Abalaka Samson Eneojo, Idoko Idoko Sunday, Adamu Andrew Musa, Nafarnda Wesley Daniel, Machunga-Mabunla Salamatu, Audu Zakariya, Sani Nuhu Abdulazeez, Tenuche Oremeyi Zaynab, Ejeh Sunday Augustine
Department of Veterinary Pathology, University of Abuja, Abuja, Nigeria.
Australian Institute of Tropical Health and Medicine, Townsville, QLD, Australia.
Environ Monit Assess. 2023 Feb 18;195(3):411. doi: 10.1007/s10661-023-10990-8.
There is heightening concern regarding heavy metals environmental pollution requiring renewed global attention because of their bioaccumulation and toxicity at varying levels. The concern is most important in the highly migratory Eidolon helvum (E. helvum) that is very common and traverses wide geographical areas within the sub-Saharan Africa. The present study aimed to evaluate levels of cadmium (Cd), lead (Pb), and zinc (Zn) bioaccumulation in 24 E. helvum of both sexes from Nigeria to assess their indirect health risks to the human consumers of the bats in addition to their direct bioaccumulation and toxic damages in the bats themselves based on standard procedures. Lead, Zn, and Cd bioaccumulation concentrations were 2.83 ± 0.35, 0.42 ± 0.03, and 0.05 ± 0.01 mg/kg, respectively, with significant (p < 0.05) Pb bioaccumulation compared to either Cd or Zn in the affected bats. However, only Pb (markedly) and Cd (marginally) bioaccumulated above small mammals' critical threshold levels as there are no existing established threshold levels for bats. Sex played no major role in their bioaccumulation levels. The bioaccumulation levels posed no life-long non-carcinogenic nor carcinogenic risks to the human consumers of the bats at detected concentrations. The observed lungs, liver, and kidney histopathological changes suggested the possible direct effects of the metals in the bats. Nevertheless, other anthropogenic factors might be responsible as no significant (p > 0.05) correlation existed between cellular changes and the bioaccumulation levels. The presence of the heavy metals and their bioaccumulations above critical threshold levels suggested some levels of environmental contamination and pollution, which might have direct and indirect health implications to the bats and their human consumers.
由于重金属的生物累积性及其在不同程度上的毒性，人们对重金属环境污染的担忧日益加剧，这需要全球重新予以关注。这种担忧在高度迁徙的锤头果蝠（Eidolon helvum，简称E. helvum）身上最为突出，该物种非常常见，遍布撒哈拉以南非洲的广大地理区域。本研究旨在评估来自尼日利亚的24只雌雄锤头果蝠体内镉（Cd）、铅（Pb）和锌（Zn）的生物累积水平，依据标准程序，除了评估这些重金属在蝙蝠自身的直接生物累积和毒性损害外，还评估它们对食用蝙蝠的人类消费者的间接健康风险。铅、锌和镉的生物累积浓度分别为2.83±0.35、0.42±0.03和0.05±0.01毫克/千克，与受影响蝙蝠体内的镉或锌相比，铅的生物累积具有显著性差异（p<0.05）。然而，由于目前尚无针对蝙蝠的既定阈值水平，只有铅（显著）和镉（略微）的生物累积量超过了小型哺乳动物的临界阈值水平。性别在它们的生物累积水平上没有起到主要作用。在所检测的浓度下，生物累积水平对食用蝙蝠的人类消费者没有造成终身非致癌或致癌风险。观察到的肺、肝和肾组织病理学变化表明这些金属可能对蝙蝠有直接影响。尽管如此，可能还有其他人为因素在起作用，因为细胞变化与生物累积水平之间不存在显著相关性（p>0.05）。重金属的存在及其生物累积量超过临界阈值水平表明存在一定程度的环境污染，这可能对蝙蝠及其人类消费者的健康产生直接和间接影响。
