Andreas Zober

Assessment of past occupational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin using blood lipid analyses.

SummaryCurrent 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations were determined in blood samples for 138 persons who had been involved in assessment, clean-up and demolition activities after the 1953 BASF trichlorophenol reactor accident. From these data and detailed descriptions of the circumstances and duration of individual exposure, a regression model was developed for describing the relationships between various exposure situations and TCDD concentration. The model explained 65% of the variability in log (TCDD) concentration. Using half-life assumptions and the regression model parameters we estimated cumulative TCDD concentrations back-calculated to the time of exposure for all 254 members of the accident cohort. The geometric mean cumulative TCDD concentration for all cohort members averaged 137.7 ppt. Estimated cumulative TCDD concentrations correlated well with chloracne severity. The mean TCDD concentrations were 38.4 ppt for the no chloracne subgroup (n = 139), 420.8 ppt for the moderate chloracne subgroup (n = 59) and 1008 ppt for the severe chloracne subgroup (n = 56). The estimation procedure should be helpful in assessing the relationships between various health outcomes and TCDD exposure in this cohort.

Helicobacter pylori infection: prevalence and clinical relevance in a large company.

Although gastrointestinal (GI) illnesses account for considerable sick absenteeism, there have been few workplace studies of GI disorders. We determined the prevalence of Helicobacter pylori infection by serology and assessed its relation to upper GI tract complaints, personal ulcer history, and family history of stomach cancer in 6,143 employees (mean age, 40.4 years) at BASFs main chemical production facilities in Ludwigshafen, Germany. Employees were recruited during occupational health clinic visits (n = 4,488) and through broad communications efforts (n = 1,655). Participation among clinic attendees was 66%, and this recruitment method was particularly effective in reaching shift employees. Positive immunoglobulin G (IgG) serology (38.2%), ulcers (4.9%), nonulcer dyspepsia (20.4%), and a family history of stomach cancer (6.1%) were common occurrences in this work setting. Further diagnostic evaluation and eradication therapy was recommended for 795 employees (12.9%), based on a combination of positive serology and either upper GI tract complaints or family stomach cancer history, and has been completed for 541 employees. A weak but consistent association was seen between positive serology and cigarette smoking, and shift work was found to be associated with positive serology, but not with ulcer or nonulcer dyspepsia occurrence.

Biological monitoring and risk assessment in occupational settings

Summary and conclusionIn summary, we have found biomonitoring to be a valuable adjunct to medical surveillance in a number of situations. Although the potential benefits are relatively easy to demonstrate, clear guidance must be provided to assure that no harm will result from a biomonitoring program. A critical step in this regard is attention to the communication of objectives and results. This is especially true where biomonitoring of carcinogenic substances or surrogate measures for these substances are being considered. In such situations, action levels are helpful for interpretative purposes and immediate decision-making, but not for determining individual health risks. However, the quantitative results may be suitable for use in future health studies and risk assessments.

Dyspepsie und Helicobacter-pylori-Infektion bei Beschäftigten eines großen Industrieunternehmens Ergebnisse der prospektiven BASF-Helicobacter-pylori-Vorsorgeaktion

ZusammenfassungHintergrund: Die Assoziation zwischen Helicobacter-pylori-(H.-pylori-)Infektion und Dyspepsie wird kontrovers diskutiert. Im Rahmen der BASF-H.-pylori-Vorsorgeaktion wurde u. a. die Prävalenz von Dyspepsie bei arbeitsfähigen Personen ermittelt sowie der Zusammenhang mit der H.-pylori-Infektion und der Erfolg einer Eradikationstherapie untersucht.nn Probanden und Methodik: 6 132 Beschäftigte der BASF wurden untersucht und im Rahmen einer standardisierten Anamnese u. a. zu dyspeptischen Beschwerden befragt. Diese wurden entsprechend der führenden Symptomatik den Dyspepsiesubtypen vom Ulkustyp, Dysmotilitätstyp, Refluxtyp und unspezifischen Typ zugeordnet. Bei allen Beschäftigten wurde die Seroprävalenz (IgG-ELISA) der H.-pylori-Infektion bestimmt. Allen H.-pylori-positiven Personen mit Dyspepsie wurde weitere Diagnostik in Form einer Ösophagogastroduodenoskopie und einer Sonographie des Abdomens bei Fachärzten empfohlen und eine H.-pylori-Eradikationstherapie (Italian-Triple-Therapie) angeboten. In einer Untergruppe endoskopisch untersuchter Beschäftigter mit peptischer Ulkuskrankheit (PUD, n = 37) bzw. Non-Ulcer-Dyspepsie (NUD; n = 39) wurde der prognostische Wert der im Western Blot ermittelten Antikörper gegen CagA und VacA untersucht.nn Ergebnisse: 1 255 der 6 143 Beschäftigten (20,4%) berichteten über Dyspepsie. 492 Personen mit Dyspepsie (39,2%) waren gleichzeitig H.-pylori-positiv. Bei Personen ohne dyspeptische Symptome betrug die H.-pylori-Prävalenz 35,8%. Personen mit unterschiedlichen Dyspepsiesubtypen unterschieden sich nicht hinsichtlich der H.-pylori-Prävalenz. Personen, die häufige und intensive dyspeptische Beschwerden angaben, waren allerdings signifikant häufiger H.-pylori-positiv (OR 2,09, CI 1,43–3,05). Die Seroprävalenz von CagA und VacA bei Personen mit PUD unterschied sich nicht signifikant von derjenigen bei Personen mit NUD. 458 H.-pylori-positiven Personen wurde die Eradikation empfohlen. 330 Personen (72,1%) folgten der Empfehlung. 128 (27,9%) ließen sich nicht behandeln. An der Nachkontrolle nach 12 Monaten nahmen 402 Personen (87,8%) teil, davon waren 300 behandelt, 102 nicht. Der serologisch analysierte Eradikationserfolg lag bei 81,5%. 42,8% der erfolgreich behandelten Personen berichteten über Besserung ihrer Beschwerden, 33,2% über Beschwerdefreiheit. Bei den nicht behandelten Personen war dies nur in 16,7% bzw. in 37,3% der Fall. Vermehrte Refluxbeschwerden traten nach erfolgreicher Eradikation nicht auf.nn Schlussfolgerung: Wir konnten keinen generellen Zusammenhang zwischen Dyspepsie und H.-pylori-Infektion in einem großen Kollektiv arbeitsfähiger Personen erkennen. Häufige und intensive dyspeptische Symptome scheinen allerdings ein prädikativer Faktor für die H.-pylori-Seropositivität zu sein. Die serologisch bestimmbaren Virulenzfaktoren tragen nicht zur Unterscheidung PUD oder NUD bei. Die Eradikationstherapie führte nach 1 Jahr zwar häufiger zur Besserung, aber nicht häufiger zu Beschwerdefreiheit bei Beschäftigten mit dyspeptischen Beschwerden im Vergleich zu unbehandelten Personen.AbstractBackground: The role of Helicobacter pylori (H. pylori) infection in dyspepsia is controversial. In the course of a health initiative within a large industrial corporation, we investigated the prevalence of both dyspepsia and positive H. pylori serology and the outcome of eradication therapy in symptomatic H. pylori positive employees.nn Test Persons and Methods:H. pylori serology (IgG ELISA) was determined in 6,143 employees of BASF AG Ludwigshafen/Germany who were also asked to complete a standardized health history administered by a physician. Peptic ulcer disease (PUD) and dyspepsia subgroups were defined based on past medical history and symptom profiles using the criteria of Heading. Upper GI endoscopy, abdominal ultrasound and eradication therapy (Italian Triple Therapy) was recommended for symptomatic H. pylori positive individuals. The prognostic value of antibodies against CagA and VacA was evaluated in 37 and 39 employees with PUD and non-ulcer dyspepsia (NUD) confirmed by endoscopy, respectively.nn Results: Of 6,143 employees, 1,255 (20.4%) were classified as dyspeptic, 492 (39.2%) of whom were H. pylori positive. The seroprevalence of H. pylori in asymptomatic employees was 35.8%. There were no significant differences in H. pylori seroprevalence among dyspepsia subgroups (reflux only, dysmotility only, reflux/dysmotility, ulcer-like and non-specific). However, individuals reporting severe dyspeptic symptoms were significantly more likely to be H. pylori positive (OR 2.09, CI 1.43–3.05). The seroprevalence of CagA and VacA was not significantly different among employees with NUD compared to referents or among employees with NUD compared to those with PUD. 330 (72%) of 458 employees with dyspepsia received eradication therapy, 128 persons refused therapy. Based on a 12-month follow-up of 402 individuals (300 of whom had received therapy), eradication success was 81.5% as judged by serology. Of the successfully treated employees, 33.2% reported a total absence and 42.8% reported a decrease in symptoms. Among the employees who refused therapy, the corresponding percentages were 37.3% and 16.7%, respectively. An increase in reflux complaints was not observed among treated employees.nn Conclusion: In a large active employee population, at most a very weak association was observed between the prevalence of H. pylori seropositivity and dyspepsia. Frequent and severe dyspeptic symptoms were associated with an increased rate of H. pylori seropositivity. The analysis of the virulence factors is not particularly helpful in discriminating PUD or NUD. Eradication of H. pylori infection leads to a decrease in dyspeptic symptoms after 12 months, but not more often to their complete absence compared to untreated individuals.

Pregnancy protection program in a large chemical company: design and initial survey results.

Objectives: To describe the BASF pregnancy protection program and provide initial results regarding selected pregnancy outcomes. Methods: Pregnancies (n = 1148) occurring between 1997 and 2002 were identified and outcomes were documented by questionnaires administered after the pregnancy announcement, end of pregnancy, and one year later. Potential maternal exposures were assessed via job histories, workplace inspections, and questionnaire. Results: Participation was 90% overall and was consistently high across employee subgroups. Pregnancy losses (11.5%) did not differ significantly by type of work. Among pregnancy symptoms vaginal bleeding was weakly associated with two exposure measures. Preterm births (8.7%) were in agreement with general population norms and did not vary by maternal exposure category. Conclusions: High participation rates and a structured approach to employee education and documentation of reproductive outcomes may be of value in addressing reproductive health issues in the workplace.

Pregnancy protection program in a large chemical company : Infant outcomes

Objectives: The purpose of this study was to investigate reproductive outcomes in infants relative to maternal exposures in the chemical industry. Methods: Via questionnaires administered after the pregnancy announcement, end of pregnancy, and 1 year later, infant outcomes were documented for 1147 live births. Maternal exposure factors were evaluated relative to birth height and weight, sex ratio, Apgar score at 5 minutes, and major malformations. Results: Birth height and weight, sex ratio, and Apgar score did not differ by maternal work area or chemical hazard categories. Major malformations (3.1%) and organ-specific anomalies were consistent with the experience of a regional birth defects registry. Rates of malformation were marginally higher in infants born to women assigned to chemical versus office jobs. Conclusions: Infant outcomes to date have been consistent with comparable findings from population-based studies. Longer-term observation will be needed to assess trends for low-frequency outcomes and more specific maternal exposures.

Cancer incidence in the wastewater treatment plant of a large chemical company

ObjectivesTo evaluate cancer incidence among employees assigned to BASF’s wastewater treatment plant.MethodsWe conducted a retrospective cohort study including 477 male employees who had ever worked in the facility for at least 1xa0year since the start of operations in 1974. Cancers were identified by review of occupational medical records and a standardized questionnaire completed by the participants or their next of kin. Confirmation through hospital records was sought for all reported cases after obtaining informed consent. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were computed using comparison data provided by the Saarland Cancer Registry. Further comparisons were made between three different subgroups of employees, working in maintenance, wastewater processing, and sewage sludge treatment.ResultsA total of 50 cancers were observed (SIR 1.14, CI 0.85–1.51). Colorectal (1.14, 0.42–2.48), bronchial (1.40, 0.67–2.57) and prostate (1.15, 0.42–2.50) were the most frequently observed cancers. Five cases of bladder cancer were found in the total cohort (1.75, 0.57–4.09), with four of them occurring in the sewage sludge treatment area (6.82, 1.86–17.46). Allowing for a 10-year lag did not significantly change the results.ConclusionsThe overall cancer experience among employees of the wastewater treatment plant was similar to that of the corresponding general population. The finding of an excess risk for bladder cancer in one subgroup of workers was unexpected with regard to the available literature. There is no straightforward explanation for this finding, and it may be due to chance. An extended follow-up of this cohort will take place after 5xa0years. Annual bladder cancer screening is offered to active and retired employees from this plant for the time being. The current working conditions and work practices have been re-assessed by occupational hygienists and deemed to be safe.

Illness experience before and after an initiative to identify, treat, and prevent Helicobacter pylori-related diseases in the workplace.

Objective outcome measures are needed to confirm the merits of large-scale health initiatives in the workplace. We used aggregate medical claims data to evaluate the illness experience of 5160 employees during the 2 years after versus the 2 years before an intervention intended to identify, treat, and prevent Helicobacter pylori-related illnesses. Across all participants, a 2.1-fold reduction (95% confidence interval 1.4–3.1) in ulcer-related illness episodes and a marginal 1.1-fold reduction (95% confidence interval 0.9–1.4) in episodes due to other stomach and duodenal diseases were achieved. Improvement in claims experience was most notable among 250 employees with ulcer findings on the screening examination. This H. pylori health initiative appears to have contributed to a cost-effective reduction in subsequent illness episodes due to ulcer and possibly due to other stomach and duodenal disease.