Exploring the Toxicity of Secondary Organic Aerosol formed from Atmospheric Oxidation of Pesticides

探讨农药大气氧化形成的二次有机气溶胶的毒性

• 批准号: NE/X010198/1
• 负责人: Gordon McFiggans
• 金额: $ 10.06万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX010198%2F1
• 关键词: Exploring; Toxicity; Secondary; Organic; Aerosol

Global usage of pesticides (all agents that target pests and including insecticides, herbicides, fungicides, and bactericides) was estimated at 4.1 million tonnes of active ingredient in 2015 and is expected to increase by 25% by 2025. Pesticides mainly enter the atmosphere during the spraying application followed by gas-to-particle partitioning, volatisation from surfaces and wind drifting processes. Their atmospheric fate is largely dependent on their physicochemical properties such as their reactivity towards atmospheric oxidants, their vapour pressure dictating their partitioning to particles as well as their potentially significant photolysis rates. Over the past decade, a number of laboratory and field studies have shown that the reaction of current-use pesticides with atmospheric oxidants (such as the hydroxyl radical, OH and ozone, O3) can yield to significant amounts of secondary organic aerosol (SOA) mass. The SOA produced from the oxidation of pesticides can yield products that are potentially more persistent and/or more toxic and can additionally contribute to tropospheric O3 production. Such an increase in the toxicity of the by-products of UV treatment of certain pesticides in water samples has been shown, effected by the UV generation of OH. Similarly, SOA formation from the atmospheric oxidation of pesticides may also increase the toxicity burden. The atmospheric oxidation of organic compounds from biogenic sources have recently found to increase to toxicity burden due to the reactions with OH and O3, and it is reasonable to expect that the SOA formed from the oxidation of the pesticides could affect human and animal health.We propose to combine cutting-edge, atmospheric simulation chamber (the Manchester Aerosol Chamber, MAC), oxidation flow reactor (OFR) chemistry and cell biology approaches to explore the SOA formation and toxicity from the photo-oxidation of current-use pesticides (i.e. in the presence of OH and O3). The MAC and OFR can provide a controlled environment under atmospherically-relevant environmental conditions that can be used to simulate the atmospheric oxidation of pesticides. Pesticides will be introduced into MAC and OFR by spraying, a process similar to that used in the crops. Subsequently, the lights of the chambers will be switched on, initiating the photochemistry and oxidant production, leading to SOA formation. MAC light sources provide similar actinic flux spectrum to that of the real atmosphere, yet with lower intensity thus resulting to low SOA mass formed. OFR's extensive UV light sources can generate high concentrations of oxidants, yielding high levels of SOA mass that is necessary for the subsequent toxicological assays. State-of-the-science mass spectrometry techniques will be used to benchmark the SOA composition generated from the OFR against those from the MAC, as well as to monitor the physical and chemical properties of the generated SOA. This will further enable the research team to explore their key-properties providing information about their atmospheric lifetimes and fate. The OFR SOA will be sampled in simulated extracellular fluid (SEF) by impingment and aliquots of the samples will be used to assess their cardiac toxicity using a combination of cell lines and intact hearts approaches to evaluate key aspects of cardiac function and markers of dysfunction. Our proposed series of interdisciplinary experiments in our unique facilities will explore our capability to provide information essential to understanding the atmospheric fate, properties and toxicity of SOA generated from the current-use pesticides. Such information is essential in informing policy makers, pesticide manufacturers and users in the development of adequate guidelines and sustainable products. Involvement of project partner Ian Mudway will provide a pathway through to Government via UKHSA through his work on pesticides with the NIHR Health Protection Research Unit.

2015 年，全球农药（针对害虫的所有药剂，包括杀虫剂、除草剂、杀菌剂和杀菌剂）的使用量估计为 410 万吨活性成分，预计到 2025 年将增加 25%。农药主要在喷涂应用，然后是气体到颗粒的分配、表面挥发和风飘移过程。它们在大气中的命运很大程度上取决于它们的物理化学特性，例如它们对大气氧化剂的反应性、决定它们对颗粒的分配的蒸气压以及它们潜在的显着光解速率。在过去的十年中，许多实验室和现场研究表明，当前使用的农药与大气氧化剂（例如羟基自由基，OH和臭氧，O3）的反应会产生大量的二次有机气溶胶（SOA）大量的。农药氧化产生的 SOA 可能产生更持久和/或更具毒性的产物，并且还可能有助于对流层 O3 的产生。水样中某些农药经紫外线处理后副产物的毒性增加，是受到紫外线产生 OH 的影响。同样，农药在大气中氧化形成的 SOA 也可能增加毒性负担。最近发现，生物源有机化合物的大气氧化由于与 OH 和 O3 的反应而增加了毒性负担，并且有理由预期农药氧化形成的 SOA 可能会影响人类和动物健康。建议结合尖端的大气模拟室（曼彻斯特气溶胶室，MAC）、氧化流反应器（OFR）化学和细胞生物学方法来探索当前使用的农药（即在的存在OH 和 O3)。 MAC和OFR可以在大气相关的环境条件下提供受控环境，可用于模拟农药的大气氧化。农药将通过喷雾引入 MAC 和 OFR，这一过程与农作物中使用的过程类似。随后，室的灯将打开，启动光化学和氧化剂的产生，从而形成 SOA。 MAC 光源提供与真实大气相似的光化通量光谱，但强度较低，从而导致形成的 SOA 质量较低。 OFR 广泛的紫外线光源可以产生高浓度的氧化剂，从而产生后续毒理学测定所需的高水平 SOA 质量。最先进的质谱技术将用于对 OFR 生成的 SOA 成分与 MAC 生成的 SOA 成分进行基准测试，并监测生成的 SOA 的物理和化学特性。这将使研究团队进一步探索它们的关键特性，提供有关它们的大气寿命和命运的信息。 OFR SOA 将通过撞击在模拟细胞外液 (SEF) 中取样，样品的等分部分将用于评估其心脏毒性，使用细胞系和完整心脏方法的组合来评估心脏功能的关键方面和功能障碍标志物。我们提议在我们独特的设施中进行一系列跨学科实验，将探索我们提供重要信息的能力，以了解当前使用的农药产生的 SOA 的大气命运、特性和毒性。这些信息对于决策者、农药制造商和用户制定适当的指南和可持续产品至关重要。项目合作伙伴 Ian Mudway 的参与将通过他与 NIHR 健康保护研究单位在农药方面的工作，为通过 UKHSA 与政府接触提供一条途径。