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J P Bonde

Publications and source records attributed to J P Bonde.

At least 19 recordsLinked to original sources
PubMed2006

The risk of infertility among hairdressers. Five-year follow-up of female hairdressers in a Danish national registry.

BACKGROUND: One in seven married couples is involuntarily infertile. Several chemical exposures in the work environment have been hypothesized to affect female reproduction, and some are present in products used in hairdressing and related trades. Recent Swedish findings indicate that employment in hairdressing poses a risk for female reproductive function. This study examined the possible association between work as a hairdresser and subsequent hospital contact due to female infertility. METHODS: A cohort of all women in Denmark aged 20-44 years on 1 January 1998 (baseline) and registered as economically active hairdressers, according to national registers, was formed to calculate age-standardized risk ratios (RRs) for hospital contacts due to female infertility during a 5-year follow-up period. Hairdressers were compared to a standard population, that is, all economically active women in Denmark aged 20-44 years at baseline, and to women working as shop assistants. RESULTS: Sixty-eight cases of hospital contact due to female infertility were observed among the female hairdressers. On the basis of the standard population, the expected number was 73.27, which gives an observed RR of 0.928 (95% CI: 0.72-1.18). Hairdressers and shop assistants exhibited similar rates of hospital contact due to female infertility (1.01; 95% CI: 0.77-1.29). CONCLUSION: The findings are not corroborating the hypothesis that hairdressers are at increased risk of infertility, but small risks in the entire group or high risks in small subgroups may not be detected by the study.

Adult↗
PubMed2006

Is smoking a risk factor for decreased semen quality? A cross-sectional analysis.

BACKGROUND: Previous studies suggest a deleterious effect of cigarette smoking on semen quality, but their results have not been consistent. We studied the association between current smoking and semen characteristics and hormonal levels in a large group of healthy men. METHODS: From 1987 to 2004, seven separate occupational or environmental semen quality studies were co-ordinated by our department. A total of 2562 men participated, each providing semen and blood sample and answering a questionnaire about lifestyle and factors related to health. Appropriate semen and smoking data were available for 2542 men. RESULTS: Adjusting for study, age and other covariates, we observed an inverse dose-response relation between smoking and semen volume, total sperm count and percentage motile sperm. Heavy smokers had a 19% lower sperm concentration than non-smokers. We found a positive dose-response relationship between smoking and testosterone, LH and the LH/free testosterone ratios. CONCLUSION: Current smoking in adult life moderately impairs the semen quality. It is well known that semen quality is associated to fecundity. Therefore, it would be sensible to advise men to abstain from smoking to avoid decreased fecundity.

Adult↗
PubMed2006

Wheezing, asthma, hay fever, and atopic eczema in relation to maternal occupations in pregnancy.

OBJECTIVES: To examine whether prenatal occupational exposures, especially to organic solvents, are associated with atopic diseases in childhood. METHODS: The study comprised children born in Odense or Aalborg, Denmark between 1984 and 1987. Occupational job titles were derived from questionnaires filled out by the mothers when attending midwife centres. Assessment of organic solvent exposures was based on job titles selected by occupational specialists. A follow up questionnaire to the parents provided data on medical diagnoses as well as wheezing symptoms for 7844 children aged 14-18. Multivariate logistic regression analyses were performed to estimate the cumulative risk for wheezing (early wheezing not diagnosed as asthma), asthma, hay fever, and atopic eczema during childhood by means of odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Explorative analyses by maternal job titles in pregnancy showed elevated odds ratios concerning different atopic diseases for occupational groups such as "bakers, pastry cooks, and confectionary makers", "dental assistants", "electrical and electronic assemblers", "sewers and embroiders", and "bookbinders and related workers". An excess risk ratio for hay fever (OR 2.8, CI 1.1 to 7.5) was found following maternal gestational exposure to organic solvents. Furthermore, a slightly raised odds ratio for asthma was observed in children of shift workers (OR 1.2, CI 1.0 to 1.5). CONCLUSION: The data suggest links between certain maternal occupations during pregnancy and atopic diseases, which merits further scrutiny. However, no consistent pattern was seen across the different atopic diseases.

Adolescent↗
PubMed2006

Risk of affective and stress related disorders among employees in human service professions.

OBJECTIVES: To examine the risk of affective and stress related disorders among men and women employed in human service professions. METHODS: Population based case-control study using data from national registers. Cases (n = 28 971) were identified in the Danish Psychiatric Central Research Register among all hospitalised patients and outpatients aged 18-65 who received a first time ever diagnosis of affective (ICD-10, F30-39) or stress related (ICD-10, F40-48) disorder from 1 January 1995 to 31 December 1998. Each case was assigned five never admitted referents (n = 144 855) of the same gender and age, randomly drawn from a 5% sample of the Danish population obtained from Statistics Denmark's Integrated Database for Labour Market Research. Occupation held the year before matching was classified according to the Danish version of the International Classification of Occupation. Health care, education, social work, and customer services were defined as human service professions and constituted 21% of all employed in the study. Adjusted risks (hazard ratios) relative to all other occupations were calculated for 24 human service occupations. RESULTS: The relative risk of depression in human service professions was 1.35 (95% CI 1.24 to 1.47) for women and 1.49 (95% CI 1.29 to 1.73) for men. The risk of stress was 1.18 (95% CI 1.11 to 1.26) for women and 1.49 (95% CI 1.32 to 1.67) for men. Specific professions contributed differentially to the magnitude of risk, with education and social services displaying the highest risks. No increase in risks was found in customer service occupations. Gender was a significant modifying factor with the highest risk levels in men. CONCLUSIONS: There was a consistent association between employment in human service occupations and the risk of affective and stress related disorders. Risks were highest for men working in these typically female professions. More work is needed to distinguish work hazards from effects attributable to selection mechanisms and personality characteristics.

Adult↗
PubMed2006

Relationships between sperm DNA fragmentation, sperm apoptotic markers and serum levels of CB-153 and p,p'-DDE in European and Inuit populations.

Persistent organochlorine pollutants (POPs) are suspected to interfere with hormone activity and the normal homeostasis of spermatogenesis. We investigated the relationships between sperm DNA fragmentation, apoptotic markers identified on ejaculated spermatozoa and POP levels in the blood of 652 adult males (200 Inuits from Greenland, 166 Swedish, 134 Polish and 152 Ukrainian). Serum levels of 2, 2', 4, 4', 5, 5'-hexachlorobiphenyl (CB-153), as a proxy of the total POP burden, and of 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE), as a proxy of the total DDT exposure were determined. Sperm DNA fragmentation was measured by using the TUNEL assay, whereas immunofluorescence methods were utilized for detecting pro-apoptotic (Fas) and anti-apoptotic (Bcl-xL) markers. Both TUNEL assay and apoptotic markers were statistically differed across the four populations. No correlation between neither sperm DNA fragmentation nor apoptotic sperm parameters and the large variations in POPs exposure was observed for the separate study groups. However, considering the European populations taken together, we showed that both %TUNEL positivity and Bcl-xL were related to CB-153 serum levels, whereas our study failed to demonstrate any relations between DDE and %TUNEL positivity and apoptotic sperm biomarkers (Fas and Bcl-xL) in any region or overall regions. These results suggest that CB-153 and related chemicals might alter sperm DNA integrity and Bcl-xL levels in European adult males, but not in the highly exposed Inuit men. Additional issues (genetic background, lifestyle habits and characterization of total xeno-hormonal activities) need to be investigated in order to fully assess the population variations observed.

Adult↗
PubMed2005

Exposure to PCB and p, p'-DDE in European and Inuit populations: impact on human sperm chromatin integrity.

BACKGROUND: Persistent organochlorine pollutants (POP), such as polychlorinated biphenyls (PCB) and dichlorodiphenyldichloroethylene (p, p'-DDE), are widely found in the environment and considered potential endocrine-disrupting compounds (EDC). Their impact on male fertility is still unknown. METHODS: To explore the hypothesis that POP is associated with altered sperm chromatin integrity, a cross-sectional study involving 707 adult males (193 Inuits from Greenland, 178 Swedish fishermen, 141 men from Warsaw, Poland, and 195 men from Kharkiv, Ukraine) was carried out. Serum levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), as a proxy of the total PCB burden, and of p,p'-DDE were determined. Sperm chromatin structure assay (SCSA) was used to assess sperm DNA/chromatin integrity. RESULTS: We found a strong and monotonically increasing DNA fragmentation index with increasing serum levels of CB-153 among European but not Inuit men, reaching a 60% higher average level in the highest exposure group. No significant associations were found between SCSA-derived parameters and p, p'-DDE serum concentrations. CONCLUSION: These results suggest that human dietary PCB exposure might have a negative impact on the sperm chromatin integrity of adult males but additional issues, including differences in the genetic background and lifestyle habits, still need to be elucidated.

Adolescent↗
PubMed2005

Using infertile patients in epidemiologic studies on subfecundity and embryonal loss.

Subfecundity is a frequent and serious problem that may sometimes be preventable, but we need to know more about its determinants. Different epidemiologic designs are available. The best of these use prospectively collected data from the population, but they are time consuming, expensive and often hampered by low-participation rates. Most patients undergoing infertility treatment are closely monitored for clinical reasons, making it feasible to use secondary data to study the period from conception to implantation and pregnancy. In spite that infertility patients are highly selected, there are specific exposure-effect relations that can be studied in cohorts of infertility patients. These patients offer a potentially useful setting for studying exposures that operate late in fertilization, whereas the designs may be inadequate to identify exposures that cause reduced sperm counts, anovulation and total occlusion. The clinical sampling and the treatment set limitations for what can be studied. In certain situations, infertile patients can, however, provide useful epidemiologic evidence for learning about the causes of subfecundity.

Abortion, Spontaneous↗
PubMed2005

Fecundability according to male serum inhibin B--a prospective study among first pregnancy planners.

BACKGROUND: New biological markers of male fecundity are needed for use in large-scale epidemiological studies. We studied the association between male inhibin B and fecundability. METHODS: Four hundred and thirty Danish couples without previous reproductive experience were followed from termination of contraception until pregnancy or for a maximum of six menstrual cycles. At enrolment we obtained semen samples (n = 418) and blood samples to measure reproductive hormones, including inhibin B (n = 343). RESULTS: The fecundability odds ratio for an increment of male inhibin B by 1 log pg/ml was 1.428 (95% confidence interval 1.022-1.994), adjusted for factors influencing the crude estimate. Only inhibin B values below 100 pg/ml were strongly related to fecundability. We designed a receiver operating characteristic curve based on the 29 males with serum inhibin B #100 pg/ml. The area under the curve (AUC) for inhibin B was 0.787 and the corresponding AUCs for sperm density and FSH were 0.913 and 0.800, respectively. CONCLUSION: Serum inhibin B may be a reliable marker of male fecundity for epidemiological research and may have some advantages over sperm density. Our findings do not support the replacement of sperm density by male inhibin B when obtaining sperm data is an option.

Adult↗
PubMed2005

Lower sperm counts following prenatal tobacco exposure.

BACKGROUND: Recent findings have indicated that prenatal exposure to tobacco smoke may cause lower sperm concentration in ejaculates of adult men. To extend the research on this hypothesis we investigated the dose-dependency of the association, controlling for other prenatal exposures. METHODS: From 1987 to 1996, four separate occupational semen studies were conducted at three centres in Denmark. A total of 945 men provided semen and blood samples, and information on reproductive and lifestyle factors. In 2004, we collected data on the maternal smoking habits during pregnancy from 522 mothers of the participating men. RESULTS: Adjusting for study subgroup, abstinence time and other factors, we found statistically non-significant differences in mean sperm concentrations: 65.0 x 10(6)/ml [95% confidence interval (CI) 51, 81] among sons of non-smokers; 59.1 x 10(6)/ml (95% CI 46, 75) among sons of mothers who had smoked 1-10 cigarettes/day; and 57.7 x 10(6)/ml (95% CI 40, 81) among those whose mothers had smoked >10 cigarettes/day. The former group had a higher odds ratio (OR) for oligozoospermia (sperm concentration < or =20 x 10(6)/ml) of 1.5 (95% CI 0.9, 2.8), the latter group an OR of 2.6 (95% CI 1.2, 5.8). CONCLUSION: We observed a dose-dependent association between prenatal tobacco exposure, lower sperm concentration and higher risk of oligozoospermia.

Adult↗
PubMed2005

Spontaneous abortion in IVF couples--a role of male welding exposure.

BACKGROUND: Fume from welding of stainless steel contains hexavalent chromium, which in animal studies can induce paternally mediated spontaneous abortion. Human studies have shown conflicting results. The best studies include early pregnancy experience, but these are expensive to conduct. In vitro fertilization (IVF) provides new design opportunities. Our aim was to study pregnancy survival in IVF treated women with respect to paternal welding exposure. METHODS: We mailed a questionnaire to 5879 couples from the Danish IVF register that covers all IVF treatments after 1993 (response ratio 68.2%). A subgroup of male metal workers received a second questionnaire on exposure to welding (n = 319 men, response ratio 77%). Information on outcome was collected from national health registers. Survival of the first hCG-positive pregnancy was analysed using Cox regression. RESULTS: The proportion of pregnancies terminated by spontaneous abortion before 28 gestational weeks was 18% (n = 91 pregnancies) and 25% (n = 128) in pregnancies with paternal exposure to stainless steel welding and mild steel welding, respectively. In the reference group of 2925 pregnancies the abortion ratio was 28%. The risk ratio for pregnancies with paternal exposure to stainless steel was 0.6 (95% CI 0.4-1.0). CONCLUSIONS: We found no increased risk of spontaneous abortion in IVF treated women, who became pregnant by a man exposed to welding of any sort. Since the process of fertilization and selection of IVF pregnancies differs from natural pregnancies the negative results need not apply to other pregnancies.

Abortion, Spontaneous↗
PubMed2005

Understanding work related musculoskeletal pain: does repetitive work cause stress symptoms?

BACKGROUND: Pain in the neck and upper extremity is reported with high frequency in repetitive work. Mechanical overload of soft tissues seems a plausible mechanism, but psychological factors have received considerable attention during the past decade. If psychological factors are important for development of regional pain in repetitive work, stress symptoms would likely be on the causal path. AIMS: To examine whether objective measures of repetitive monotonous work are related to occurrence and development of stress symptoms. METHODS: In 1994-95, 2033 unskilled workers with continuous repetitive work and 813 workers with varied work were enrolled. Measures of repetitiveness and force requirements were quantified using video observations to obtain individual exposure estimates. Stress symptoms were recorded at baseline and after approximately one, two, and three years by the Setterlind Stress Profile Inventory. RESULTS: Repetitive work, task cycle time, and quantified measures of repetitive upper extremity movements including force requirements were not related to occurrence of stress symptoms at baseline or development of stress symptoms during three years of follow up. CONCLUSIONS: The findings do not indicate that repetitive work is associated with stress symptoms, but small effects cannot be ruled out. Thus the results question the importance of mental stress mechanisms in the causation of regional pain related to repetitive work. However, the findings should be interpreted with caution because the stress inventory has not been validated against a gold standard.

Adult↗
PubMed2005

Task based exposure assessment in ergonomic epidemiology: a study of upper arm elevation in the jobs of machinists, car mechanics, and house painters.

AIMS: To explore the precision of task based estimates of upper arm elevation in three occupational groups, compared to direct measurements of job exposure. METHODS: Male machinists (n = 26), car mechanics (n = 23), and house painters (n = 23) were studied. Whole day recordings of upper arm elevation were obtained for four consecutive working days, and associated task information was collected in diaries. For each individual, task based estimates of job exposure were calculated by weighting task exposures from a collective database by task proportions according to the diaries. These estimates were validated against directly measured job exposures using linear regression. The performance of the task based approach was expressed through the gain in precision of occupational group mean exposures that could be obtained by adding subjects with task based estimates to a group of subjects with measured job exposures in a "validation" design. RESULTS: In all three occupations, tasks differed in mean exposure, and task proportions varied between individuals. Task based estimation proved inefficient, with squared correlation coefficients only occasionally exceeding 0.2 for the relation between task based and measured job exposures. Consequently, it was not possible to substantially improve the precision of an estimated group mean by including subjects whose job exposures were based on task information. CONCLUSIONS: Task based estimates of mechanical job exposure can be very imprecise, and only marginally better than estimates based on occupation. It is recommended that investigators in ergonomic epidemiology consider the prospects of task based exposure assessment carefully before placing resources at obtaining task information. Strategies disregarding tasks may be preferable in many cases.

Adult↗
PubMed2004

Pesticide exposure in male farmers and survival of in vitro fertilized pregnancies.

BACKGROUND: Male-mediated spontaneous abortion is well described among animals, but less well documented in humans. Studies that include early pregnancy experience are expensive to conduct, but IVF provides new opportunities. MATERIALS AND METHODS: The Danish IVF register covers all IVF treatments performed after 1993. We mailed a questionnaire to 5879 women (response rate 68.2%). A subgroup of exposed male partners received a questionnaire on specific exposure to pesticides and growth retardants (n = 128 men, response rate 81.3%). Information on outcome was collected from national health registers. Survival of the first HCG-positive pregnancy was analysed using Cox regression. RESULTS: The proportion of pregnancies terminated by spontaneous abortion before 28 gestational weeks was 19.7% (n = 66 pregnancies), 19.7% (n = 61), 21.3% (n = 47) and 22.2% (n = 18) in pregnancies with paternal exposure to herbicides, fungicides, pesticides and growth retardants. respectively. In the reference group of 2925 pregnancies, the abortion rate was 28.4%. The differences in survival were not statistically significant. CONCLUSIONS: We found no increased risk of spontaneous abortion in IVF-treated women attributable to paternal agricultural application of pesticides and growth retardants. Exposure to potentially harmful pesticides in Denmark is relatively low, and the findings are restricted to countries with similar standards of protection.

Abortion, Spontaneous↗
PubMed2004

Work related shoulder disorders: quantitative exposure-response relations with reference to arm posture.

AIMS: To determine quantitative exposure-response relations between work with highly elevated arms and supraspinatus tendinitis, shoulder pain with disability, and shoulder pain without disability. METHODS: A cross sectional study was conducted in a historical cohort of 1886 males from three occupational groups. Exposure measurements were performed for four consecutive working days in a random sample of 72 currently employed subjects. Individual work histories were obtained by questionnaire and register data. Health status was ascertained by physical examination blinded towards exposure and symptoms. Data were analysed by generalised estimating equation and multiple logistic regression with adjustment for potential confounders. RESULTS: For current upper arm elevation above 90 degrees, a duration increment of 1% of the daily working hours was associated with odds ratios of 1.23 (95% CI 1.10 to 1.39) for supraspinatus tendinitis, 1.16 (95% CI 1.08 to 1.24) for shoulder pain with disability, and 1.08 (95% CI 1.04 to 1.13) for shoulder pain without disability. The outcomes were not related to duration of employment in one of the three trades. CONCLUSIONS: Quantitative exposure-response relations were established between current work with highly elevated arms and clinically verified shoulder disorders. Substantial long term cumulative effects were not shown. A potential for primary prevention was revealed.

Adult↗
PubMed2004

Surveillance of noise exposure in the Danish workplace: a baseline survey.

AIMS: To evaluate an epidemiological approach to a national noise hazard surveillance strategy, and report current exposure levels in the Danish workplace. METHODS: A study base of 840 companies in 10 selected high risk industries in the largest county in Denmark was identified from a national register. Noise exposure was measured among manual workers recruited from a random sample of workplaces in each industry. For reference, financial companies and a sample of residents were investigated according to the same protocol. The A-weighted equivalent sound level (L(Aeq)) for a full shift was measured by portable dosimeters worn by 830 workers employed at 91 workplaces (67% of 136 eligible companies). RESULTS: The epidemiological design proved feasible and established a baseline for future noise surveillance. Substantial resources were needed to motivate workplaces to enlist and the final participation rate was less than optimal (66.9%). The L(Aeq (8)) values in the selected industries were highly elevated (mean 83.7 dB(A) (95% CI 83.3 to 84.1) in comparison with residents and office workers (mean 69.9 dB(A), 95% CI 68.8 to 71.0). Some 50% of the workers were exposed to more than 85 dB(A) and some 20% to more than 90 dB(A) in several industries. CONCLUSION: Noise levels in Danish high risk industries remain high. A substantial proportion of workers are exposed to noise levels above the current threshold limit of 85 dB(A). Ongoing surveillance of noise exposure using full shift dosimetry of workers in random samples of workplaces most at risk to high noise levels may help reinforce preventive measures. Such a programme would benefit from compulsory workplace participation.

Adult↗
PubMed2003

Risk factors in the onset of neck/shoulder pain in a prospective study of workers in industrial and service companies.

AIMS: To quantify the relative contribution of work related physical factors, psychosocial workplace factors, and individual factors and aspects of somatisation to the onset of neck/shoulder pain. METHODS: Four year prospective cohort study of workers from industrial and service companies in Denmark. Participants were 3123 workers, previously enrolled in a cross sectional study, where objective measurement of physical workplace factors was used. Eligible participants were followed on three subsequent occasions with approximately one year intervals. Outcomes of interest were: new onset of neck/shoulder pain (symptom cases); and neck/shoulder pain with pressure tenderness in the muscles of the neck/shoulder region (clinical cases). RESULTS: During follow up, 636 (14.1%) participants reported neck/shoulder pain of new onset; among these, 82 (1.7%) also had clinical signs of substantial muscle tenderness. High shoulder repetition was related to being a future symptom case, and a future clinical case. Repetition was strongly intercorrelated with other physical measures. High job demands were associated with future status as a symptom case, and as a clinical case. A high level of distress predicted subsequent neck/shoulder pain, and neck/shoulder pain with pressure tenderness. CONCLUSIONS: High levels of distress, and physical and psychosocial workplace factors are predictors of onset of pain in the neck and/or shoulders, particularly pain with pressure tenderness in the muscles.

Cohort Studies↗
PubMed2003

Prognosis of shoulder tendonitis in repetitive work: a follow up study in a cohort of Danish industrial and service workers.

BACKGROUND: The physical and psychosocial work environment is expected to modify recovery from shoulder disorders, but knowledge is limited. METHODS: In a follow up study of musculoskeletal disorders in industrial and service workers, 113 employees were identified with a history of shoulder pain combined with clinical signs of shoulder tendonitis. The workers had yearly re-examinations up to three times. Quantitative estimates of duration, repetitiveness, and forcefulness of current tasks were obtained from video recordings. Perception of job demands, decision latitude, and social support was recorded by a job content questionnaire. Recovery of shoulder tendonitis was analysed by Kaplan-Meier survival technique and by logistic regression on exposure variables and individual characteristics in models, allowing for time varying exposures. RESULTS: Some 50% of workers recovered within 10 months (95% CI 6 to 14 months). Higher age was strongly related to slow recovery, while physical job exposures were not. Perception of demands, control, and social support at the time when the shoulder disorder was diagnosed, were associated with delayed recovery, but these psychosocial factors did not predict slow recovery in incident cases identified during follow up. CONCLUSION: The median duration of shoulder tendonitis in a cross sectional sample of industrial and service workers was in the order of 10 months. This estimate is most likely biased towards too high a value. Recovery was strongly reduced in higher age. Physical workplace exposures and perceived psychosocial job characteristics during the period preceding diagnosis seem not to be important prognostic factors.

Aged↗