No abstract

Accumulation of heavy metals in tissues of the crayfish Procambarus clarkii and in water were evaluated in areas located in the Egyptian Delta (Gharbiya, Kafr El-Shaikh, and Menofiya) in 2010 and 2021. Statistics showed that in 2010 the highest concentration of heavy metals in the digestive gland and in muscles was Zn, both in Gharbiya and Menofiya, while Fe was the highest accumulated in the digestive gland, and Pb was the highest in muscles of samples from Kafr El-Shaikh. The results showed that heavy metal loads decreased in Kafr El-Shaikh in 2021, whereas Fe increased significantly () in Gharbiya and Menofiya (41.44 ± 2.32, 47.25 ± 2.64 μg/g). Accumulation of Cd and Zn in gills and muscles decreased in all areas from 2010 to 2021, while a significant increase () was shown in Fe and Cu in 2021. All heavy metals significantly decreased () in waters of the studied areas from 2010 to 2021.