Volatile organic compounds (VOCs) are a broad class of air pollutants which act as precursors to tropospheric ozone and secondary organic aerosols. Total UK emissions of anthropogenic VOCs peaked in 1990 at 2,840 kt yr−1 and then declined to approximately 810 kt yr−1 in 2017 with large reductions in road transport and fugitive fuel emissions. The atmospheric concentrations of many non-methane hydrocarbons (NMHC) in the UK have been observed to fall over this period in broadly similar proportions. The relative contribution to emissions from solvents and industrial processes is estimated to have increased from approximately 35% in 1990 to approximately 63% in 2017. In 1992, UK national monitoring quantified 19 of the 20 most abundant individual anthropogenic VOCs emitted (all were NMHCs), but by 2017 monitoring captured only 13 of the top 20 emitted VOCs. Ethanol is now estimated to be the most important VOC emitted by mass (in 2017 approx. 136 kt yr−1 and approx. 16.8% of total emissions) followed by n-butane (52.4 kt yr−1) and methanol (33.2 kt yr−1). Alcohols have grown in significance representing approximately 10% of emissions in 1990 rising to approximately 30% in 2017. The increased role of solvent emissions should now be reflected in European monitoring strategies to verify total VOC emission reduction obligations in the National Emissions Ceiling Directive. Adding ethanol, methanol, formaldehyde, acetone, 2-butanone and 2-propanol to the existing NMHC measurements would provide full coverage of the 20 most significant VOCs emitted on an annual mass basis. This article is part of a discussion meeting issue ‘Air quality, past present and future’.

中文翻译：

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溶剂排放的日益重要的作用以及对未来挥发性有机化合物测量的影响

挥发性有机化合物 (VOC) 是一大类空气污染物，可作为对流层臭氧和二次有机气溶胶的前体。英国人为 VOC 的总排放量在 1990 年达到峰值 2,840 kt yr-1，然后在 2017 年下降到大约 810 kt yr-1，道路运输和逃逸燃料排放量大幅减少。据观察，英国许多非甲烷碳氢化合物 (NMHC) 的大气浓度在此期间以大致相似的比例下降。溶剂和工业过程对排放的相对贡献估计已从 1990 年的约 35% 增加到 2017 年的约 63%。 1992 年，英国国家监测量化了排放的 20 种最丰富的个体人为 VOC 中的 19 种（均为 NMHC） , 但到 2017 年，监测仅捕获了前 20 种排放的 VOC 中的 13 种。现在估计乙醇是按质量排放的最重要的 VOC（2017 年约 136 kt yr-1，约占总排放量的 16.8%），其次是正丁烷（52.4 kt yr-1）和甲醇（33.2 kt yr-1） -1). 酒精在 1990 年占排放量的约 10% 的重要性增加到 2017 年的约 30%。溶剂排放增加的作用现在应该反映在欧洲监测战略中，以验证国家排放上限指令中的 VOC 总减排义务。在现有的 NMHC 测量中添加乙醇、甲醇、甲醛、丙酮、2-丁酮和 2-丙醇，将全面覆盖每年排放的 20 种最重要的 VOC。本文是讨论会问题“空气质量，