PubMed · 7532968
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C Mancini. [Radon pollution].. https://pubmed.ncbi.nlm.nih.gov/7532968/
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The degradation of methamidophos in pure bi-distilled water (with initial concentration 5 mg L(-1), pH = 7 at the beginning) was studied. For the first time, 2 ionised air water treatment pilot systems (IAPS-1, -2, no additives) were set up (Figs. 1 and 2). The degradation of methamidophos was carried out with only the IAPS-2 and with two different ultraviolet (UV) lamps: high- and low-pressure mercury lamps (HP and LP, with or without H202). The kinetics of these oxidative processes was investigated. The highest rate constant was reached by the LP, 0.2% H2O2 (k = 0.7524min(-1), t 1/2 = 0.9min), followed closely by both treatments with the HP, 0.2% H202 (k = 0.6328min(-1), t 1/2 = 1.1 min) and LP, 0% H202 (k = 0.4749min(-1), t 1/2 = 1.5 min). The lowest rate constants were achieved from the HP, 0% H202 process (k = 0.0303min(-1), t 1/2 = 22.9min) and from the IAPS-2 (k = 0.0117 min(-1), t 1/2 = 59.2min). The mineralisation of methamidophos was confirmed by the determination of the anions produced including NO3-, PO4(3-) and SO4(2-) during and at the end of each experiment. The toxicity of water samples before, during and after the experiments was tested with Daphnia test.
Recent mass spectrometric studies of species and processes relevant to the chemistry of atmospheres are reported. New species have been detected, including HO(3); a stratospheric reservoir of OH radicals; the [H(2)O(+)O(2)(-)] charge transfer complex, central to the atmospheric photonucleation theory; and the OSOSO oxide and its cation, likely present in the Io's atmosphere. As to ionic processes, a new route to tropospheric N(2)O in air ionized by lightning and coronas is reported, as well as the complex chemistry promoted by ionization of ozone/freon and ozone/carbonyl sulfide mixtures and the formation of O(5)(+), relevant to the problem of (18)O excess in stratospheric ozone.
BACKGROUND: To reduce the risk of sensitization and the elicitation of allergy symptoms, it is important to reduce the level of allergens in the home. It has previously been demonstrated that corona discharge, the process by which ionizers produce ions, can destroy the major house dust mite allergen Der p 1. OBJECTIVE: In this paper the denaturing efficacy of an experimental ionizer and two commercially available products are evaluated. METHODS: The first test was conducted in an electrically grounded chamber with samples of Der p 1 placed in various positions for 1, 2 and 3 weeks. The second test was conducted in situ in an unoccupied, furnished office room for 1 week. Der p 1 concentration was quantified by two-site monoclonal antibody enzyme-linked immunosorbent assay (ELISA). RESULTS: All ionizers in both tests caused significant reductions in allergen concentration (P < 0.05), reaching a maximum of 92% with the experimental ionizer in the chamber after 3 weeks. The percentage reductions observed in situ with the experimental and the larger commercial ionizer were similar, reaching a maximum of 32% at a distance of 4 m away from the experimental ionizer after 1 week of exposure. CONCLUSION: With a revised protocol for use, air ionizers may offer a simple, efficient and inexpensive way to reduce allergen levels in the domestic environment.