Hazardous of waste water irrigation on quality attributes and contamination of citrus fruits.

摘要

There is an increasing concern regarding the potential health risks associated with consuming crops grown on sewage irrigated soils. The present study was carried out to assess levels of different heavy metals like iron, manganese, copper and zinc, in citrus fruits irrigated with water from two places in Jeddah; namely Al Hada site (as a control) and Al Musk Lake (as a contaminated site). Heavy metal concentrations were several fold higher in all the collected samples (water, soils and fruits) from wastewater irrigated site compared to potable water irrigated ones. Fruits collected from contaminated soils had lower firmness (30% less that collected from the reference site), while their size, weight and their soluble solids content (SSC) increased up to 3.5 cm in diameter, 22% and 14%, respectively. We found central axis of the orange fruits irrigated with wastewater was infected by the fungus Alternaria citri in the form of a rot, with hardly any external symptoms. Assessment of water and soils collected from Al Musk Lake indicated that they are not suitable for any uses. Moreover, these higher levels of metal pollution in the wastewater irrigated site presented a significant threat of negative impact on human health. The results presented demonstrate that there is a risk associated with consumption of fruits and vegetables irrigated with wastewater, with the fruits still looking apparently healthy and growing well despite accumulating heavy metals to concentrations which substantially exceed maximum values considered safe for human consumption.