Philippe Kiss

Sperm count and chromatin structure in men exposed to inorganic lead: lowest adverse effect levels

Objectives: To obtain knowledge on male reproductive toxicity of inorganic lead at current European exposure levels and to establish lowest adverse effect levels, if any. Methods: A cross sectional survey of the semen of 503 men employed by 10 companies was conducted in the United Kingdom, Italy, and Belgium. The mean blood lead concentration was 31.0 μg/dl (range 4.6–64.5) in 362 workers exposed to lead and 4.4 μg/dl (range below the detection limit of 19.8) in 141 reference workers. Semen volume and sperm concentration were determined in a fresh semen sample according to an agreed protocol subject to quality assurance. The sperm chromatin structure assay (SCSA) was performed at a centralised laboratory. Extraneous determinants including centre, period of sexual abstinence, and age were taken into account in the statistical analysis. If appropriate, possible thresholds were examined by iterative threshold slope linear regression. Results: The median sperm concentration was reduced by 49% in men with blood lead concentration above 50 μg/dl. There was no indication of a linear trend of lower sperm concentration with increasing blood lead values, but threshold slope least square regression identified a blood lead concentration of 44 μg/dl (β=−0.037, F=4.35, p=0.038) as a likely threshold. Abnormal sperm chromatin structure was not related to blood lead concentration, but some indications of deterioration of sperm chromatin was found in men with the highest concentrations of lead within spermatozoa. Biological monitoring data did not indicate long term effects of lead on semen quantity or sperm chromatin. Conclusion: Adverse effects of lead on sperm concentration and susceptibility to acid induced denaturation of sperm chromatin are unlikely at blood lead concentrations below 45 μg/dl. Effects of low level exposure to lead on other measures of testicular function cannot be ruled out.

Male reproductive toxicity of lead in animals and humans

OBJECTIVE: To critically review the literature on male reproductive toxicity of lead in animals and humans. METHODS: A systematic literature search identified a total of 32 experimental studies in animals and 22 epidemiological studies, one case report on humans and five review articles or documents. The studies were evaluated by paying attention mainly to sample size, study design, exposure, and dose characterisation, analytical method standardisation, and quality assurance. RESULTS: Several studies on rats and other rodents indicated that blood lead concentrations > 30-40 micrograms/dl were associated with impairment of spermatogenesis and reduced concentrations of androgens. However, other animal studies, mainly about histopathological, spermatozoal, and hormonal end points, indicated that certain species and strains were quite resistant to the reproductive toxicity of lead and that different testicular lead concentrations could account for these differences. The human studies focused mainly on semen quality, endocrine function, and birth rates in occupationally exposed subjects, and showed that exposure to concentrations of inorganic lead > 40 micrograms/dl in blood impaired male reproductive function by reducing sperm count, volume, and density, or changing sperm motility and morphology. No relevant effects were detected on endocrine profile. CONCLUSION: Several factors make it difficult to extrapolate the animal data to the human situation. The difficulties are mainly due to differences between species in reproductive end points and to the level of exposure. Concentrations of blood lead > 40 micrograms/dl seemed to be associated with a decrease in sperm count, volume, motility, and morphological alterations and a possible modest effect on endocrine profile. Dose-response relation, in particular at a threshold level, is poorly understood, and site, mode, or mechanism of action are unknown. Also, the effects were not always the same or associated in the same on sperm count and concentration. Some methodological issues and indications for future studies are discussed.

Time To Pregnancy and occupational lead exposure

Background: Lead exposure is known to be harmful to the male reproductive system, including impairment of fertility. However, it is unclear whether currently existing low levels of exposure have this effect. Aims: To study retrospectively current workers in lead using industries (battery manufacture, smelting, etc), and in non-lead using control industries, in four European countries, with Time To Pregnancy as the outcome variable, as part of the EU funded Asclepios Project. Methods: Exposure assessment was mainly by blood lead values, which were available from the late 1970s, supplemented by imputed values where necessary. Three exposure models were studied: (1) short term (recent) exposure; (2) total duration of work in a lead using industry; and (3) cumulative exposure. A Cox proportional hazards model with discrete ties was used for the statistical analysis, with covariates for both partners. Results: A total of 1104 subjects took part, of whom 638 were occupationally exposed to lead at the relevant time. Blood lead levels were mainly less than 50 μg/dl. No consistent association of Time To Pregnancy with lead exposure was found in any of the exposure models, although reduced fertility was observed in one category each in models (2) and (3). Conclusions: This basically negative result is unlikely to be due to the misclassification of key variables, to insufficient statistical power, or to bias, for example, response bias. If any impairment of male reproductive function exists at the levels of occupational lead exposure now current, it does not appear to reduce biological fertility.

Needlestick Injuries in Nursing Homes: The Prominent Role of Insulin Pens

Causes and circumstances related to 162 needlestick injuries in nursing homes were analyzed. In addition to nurses, geriatrics helpers were found to be an important occupational group at risk. Insulin pens were the most frequent cause of needlestick injuries among nursing personnel. Insulin pens are a major instrument involved with unsafe needle-handling practices.

Workplace visits versus case studies in undergraduate occupational medicine teaching.

Objective: To examine the effectiveness and acceptability of two active approaches in teaching occupational medicine to undergraduate medical students. Methods: Two training formats were compared: in 2007, fourth year students were sent on a workplace visit, and the next-year group discussed real life case studies. Students’ perceptions were obtained by assessment questionnaire. Results: In both the groups, all learning objectives were equally achieved with one exception. Awareness of risk factors and preventive measures was significantly higher in the group with workplace visits. However, students rated the case scenarios as more relevant. Conclusions: Until now, many training methods have not been fully investigated. Our study demonstrates that depending on the interest, experiences, and resources of teachers, students, and universities, both worksite visits and case studies can be effectively applied in teaching occupational medicine.

Cytomegalovirus Infection: An Occupational Hazard to Kindergarten Teachers Working with Children Aged 2.5–6 Years

Abstract The aims of the study were to evaluate the occupational risk of cytomegalovirus (CMV) infection in kindergarten teachers working with children aged 2.5–6 years, and to determine occupational risk factors within the occupation of kindergarten teaching. A cross-sectional seroprevalence study was conducted in 211 kindergarten teachers and 283 administrative workers. Relevant confounding factors were considered. Overall seropositivity rates ranged from 16.4% in childless women to 33.7% in women with one child or more. Raising own children was the major risk factor for CMV seropositivity: adjusted OR 2.25. Kindergarten teaching showed to have a significantly increased CMV seropositivity rate: adjusted OR 1.54. Among kindergarten teachers, washing hands at school, number and age of the pupils, and seniority had no significant influence on seropositivity. The results indicated an increased risk of CMV infection in kindergarten teachers and an insufficiency of hygienic measures to prevent seropositivity.

1199 How do occupational health physicians in a belgian occupational health service perceive their current and future role in re-integration?

Introduction Recently a new legislation on re-integration of employees on long-term sick leave was introduced in Belgium. The purpose is to facilitate return to work of disabled employees with adapted or other work. The more prominent social importance and government demand could change the role of the occupational health physician (OHP). The question could be asked how OHP’s perceive their changing role in the re-integration process? Methods 61 OHP’s (93.8% response) working in a Belgian occupational health service participated in a survey. Five function roles were defined: ‘healthcare provider’: helping the employee (trust relationship); ‘coach’: coaching and motivating the employee; ‘service provider’: focus on employer’s situation; ‘expert’: focus on evidence based medical evaluation; ‘controller’: employees who are able to work, obligate to do so. The frequency of each role was asked for three different situations: occupational medical examination (OME), current attitude in re-integration examination (CARE), best possible attitude to assume in re-integration examination (BARE). Mean scores (0–10) were calculated per function role, a higher score was concordant with a higher frequency. Results In all 3 situations the roles of healthcare (7.3–7.7) and service provider (5.8–6.2) scored similarly. The coach role was highest in the BARE (8.2), followed by the OME (7.7) and the CARE (7.0). The expert role was predominantly in the BARE (8.2) compared to the OME (6.7) and the CARE (6.6). The score for controller increased gradually from 2.9 (OME), over 3.5 (CARE) to 4.8 (BARE). Discussion The OHP is a healthcare and service provider in all circumstances. In the BARE the most important roles were those of expert and coach, followed by healthcare and service provider. Although the role of controller had the highest score in this situation, it still remained the less important of the five roles.

153 Organisational social capital: the missing link between organisational culture and safety awareness

Introduction Occupational Health and Safety has known several waves to prevent injuries and worker’s drop out. First, mainly technical measures were implemented. In the 1990’s management systems introduced organisational measures. More recently, one became aware of the vital role of the individual (who uses the techniques according to the management system). The worker’s behaviour (safety awareness) is the missing link between technical and organisational measures. The aim was to explore the relation between organisational culture and safety awareness. Methods 17400 employees, working in 128 (private and public) organisations (79.0% participation), filled out a self-completed questionnaire. Group level analyses on company level were performed to explore the relationship between organisational social capital (OSC) and 4 safety parameters: importance of safety in the organisation, presence of clear safety rules, recognition of working practices and knowing whom to turn to. Organisations were divided according to size (<50, 50–99, 100–199, ≥200 employees). 113 organisations were grouped into 10 similar activity groups. Prevalence rates of the considered safety parameters were calculated by organisation size and activity group. Relationships between OSC and safety parameters were explored within same activity groups by correlation coefficients. Results Analyses by company size revealed similar patterns in safety parameters: companies with <50 employees scored best, followed by companies with 100–199 employees, companies with 50–99 employees and worst in companies with ≥200 employees. Safety parameters scored best in construction and industries, while information and communication companies scored worst. Depending on activity group and considered safety parameter highly significant correlations were found with OSC (R2 reaching up to 0.87). Discussion The results indicated a clear link between organisational culture and safety awareness according to company size, but regardless of activity group. The strong relationship between OSC and safety parameters indicates a predominant role of OSC within a preventative approach in safety management.

0179 Factors associated with high need for recovery in different age groups

Aim To explore associations of occupational factors with a high need for recovery (HNFR) in different age groups. Methods The need for recovery (NFR) is a short term health effect, predictive for future long term adverse mental health effects. This was a cross-sectional study in 17 400 subjects (75.7% participation rate), working in 128 organisations (both private and public). The subjects were divided into 8 age groups. NFR was assessed by the NFR scale questionnaire (0–100 scale). High need for recovery (NFR >45) was used as outcome variable. 20 work related psychosocial factors were assessed: 13 originating from the Copenhagen Psychosocial Questionnaire (COPSOQ II short version) and 7 were developed within our service. Other variables were: physical workload, gender and age (total study population). Multivariate log-binomial regression analyses were used to calculate regression coefficients for a HNFR, for the total population and for each age group separately. Results General prevalence of HNFR was 35.9%. Prevalences were significantly different between the different age groups, ranging from 23.8% to 39.1%. Physical workload, quantitative demands, work-life balance and discomfort from physical work environment had a significant association with HNFR in all age groups. Emotional demands, organisational social capital, participation in decision making, possibilities for development, growth opportunities, working more hours than desired, job insecurity, undesirable behaviour and gender were additionally significant in one or more age groups. Conclusions Four occupational factors need to be considered throughout the whole career. Additional and different factors need to be taken into account according to age group.

Age trends in the need for recovery after work

Lifting is said to be on of the major risk factors for the onset of low back pain, several different measures has been developed to study this. Several programs are available in order to measure these components, or to determine the ability of an individual to perform a certain job or to discover if the job creates dangerous positions for the worker. In these different fields reliable and valid instruments exist but they are costly and time spending. We present a simplified functional capacity measuring that we use daily in practise. Method: 280 patients have been evaluated on this base. The majority was referred to multidisciplinary rehabilitation treatment. The patients had recurrent back problems for months or years. Inclusion criteria were between 18 and 64 years, currently of work, no work compensation. Exclusion criteria were chronic low back pain with a specific cause. They followed a one-hour evaluation test as a functional capacity evaluation at the end of the multidisciplinary treatment period, it was compared to the PILE-test done at the beginning and at the end. Results: We included 280 subjects: 160 men and 120 women. Mean age 43.6 by the women and 44 years by the men. We studied the caring foot-hip, hip-shoulder, 5 m carrying, pushing and tiring and the global weight carried during the test. We found this global value to be 696 kg by men and 422 kg by women suffering from chronic lumbar pain. The increase in this value had a clear incidence on a greater work ability, as had a decrease. Conclusions: We were able to develop a lifting capacity program that is easy to reproduce and not expensive, giving us the possibility to have an idea on how to reorient the patients according to their work place and their capacities. We could also have an information of work performance and power consumption. It should be more tested and compared to standard capacity in the healthy population.