The Effects of Irrigation with Diverse Wastewater Sources on Heavy Metal Accumulation in Kinnow and Grapefruit Samples and Health Risks from Consumption

Abstract

This study aimed to assess the concentrations of Pb, Cr, Cd, and Ni in the edible parts of grapefruit and kinnow fruit irrigated with sewage water, tube-well water, and canal water. Preparation of the samples used in the study for metal analysis was carried out by the wet acid digestion method. Atomic absorption spectrometry was used for metal determination. All of the studied metals were more abundant in water, soil, and fruit samples from sites irrigated with sewage water than from those irrigated with tube-well and canal water. The concentrations of Pb were established in the range of 0.047 to 0.175 mg/L in water, 12.652 to 47.863 mg/kg in soil, and 0.023 to 0.124 mg/kg in fruit samples of both varieties. The range of Cr varied from 0.107 to 0.741 mg/L in water, from 1.121 to 5.835 mg/kg in soil, and from 0.054 to 0.784 mg/kg in fruit samples of both varieties. The range of Cd varied from 0.004 to 0.028 mg/L in water, from 1.258 to 4.246 mg/kg in soil, and from 0.012 to 0.131 mg/kg in fruit samples of both varieties. The range of Ni varied from 0.384 to 1.815 mg/L in water, from 5.367 to 18.658 mg/kg in soil, and from 0.028 to 1.475 mg/kg in fruit samples of both varieties. The pollution load index indicated that Pb exceeded a value of 1, while Cd and Ni exceeded 1 only in sewage-water-irrigated sites. The bioconcentration factor, enrichment factor, daily intake of metal, and health risk index values for all metals were below 1, within permissible limits, indicating no immediate health risks associated with consuming these fruits.

The Effects of Heavy Metal Pollution on Soil Nitrogen Transformation and Rice Volatile Organic Compounds under Different Water Management Practices

“…In Changsha City, which is the capital of the Hunan Province of China, dust analysis showed that 50% of the Cd was insoluble and reducible fractions in PM 2.5 (particulate matter with aerodynamic diameters equal to or less than 2.5 µm) from the re-suspension of dust, fuel combustion, vehicular emissions, and other pollution sources were based on speciation analysis during spring [ 97 ]. Nevertheless, the predominant source of Cd input into the soil arises from agricultural activities, such as the irrigation with wastewater, unnecessary phosphate and organic fertilizer applications, and the random disposal of untreated urban sewage sludge and garbage [ 98 ]. The issue of Cd input via phosphate fertilizer application in the agricultural soils of China is controllable because phosphate and Cd content are naturally low in the native phosphate rocks of China, which leads to imports of high-quality phosphate fertilizers that contain a high level of Cd [ 99 ].…”