Microcystin (MC), a hepatotoxin that is harmful to human health, has frequently increased in freshwaters
worldwide due to the increase in toxic cyanobacterial blooms. Despite many studies reported the human
exposure to MC through drinking water, the potential transfer of this toxin to human via consumption of vegetables
grown on farmlands that are naturally irrigated with contaminated water has not been largely investigated.
Therefore, this study investigates the presence of MC in irrigation water and its potential accumulation in
commonly consumed vegetables from Egyptian farmlands. The results of toxin analysis revealed that all irrigation
water sites contained high MC concentrations (1.3–93.7 μg L􀀀 1) along the study period, in association
with the abundance of dominant cyanobacteria in these sites. Meanwhile, MCs were detected in most vegetable
plants surveyed, with highest levels in potato tubers (1100 μg kg􀀀 1 fresh weight, FW) followed by spinach (180
μg kg􀀀 1 FW), onion (170 μg g􀀀 1 FW), Swiss chard (160 μg kg􀀀 1 FW) and fava bean (46 μg kg􀀀 1 FW). These MC
concentrations in vegetables led to estimated daily intake (EDI) values (0.08–1.13 μg kg bw􀀀 1 d􀀀 1 for adults and
0.11–1.5 μg kg bw􀀀 1 d􀀀 1 for children), through food consumption, exceeding the WHO recommended TDI (0.04
μg kg bw􀀀 1 d􀀀 1) for this toxin. As eutrophic water is widely used for irrigation in many parts of the world, our
study suggests that cyanotoxins in irrigation waters and agricultural plants should be regularly monitored to
safeguard the general public from inadvertent exposure to harmful toxins via food consumption.