Harding-Smith Ellen, Davies Helen L, O'Leary Catherine, Winkless Ruth, Shaw Marvin, Dillon Terry, Jones Benjamin, Carslaw Nicola
Department of Environment and Geography, University of York, UK.
Wolfson Atmospheric Chemistry Laboratory, Department of Chemistry, University of York, UK.
Environ Sci Process Impacts. 2024 Sep 13. doi: 10.1039/d4em00410h.
Cooking and cleaning are common sources of indoor air pollutants, including volatile organic compounds (VOCs). The chemical fate of VOCs indoors is determined by both gas-phase and multi-phase chemistry, and can result in the formation of potentially hazardous secondary pollutants. Chemical interactions at the gas-surface boundary play an important role in indoor environments due to the characteristically high surface area to volume ratios (SAVs). This study first characterises the VOC emissions from a typical cooking and cleaning activity in a semi-realistic domestic kitchen, using real-time measurements. While cooking emitted a larger amount of VOCs overall, both cooking and cleaning were sources of chemically reactive monoterpenes (peak mixing ratios 7 ppb and 2 ppb, respectively). Chemical processing of the VOC emissions from sequential cooking and cleaning activities was then simulated in a kitchen using a detailed chemical model. Results showed that ozone (O) deposition was most effective onto plastic and soft furnishings, while wooden surfaces were the most effective at producing formaldehyde following multi-phase chemistry. Subsequent modelling of cooking and cleaning emissions using a range of measured kitchen SAVs revealed that indoor oxidant levels and the subsequent chemistry, are strongly influenced by the total and material-specific SAV of the room. O mixing ratios ranged from 1.3-7.8 ppb across 9 simulated kitchens, with higher concentrations of secondary pollutants observed at higher O concentration. Increased room volume, decreased total SAV, decreased SAVs of plastic and soft furnishings, and increased wood SAV contributed to elevated formaldehyde and total peroxyacetyl nitrates (PANs) mixing ratios, of up to 1548 ppt and 643 ppt, respectively, following cooking and cleaning. Therefore, the size and material composition of indoor environments has the potential to impact the chemical processing of VOC emissions from common occupant activities.
烹饪和清洁是室内空气污染物的常见来源，包括挥发性有机化合物（VOCs）。室内VOCs的化学归宿由气相和多相化学共同决定，并可能导致潜在有害的二次污染物形成。由于室内环境具有较高的表面积与体积比（SAVs），气-固界面的化学相互作用起着重要作用。本研究首次通过实时测量，对一个半真实家庭厨房中典型烹饪和清洁活动产生的VOC排放特征进行了表征。虽然烹饪总体上排放的VOCs量更大，但烹饪和清洁都是化学反应性单萜烯的来源（峰值混合比分别为7 ppb和2 ppb）。然后，使用详细的化学模型在厨房中模拟了连续烹饪和清洁活动产生的VOC排放的化学过程。结果表明，臭氧（O）在塑料和软质家具上的沉积最为有效，而木质表面在多相化学反应后产生甲醛的效率最高。随后，使用一系列测量的厨房SAVs对烹饪和清洁排放进行建模，结果表明室内氧化剂水平及后续化学反应受到房间的总SAV和特定材料SAV的强烈影响。在9个模拟厨房中，O的混合比范围为1.3 - 7.8 ppb，在较高的O浓度下观察到更高浓度的二次污染物。增加房间体积、降低总SAV、降低塑料和软质家具的SAV以及增加木质SAV，会导致烹饪和清洁后甲醛和总过氧乙酰硝酸酯（PANs）的混合比升高，分别高达1548 ppt和643 ppt。因此，室内环境的大小和材料组成有可能影响常见居住者活动产生的VOC排放的化学过程。
