Carbonyl compounds are critical components of volatile organic compounds, which significantly participate in the photochemical formation of atmospheric ozone and thus threaten human health. Here we measured 15 C₁–C₈ carbonyl compounds at an urban site in Linyi, a typically industrialised city in the North China Plain (NCP). Formaldehyde (3.89 ppbv), acetaldehyde (1.66 ppbv) and acetone (2.03 ppbv) were found to be the top three carbonyl compounds, accounting for 76.11% of the total concentration of carbonyl compounds. Anthropogenic secondary formation was recognised as the main source of the top five carbonyl compounds, which included formaldehyde, acetaldehyde, acetone, butyraldehyde and benzaldehyde, and accounted for 46–54% of all sources. Alkenes were the most important precursors of formaldehyde and acetaldehyde, suggesting that reducing the emission of alkenes from anthropogenic sources is an effective way to control carbonyl compound pollution in Linyi. Furthermore, the photolysis of carbonyl compounds played a significant role (68–75%) as sources of HO₂• and RO₂• and thus made a significant contribution (14.6%) to the photochemical formation of O₃. This study highlights the importance of anthropogenic secondary formation as a source of carbonyl compounds and provides a scientific basis for O₃ pollution control in carbonyl compound-enriched cities in the NCP.

羰基化合物是挥发性有机化合物的重要组成部分，其显着参与大气臭氧的光化学形成，从而威胁人类健康。在这里，我们在临沂的一个城市站点测量了 15 C ₁ –C ₈羰基化合物，临沂是华北平原 (NCP) 典型的工业化城市。发现甲醛（3.89 ppbv）、乙醛（1.66 ppbv）和丙酮（2.03 ppbv）是前三位的羰基化合物，占羰基化合物总浓度的76.11%。人为次生形成被认为是甲醛、乙醛、丙酮、丁醛和苯甲醛前五位羰基化合物的主要来源，占所有来源的46-54%。烯烃类是甲醛和乙醛最重要的前体物质，表明减少人为源烯烃排放是控制临沂羰基化合物污染的有效途径。此外，羰基化合物的光解作为 HO ₂ • 和 RO ₂ • 的来源发挥了重要作用 (68–75%)，因此对 O ₃的光化学形成做出了重要贡献 (14.6%) 。本研究强调了人为二次形成作为羰基化合物来源的重要性，为华北地区羰基化合物富集城市的O _{3污染控制提供了科学依据。}