Mortazavi Mohammad Seddiq, Sharifian Sana, Nozar Seyedeh Laili Mohebbi, Koohkan Hadi
Persian Gulf and Oman Sea Ecological Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Hormozgan, Iran.
Persian Gulf and Oman Sea Ecological Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Hormozgan, Iran.
J Trace Elem Med Biol. 2025 Feb;87:127574. doi: 10.1016/j.jtemb.2024.127574. Epub 2024 Nov 30.
Heavy metals and total petroleum hydrocarbons (TPHs) are important pollutants in the aquatic ecosystem, and their long-term resistance, bio-accumulation, and bio-magnification during the food chain may cause adverse ecological and health risks.
In here, the distribution and risk assessment of six heavy metals Cd, Pb, Ni, Cu, Zn, Cr, and TPHs were performed in the sediments of 32 regions situated in two mangroves (Tiab and Azini estuaries, Hara Mangrove forest protected area) and coral habitats (Larak and Hengam Islands) in Northeast of the Persian Gulf during 2020-2021. An atomic absorption device was used to determine the concentrations of heavy metals. Ecological risk of heavy metals is assessed through indices contamination factor (CF), contamination degree (CD), modified contamination degree (MCD), pollution load index (PLI), potential ecological risk index (PERI), and geoaccumulation index (Igeo). The spatial distribution of heavy metals was mapped through the inverse distance weighting (IDW) method in ArcMap.
The concentration of heavy metals indicated significant differences in spatial distribution. The maximum concentration of Cd 1.64 ± 0.001, Cr 18.41 ± 0.41 and Cu 40.5 ± 0.28 µg/g was observed at the regions situated in the Hara Mangrove forest protected area. Azini estuary had the maximum value of Zn 94.61 ± 30.74 and TPHs 4.47 ± 1.93 µg/g and finally, the highest value of concentration Ni 135.22 ± 1.85 µg/g and Pb 17.87 ± 2.17 g/gµ was found in Tiab estuary. The studied regions in the Tiab estuary and Hara Mangrove forest protected area were more contaminated than others and had considerable risks of Ni and Cd. Average ecological indices indicated the sediments of these areas especially Tiab, Hara Mangrove forest protected area, and Azini are moderately to considerably contaminated with Cd and Ni. Tiab was identified as the most contaminated area and all stations except Hengam Island were exposed to considerable ecological risks. Cadmium was found to be the riskiest heavy metal in the investigated region. The distribution of TPHs indicated there is no pollution of TPHs in the region. In all studied stations, the PELq (Toxicity of TPHs) and CF values showed the absence of potential risks of TPHs in sediments.
The findings indicated considerable contamination of Cd and Ni in the mangrove areas, especially Tiab, and it seems necessary to identify, manage, and control possible sources of contamination.
重金属和总石油烃（TPHs）是水生生态系统中的重要污染物，它们在食物链中的长期抗性、生物累积和生物放大作用可能会导致不利的生态和健康风险。
在此，于2020 - 2021年期间，对位于波斯湾东北部两个红树林（提亚卜和阿齐尼河口、哈拉红树林保护区）和珊瑚栖息地（拉腊克岛和亨加姆岛）的32个区域的沉积物中六种重金属镉（Cd）、铅（Pb）、镍（Ni）、铜（Cu）、锌（Zn）、铬（Cr）以及总石油烃进行了分布和风险评估。使用原子吸收装置测定重金属浓度。通过污染因子（CF）、污染程度（CD）、修正污染程度（MCD）、污染负荷指数（PLI）、潜在生态风险指数（PERI）和地累积指数（Igeo）等指标评估重金属的生态风险。在ArcMap中通过反距离加权（IDW）方法绘制重金属的空间分布图。
重金属浓度在空间分布上存在显著差异。在哈拉红树林保护区的区域观察到镉的最高浓度为1.64 ± 0.001、铬为18.41 ± 0.41以及铜为40.5 ± 0.28μg/g。阿齐尼河口锌的最大值为94.61 ± 30.74以及总石油烃为4.47 ± 1.93μg/g，最后，在提亚卜河口发现镍的最高浓度值为135.22 ± 1.85μg/g以及铅为17.87 ± 2.17μg/g。提亚卜河口和哈拉红树林保护区的研究区域比其他区域污染更严重，并且存在相当大的镍和镉风险。平均生态指数表明这些区域尤其是提亚卜、哈拉红树林保护区和阿齐尼的沉积物受到镉和镍的中度至重度污染。提亚卜被确定为污染最严重的区域，除亨加姆岛外的所有站点都面临相当大的生态风险。镉被发现是研究区域中风险最高的重金属。总石油烃的分布表明该区域不存在总石油烃污染。在所有研究站点，PELq（总石油烃毒性）和CF值表明沉积物中不存在总石油烃的潜在风险。
研究结果表明红树林区域尤其是提亚卜受到镉和镍的严重污染，似乎有必要识别、管理和控制可能的污染源。
