Polycyclic Aromatic Hydrocarbons in Street Dust of Bushehr City, Iran: Status, Source, and Human Health Risk Assessment

This study identified concentrations, molecular distributions, toxicities, and sources of polycylic aromatic hydrocarbons (PAHs) in street dust from different land use of Bushehr city in southwest of Iran. For this purpose, 19 street dust samples were collected from different land use of the city and analyzed using GC–MS. Σ16PAHs (16 USEPA priority PAHs) concentrations ranged between 73.6 and 9491 µg kg⁻¹, with a mean of 1116.02 µg kg⁻¹. The high-molecular-weight (HMW) PAHs (4–6 rings), that make 65.22% of the total, were the dominant in almost all dust samples. In the northern part of the city, the concentration of PAHs especially HMW is high, reflecting high traffic density. PAH sources were identified statistically. It is demonstrated that the PAHs in Bushehr street dust are mainly petrogenic derived from traffic emission. A significant positive correlation coefficient also exists between the ∑PAH concentration and toxic equivalency concentration (TEQ). Estimated incremental lifetime cancer risk (ILCR) results indicated that Bushehr residents are potentially exposed to a high cancer risk, especially via dust ingestion and dermal contact.

本研究针对伊朗西南部布什尔市不同土地利用类型街道灰尘中的多环芳烃（Polycyclic Aromatic Hydrocarbons, PAHs）的浓度、分子分布、毒性及来源开展系统分析。为此，研究人员从该市各类土地利用功能区共采集19份街道灰尘样品，并采用气相色谱-质谱联用仪（GC–MS）完成实验室分析。16项美国环境保护署（USEPA）优先管控多环芳烃的总浓度（Σ16PAHs）介于73.6~9491 µg·kg⁻¹区间，平均值为1116.02 µg·kg⁻¹。占总浓度65.22%的高分子量（High-Molecular-Weight, HMW）多环芳烃（4~6环）为绝大多数样品中的优势组分。该市北部区域的多环芳烃（尤其是高分子量多环芳烃）浓度显著偏高，这与该区域较高的交通流量特征相吻合。研究通过统计学手段解析了多环芳烃的来源，结果表明布什尔市街道灰尘中的多环芳烃主要为交通排放带来的石油成因源。总多环芳烃浓度与毒性当量浓度（Toxic Equivalency Concentration, TEQ）之间存在显著的正相关关系。增量终身癌症风险（Incremental Lifetime Cancer Risk, ILCR）估算结果显示，布什尔市居民面临较高的潜在癌症暴露风险，其中经灰尘摄入与皮肤接触的风险最为突出。