AESP_HOP · Atmospheric Behaviour and Environmental Fate of Semivolatile Pesticides; Heterogeneous Oxidation and Photochemical Degradation
6РП — Действия „Мария Кюри“
- Период
- 2006-02-01 → 2008-01-31
- Финансиране от ЕС
- 80 000 €
- Участници
- 1
- Схема
- IRG
Линиите свързват координатора с партньорите.
Накратко на български
Атмосферните взаимодействия на пестицидите метилпаратион и циперметрин се анализират чрез тяхното разграждане под влияние на озон и светлина. Това помага да се разбере как тези вещества се разпадат в природата и дали продуктите от този процес са токсични.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - AESP_HOP (Atmospheric Behavior and Environmental Fate of Semivolatile Pesticides; Heterogeneous Oxidation and Photochemical Degradation)
The present project investigates the atmospheric interactions of two commonly used pesticides (methyl parathion and cypermethrin) in order to better understand their environmental fate. For this purpose, a novel experimental apparatus combing two FTIR techniques was set, allowing simultaneous real-time monitoring of both condensed and gaseous phases. The heterogeneous oxidation of thin cypermethrin film by ozone was investigated, including determination of reaction rate constants, identification of volatile and non-volatile products and checking the effect of relative humidity and gaseous ozone levels on the reaction in order to better evaluate its mechanism. The results indicate that oxidation of sorbed cypermethrin by ozone cannot be neglected in the overall environmental fate cycle for this material and that several of the yielded products (condensed and gaseous) are toxic and may pose further environmental problems. The ozonolysis of methyl parathion was found to be very slow and insignificant relative to its other degradation processes. The photo-degradation of thin films of cypermethrin and methyl parathion under artificial UV light (254, 302, and 365 nm) and solar radiation was also investigated. As part of these studies we examined the effect of radiation wavelength, substrate type and the presence of gaseous oxygen on the photolysis quantum yield and products formation. The photochemical degradation rates of thin films of these pesticides were found to be much faster than in aqueous solutions, and indicate that photolysis is a major degradation path for both compounds. No significant difference was found in the degradation rates of methyl parathion on artificial and natural surfaces (i.e. glass, quartz, apple leaves and peach leaves). Changes in water uptake by the pesticides films following exposure to ozone or UV radiation were measured in a separate set of experiments using quartz crystal microbalance (QCM). The results suggest that such atmospheric aging cause the pesticides residue to become more hygroscopic and possibly results in increase exposure of the substrate material.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Due to growing awareness (and legislation) there is currently high interest in the atmospheric behaviour and environmental fate of trace-level semivolatile organic pollutants, such as pesticides. However, comprehensive studies on their atmospheric behaviour are limited and are hard to obtain due to the tendency of such compounds to adsorb to the walls and surfaces of experimental apparatuses. Thus, although previous studies indicated that a major portion of applied pesticides wind up in the atmosphere, this i s the medium about which we know the least regarding pesticide fate. We propose to addresses this issue by applying a powerful combination of spectroscopic techniques (ATR-FTIR and long pass IR chamber), which will enable simultaneous monitoring of the gas and condensed phases, in order to gain fundamental information on the reactivity of such semivolatile organic compounds. The proposed research will focus on the oxidation (by O3 and OH radicals) and photolysis of commonly used pesticides, in the gas phase, in the condensed phase, and adsorbed on materials that are typically found in the atmosphere (e.g., aerosols).The results from these studies (including identification and characterization of volatile and non volatile products) will significantly contribute to a more reliable risk assessments of these pesticides. To further understand the impact of pesticides in the atmosphere, we propose to investigate (using the same apparatus) the effect of pesticides adsorption on atmospheric aerosols on the physical and chemical properties of the later. This information is very important as aerosols play a major role in atmospheric chemistry, radiative balance and human health, and therefore changes in their properties are likely to affect tropospheric chemistry, climate, and their direct impact human health.
Оригинален текст от CORDIS (на английски).
Участници
- TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY · HAIFAКоординаторИзраел
Връзки
Данни: CORDIS, © Европейски съюз