This study reports a spatiotemporal characterization of formaldehyde and acetaldehyde in the summer and winter of 2017 in the urban area of Shiraz, Iran. Sampling was fulfilled according to EPA Method TO-11 A. The inverse distance weighting (IDW) procedure was used for spatial mapping. Monte Carlo simulations were conducted to evaluate carcinogenic and non-cancer risk owing to formaldehyde and acetaldehyde exposure in 11 age groups. The average concentrations of formaldehyde/acetaldehyde in the summer and winter were 15.07/8.40 μg m⁻³ and 8.57/3.52 μg m⁻³, respectively. The formaldehyde to acetaldehyde ratios in the summer and winter were 1.80 and 2.43, respectively. The main sources of formaldehyde and acetaldehyde were photochemical generation, vehicular traffic, and biogenic emissions (e.g., coniferous and deciduous trees). The mean inhalation lifetime cancer risk (LTCR) values according to the Integrated Risk Information System (IRIS) for formaldehyde and acetaldehyde in summer and winter ranged between 7.55 × 10⁻⁶ and 9.25 × 10⁻⁵, which exceed the recommended value by US EPA. The average LTCR according to the Office of Environmental Health Hazard Assessment (OEHHA) for formaldehyde and acetaldehyde in summer and winter were between 4.82 × 10⁻⁶ and 2.58 × 10⁻⁴, which exceeds recommended values for five different age groups (Birth to <1, 1 to <2, 2 to <3, 3 to <6, and 6 to <11 years). Hazard quotients (HQs) of formaldehyde ranged between 0.04 and 4.18 for both seasons, while the HQs for acetaldehyde were limited between 0.42 and 0.97.

本研究报告了伊朗设拉子市区 2017 年夏季和冬季甲醛和乙醛的时空特征。根据 EPA 方法 TO-11 A 进行采样。使用反距离加权 (IDW) 程序进行空间绘图。通过蒙特卡罗模拟评估 11 个年龄组因接触甲醛和乙醛而导致的致癌和非癌症风险。夏季和冬季甲醛/乙醛平均浓度分别为15.07/8.40 μg m ^-3和8.57/3.52 μg m ^-3。夏季和冬季甲醛与乙醛的比值分别为1.80和2.43。甲醛和乙醛的主要来源是光化学产生、车辆交通和生物排放（例如针叶树和落叶树）。根据甲醛和乙醛综合风险信息系统（IRIS）显示，夏季和冬季的平均吸入终生癌症风险（LTCR）值在 7.55 × 10 -6 至 9.25 × 10 -5 之间，超出了 US ^EPA的^推荐值。根据环境健康危害评估办公室 (OEHHA) 的数据，夏季和冬季甲醛和乙醛的平均 LTCR 介于 4.82 × 10 ^-6至 2.58 × 10 ^-4之间，超出了五个不同年龄组（出生至 < 1、1 至<2、2 至<3、3 至<6 和6 至<11 岁）。两个季节甲醛的危害商 (HQ) 均在 0.04 至 4.18 之间，而乙醛的危害商 (HQ) 则限制在 0.42 至 0.97 之间。