Vertical distribution of organochlorine pesticides in humus along Alpine altitudinal profiles in relation to ambiental parameters.

In forest soils along vertical profiles located in different parts of the Alps, concentrations of persistent organic pollutants (POPs), namely organochlorine pesticides (OCPs) like dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), heptachlor, aldrin, dieldrin and mirex, were measured. Though local characteristics of the sites are influenced by numerous factors like orographic and meteorological parameters, forest stand characteristics and humus parameters, we ascertained a marked vertical increase of concentrations of some organochlorine compounds in the soil. On the basis of climatological values of each site, we found that the contamination increase with altitude can be ascribed to a certain 'cold condensation effect'. In addition, the perennial atmospheric deposition of POPs is controlled by precipitation. Other key parameters explaining the accumulation of POPs are the soil organic carbon stocks, the turnover times, the re-volatilisation and degradation processes, which vary with altitude.

Evaluation of a rapid whole blood test to detect Helicobacter pylori infection in children.

BACKGROUND: Rapid, patient near tests for detecting antibodies against Helicobacter pylori are offered for clinical use. We evaluated the BM-Test (Boehringer Mannheim, Germany; identical to the Helisal Rapid Blood Test) in children with recurrent abdominal pain. METHODS: The BM-Test and 13C-urea breath test (UBT) were performed in 195 children (4-18 years). Symptoms were assessed using a 4-week diary. Upper endoscopy was performed in all UBT-positive children and in UBT-negative children with symptoms suggestive of organic disease. H. pylori status was considered positive if at least two of three methods (UBT, histology or rapid urease test) or culture were positive. RESULTS: After exclusion of children with previous H. pylori therapy (n = 8) and undetermined H. pylori status (n = 1), 61/186 (33%) children were H. pylori positive. The BM-Test in relation to H. pylori status revealed a sensitivity of 54%, specificity of 90%, a likelihood ratio of 5.2 for a positive, and of 0.4 for a negative test result. Accuracy of the test was independent of ethnicity, gender, age, family history for ulcer disease, frequency or severity of abdominal symptoms, epigastric tenderness, type of blood sampling (capillary versus venous) and DOB values of the UBT. In eight previously treated children, the test gave one false-positive and three false-negative results. CONCLUSIONS: Almost half of H. pylori-infected children and 10% of non-infected children were misclassified by the BM-Test. False-negative results are not related to young age or certain ethnic groups. The poor performance makes the test unsuitable for epidemiological and clinical use in children.

[Secondary data analysis within the scope of occupational medicine epidemiology]. / Sekundärdatenanalyse im Rahmen der arbeitsmedizinischen Epidemiologie.

The analysis of large administrative data sets plays an important rôle in occupational epidemiology in Germany. In this article, examples of such data sets and their use in epidemiologic investigations are presented. The validity of administrative data is discussed.

A review of epidemiological methods applied in studies on laboratory animal allergy. With a discussion of the relation between prevalence and risk of an irreversible disease in a dynamic population of constant size.

The risk of developing an occupational allergic respiratory disease depends strongly on the duration of exposure. For estimating the instantaneous risk (hazard function) in a dynamic cohort, information is required for each cohort member on the time of exposure either until disease onset or until termination by leaving the job or the end of the study. However, most existing epidemiological studies on occupational allergies are cross-sectional, computing prevalences; no information on job-leavers and on their disease status is obtained. The functional dependency of prevalence on risk, as well as on the rate of leaving the job among the diseased and on the distribution of exposure duration, is described, with special attention to the sensitivity of the prevalence to differences of the rate of leaving the job. A literature review of 15 studies on laboratory animal allergy is given; none of the studies collected and reported all the information necessary for risk estimation.