UTAD-University of Trás-os-Montes e Alto Douro, ECVA-School of Life and Environmental Sciences, CITAB-Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Quinta de Prados, Apartado 1013, 5001-801, Vila Real, Portugal.
Environ Sci Pollut Res Int. 2014 May;21(9):6057-68. doi: 10.1007/s11356-014-2537-0. Epub 2014 Jan 28.
Fish are bioindicators of water pollution, and an increased rate of their erythrocyte nuclear morphological abnormalities (ENMAs)-and particularly of erythrocyte micronuclei (EMN)-is used as a genotoxicity biomarker. Despite the potential value of ENMAs and MN, there is scarce information about fish captured in Iberian estuaries. This is the case of the Portuguese estuaries of the Mondego, Douro and Ave, suffering from different levels of environmental stress and where chemical surveys have been disclosing significant amounts of certain pollutants. So, the aim of this study was to evaluate genotoxicants impacts and infer about the exposure at those ecosystems, using the grey mullet (Mugil cephalus) as bioindicator and considering the type and frequency of nuclear abnormalities of erythrocytes as proxies of genotoxicity. Sampling of mullets was done throughout the year in the important Mondego, Douro and Ave River estuaries (centre and north-western Portugal). The fish (total n = 242) were caught in campaigns made in spring-summer and autumn-winter, using nets or fishing rods. The sampled mullets were comparable between locations in terms of the basic biometric parameters. Blood smears were stained with Diff-Quik to assess the frequencies of six types of ENMAs and MN (given per 1,000 erythrocytes). Some basic water physicochemical parameters were recorded to search for fluctuations matching the ENMAs. Overall, the most frequent nucleus abnormality was the polymorphic type, sequentially followed by the blebbed/lobed/notched, segmented, kidney shaped, vacuolated, MN and binucleated. The total average frequency of the ENMAs ranged from 73 ‰ in the Mondego to 108 ‰ in the Ave. The polymorphic type was typically ≥50 % of the total ENMAs, averaging about 51 ‰, when considering all three estuaries. The most serious lesion-the MN-in fish from Mondego and Douro had a similar frequency (≈0.38 ‰), which was significantly lower than that in the Ave (0.75 ‰). No significant seasonal differences existed as to the MN rates and seasonal differences existed almost only in the Douro, with the higher values in AW. In general, the pattern of ENMAs frequencies was unrelated with the water physicochemical parameters. Considering the data for both the total ENMAs and for each specific abnormality, and bearing in mind that values of MN in fish erythrocytes >0.3 ‰ usually reflect pollution by genotoxicants, it is suggested that mullets were likely being chronically exposed to such compounds, even in the allegedly less polluted ecosystem (Mondego). Moreover, data supported the following pollution exposure gradient: Mondego < Douro < Ave. The scenario and inferences nicely agree with the published data from chemical monitoring.
鱼类是水污染的生物指示剂，其红细胞核形态异常（ENMAs）的发生率增加，特别是红细胞微核（EMN）的发生率增加，可作为遗传毒性的生物标志物。尽管 ENMAs 和 MN 具有潜在价值，但关于伊比利亚河口捕获的鱼类的信息却很少。这就是葡萄牙蒙德古河、杜罗河和阿夫河的情况，这些河口遭受着不同程度的环境压力，化学调查显示存在大量的某些污染物。因此，本研究旨在评估遗传毒性物质的影响，并推断这些生态系统的暴露情况，使用灰鲻作为生物指示剂，并考虑红细胞核异常的类型和频率作为遗传毒性的替代物。在葡萄牙中心和西北部的重要蒙德古河、杜罗河和阿夫河河口全年对鲻鱼进行了采样。在春季-夏季和秋季-冬季的捕捞活动中，用网或钓竿捕获了这些鲻鱼（总数 n=242）。在基本的生物测量参数方面，采样的鲻鱼在地点之间具有可比性。用 Diff-Quik 染色血液涂片以评估 6 种类型的 ENMAs 和 MN（每 1000 个红细胞计算）的频率。记录了一些基本的水物理化学参数，以寻找与 ENMAs 相匹配的波动。总体而言，最常见的核异常是多态型，其次是起泡/裂片/有缺口、分段、肾形、空泡、MN 和双核。ENMAs 的总平均频率范围从蒙德古河的 73‰到阿夫河的 108‰。在考虑到所有三个河口时，多态型通常占 ENMAs 总数的≥50%，平均约为 51‰。在蒙德古河和杜罗河的鱼类中，最严重的病变-微核-的频率相似（≈0.38‰），明显低于阿夫河（0.75‰）。MN 率没有明显的季节性差异，除了杜罗河外，几乎没有季节性差异，AW 的值较高。一般来说，ENMAs 频率的模式与水物理化学参数无关。考虑到总 ENMAs 和每种特定异常的数据，并考虑到鱼类红细胞 MN 大于 0.3‰的值通常反映遗传毒性物质的污染，因此，鲻鱼可能长期暴露于此类化合物中，即使在据称污染较少的生态系统（蒙德古河）中也是如此。此外，数据支持以下污染暴露梯度：蒙德古河<杜罗河<阿夫河。这种情况和推断与化学监测的已发表数据非常吻合。
