Abstract
Background Egypt’s food security depends heavily on aquaculture, however fish farmed on farms that receive agricultural
drainage water may be subjected to pesticide pollution. Such contamination can impair fish health, alter physiological func‑
tions, and pose potential risks to consumers. This study investigated the occurrence and distribution of pesticide residues
in water and in the gill, liver, and muscle tissues of two economically important species, Oreochromis niloticus and Mugil
cephalus, collected from four fish farms that differ in their water sources in Fayoum Governorate, Egypt. The control farm
wasirrigated with fresh water, while the other farms were irrigated with agricultural drainage water. It also evaluated the bio‑
chemical and stress-related responses in fish and assessed potential risks associated with human consumption.
Results Farms supplied with drainage water exhibited higher salinity and nutrient pollution compared to the freshwater
control farm. Multiple classes of pesticides, including organochlorine insecticides, pyrethroid insecticides, and herbicides, were
detected in both water and fish tissues, with the highest concentrations found at the El-Bats and Dayer El-Berka farms. Pesti‑
cide accumulation varied by species and organ: O. niloticus accumulated the highest levels in the liver, whereas M. cephalus
accumulated more in the gills. Fish from polluted farms showed reduced activities of the liver enzymes aspartate aminotrans‑
ferase and alanine aminotransferase, alongside increased concentrations of triglycerides, cholesterol, and total lipids in muscle
tissue. Oxidative and cellular stress markers, including malondialdehyde and caspase-12, were elevated in all examined
tissues, while catalase activity was reduced.
Conclusions Fish raised in agriculture drainage-fed aquaculture systems showed clear evidence of pesticide exposure,
organ-specific accumulation patterns, and associated biochemical and stress responses. Despite exceedances of regulatory
residue limits forsome compounds, the overall dietary risk to consumers wasfound to be low based on estimated intake
calculations. Nevertheless, the high prevalence of pesticide mixtures in water and fish highlights the need for continuous
monitoring and management of agricultural runoff to maintain aquaculture productivity and ensure safe consumption |
