Assessment of PAH pollution in mediterranean lakes and health implications for fish and consumers, case study: Manzala Lake, Egypt

Abstract

This study aims to investigate the distribution, sources, and compositions of 16 polycyclic aromatic hydrocarbons (PAH) in Manzala Lake water and the organs of two fish species: M. cephalus and O. niloticus. In addition, it aims to assess associated health risks and examine protein pattern responses and histopathological lesions in fish from different lake sectors. ∑PAH, ∑COMB, and ∑CAR varied between (0.122–51.895), (0.1–49.63), and (0.08–19.949) μg/L, respectively. Many PAH compounds in the water exceeded the guidelines; benzo[a]pyrene in the muscles of O. niloticus exceeded the European Union (EU) guidelines (2 μg/kg), recording 14.18 and 4.59 μg/kg in the eastern and southern sectors, respectively. In general, the ∑PAH in the muscles of O. niloticus (799.79 ± 26.02 μg/kg) were higher than those of M. cephalus (213.75 ± 8.69 μg/kg) in the eastern sector, which indicates a high potential risk associated with the consumption of O. niloticus. The electrophoresis of protein patterns of the fish muscles recorded site- and species-specific alterations in the proteinogram. M. cephalus exhibited higher sensitivity to PAH but developed a greater tolerance to PAH contamination than O. niloticus. The histopathological investigation reported several lesions in both fish tissue samples, particularly from the southern sector. Fish from Manzala Lake can pose a carcinogenic risk to consumers, mainly O. niloticus, where the PAH4 carcinogenic index was above the EU guidelines (12 μg/kg) in O. niloticus from all sectors. The study highlights lake management's importance in preserving biodiversity and ensuring food safety.