon three (EPHX*3) affect the risk of developing polyneuropathy. The enzymes of these genes are important in the metabolism of toxic compounds. Seventy-nine patients with cryptogenic polyneuropathy (equivalent to chronic idiopathic axonal neuropathy) and 398 controls were tested for the genetic polymorphism. Medical records were reviewed to collect data regarding clinical findings at diagnosis, and exposure data was collected via questionnaires. The odds ratios (ORs) for the null forms of GSTM1 and GSTT1 and the normal activity YY form of EPHX*3 were close to one except GSTT1, which reached 1.86. The highest risk of polyneuropathy was found in smokers with GSTT1 null, who had a 3.7 times increased risk. Interactions between genes were analyzed and confirmed the increased OR for GSTT1, which was strongest if the patients had the low-activity HH form of EPHX*3 (OR 2.37). Our hypothesis is that the GSTT1 null polymorphism may be related to an impaired metabolism of toxic substances that could lead to nerve damage in the peripheral nervous system.

Health-related quality of life in patients with cryptogenic polyneuropathy compared with the general population.

PURPOSE: To evaluate the quality of life (QOL) in patients with cryptogenic polyneuropathy. METHOD: Two validated instruments (SF-36 and EQ-5D) were sent to 86 patients with a 72% response rate (44 men, 18 women). As reference, 2721 individuals (1292 men, 1429 women; 59% response rate) from the general population responded to the same QOL instruments. RESULTS: Compared to the general population, QOL was significantly more affected in patients with polyneuropathy concerning motor functions, with 42% of the patients reporting problems with walking, 7% having difficulties with washing and dressing, and 31% having problems with usual activities (work, study, household work, and family or leisure activities). The EQ-5D results showed that 85% of the patients were suffering from pain compared to 56% of the general population. Mental health was preserved among patients with polyneuropathy. Mobility was declining with increasing age in patients, but was not affected by disease duration. CONCLUSIONS: Our study showed that patients with cryptogenic polyneuropathy have a lower QOL compared to the general population, although mental health scores did not differ between the groups. This information may be helpful when explaining the disease and its impact on newly diagnosed patients.

Cancer mortality in a Swedish cohort of pulp and paper mill workers.

PURPOSE: To study cancer mortality among Swedish pulp and paper mill workers by main mill pulping process and department, and to present the Swedish part of an international exposure measurements database. METHODS: A cohort of 18,163 male and 2,290 female workers at four sulfate and four sulfite mills, enrolled from 1939 to 1999, was followed up for mortality during 1952-2001. Standardized mortality ratios (SMRs) relative to the general Swedish population were calculated. RESULTS: There were 1,340 malignant cases out of 5,898 deaths. Total cancer mortality was not increased in either sulfate or sulfite mill workers, or by gender. Lung cancer mortality was increased among female workers (SMR 1.70, 95% CI 1.04-2.63), especially in paper production, but not among male workers (SMR 0.91, 95% CI 0.79-1.04). Exposure to wood dust and sulfur dioxide frequently exceeded occupational exposure limits. CONCLUSIONS: Female paper production workers had an increased mortality from lung cancer.

Parish classification or dwelling coordinate for exposure assessment in environmental epidemiology - a comparative study using Geographical Information System.

BACKGROUND: Two previous epidemiological studies on the incidence of total malignancies in Sweden after the Chernobyl accident have shown consistently increased risks. The first study used an analogue map on (137)Cs from 1986 to classify individuals in terms of the parish they lived in. In the second study, dwelling coordinates were matched to a digital map from the year 2000 to assess the individual exposure. To establish the accuracy of the exposure assessment using the larger unit of parish, instead of coordinates, we decided to compare the methods. METHODS: On the analogue map eleven isolines on the deposition of (137)Cs (kBq/m(2)) were used to classify all individuals in each of the 450 parishes. Using the digital map, by contrast, each dwelling with its inhabitants could be matched to (137)Cs deposition at a coordinate level. A population-weighted average of (137)Cs deposition was calculated for each parish. In total, 1,126,960 individuals and 450 parishes were included and analysed into six different exposure categories. RESULTS: Using the new parish exposure index, 111 out of the 450 parishes were reclassified as a result of the increased resolution of the digital map (86 parishes) or unequal distribution of the population compared with the deposition (25 parishes). Seventy-five per cent of the parishes remained in the same exposure category as on the analogue map. CONCLUSION: Using dwelling coordinates for exposure assessment may not always be superior to parish classification. Nor is it always a cost-effective way of estimating the exposure, especially if the exposure in a parish is relatively homogenous or if parishes can be merged into broader categories with little intra-parish difference.

Cardiovascular mortality among Swedish pulp and paper mill workers.

BACKGROUND: Malignant diseases but also cardiovascular and respiratory disorders and diabetes mellitus have been associated with work in pulp and paper production. The present cohort focuses on cardiovascular mortality in relation to various exposures in this industry. METHODS: The cohort, followed-up for mortality, includes 7,107 workers, 6,350 men and 757 women, from three major old mills in the middle of Sweden. RESULTS: Instead of a healthy-worker effect, a slightly increased risk for death in diseases of the circulatory system was found for male workers. Notably, work with sulfate digestion, steam and power generation and maintenance was associated with significantly increased risks. Cerebrovascular diseases showed non-significantly increased risks for maintenance and paper and paperboard production and manufacture. CONCLUSIONS: The differences in risk among various parts of the production are striking although it is hard to pinpoint any specific exposures. Dust and small particles along with sulfur compounds might be suspected.

Cadmium exposure pathways in a population living near a battery plant.

OBJECTIVES: The objectives of the present study were to assess the relative impact of different pathways of environmental cadmium (Cd) exposure and to evaluate the contribution from locally produced vegetables and root crops to the total dietary intake of Cd. METHODS: Cadmium in urine was determined for 492 individuals living near a closed down battery factory in Sweden. For each individual we created an environmental exposure-index based on Cd emissions to ambient air and number of years living at various distances from the plant. This information as well as dietary data were collected via questionnaires. Samples of soil, carrots and/or potatoes were collected from 37 gardens and analysed for Cd concentration. RESULTS: Eating home grown vegetables/potatoes, environmental Cd-exposure-index, female gender, age above 30 years and smoking more than one pack of cigarettes daily for at least 10 years were found to be significantly associated with increased urine concentrations of Cd (UCd>1.0 nmol/mmol creatinine). We found a statistically significant relation between Cd in urine and environmental Cd-exposure-index in persons eating home grown vegetables/potatoes regularly. Cd concentrations in home grown carrots, potatoes and in garden soil were highest in the area closest to the factory. Daily consumption of potatoes and vegetables cultivated in the vicinity of the closed battery factory was estimated to increase Cd intake by 18-38%. CONCLUSION: The present study shows that consumption of locally grown vegetables and root crops was an important exposure pathway, in subjects living near a nickel-cadmium battery plant, whereas direct exposure via ambient air was less important.

Cohort mortality study of Swedish pulp and paper mill workers-nonmalignant diseases.

OBJECTIVES: The aim of this study was to determine mortality among pulp and paper mill workers according to the main mill pulping process, department, and gender, particular reference being given to diseases of the circulatory and respiratory systems. METHODS: The cohort of 18 163 men and 2 291 women employed between 1939 and 1999 and with >1 year of employment was followed for mortality from 1952 to 2001 (acute myocardial infarction from 1969). Standardized mortality ratios (SMR) with 95% confidence intervals (95% CI) were estimated by comparing the observed number of deaths with the expected number for the entire Swedish population. Exposure was assessed from personnel files in the mills. Data from an exposure measurement database are also presented. RESULTS: There were 5898 deaths in the cohort. Total mortality had an SMR of 1.02 (95% CI 0.98-1.06) for the men in the sulfate mills and an SMR of 0.93 (95% CI 0.90-0.97) for the men in the sulfite mills. Mortality from acute myocardial infarction was increased among the men in both the sulfate and sulfite mills [SMR 1.22 (95% CI 1.12-1.32) and SMR 1.11 (95% CI 1.02-1.21), respectively] and by department in sulfate pulping (SMR 1.29, 95% CI 1.07-1.54), paper production (SMR 1.26, 95% CI 1.06-1.49), and maintenance (SMR 1.16, 95% CI 1.02-1.30). Mortality from cerebrovascular disease, diabetes mellitus, and nonmalignant respiratory diseases was not increased. CONCLUSIONS: Death from acute myocardial infarction, but not cerebrovascular diseases, was increased in this cohort and was probably related to a combination of different occupational exposures (eg, dust, sulfur compounds, shift work, and noise).

Cancer mortality in workers exposed to organochlorine compounds in the pulp and paper industry: an international collaborative study.

The objective of this study was to evaluate cancer mortality in pulp and paper industry workers exposed to chlorinated organic compounds. We assembled a multinational cohort of workers employed between 1920 and 1996 in 11 countries. Exposure to both volatile and nonvolatile organochlorine compounds was estimated at the department level using an exposure matrix. We conducted a standardized mortality ratio (SMR) analysis based on age and calendar-period-specific national mortality rates and a Poisson regression analysis. The study population consisted of 60,468 workers. Workers exposed to volatile organochlorines experienced a deficit of all-cause [SMR = 0.91; 95% confidence interval (CI), 0.89-0.93] and all-cancer (SMR = 0.93; 95% CI, 0.89-0.97) mortality, with no evidence of increased risks for any cancer of a priori interest. There was a weak, but statistically significant, trend of increasing risk of all-cancer mortality with increasing weighted cumulative exposure. A similar deficit in all-cause (SMR = 0.94; 95% CI, 0.91-0.96) and all-cancer (SMR = 0.94; 95% CI, 0.89-1.00) mortality was observed in those exposed to nonvolatile organochlorines. No excess risk was observed in cancers of a priori interest, although mortality from Hodgkin disease was elevated (SMR = 1.76; 95% CI, 1.02-2.82) . In this study we found little evidence that exposure to organochlorines at the levels experienced in the pulp and paper industry is associated with an increased risk of cancer, apart from a weak but significant association between all-cancer mortality and weighted cumulative volatile organochlorine exposure.

Occupational determinants of cryptogenic polyneuropathy.

OBJECTIVES: The aim was to investigate different occupational and leisure time exposures as determinants for cryptogenic polyneuropathy. METHODS: A case-referent study was conducted in Sweden including 232 cases of cryptogenic polyneuropathy 40-79 years of age at diagnosis who were enrolled from the out-patient neurology departments of 3 hospitals. From the population register 853 referents were randomly selected. Information on occupational and leisure time exposure was obtained from a postal questionnaire. The response rate was 71% for cases and for referents. Crude odds ratios (CORs) and logistic regression odds ratios (LORs) were calculated for exposures with 5 or more exposed cases and referents taken together. The reference category was defined as individuals unexposed to any of the occupational or leisure time risk factors in the questionnaire. RESULTS: As expected, male sex and increasing age were significant determinants for cryptogenic polyneuropathy. Occupational exposures in men to Stoddard solvent, petrol exhausts, herbicides or hand and foot vibrations generated significantly increased CORs. LORs >3.50 were found in men for occupational exposure to sulphur dioxide, xylene, methyl ethyl ketone, herbicides and in women for occupational exposure to lead, nitrous oxide and insecticides. Only solvent exposure in leisure time remained significant in the regression analysis indicating that not only occupational exposures were of importance. Interactions between occupational and leisure time exposure were seen for several agents. CONCLUSIONS: Several known determinants for polyneuropathy, from animal studies and case reports, were confirmed. New determinants were also indicated, i.e. sulphur dioxide, xylene and methyl ethyl ketone.

Increased incidence of malignancies in Sweden after the Chernobyl accident--a promoting effect?

BACKGROUND: After the Chernobyl accident in 1986, as much as 5% of the released caesium-137 was deposited in Sweden due to a heavy rainfall 2 days after the event. A study of increased incidence of malignancies was initiated after the accident. METHODS: The cohort included 1,137,106 inhabitants who were 0-60 years old in 1986 and lived in 8 counties of Sweden with the highest fallout of caesium-137. With the dwelling coordinate, GIS-technique and a digital map on caesium-137, each individual was matched for the exposure. Adjustments were made for several potential confounding factors. During the follow-up 33,851 malignancies was recorded 1988-1999. RESULTS: Exposure categories were: 0-8 (reference), 9-23, 24-43, 44-66, 67-84, and > or =85 nGy/hr. The corresponding adjusted Mantel-Haenszel incidence rate ratios for total malignancies during follow-up amounted to 1.000, 0.997, 1.072, 1.114, 1.068, 1.125, respectively. The excess relative risk per 100 nGy/hr with the same adjustments and time period was 0.042 95% confidence limit 0.001;0.084. An excess for thyroid cancer or leukemia could not be ruled out. CONCLUSION: Increased incidence of total malignancies possibly related to the fallout from the Chernobyl accident is seen.

Using environmental concentrations of cadmium and lead to assess human exposure and dose.

OBJECTIVES: Using environmental concentrations and Geographic Information Systems (GIS) to model human exposure is an emerging tool in environmental epidemiology. To evaluate the usefulness of this, we investigated to what extent cadmium and lead concentrations in soil and moss could be used as potential determinants for cadmium and lead exposure for a population living near a battery plant. METHODS: Cadmium in urine and blood and lead in blood, as well as food, smoking habits, places of residence, occupations and health, were determined for 512 individuals living near a closed down battery factory in Sweden. Cadmium and lead contents in moss were available through previous assessments by the Geological Survey of Sweden. Soil samples had been collected at various distances from the factory, and analyzed for cadmium and lead contents in 1990. Kriging technique in GIS was used to create areas with different metal concentrations based on these measurements. By linking individual address coordinates to mapped concentration levels, each study subject home address received a value of cadmium and lead in moss and soil. RESULTS: We found a statistically significant association between lead in soil and lead in blood, for female subjects eating homegrown vegetables regularly. No significant association was found between cadmium in soil and cadmium in urine for either gender in the study population. No clear associations were found for either gender regarding lead and cadmium in moss and lead in blood or cadmium in urine or in blood. CONCLUSION: In general, environmental concentrations may not be useful surrogates for assessing human exposure to lead and cadmium, but concentrations of metals in soil around emitting point sources can be a complement for estimating the exposure in certain subgroups.

Mortality from lung cancer in workers exposed to sulfur dioxide in the pulp and paper industry.

Our objective in this study was to evaluate the mortality of workers exposed to sulfur dioxide in the pulp and paper industry. The cohort included 57,613 workers employed for at least 1 year in the pulp and paper industry in 12 countries. We assessed exposure to SO(2) at the level of mill and department, using industrial hygiene measurement data and information from company questionnaires; 40,704 workers were classified as exposed to SO(2). We conducted a standardized mortality ratio (SMR) analysis based on age-specific and calendar period-specific national mortality rates. We also conducted a Poisson regression analysis to determine the dose-response relations between SO(2) exposure and cancer mortality risks and to explore the effect of potential confounding factors. The SMR analysis showed a moderate deficit of all causes of death [SMR = 0.89; 95% confidence interval (CI), 0.87-0.96] among exposed workers. Lung cancer mortality was marginally increased among exposed workers (SMR = 1.08; 95% CI, 0.98-1.18). After adjustment for occupational coexposures, the lung cancer risk was increased compared with unexposed workers (rate ratio = 1.49; 95% CI, 1.14-1.96). There was a suggestion of a positive relationship between weighted cumulative SO(2) exposure and lung cancer mortality (p-value of test for linear trend = 0.009 among all exposed workers; p = 0.3 among workers with high exposure). Neither duration of exposure nor time since first exposure was associated with lung cancer mortality. Mortality from non-Hodgkin lymphoma and from leukemia was increased among workers with high SO(2) exposure; a dose-response relationship with cumulative SO(2) exposure was suggested for non-Hodgkin lymphoma. For the other causes of death, there was no evidence of increased mortality associated with exposure to SO(2). Although residual confounding may have occurred, our results suggest that occupational exposure to SO(2) in the pulp and paper industry may be associated with an increased risk of lung cancer.

Exposure to asbestos and lung and pleural cancer mortality among pulp and paper industry workers.

We studied the mortality from lung and pleural cancers in a cohort of 62,937 male workers employed for at least 1 year in the pulp and paper industry in 13 countries during 1945 to 1996. Mill departments were classified according to probability and level of exposure to asbestos on the basis of available dust measurements and mill-specific information on exposure circumstances. Thirty-six percent of workers were classified as ever exposed to asbestos. Standardized mortality ratios of lung cancer were 0.99 (95% confidence interval [CI], 0.90 to 1.08) among unexposed and 1.00 (95% CI, 0.90 to 1.11) among ever exposed workers. The number of pleural cancer deaths among unexposed workers was 10; that among exposed workers was 14, most of which occurred among maintenance workers. In internal analyses, a trend in mortality from either neoplasm was suggested for estimated cumulative exposure to asbestos, weighted for the individual probability of exposure within the department and for duration of exposure (relative risk for lung cancer for 0.78+ f/cc-years, as compared with < or = 0.01 f/cc-years: 1.44; 95% CI, 0.85 to 2.45; corresponding relative risk for pleural cancer: 2.43; 95% CI, 0.43 to 13.63). Despite a possible nondifferential misclassification of exposure and outcome, this study suggests that the carcinogenic effect of asbestos can be detected among workers employed in industries such as the pulp and paper industry, in which it is not considered to be a major hazard.