[Hearing disability in relation to audiometric threshold values: hypothesis on the determination of the onset of hearing loss]. / Disability uditiva in rapporto alla soglia audiometrica: ipotesi sulla determinazione di insorgenza dell'indebolimento del senso dell'udito.

BACKGROUND: The term auditory disability (AD) means the presence of auditory symptoms due to hearing loss. Until now the audiometric threshold cut-off between the presence or absence of AD was not clear. OBJECTIVES: In this study we attempted to define the value of audiometric threshold that could be considered as the limit between the presence or absence of weakness of auditory function, considered as the threshold as the 95th percentile of subjects that did not report AD. METHODS: The study group consisted of 1641 males, 891 normally hearing and 750 affected by noise-induced hearing loss (NIHL) Each subject was submitted to a questionnaire specifically created in order to determine the presence of AD. RESULTS: Statistical analysis confirmed the reliability of answers to items. AD was present in 577 subjects, not all affected by NIHL. Audiometric threshold and age correlated significatively with the degree of AD. CONCLUSIONS: The results obtained allowed the audiometric threshold values to be determined at the 95th percentile of subjects who did not report AD, in relation to the average of frequencies normally used in hearing loss evaluation.

The role of metals in autoimmune vasculitis: epidemiological and pathogenic study.

BACKGROUND: A possible relationship between Silica (Si) exposure and antineutrophil cytoplasm antibodies (ANCA)-associated vasculitis has been reported. Furthermore, tuberculosis (TBC) has been frequently described in patients with silicosis, and TBC infection shares with ANCA-associated vasculitis the formation of granulomas. Therefore, an intriguing network including Silica, Vasculitis, TBC and ANCA might be hypothesized. The aim of this work was to further investigate these correlations using both epidemiological and pathogenic approaches. METHODS: Study I--epidemiological study. A case-control study to compare the occupational histories of 31 cases of biopsy proven vasculitis (18 pauci-immune crescentic glomerulonephritis, 9 microscopic polyangitis, 4 Wegener's granulomatosis) with those of 58 age, sex and residence-matched controls (affected by other kidney diseases), was performed. Occupational Health physicians designed an appropriate questionnaire in order to evaluate a wide spread of exposures and calculate their entity by the product of Intensity x Frequency x Duration. Study II--tuberculosis association. A case-control study to evaluate the frequency of a previous history of tuberculosis (TBC) in 45 patients with vasculitis and 45 controls were performed. Study III--ANCA positivity. A case-control study to evaluate the presence of ANCA was performed by testing blood samples of 64 people with previous professional exposure and 65 sex/age matched patients hospitalized in a General Medicine Unit. Furthermore, the same evaluation was made in a pilot study in 16 patients with ongoing or previous TBC. Study IV--experimental study. The oxygen free radicals (OFR) and IL-12 production (both involved in the pathogenesis of vasculitis) from human phagocytic cells stimulated with an amorphous (diatomaceous earth) and a crystalline (quartz) form of Si at the doses of 10 and 100 microg ml(-1) was evaluated. RESULTS: Study I--a positive history of exposure to Si resulted in significantly more present in cases (14/31 = 45%) than in controls (14/58 = 24%, P = 0.04, OR = 2.4) and no other significant exposure association was found (including asbestos, mineral oil, formaldehyde, diesel and welding fumes, grain and wood dust, leather, solvents, fungicides, bitumen, lead and paint). Study II--past TBC infection was significantly more present in patients with vasculitis (12/45 = 26%) than in controls (4/45 = 8%, P < 0.05). Study III--ANCA was present in 2/64 exposed people (vs. 0/65 controls, P = NS) and 0/16 patients with TBC. Study IV--both amorphous and crystalline Si forms represented a stimulus for OFR and IL-12 production, but quartz resulted as a greater inductor. CONCLUSIONS: We conclude that Si exposure might be a risk factor for ANCA-associated vasculitis, possibly enhancing endothelial damage by phagocyte generation of oxygen free radicals and Th1 differentiation by an excessive IL-12 phagocyte production. Frequency of TBC was significantly higher in vasculitis patients. ANCA was not frequent in the preliminary examination of people with previous professional exposure or patients with TBC, but the number of samples evaluated is too small to allow conclusions.

Cancer risk among female agricultural workers: a multi-center case-control study.

BACKGROUND: Cancer risk among women engaged in farming has been poorly investigated. This group of female workers is of particular interest, however, since they may experience exposure to several potential agricultural hazards. METHODS: A hospital-based case-control study was conducted in five Italian rural areas to examine the association between cancer and farming among women. The areas selected were located in three different regions (i.e., Piedmont, Tuscany, and Emilia-Romagna). The following cancer sites were selected for the study: stomach, colon, rectum, lung, skin melanoma, skin non-melanoma, breast, cervix and corpus uteri, ovary, bladder, kidney. Cases of non-Hodgkin's lymphoma were also included. Altogether, 1,044 newly diagnosed cases aged 20-75 years were ascertained from hospital records from March 1990 to September 1992, and for 945 of them detailed information was collected by a standard questionnaire. The analyses of data were performed comparing each case series to a reference group drawn from among the other sites. Unconditional logistic regression models were used in the statistical analyses. RESULTS: Statistically significant increased risks in association with farming were estimated for skin melanoma (OR 2.7, 95% CI 1.2-5.8) and bladder cancer (OR 2.7, 95% CI 1.2-6.1). Lung cancer was also found increased but not at a statistically significant level (OR 1.7, 95% CI 0.7-4.4). An OR lower than unity was observed for postmenopausal breast cancer (OR 0.4, 95% CI 0.3-0.7). CONCLUSIONS: The present study suggests that women in farming might experience increased risk of cancers, not usually found in excess among male farmers, as well as a protective effect for postmenopausal breast cancer. The role of different patterns of exposure or gender specific responses should be considered in further studies.

Using reference values in pulmonary ventilation studies.

The aim of this study was to examine the discriminating power of six widely used, or recently introduced, reference values in the interpretation of pulmonary ventilation (FVC and FEV1) in occupational health surveys. These six reference values were applied to a sample of 400 Italian males; 200 of the sample were foundry workers and the other 200 were workers who were not occupationally exposed to dusts; 50% of each group were smokers. The relationship between the reference values and their capacity to discriminate between the workers occupationally exposed to dusts and the workers who smoked in each group was evaluated. The results showed very significant differences among the various reference values. Generally speaking these differences may be determined by the different selection criteria of the subjects under study, or may be a result of the different characteristics of the population included in the various studies. Our conclusions show the need for a critical approach to the use of reference values, particularly during screening tests.