Deciphering integrated soil potential ecological and human health risks attributable to industrial effluents irrigation and wheat consumption.

ABSTRACT

Iron-steel (IS) and textile (T) are among the major polluting industries worldwide which generate large quantities of effluents containing potentially toxic metals (PTMs). Irrigation application of these effluents due to freshwater shortage is a common practice in developing countries. The current research endeavors to investigate potentially toxic metals in IS and T effluents, contamination status and ecological risk assessment of irrigated soils, PTMs accumulation in grains of diverse wheat germplasm and human health risk appraisal. Soil irrigation with effluents significantly enhanced soil nitrate-nitrogen (T, 285.86 mg/kg; IS, 539.70 mg/kg), phosphorus (T, 8.35 mg/kg; IS, 11.44 mg/kg), organic matter (T, 6.05%; IS, 4.48%) and PTMs contents compared to control (C). Enrichment factor and geo-accumulation index revealed substantial contamination trend of PTMs in IS (Ni > Cr > Co > Cd > Pb > Zn > Mn) and T (Co > Cd > Ni > Cu > Cr) treated soils. Potential ecological risk index and modified potential ecological risk index placed T (very high risk) and IS (considerable risk) irrigated soils in respective categories, with highest risk contributions from Cd, Co and Ni. The interactive effects for PTMs accumulation in grains of 30 wheat genotypes were recorded significant. Average PTMs accumulation in grains for the three irrigation treatments was IS > T > C for Zn, Cr, Mn, Pb, Fe, Ni and T > IS > C for Co, Cd, Cu. Multivariate statistical analysis ( principal component analyses) was used to identify the wheat genotypes with higher or lower grain PTMs accumulative potential on effluent irrigation. The genotypes with a lower grain PTMs accumulation and human health risks are recommended for cultivation in agro-systems receiving IS and T effluents, in order to safeguard wheat crop and human health.