Pathological Internet Use and Risk-Behaviors among European Adolescents.

Risk-behaviors are a major contributor to the leading causes of morbidity among adolescents and young people; however, their association with pathological Internet use (PIU) is relatively unexplored, particularly within the European context. The main objective of this study is to investigate the association between risk-behaviors and PIU in European adolescents. This cross-sectional study was conducted within the framework of the FP7 European Union project: Saving and Empowering Young Lives in Europe (SEYLE). Data on adolescents were collected from randomized schools within study sites across eleven European countries. PIU was measured using Young's Diagnostic Questionnaire (YDQ). Risk-behaviors were assessed using questions procured from the Global School-Based Student Health Survey (GSHS). A total of 11,931 adolescents were included in the analyses: 43.4% male and 56.6% female (M/F: 5179/6752), with a mean age of 14.89 ± 0.87 years. Adolescents reporting poor sleeping habits and risk-taking actions showed the strongest associations with PIU, followed by tobacco use, poor nutrition and physical inactivity. Among adolescents in the PIU group, 89.9% were characterized as having multiple risk-behaviors. The significant association observed between PIU and risk-behaviors, combined with a high rate of co-occurrence, underlines the importance of considering PIU when screening, treating or preventing high-risk behaviors among adolescents.

Interaction Effects of Social Isolation and Peripheral Work Position on Risk of Disability Pension: A Prospective Study of Swedish Women and Men.

PURPOSE: The study examines various combinations of levels of social isolation in private life and peripheral work position as predictors of disability pension (DP). A second aim was to test the potential interaction effects (above additivity) of social isolation and peripheral work position on the future risk of DP, and to provide results for men and women by age. METHOD: The study was based on a sample of 45567 women and men from the Swedish population who had been interviewed between 1992 and 2007. Further information on DP and diagnoses was obtained from the Swedish Social Insurance Agency's database (1993-2011). The studied predictors were related to DP using Cox's proportional hazard regression. The analyses were stratified on sex and age (20-39 years, 40-64 years), with control for selected confounders. RESULTS: Increased risks of DP were found for most combinations of social isolation and peripheral work position in all strata. The hazard ratios (HRs) for joint exposure to high degree of social isolation and a peripheral work position were particularly strong among men aged 20-39 (HR 5.70; CI 95% 3.74-8.69) and women aged 20-39 (HR 4.07; CI 2.99-5.56). An interaction effect from combined exposure was found for women in both age groups as well as a tendency in the same direction among young men. However, after confounder control the effects did not reach significance. CONCLUSIONS: Individuals who were socially isolated and in a peripheral work position had an increased risk of future DP. The fact that an interaction effect was found among women indicates that a combination of social isolation and peripheral work position may reinforce adverse health effects. There was no evidence that a peripheral work position can be compensated by a high degree of social intergration in private life.

Peripheral labour market position and risk of disability pension: a prospective population-based study.

OBJECTIVE: To investigate what impact individuals' position in a labour market core-periphery structure may have on their risk of disability pension (DP) in general and specifically on their risk of DP based on mental or musculoskeletal diagnoses. METHODS: The study comprised 45,567 individuals who had been interviewed for the annual Swedish Surveys of Living Conditions (1992-2007). The medical DP diagnoses were obtained from the Swedish Social Insurance Agency (1993-2011). The assumed predictors were studied in relation to DP by Cox's proportional hazards regression. The analyses were stratified on sex and age, controlling for social background and self-reported long-standing illness at baseline. RESULTS: All three indicators underlying the categorisation of the core-periphery structure: employment income, work hours and unemployment, increased the risk of DP in all strata. The risk of DP tended to increase gradually the more peripheral the labour market position was. The risk estimates for DP in general and for DP based on mental diagnoses were particularly high among men aged 20-39 years. CONCLUSIONS: The core-periphery position of individuals, representing their labour market attachment, was found to be a predictor of future DP. The association was most evident among individuals below 40 years of age with regard to DP based on mental diagnoses. This highlights the need for preventative measures that increase the participation of young people in working life.

Pathological Internet use among European adolescents: psychopathology and self-destructive behaviours.

Rising global rates of pathological Internet use (PIU) and related psychological impairments have gained considerable attention in recent years. In an effort to acquire evidence-based knowledge of this relationship, the main objective of this study was to investigate the association between PIU, psychopathology and self-destructive behaviours among school-based adolescents in eleven European countries. This cross-sectional study was implemented within the framework of the European Union project: Saving and Empowering Young Lives in Europe. A representative sample of 11,356 school-based adolescents (M/F: 4,856/6,500; mean age: 14.9) was included in the analyses. PIU was assessed using the Young's Diagnostic Questionnaire. Psychopathology was measured using the Beck Depression Inventory-II, Zung Self-Rating Anxiety Scale and Strengths and Difficulties Questionnaire. Self-destructive behaviours were evaluated by the Deliberate Self-Harm Inventory and Paykel Suicide Scale. Results showed that suicidal behaviours (suicidal ideation and suicide attempts), depression, anxiety, conduct problems and hyperactivity/inattention were significant and independent predictors of PIU. The correlation between PIU, conduct problems and hyperactivity/inattention was stronger among females, while the link between PIU and symptoms of depression, anxiety and peer relationship problems was stronger among males. The association between PIU, psychopathology and self-destructive behaviours was stronger in countries with a higher prevalence of PIU and suicide rates. These findings ascertain that psychopathology and suicidal behaviours are strongly related to PIU. This association is significantly influenced by gender and country suggesting socio-cultural influences. At the clinical and public health levels, targeting PIU among adolescents in the early stages could potentially lead to improvements of psychological well-being and a reduction of suicidal behaviours.

Social integration, socioeconomic conditions and type of ill health preceding disability pension in young women: a Swedish population-based study.

BACKGROUND: Disability pension has increased in recent decades and is seen as a public health and socioeconomic problem in Western Europe. In the Nordic countries, the increase has been particularly steep among young women. PURPOSE: The aim was to analyze the influence of low social integration, socioeconomic risk conditions and different measures of self-reported ill health on the risk of receiving disability pension in young women. METHOD: The study comprised all Swedish women born in 1960 to 1979, who had been interviewed in any of the annual Swedish Surveys of Living Conditions (1990-2002). The assumed predictors were related to disability pension by Cox proportional hazard regression. The mean number of years of follow-up for the 10,936 women was 7 years (SD 3.8), and the study base was restricted to the ages 16 to 43 years of age. RESULTS: An increased risk of receiving a disability pension was found among lone women, those who had sparse contacts with others, job-seeking women, homemakers, as well as women with low education, and poor private financial situations. A tenfold increase in the risk of receiving a disability pension was found among women reporting a long-standing illness and poor self-rated health, compared to women without a long-standing illness and good self-rated health. Psychiatric diagnoses and symptoms/unspecified illness were the strongest predictors of disability pension, particularly before 30 years of age. CONCLUSION: The study suggests that weak social relations and weak connections to working life contribute to increase the risk of disability pension in young women, also after control for socioeconomic conditions and self-reported ill health. Self-rated health was the strongest predictor, followed by long-standing illness and not having a job (job seekers and homemakers).

Does social isolation and low societal participation predict disability pension? A population based study.

PURPOSE: The aim was to examine the potential influence of social isolation and low societal participation on the future risk of receiving disability pension among individuals in Sweden. A specific aim was to describe differences depending on disability pension diagnoses, and how the results were modified by sex and age. METHOD: The study comprised representative samples of Swedish women and men, who had been interviewed in any of the annual Swedish Surveys of Living Conditions between 1990 and 2007. Information on disability pension and diagnoses was added from the Swedish Social Insurance Agency's database (1991-2011). The mean number of years of follow-up for the 53920 women and men was twelve years (SD 5.5), and the study base was restricted to the ages 20 to 64 years of age. The predictors were related to disability pension by Cox's proportional hazards regression. RESULTS: Social isolation and low societal participation were associated with future disability pension also after control for age, year of interview, socio demographic conditions and self reported longstanding illness. Lone individuals were at increased risk of disability pension, and the effect of living without children was modified by sex and age. An increase in risk was particularly noticeable among younger women who reported that they had sparse contacts with others, and no close friend. Both women and men who reported that they did not participate in political discussions and who could not appeal on a decision by a public authority were also at increased risk. The effects of social isolation were mainly attributed to disability pension with mental diagnoses, and to younger individuals. CONCLUSIONS: The study suggests that social isolation and low societal participation are predictors of future disability pension. Social isolation and low societal participation increased particularly the risk of future disability pension in mental diagnoses among younger individuals.

Disability pension among young women in Sweden, with special emphasis on family structure: a dynamic cohort study.

OBJECTIVES: The influence of family structure on the risk of going on disability pension (DP) was investigated among young women by analysing a short-term and long-term effect, controlling for potential confounding and the 'healthy mother effect'. DESIGN AND PARTICIPANTS: This dynamic cohort study comprised all women born in Sweden between 1960 and 1979 (1.2 million), who were 20-43 years of age during follow-up. Their annual data were retrieved from national registers for the years 1993-2003. For this period, data on family structure and potential confounders were related to the incidence of DP the year after the exposure assessment. Using a modified version of the COX proportional hazard regression, we took into account changes in the study variables of individuals over the years. In addition, a 5-year follow-up was used. RESULTS: Cohabiting working women with children showed a decreased risk of DP in a 1-year perspective compared with cohabiting working women with no children, while the opposite was indicated in the 5-year follow-up. Lone working women with children had an increased risk of DP in both the short-term and long-term perspective. The risk of DP tended to increase with the number of children for both cohabiting and lone working women in the 5-year follow-up. CONCLUSIONS: The study suggests that parenthood contributes to increasing the risk of going on DP among young women, which should be valuable knowledge to employers and other policy makers. It remains to be analysed to what extent the high numbers of young women exiting from working life may be counteracted by (1) extended gender equality, (2) fewer work hours among fathers and mothers of young children and (3) by financial support to lone women with children.

Prevalence of pathological internet use among adolescents in Europe: demographic and social factors.

AIMS: To investigate the prevalence of pathological internet use (PIU) and maladaptive internet use (MIU) among adolescents in 11 European countries in relation to demographic, social factors and internet accessibility. DESIGN: Cross-sectional survey. SETTING: The 7th Framework European Union (EU) funded project, Saving and Empowering Young Lives in Europe (SEYLE), is a randomized controlled trial (RCT) evaluating interventions for risk behaviours among adolescents in Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia and Spain, with Sweden serving as the coordinating centre. PARTICIPANTS: A total of 11 956 adolescents (female/male: 6731/5225; mean age: 14.9 ± 0.89) recruited from randomly selected schools within the 11 study sites. MEASUREMENTS: Internet users were classified by gender into three categories: adaptive, maladaptive and pathological, based on their score in the Young Diagnostic Questionnaire for Internet Addiction (YDQ). FINDINGS: The overall prevalence of PIU was 4.4%; it was higher among males than females (5.2% versus 3.8%) and differed between countries (χ(2) = 309.98; d.f. = 20; P < 0.001). PIU correlated significantly with mean hours online and male gender. The highest-ranked online activities were watching videos, frequenting chatrooms and social networking; significantly higher rates of playing single-user games were found in males and social networking in females. Living in metropolitan areas was associated with PIU. Students not living with a biological parent, low parental involvement and parental unemployment showed the highest relative risks of both MIU and PIU. CONCLUSIONS: Across a range of countries in Europe, using the Young Diagnostic Questionnaire for Internet Addiction yields a prevalence of 'pathological internet use' of 4.4% among adolescents, but varies by country and gender; adolescents lacking emotional and psychological support are at highest risk.

Exposure to parental mortality and markers of morbidity, and the risks of attempted and completed suicide in offspring: an analysis of sensitive life periods.

BACKGROUND: There is evidence of parental risk factors for suicidal behaviour in offspring, but research on variations in their effects with offspring's age at first exposure is sparse. AIMS: To explore the effects of age at exposure to parental mortality and markers of morbidity on the risks of suicide and attempted suicide in offspring. METHODS: This was a case-control study effected through record linkage between Swedish registers. Individuals born 1973-83 who committed suicide (n=1407) or were hospitalised due to an attempted suicide (n=17 159) were matched to ≤10 controls by sex, month and county of birth. ORs were measured in time windows representing age at first exposure. RESULTS: A general pattern of increasing risks of suicide and attempted suicide in offspring with decreasing age at exposure to parental risk factors emerged. Adjusted suicide risk (OR (95% CI)) was most pronounced in the youngest exposure window for parental psychiatric disability pension (3.1 (1.6 to 5.8)), somatic disability pension (1.9 (1.0 to 3.4)), psychiatric inpatient care (2.5 (2.0 to 3.1)), parental attempted suicide (2.9 (2.0 to 4.1)) and suicide (2.9 (1.7 to 5.2)). For parental non-suicidal deaths, the general pattern was the opposite. Patterns in offspring attempted suicide were similar to completed suicide for parental disability pension, psychiatric inpatient care and non-suicidal death. Attempted suicide risk after parental suicide showed an increasing trend with increasing age at exposure. CONCLUSION: Parental morbidity and parental suicidal behaviour show the most detrimental effects on completed suicide among offspring when they appear early in life. Early interventions in families at risk are necessary to prevent suicide in offspring.

Medically certified sickness absence with insurance benefits in women with and without children.

BACKGROUND: Sickness absence in Sweden is high, particularly in young women and the reasons are unclear. Many Swedish women combine parenthood and work and are facing demands that may contribute to impaired health and well-being. We compared mothers and women without children under different conditions, assuming increased sickness absence in mothers, due to time-based stress and psychological strain. METHODS: All women born in 1960-79 (1.2 million) were followed from 1993 to 2003. Information on children in the home for each year was related to medically certified sickness absence with insurance benefits the year after. We used age and time-stratified proportional hazard regression models accounting for the individual's changes on study variables over time. Data were retrieved from national administrative registers. RESULTS: Sickness absence was higher in mothers than in women without children, the relative risks decreased by age, with no effect after the age of 35 years. An effect appeared in lonely women irrespective of age, while in cohabiting women only for the ages 20-25 years. Mothers showed increased sickness absence in all subgroups of country of birth, education, income, sector of employment and place of residence. The relation between number of children and sickness absence was nonlinear, with the highest relative risks for mothers of one child. The upward trend of sickness absence at the end of 1990s was steeper for mothers compared to women without children. CONCLUSION: Despite the well-developed social security system and child care services in Sweden, parenthood predicts increased sickness absence, particularly in young and in lone women.

Personality traits and cancer risk and survival based on Finnish and Swedish registry data.

Personality traits have been studied extensively as risk and prognostic factors for cancer; however, the association remains unclear. This prospective, population-based cohort study comprised 59,548 Swedish (1974-1999) and Finnish (1976-2004) participants who completed a questionnaire eliciting information for the Eysenck Personality Inventory and on health behavior at baseline. To analyze the association of personality traits extraversion and neuroticism with risk of cancer, the authors identified 4,631 cancer cases for a maximum 30 years of follow-up. To assess the association with cancer survival among the Finnish participants, they identified 2,733 cancer cases and, later, 1,548 deaths for a maximum 29 years of follow-up. Hazard ratios were estimated by treating the personality scales as continuous variables and are presented per one increase in score on each scale. In multivariate analyses, extraversion and neuroticism were not significantly associated with risk of cancers at all sites (extraversion: hazard ratio = 0.99, 95% confidence interval: 0.98, 1.01; neuroticism: hazard ratio = 1.00, 95% confidence interval: 0.99, 1.02). Results showed no significant association between these traits and the hazard ratio for death after cancers at all sites, and they do not support the hypothesis that extraversion and neuroticism are direct risk factors for cancer or survival after cancer.

Self-reported health in mothers: the impact of age, and socioeconomic conditions.

The aim of the present analysis was to study health and well-being in mothers compared to women without children, and to analyze potential interactions with age and socioeconomic conditions. The study comprised 5,368 Swedish women born in 1960-1979 who were interviewed in any of the population-based Surveys of Living Conditions during the period 1996-2003. Having children at home was related to self-reported health symptoms and long-standing illness in multiple logistic regression models. The impact of age, cohabitation status, full-time or part-time work, and income level were analyzed. While mothers were less burdened by long-standing illness, partly due to selection mechanisms (a "healthy mother effect"), they experienced worse self-rated health and more fatigue than women without children, and the odds of poor self-rated health and fatigue increased by number of children. Conditions that strengthened the association between motherhood and impaired health were young maternal age, full-time employment, high income, and being alone. The study indicates a need for improved negotiations between parents regarding a fair share of work and family duties and extended support for lone mothers to prevent adverse health effects in women combining children and work. The results may be useful to policy-makers and employers in developing new policies.

Musculoskeletal symptoms in relation to work exposures at call centre companies in Sweden.

OBJECTIVES: Call centres (CCs) are one of the most rapidly growing types of workplaces in Sweden. The purpose of the study was to assess associations between exposures at CC work and symptoms in the Neck/shoulders and Arm/hand. Comparisons were made between internal and external CCs. An internal CC is a department or separate unit within a larger company with another main core business, while an external CC is a free-standing company. METHODS: A cross-sectional study of a selected sample of CCs was conducted. A questionnaire, covering characteristics of work and management, physical and psychosocial exposures and symptoms during the last month, was answered by 1,183 operators from 28 CCs. RESULTS: Three out of four operators reported pain or aches in one or more of the requested body regions, with no major difference between internal and external CC operators. Comfort of the work environment, showed the strongest association with symptoms in the Neck/shoulder and Arm/hand, in both types of CCs. Other exposures associated with symptoms in the Neck/shoulder or Arm/hand in either type of CC were: low complexity of work, long total time of customer calls per day, continuous computer work without a break, high psychological demands, low decision latitude, lack of social support from colleagues and supervisor. CONCLUSIONS: The study is unique in that there are no previous studies focusing on a large variety of exposures specific to CC work, based on a large number of workers from different types of CCs. The study confirms previously suggested associations between unfavourable work characteristics and management, a poor physical and psychosocial environment, and musculoskeletal symptoms in computer-telephone interactive tasks. The nature of calls during work were related to symptoms of persons working in internal CCs, whereas the time spent seated and continuous computer work were related to symptoms of those in external CCs.

Occupational exposure to ionizing radiation and electromagnetic fields in relation to the risk of thyroid cancer in Sweden.

OBJECTIVES: This study sought to ascertain the risk of thyroid cancer in relation to occupational exposure to ionizing radiation and extremely low-frequency magnetic fields (ELFMF) in a cohort representative of Sweden's gainfully employed population. METHODS: A historical cohort of 2 992 166 gainfully employed Swedish male and female workers was followed up from 1971 through 1989. Exposure to ELFMF and ionizing radiation was assessed using three job exposure matrices based on industrial branch or occupational codes. Relative risks (RR) for male and female workers, adjusted for age and geographic area, were computed using log-linear Poisson models. RESULTS: Occupational ELFMF exposure showed no effect on the risk of thyroid cancer in the study. However, female workers exposed to high intensities of ionizing radiation registered a marked excess risk (RR 1.85, 95% confidence interval (95% CI) 1.02-3.35]. This trend was not in evidence among the men. CONCLUSIONS: While the study confirms the etiologic role of ionizing radiation, with a higher incidence of thyroid cancer being recorded for the most-exposed female workers, our results do not support the possibility of occupational exposure to ELFMF being a risk factor for the development of thyroid cancer.

Self-estimated life situation in patients on long-term sick leave.

OBJECTIVE: To analyse the influence of long-term sick leave on patients' life situation. DESIGN AND SUBJECTS: Cross-sectional study based on 1350 individuals with a consecutive sick leave period of 12-18 months. Half were still on sick leave, half were no longer sick-listed. METHODS: A total of 862 participants answered a postal questionnaire including 24 questions on consequences of their sick leave on daily life. Results were analysed by gender, age and type of sick leave diagnosis. Associations between consequences and return to work were analysed by multiple logistic regression. RESULTS AND CONCLUSION: Negative effects of long-term sick leave were particularly related to leisure activities, sleep and psychological well-being. A reduced alcohol intake was more prevalent than increased consumption. Among individuals with psychiatric diagnoses the consequences were polarized, with few persons unaffected, while the effects were more unipolar and negative in other diagnostic groups. Women experienced positive consequences more often than men, attributed to relationships with children and partner, sleep and psychological well-being. Improved sleep was associated with return to work, particularly among older individuals. Negative consequences on life situation are far more common than positive consequences among patients on long-term sick leave. Benefits as well as adverse effects differ depending on diagnosis, age and gender.

Personality traits, health behavior, and risk for cancer: a prospective study of Swedish twin court.

BACKGROUND: The authors conducted a prospective investigation into the relation between personality traits and the risk for cancer. METHODS: The study cohort consisted of 29,595 Swedish twins from the national Swedish Twin Registry who were ages 15-48 years at time of entry. In 1973, the twins completed a questionnaire eliciting information on personality traits and health behavior. The Eysenck Personality Inventory was used to measure neuroticism and extroversion as two personality dimensions. A Cox proportional hazards model was used to estimate hazard ratios and 95% confidence intervals for extroversion and neuroticism separately as well as for their joint effect, and conditional logistic regression analyses were conducted to estimate the relation between personality traits and risks for cancer in twin pairs who were discordant for cancer. All analyses were conducted for six etiologically different groups of cancers: hormone-related organ cancers, virus-related and immune-related cancers, digestive organ cancers (excluding liver), respiratory organ cancers, cancers in other sites, and all cancer sites. RESULTS: Follow-up in the Swedish Cancer Registry for 1974-1999 revealed 1898 incidents of primary cancer. The authors found no significant association between neuroticism, extroversion, their joint effects and the risk for any cancer group. CONCLUSIONS: The current results did not support the hypothesis that certain personality traits are associated with cancer risk.

Unemployment and early cause-specific mortality: a study based on the Swedish twin registry.

OBJECTIVES: We investigated the association between unemployment and early cause-specific mortality to determine whether the relationship was modified by other risk indicators. METHODS: Female and male twins (n=20632) were followed with regard to mortality from 1973 through 1996. Questionnaire data from 1973 were used to obtain information on experience of unemployment and on social, behavioral, health, and personality characteristics. RESULTS: Unemployment was associated with an increased risk of suicide and death from undetermined causes. Low education, personality characteristics, use of sleeping pills or tranquilizers, and serious or long-lasting illness tended to strengthen the association between unemployment and early mortality. CONCLUSIONS: An increased risk of death from external causes implies a need for support for those experiencing unemployment, particularly susceptible individuals.

How do job characteristics, family situation, domestic work, and lifestyle factors relate to sickness absence? A study based on Sweden Post.

OBJECTIVE: We sought to determine how do working life and private life characteristics relate to sickness absence. METHODS: Questionnaire data for 1557 female and 1913 male employees were related to registered sickness absence by multivariate analyses. RESULTS: Apart from health problems, clear associations with sickness absence were observed for complaints attributed to heavy, arduous work, and sickness presenteeism. The use of tranquilizers, occurrence of bullying, and the existence of a high total workload from paid and unpaid work were associated with sickness absence in women. In men, the use of alcohol as sedative, anxiety of reorganization, not holding a supervisor position, adverse life events, and divorce were related with sickness absence. CONCLUSIONS: Our study identified different areas at work and outside work for women and men that could be targets for actions aiming at preventing high sickness absence.

Occupational exposure to extremely low frequency magnetic fields and mortality from cardiovascular disease.

The authors evaluated the relation between occupational exposure to extremely low frequency (ELF) magnetic fields and mortality from cardiovascular diseases. The study was based on 27,790 subjects from the Swedish Twin Registry. Exposure to ELF magnetic fields was assessed by linking occupation reported in 1967 or 1973 to a job exposure matrix. Four levels of exposure were related to cause-specific mortality through 1996, and primary and contributing causes of death were considered. The authors estimated relative risks by Cox regression, with adjustment for several cardiovascular disease risk indicators. The authors calculated the synergy index to evaluate potential interaction between exposure to ELF magnetic fields (>0.2 microT) and genetic susceptibility to acute myocardial infarction (AMI). Arrhythmia-related death, ischemic heart disease other than AMI, and atherosclerosis showed no association with ELF magnetic fields. The authors found a low-level increase in AMI risk in the highest exposure group (relative risk=1.3, 95% confidence interval: 0.9, 1.9) and suggestions of an exposure-response relation (p=0.02). A synergy index of 2.7 (95% confidence interval: 1.1, 6.6) in monozygotic twins indicated that the risk of AMI was strengthened among ELF magnetic field-exposed subjects with genetic susceptibility to the disease. The results for AMI corroborate previous findings from the United States. The unusual opportunity to include genetic susceptibility in the present analyses showed that evaluations of effect modification in vulnerable subjects are warranted in ELF magnetic field research.

Neurodegenerative diseases in welders and other workers exposed to high levels of magnetic fields.

BACKGROUND: Previous work has suggested an increase in risk of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease among workers exposed to extremely low-frequency magnetic fields (ELF-MF). We evaluated the relation between ELF-MF from occupational exposures and mortality from neurodegenerative diseases. METHODS: The study was based on a cohort of Swedish engineering industry workers, comprising 537,692 men and 180,529 women. The cohort was matched against the 3 most recent censuses and The Causes of Death Registry. Levels of ELF-MF exposure were obtained by linking occupation according to the censuses to a job exposure matrix. We used 4 levels of exposure and considered both the primary and contributing causes of death, 1985-96. RESULTS: The risk of Alzheimer's disease as primary or contributing cause of death increased with increasing exposure to ELF-MF among both men and women, with a relative risk (RR) of 4.0 and a 95% confidence interval (95% CI) of 1.4-11.7 in the highest exposure group for both sexes combined. There was a RR of 2.2 (95% CI: 1.0-4.7) for ALS in the highest exposure group with the suggestion of an exposure-response relationship. No evidence of increased risk was seen for Parkinson's disease or multiple sclerosis. CONCLUSIONS: The findings support previous observations of an increased risk of Alzheimer's disease and ALS among employees occupationally exposed to ELF-MF. Further studies based on morbidity data are warranted.