[Analysis of the natural radioactivity due to the radon gas in the underground of Rome]. / Analisi della radioattività naturale dovuta al gas radon presente negli ambienti sotterranei della metropolitana di Roma.

BACKGROUND: Radon is a decay product of 238Uranium which is classified by WHO/IARC as group 1 carcinogen, given its causal relationship with lung neoplasia. An annual concentration of this gas higher than 500 Bq/m3 in workplace is considered potentially dangerous by the italian legislation. No data are currently available on radon level in underground tunnels, which are a potentially important source of exposure both for workers and travellers. MATERIAL AND METHODS: Measurements have been performed in a station and within the trains. Two months integrated measures, and 5 days continuous (hourly) assessments have been performed. Integrated measurements have been performed by means of 12 passive dosimeters, containing a detector made of CR39 (polymeric type), whereas active scintillation-type dosimeters have been employed for continuous assessments. RESULTS: Two months integrated measures: radon level in the station was 665 +/- 71 Bq/m3, whereas values within the trains ranged between 96 and 117 Bq/m3. Continuous measurements: Mean radon level during work activities was 783 +/- 536 Bq/m3 and thereafter it rose to 850 +/- 131 Bq/m3 CONCLUSIONS: Radon nelle levels in underground tunnels may exceed attention levels, whereas within trains they remain well below these levels. Further studies focused to assess the risk of underground employers are needed.

[Determination of aromatic polycyclic hydrocarbons during the installation of bituminous acoustic insulation panels]. / Determinazione degli IPA durante la posa di pannelli fonoassorbenti bituminosi.

Two kinds of bituminous European and Asiatic origin panels, used as acoustic insulators in the production of electrical household appliances have been analysed. The tests, made at 180 degrees C, operation temperature during the assembly phases, have been executed by sampling the smokes released during the thermal treatment, subsequently analysed by GC-MS. The results showed a marked difference between the two samples in the amount of the issued compounds, essentially constituted by alkyl-aromatic hydrocarbons, IPA and Alkyl-IPA.

Interferences in the spectrophotometric S-diphenylcarbazide determination of environmental hexavalent chromium in a chromium and zinc plating plant.

A study on the determination of environmental hexavalent chromium [Cr(VI)] was carried out in a chromium and zinc plating plant. The atmospheric particulate was collected both on glass wool filters and with an electrostatic sampler; Cr(VI) was determined by the S-diphenylcarbazide method. The filtered and electrostatically collected Cr(VI) was extracted with both 1.4% sulfuric acid and 7% sodium carbonate. Strong interference was observed when extraction was carried out with the acid medium. Alkaline extraction permits 95 +/- 6 (+/- SD)% recovery of the total chromium and has been shown to be suitable in releasing Cr(VI). The analyses of the alkaline samples were carried out with the standard addition method to compensate for a depressive interference of 26 +/- 8 (+/- SD)%. The absorbance decrease of the Cr-S-diphenylcarbazide complex is a time function, and it should be measured within a few minutes of the reagent addition.