A prospective study of 337 children was carried out during a 3-month period. The purpose of the study was to evaluate the importance of indoor environmental factors in homes and day-care institutions for the incidence of middle ear effusion (MEE). The indoor environmental factors measured in institutions were carbon dioxide, temperature, and relative humidity. Conditions in the homes were assessed by a questionnaire. Middle ear effusion was measured by tympanometry. No relationship was found between indoor environmental factors and MEE, with the exception of parental smoking at home, which increased the frequency of MEE in children.
Several environmental exposures, including infection with Epstein-Barr virus, low levels of vitamin D and smoking are established risk factors for multiple sclerosis (MS). Also, high hygienic standard and infection with parasites have been proposed to influence MS risk. The aim of this study was to investigate the influence of various environmental exposures on MS risk in a Norwegian cohort, focusing on factors during childhood related to the hygiene hypothesis.
A questionnaire concerning environmental exposures, lifestyle, demographics and comorbidity was administrated to 756 Norwegian MS patients and 1090 healthy controls. Logistic regression was used to calculate odds ratio (OR) with 95% confidence interval (CI) for the risk of MS associated with the variables infectious mononucleosis, severe infection during childhood, vaccination and animals in the household during childhood. Age, gender, HLA-DRB1*15:01, smoking and infectious mononucleosis were included as covariates. General environmental exposures, including tobacco use, were also evaluated.
Infectious mononucleosis was confirmed to be significantly associated with increased MS risk, also after adjusting for the covariates (OR?=?1.79, 95% CI: 1.12-2.87, p?=?0.016). The controls more often reported growing up with a cat and/or a dog in the household, and this was significant for ownership of cat also after adjusting for the covariates (OR?=?0.56, 95% CI: 0.40-0.78, p?=?0.001). More patients than controls reported smoking and fewer patients reported snuff use.
In this Norwegian MS case-control study of environmental exposures, we replicate that infectious mononucleosis and smoking are associated with increased MS risk. Our data also indicate a protective effect on MS of exposure to cats during childhood, in accordance with the hypothesis that risk of autoimmune diseases like MS may increase with high hygienic standard.
Cites: N Engl J Med. 2000 Aug 17;343(7):481-9210944566
To investigate the influence of indoor air quality on respiratory health, a questionnaire-based study of 17,962 Canadian schoolchildren in kindergarten through grade 2 was carried out in 1988. The present report focuses on associations between several indoor environmental factors and childhood asthma. Increased reports of physician-diagnosed asthma were significantly associated (p less than 0.001) with exposure to environmental tobacco smoke (OR = 1.4), living in a damp home (OR = 1.5), the use of gas for cooking (OR = 2.0) and the use of a humidifier (OR = 1.7). Wheezing without a diagnosis of asthma also was associated (p less than 0.01) with environmental tobacco smoke (OR = 1.4, home dampness (OR = 1.6) and humidifier use (OR = 1.4), but not with gas cooking. Thus, several modifiable risk factors for respiratory illness may exist in Canadian homes. Further research is required to determine the nature of these cross-sectional observations.
In 1988, the authors conducted a questionnaire-based study on the health effects of the indoor environment in 30 Canadian communities. This paper focuses on the association between the respiratory health of young children and home dampness and molds. A total of 17,962 parents or guardians of schoolchildren received a questionnaire, and 14,948 (83.2%) questionnaires were returned. Children living in mobile homes, tents, and boats were excluded as were those with cystic fibrosis, leaving 13,495 children included in the study group. The housing stock was distributed as follows: 81% were one-family detached homes, 6% were one-family attached homes, and 13% were buildings for two or more families. Molds were reported in 32.4%, flooding in 24.1%, and moisture in 14.1% of the homes. Prevalences of all respiratory symptoms were consistently higher in homes with reported molds or dampness; i.e., adjusted odds ratios ranged from 1.32 (95% confidence interval 1.06-1.39) for bronchitis to 1.89 (95% confidence interval 1.58-2.26) for cough. The prevalence of home dampness or molds, 37.8%, indicates that it is an important public health issue. Further studies are required to elucidate the pathogenesis.
The present paper is part of a comprehensive study of dental conditions and attitudes in a Swedish county population aged 45-69 years. A questionnaire was mailed to 3000 randomly-sampled individuals. The response rate was 79.4%. Part of the questionnaire contained questions about subjective need for implant treatment. The subjects were informed of the clinical procedures as well as of the fees for implant treatment in the Swedish insurance system. The subjects wearing removable dentures were asked if, instead of their removable denture(s), they wanted dental implants if such treatment was possible. Of those wearing removable partial dentures, 23% answered "yes". The corresponding figure for subjects totally edentulous in one jaw was 17%; for subjects totally edentulous in both jaws 8%. The individuals who had reported missing teeth not replaced were asked if they wanted their missing teeth replaced by dental implants if such treatment were possible. The % answering "yes" was 21%. The subjects with all teeth remaining were hypothetically asked what kind of treatment they wanted if they would lose 1 or 2 of their teeth. The answer "dental implant" was given by 51%. Thus, subjective need for dental implants tended to decrease with poorer dental conditions. The major reason for not wanting dental implants was satisfaction with present dental conditions. Cost for treatment had some importance, while environmental and psychological factors showed only very limited influence.
Personality disorders (PDs) reduce global functioning, are associated with high levels of work disability, and are thus also likely to influence long-term sick leave (LTSL). Previous research has indicated significant genetic influence on both DSM-IV PDs and LTSL. To what degree genes contributing to PDs also influence LTSL has not been investigated. The aims of the current study were to investigate which PDs were significantly associated with LTSL, to what extent the genetic contributions to these PDs account for the heritability of LTSL, and to explore the hypothesis of a causal association between PDs and LTSL. The sample consisted of 2,771 young, adult Norwegian twins, born 1967-1979. PDs were assessed using the Structured Interview for DSM-IV Personality (SIDP-IV). The age range for the interview was 20-32. The data were subsequently linked to public records of LTSL (sick leave >16 days) up to 11 years later. The odds ratio for being in the highest LTSL category (>15% sick leave) when fulfilling the DSM-IV criteria for any PD diagnosis was 2.6 (1.8-3.8, 95% CI). Dimensional representations of schizotypal, paranoid, and borderline PD were independently and significantly associated with LTSL. The heritability of LTSL was 0.50. Genetic factors shared with the PDs accounted for 20% of this. The association between PDs and LTSL was due to shared genetic and not environmental influences, and was mainly explained by one common genetic factor. The hypothesis of a causal association was not supported, indicating that the association is explained by overlapping genetic liability between PDs and LTSL.
Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden2School of Health and Medical Sciences, Örebro University, Örebro, Sweden3Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Smoking is a risk factor for cataract development, but the effect of smoking cessation on the risk of cataract is uncertain.
To examine the association between smoking cessation and the risk of cataract extraction.
A total of 44,371 men, participating in the Cohort of Swedish Men, aged 45 to 79 years, who in 1997 completed a self-administered questionnaire on smoking habits and lifestyle factors. The men were followed up from January 1, 1998, through December 31, 2009. The cohort was matched with the Swedish National Day-Surgery Register and local registers of cataract extraction in the study area.
Incident cases of age-related cataract extraction.
During 12 years of follow-up, we identified 5713 incident cases of age-related cataract extraction. Smoking intensity and cumulative dose of smoking were associated with an increased risk of cataract extraction (P for trend
Human exposure to persistent organic pollutants (POPs) and the potential health impact in the Arctic far from the emission sources have been highlighted in numerous studies. As a supplement to human POP biomonitoring studies, a physiologically based pharmacokinetic (PBPK) model was set up to estimate the fate of POPs in Greenlandic Inuit's liver, blood, muscle and adipose tissue following long-term exposure to traditional Greenlandic diet. The PBPK model described metabolism, excretion and POP accumulation on the basis of their physicochemical properties and metabolic rates in the organisms. Basic correlations between chemically analyzed blood POP concentrations and calculated daily POP intake from food questionnaire of 118 middle age (18-35years) Greenlandic Inuits from four cities in West Greenland (Qaanaaq: n=40; Qeqertarsuaq: n=36; Nuuk: n=20; Narsaq: n=22) taken during 2003 to 2006 were analyzed. The dietary items included were polar bear, caribou, musk oxen, several marine species such as whales, seals, bird and fish as well as imported food. The contaminant concentrations of the dietary items as well as their chemical properties, uptake, biotransformation and excretion allowed us to estimate the POP concentration in liver, blood, muscle and adipose tissue following long-term exposure to the traditional Greenlandic diet using the PBPK model. Significant correlations were found between chemically analyzed POP blood concentrations and calculated daily intake of POPs for Qeqertarsuaq, Nuuk and Narsaq Inuit but not for the northernmost settlement Qaanaaq, probably because the highest blood POP level was found in this district which might mask the interview-based POP calculations. Despite the large variation in circulating blood POP concentrations, the PBPK model predicted blood concentrations of a factor 2-3 within the actual measured values. Moreover, the PBPK model showed that estimated blood POP concentration increased significantly after consumption of meals. For individuals who had a high internal burden of POPs accumulated over years, the estimated blood levels were less influenced by recent meal intake. The model results also indicated that of the POPs accumulated in the body the concentrations were highest for CB-153 (oxychlordane: 0.6%; DDE and CB-99: 2.9%; HCB: 4.4%; CB-153: 34.5%). Furthermore, the model also estimated a significant internal body POP burden even several years after the mentioned dietetic shift and that contaminant accumulation was 2-6 folds faster than the decay after a shift to a diet low in contaminants. Using the PBPK model approach, we seek to improve the knowledge on contaminant body burden in humans of the Arctic. However, it should be noted that calculations of daily POP intake may be subject to considerable uncertainty due to imprecise information from the dietary interview. Based on these results we suggest that PBPK modeling is implemented as a tool in future human health exposure and effect assessments in Greenland.
To our knowledge, no previous epidemiologic study has investigated the association between all antioxidants in the diet and age-related cataract. The total antioxidant capacity (TAC) concept aims to measure the capacity from all antioxidants in the diet by also taking synergistic effects into account.
To investigate the association between the TAC of the diet and the incidence of age-related cataract in a population-based prospective cohort of middle-aged and elderly women.
Questionnaire-based nutrition survey within the prospective Swedish Mammography Cohort study, which included 30,607 women (aged 49-83 years) who were observed for age-related cataract incidence for a mean of 7.7 years.
The TAC of the diet was estimated using a database of foods analyzed with the oxygen radical absorbance capacity assay.
Information on incident age-related cataract diagnosis and extraction was collected through linkage to registers in the study area.
There were 4309 incident cases of age-related cataracts during the mean 7.7 years of follow-up (234,371 person-years). The multivariable rate ratio in the highest quintile of the TAC of the diet compared with the lowest was 0.87 (95% CI, 0.79-0.96; P for trend =?.03). The main contributors to dietary TAC in the study population were fruit and vegetables (44.3%), whole grains (17.0%), and coffee (15.1%).
Dietary TAC was inversely associated with the risk of age-related cataract. Future studies examining all antioxidants in the diet in relation to age-related cataract are needed to confirm or refute our findings.
This paper is a report of an investigation into whether insecure work contract and shiftwork are associated with reduced wellbeing indicators, such as psychological distress, low job involvement and low work ability.
Insecure work contracts and shiftwork have repeatedly been found to contribute to the development and continuation of negative outcomes among healthcare professionals. In particular, nurses are generally considered as being at high risk of work-related stress and reduced wellbeing.
Cross-sectional survey data from the Finnish Health Care Professional Study collected in 2006 were used. The random sample of Finnish Registered Nurses comprised 2100 women and men aged 22-65 years. Information on the work contract and shiftwork were self-reported. The wellbeing indicators used were psychological distress (GHQ-12), work ability and job involvement. Psychosocial work characteristics were measured using the Job Content Questionnaire and an organizational justice scale.
Variance and linear regression analyses showed that insecure work contract was associated with lower work ability and job involvement. Shiftwork was related to psychological distress, low job involvement and low work ability. Support for a mediating role of job demands and job control and a moderating role of relational justice was obtained.
To reduce the negative effects of environmental stressors, such as insecure work contract and shiftwork, it may be better to focus on improving psychosocial work characteristics than on nurses' health-related behaviour.
To investigate the effect of exposure to damp housing on respiratory symptoms in women and men.
We examined sex differences in the relationship between damp housing and respiratory symptoms in a cross-sectional survey of 1988 adults, 18 to 74 years of age, using a self-administered questionnaire. We used chi (2) and t-tests to test associations between potential risk factors and respiratory symptoms in men and women. We used multiple logistic regression modelling to determine adjusted odds ratios for several possible symptoms and home dampness. All multivariate analyses were stratified by sex.
Men had a significantly higher prevalence of chronic wheeze compared with women. The prevalence of chronic wheeze, wheeze with shortness of breath, and allergy were higher for women reporting damp housing compared with those not reporting damp housing. No significant associations between damp housing and respiratory symptoms were found in men.
These data raise the possibility that women may be more susceptible to the effects of damp housing than men are.
Multiple chemical sensitivities (MCS) is an acquired condition in which exposure to low levels of chemicals causes symptoms in multiple organ systems. Some 12%-16% of the U.S. population has some level of chemical sensitivity, 80% of whom are women. Attempts to reduce chemical exposures leads to enormous life difficulties at home, school, and workplace. We base our article on an ethnographic study of MCS in the United States and Canada. We describe here themes related to work issues in terms of a general trajectory of becoming sick from work exposures, coping with toxic physical environments and dealing with coworkers and, when unable to continue working, applying for workers' compensation, or disability status, or both.
In the population-based Finn Twin 16 study, proportions of genetic and environmental factors contributing to muscle dissatisfaction and muscle-enhancing substance use were assessed in 319 pairs of twin brothers: 141 monozygotic (MZ) and 178 dizygotic (DZ) pairs. In addition there were 86 twin individuals from pairs in which only one co-twin responded. Of all respondents, 30% experienced high muscle dissatisfaction. The corresponding proportion of muscle-enhancing substance use was 10%. The subjects were similar in age (23.8 years, 95% confidence interval [CI] 23.76-23.84), body mass index (23.7, 95% CI 23.5-23.9), and waist circumference (84.5 cm, 95% CI 83.7-85.2), independent of their muscle dissatisfaction or muscle-enhancing substance use status and independent of their zygosity. The MZ polychoric correlation for muscle dissatisfaction was .39 (95% CI .17-.58) and .27 for DZ pairs (95% CI .07-.46). The MZ tetrachoric correlation for muscle-enhancing substance use was .65 (95% CI .28-.87) and .56 for DZ pairs (95% CI .26-.78). The AE model, where additive genetic factors (A) accounted for 42% (95% CI .23-.59) and unique environmental factors (E) 58% (95% CI .41-.77) of the liability, provided the best fit for muscle dissatisfaction. The CE model, where common environmental factors (C) accounted for 60% (95% CI .37-.77) and unique environmental factors (E) 40% (95% CI .23-.63) of the liability, provided the best fit for muscle-enhancing substance use. Both genetic and unique (nonfamilial) environmental factors are involved in muscle dissatisfaction in the population. Nongenetic factors (both familial and nonfamilial) appear to best explain the use of muscle-enhancing substances.
The aim of the study was to investigate the effects of age, sex, and body mass index (BMI) on total sitting time among the Finnish twin cohort. Also, heritability and environmental factors were analysed. The final sample included 6713 twin individuals 53-67 years of age (46% men). Among them there were 1940 complete twin pairs (732 monozygotic [MZ] and 1208 dizygotic [DZ] twin pairs). Sedentary behaviour was queried with a self-reported questionnaire with multiple-choice questions about sitting time at different domains. The mean total sitting time per day was 6 hours 41 minutes (standard deviation: 2 hours 41 minutes). The total sitting time was less in women than in men (P = 0.002). Older age was associated with less total sitting time (P
To determine the effect of lead contamination around a lead-reclamation plant on the blood lead levels of children and pregnant women living in the area.
Residents living 150 m or less (high-exposure area), 151 to 400 m (intermediate-exposure area) or 401 to 800 m (low-exposure area) southeast from the plant.
All children aged 10 years or less and all pregnant women living in the designated area.
Correlation of venous blood lead levels with soil lead concentrations in the areas in which the subjects lived and with sociodemographic and behavioural factors.
Of the estimated 57 pregnant women 38 (67%) participated: 20 were in the high-exposure area and 18 in the other two areas; their geometric mean blood lead levels were low (0.15 and 0.13 mumol/L respectively). Of the 625 eligible children 510 (82%) participated: 169 were in the high-exposure area, 179 in the intermediate-exposure area and 162 in the low-exposure area; their geometric mean lead levels were 0.43, 0.30 and 0.26 mumol/L respectively. Within each age group children in the high-exposure area had the highest levels. The mean levels for children aged 6 months to 5 years were 0.49, 0.35 and 0.28 mumol/L in the three areas respectively. Within each exposure group children aged 1 to 2 years had the highest levels. No potential confounding variables could explain the relation between blood lead level and soil lead concentration.
The pregnant women's blood lead levels did not seem to be affected by exposure level, but the children's levels were primarily related to the soil lead concentration.
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The purposes of this study were to establish baseline information about the extent of physiotherapy (PT) retention problems in Northern Ontario, and to identify potentially significant factors for retention. Potential correlates of retention were grouped into four domains: personal, professional experience, occupational and environmental factors. The questionnaire was sent to all PTs registered to practise in Northern Ontario; a response rate of 82 per cent was achieved. Multiple regression techniques were used to identify significant variables (p. less than 05) directly associated with intention to leave Northern Ontario. Path analysis was also completed to identify factors with indirect relationships to the outcome measure. The most significant factor was the perceived opportunity for career development, results have implications for health care administrators and planners in their development of strategic plans to increase employee retention.
The possible effect of genetic and environmental factors during pregnancy on the occurrence of ventricular septal defect (VSD) in the offspring was studied in 150 cases and 756 controls. The cases represented all verified VSDs in Finland during 1982-1983. The controls were randomly selected from all babies born during the same period. Case and control mothers were interviewed by midwives approximately three months after delivery using a structured questionnaire. Congenital heart disease was more prevalent among parents of cases than those of controls. Maternal alcohol consumption during the first trimester of pregnancy was more common among the mothers of VSD infants (47.0%) than among those of controls (38.0%, P less than 0.05). Exposure to organic solvents at work showed in logistic regression analysis an adjusted relative odds ratio of 1.8 (95% confidence interval 1.0-3.4). The risk of VSD was not associated with any of the maternal habits monitored, e.g. smoking, or coffee, tea, cola, acetosalicylic acid or diazepam consumption. Whether the mother was employed during the first trimester of pregnancy, and her exposure to anesthetic gases, disinfectants, pecticides, wood preservatives or video display terminals were not factors associated with the risk of ventricular septal defect.
Methods for determining personal exposure to lead and cadmium were tested in Stockholm in 1988. Lead and cadmium in breathing-zone air, 24-h duplicate diets, and feces of 15 nonsmoking women (27-46 years of age) were studied. Blood was collected at the beginning of and immediately after the test period (seven consecutive days). An extensive quality assurance program was included. Most technical problems were encountered in the 24-h collection of airborne particles. The pumps were noisy, and the batteries had to be recharged every 6-8 h. The lead and cadmium levels in feces were found to be useful indicators of the total ingested amounts of these metals. Because of the large day-to-day variation in the dietary intake of lead and cadmium, the sampling period for duplicate diets and feces should be at least 5-6 d.
The Universities of Kuopio and Tampere in collaboration with the Ministry of Social Affairs and Health and Finnish Medical Association carried out the 'Junior Physician 88' study in 1988, the purpose of which was to shed further light on the life situation and future plans of young doctors and their views concerning undergraduate and postgraduate medical education. The study concerned all the doctors registered during the years 1977-1986 in Finland (n = 5208). After randomization, a postal questionnaire was sent to one half (n = 2631) of these doctors. After the first reminder letter, 1745 questionnaires (66.3%) were returned. According to the views of the respondents undergraduate hospital teaching was adequate but the teaching of practice in health centres, school health care, team-work, health care of the elderly, home health care, rehabilitation, environmental health care and administration did not meet the professional needs of doctors. All doctors were satisfied with the hospital teaching in their undergraduate curriculum. However, only the doctors who graduated from the two modern universities in Kuopio and Tampere were satisfied with their undergraduate health centre teaching.
We investigated the possible adverse health effects to sheet-metal workers who had past exposure to asbestos. A cross-sectional medical examination of 1,330 workers was conducted during 1986 and 1987 in seven cities in the United States and Canada. A total of 1,016 workers had been employed for at least 35 y in the industry, and the mean duration from onset of asbestos exposure was 39.5 y (SD = 7.41 y). Chest x-ray abnormalities were found in more than half of the group. Pleural fibrosis, the most frequently found abnormality, was present in 47.0% of the cases and was the only abnormality found in 27.8% of cases; parenchymal interstitial fibrosis, found in 33.1% of cases, was the only abnormality found in 16.2% of cases. Radiologic abnormalities increased as duration of exposure increased. A positive smoking history was associated with a higher prevalence of radiologically detectable parenchymal abnormalities, a finding confirmed by us and others. Dyspnea on exertion was graded by a Medical Research Council questionnaire, the examinee's self-assessment, and a more detailed 12-point scale questionnaire. Few persons had marked shortness of breath, and approximately one-third had slight dyspnea. Individuals who had radiologic abnormalities experienced more shortness of breath than did those who had no radiologic abnormalities. Cigarette smoking also resulted in a higher prevalence of dyspnea. The results indicate that during the past, construction sheet-metal workers have been significantly exposed to asbestos on the job. Every effort should be made to minimize the anticipated serious health consequences, and further asbestos exposure for those who continue in this trade should be avoided.