Bioaccumulation, Biosedimentation, and Health Hazards of Elements in Crayfish, Procambarus clarkii from El-Rahawi Drain and El-Qanatir in the River Nile, Egypt.

Elements accumulation in crayfish is proportional to the increase in bioavailability (direct contact) with the surrounding water, sediment, and feeding. Five heavy metals (Cu, Cr, Mn, Ni, and Ag) and lithium (Li) were analyzed in the sediment, water, and crayfish tissues. Elements (heavy metals and lithium) concentrations in sediment, water, and crayfish tissues showed significant differences between the two sampling stations (El-Qanatir and El-Rahawi drain). However, the levels of elements in crayfish tissues were arranged in declining order as hepatopancreas > gills > exoskeleton > muscles for Cu and Cr; hepatopancreas > exoskeleton > gills > muscles for Ni and Ag; and exoskeleton > gills > hepatopancreas > muscles for Li and Mn. The human health hazard evaluation of heavy metals and lithium exposure via edible tissue consumption was assessed for both children and adult consumers. The target hazard quotient THQ values of crayfish edible tissues (less than 1) will not impose any health implications for consumers who ingest edible tissues in sufficient quantities. Furthermore, the hazard index (HI) values reported for children and adult consumers were lower than one, indicating non-carcinogenic and carcinogenic hazards, suggesting that crayfish edible tissues are safe for human ingestion. This evidence also found that Procambarus clarkii could be a good bio-indicator organism for monitoring potentially metals in aquatic systems.

Urinary and amniotic epidermal growth factor during normal and abnormal pregnancies. A comparison based upon umbilical Doppler velocimetry.

Fetal growth retardation is associated with abnormal umbilical flow velocity. We have begun a systematic study of growth factors and their relationship to this specific pattern of growth retardation. Using a specific double-antibody epidermal growth factor (EGF) 125I-radioimmunoassay, we studied urinary EGF in normal pregnancy from 5 to 42 weeks of gestation, and amniotic fluid EGF from 18 to 24 weeks. EGF levels increased from early pregnancy until 21-28 weeks, when they declined to a level at term similar to non-pregnant controls and first-trimester pregnancy levels. There was no significant difference in urinary EGF levels between women delivering appropriate-for-gestational-age (AGA) infants, and those delivering small-for-gestational-age infants (SGA). We conclude that the urinary EGF is not different in the SGA pregnancy from normal pregnancy.