A rare occupation causing mesothelioma: mechanisms and differential etiology.

BACKGROUND: In a mesothelioma lawsuit, the Public Prosecutor commissioned an expert evidence on the legal accountability for the disease, because the patient experienced multiple exposures to asbestos in both occupational and environmental settings. OBJECTIVES: To collect information on asbestos exposure from all available sources and to quantify the contribution of each source of exposure as a percentage of the total risk. METHODS: We retrieved information on jobs done and asbestos exposure from a work colleague and a database maintained by the National Institute for Insurance of Occupational Accidents/Diseases, respectively. Information on environmental exposure was searched through the scientific literature. The contribution of each source of exposure was quantified with a method of risk apportionment, taking into account time elapsed since first and last exposure, intensity and frequency of exposure and carcinogenic potency of asbestos fiber mix. RESULTS: The subject worked in the maintenance of railway electrification system. The mechanical compression stress induced on the ballast during passage of trains released chrysotile (from fragmented stones) and crocidolite (through abrasive action of crushed gravel on the underbody of rolling stocks insulated with friable crocidolite). Despite the low cumulative exposure (about 2 ff×years/cc), 99% of the mesothelioma risk was attributable to the work done because of the high content of crocidolite of inhaled asbestos. CONCLUSIONS: The report of an uncommon source of occupational asbestos exposure and a scientifically based method to allocate mesothelioma risk among multiple exposure could help to recognize mesothelioma as occupational disease in the workers employed in maintenance of the railway electrification system under the Italian National Railways.

Exposure to anesthetic gases and Parkinson's disease: a case report.

BACKGROUND: The administration of anesthetics determines depression of the central nervous system and general anesthesia by inhalation may cause an environmental pollution of the operating rooms. It may therefore conceive a possible occupational etiology of Parkinson's Disease (PD). CASE PRESENTATION: In a Caucasian male aged 59 years, PD was diagnosed by brain scans with a presynaptic radioactive tracer of the dopaminergic system. Family history was negative for Parkinson's disease or essential tremor. He was a smoker, a moderate consumer of coffee and alcohol, and never exposed to pesticides/metals. For 30 years (since the age of 29 until today), he worked as an anesthesiologist in private clinics in the Veneto (Northern Italy), exposed to anesthetic gases. The time elapsed from first exposure to onset of disease is 22 years, fulfilling the requirement of the induction/latency period. A literature search demonstrated unacceptable levels of anesthetic gases in public hospitals of the Veneto region from 1990 to 1999. This exposure was presumably high also in private hospitals of the region until at least 2007, when an overexposure to sevoflurane was repeatedly measured in this patient. The association between occupational exposure to anesthetic gases and risk of Parkinson's disease was supported by a case-control study (reporting a two-fold increase in the risk of PD associated with a clinical history of general anesthesia) and a cohort study comparing mortality from PD between US anesthesiologists and internists (showing a statistically significant excess (p=0.01) in anesthesiologists compared to internists). Numerous recent mechanistic studies (in vitro essays and in vivo short-term studies) strengthened the association between exposure to anesthetic gases (nitrous oxide, halothane, isoflurane, levoflurane) and PD. CONCLUSION: In view of the limited evidence of human studies and the sufficient evidence of experimental studies, the high exposure to anesthetic gases could have induced PD in the subject under study.

Literature search on risk factors for sarcoma: PubMed and Google Scholar may be complementary sources.

BACKGROUND: Within the context of a European network dedicated to the study of sarcoma the relevant literature on sarcoma risk factors was collected by searching PubMed and Google Scholar, the two information storage and retrieval databases which can be accessed without charge. The present study aims to appraise the relative proficiency of PubMed and Google Scholar. FINDINGS: Unlike PubMed, Google Scholar does not allow a choice between "Human" and "Animal" studies, nor between "Classical" and other types of studies. As a result, searches with Google Scholar produced high numbers of citations that have to be filtered. Google Scholar resulted in a higher sensitivity (proportion of relevant articles, meeting the search criteria), while PubMed in a higher specificity (proportion of lower quality articles not meeting the criteria, that are not retrieved). Concordance between Google Scholar and PubMed was as low as 8%. CONCLUSIONS: This study focused just on one topic. Although further studies are warranted, PM and GS appear to be complementary and their integration could greatly improve the search of references in medical research.