Okeagu Okechukwu Martin, Akinsanya Bamidele, Isibor Patrick Omoregie, Daniel-Rugu Josephine, Onadeko Abiodun Benedict, Yalwaji Babangida, Adekoya Khalid Olajide
Department of Zoology, University of Lagos, Akoka, Lagos State, Nigeria.
Department of Biological Sciences, Covenant University, Ota, Ogun State, Nigeria.
Toxicol Rep. 2022 Jan 29;9:136-146. doi: 10.1016/j.toxrep.2022.01.013. eCollection 2022.
Amphibian species are being threatened worldwide and chemical pollution is one of the leading causes of this decline. The use of agrochemicals such as organochlorine pesticides (OCPs) among the several health and ecological challenges it causes, the sharp amphibian population decline is most pressing.Toad specimens were sampled from three (3) selected areas; each comprising of natural habitat and dumpsites within Lagos metropolis.
The congeners of organochlorine pesticides were tested in the liver, intestine, and parasite ( sp.) of the toads and soil samples from the respective locations using gas chromatography-mass spectrometer (GC-MS). Histopathological analyses were conducted on the intestines and liver of the toads using hematoxylin and eosin (H&E) stain and then examined under the binocular dissecting microscope.
The concentration of aldrin in the intestine of sampled at the dumpsites was higher than the concentrations in the intestines of in the natural habitat. The concentrations of dieldrin in the uninfected at both dumpsite and natural habitat were higher than the concentrations in the infected at both environments. This indicated that the parasite sp. may have played a depurative role in sequestering the concentration of dieldrin in the toads irrespective of the location. The parasites exhibited marked sequestration capacity characterized by the notably high total bioaccumulation rate both in the liver and the intestine at the dumpsite. The stunted villi being the common histological alteration in the infected and uninfected toads at the dumpsite but missing in the uninfected counterparts at the natural habitat may be attributed to the differences in the background concentration of the OCP congeners.
The parasite- sp. has been shown to be a potential tool in the biomonitoring of these OCP congeners which persists in the environment. Continuous research on these congeners is a searchlight to checkmate the environment to see how compliant industries and the consumers are in terms of regulation of these chemicals.
两栖动物物种在全球范围内受到威胁，化学污染是导致其数量下降的主要原因之一。在农业化学品（如有机氯农药，OCPs）所造成的诸多健康和生态挑战中，两栖动物数量的急剧下降最为紧迫。从拉各斯市选定的三个区域采集蟾蜍样本；每个区域都包括自然栖息地和垃圾场。
使用气相色谱 - 质谱联用仪（GC - MS）对蟾蜍的肝脏、肠道和寄生虫（某种寄生虫）以及来自相应地点的土壤样本中的有机氯农药同系物进行检测。使用苏木精和伊红（H&E）染色对蟾蜍的肠道和肝脏进行组织病理学分析，然后在双目解剖显微镜下检查。
在垃圾场采集的蟾蜍肠道中艾氏剂的浓度高于自然栖息地蟾蜍肠道中的浓度。在垃圾场和自然栖息地未感染寄生虫的蟾蜍体内狄氏剂的浓度均高于两种环境中感染寄生虫的蟾蜍体内的浓度。这表明无论位置如何，寄生虫（某种寄生虫）可能在隔离蟾蜍体内狄氏剂浓度方面发挥了净化作用。寄生虫表现出显著的隔离能力，其特征是在垃圾场的肝脏和肠道中总生物累积率都非常高。绒毛发育不良是垃圾场感染和未感染寄生虫的蟾蜍中常见的组织学改变，但在自然栖息地未感染寄生虫的蟾蜍中不存在，这可能归因于有机氯农药同系物背景浓度的差异。
已证明寄生虫（某种寄生虫）是对环境中残留的这些有机氯农药同系物进行生物监测的潜在工具。对这些同系物的持续研究是一盏探照灯，用于审视环境，以检查行业和消费者在这些化学品监管方面的合规情况。
