Increased health risk assessment in different vegetables grown under untreated sewerage irrigation regime due to higher heavy metals accumulation.

Heavy metals are environmental pollutants and carcinogenic for human health if ingested. In developing countries, including Pakistan, untreated sewerage water is one of the major sources of irrigation for vegetable production in the vicinities of urban areas which might be toxic to human health due to heavy metals contamination. The present study was conducted to investigate the uptake of heavy metals by sewage water application and its impact on human health. The experiment consisted of five vegetable crops (Raphanus sativus L, Daucus carota, Brassica rapa, Spinacia oleracea, and Trigonella foenum-graecum L.) and two irrigation sources (clean water irrigation and sewage water irrigation). Each treatment was three time replicated for all five vegetables, and standard agronomic practices were applied. The results demonstrated that shoot and root growth in radish, carrot, turnip, spinach, and fenugreek was enhanced significantly with sewerage water, probably due to enhanced organic matter. However, pithiness was observed in the root of radish under sewerage water treatment. Very high concentrations of Cd, up to 7.08 ppm in turnip roots while up to 5.10 ppm in fenugreek shoot, were observed, and other vegetables also contained higher concentrations of Cd. Zn concentrations in the edible parts of carrot (control (C) = 129.17 ppm, sewerage (S) = 164.10 ppm), radish (C = 173.73 ppm, S = 253.03), turnip (C = 109.77 ppm, S = 149.67 ppm), and fenugreek (C = 131.87 ppm, S = 186.36 ppm) were increased by sewerage water treatment but a decrease in Zn concentration in spinach (C = 262.17 ppm, S = 226.97 ppm) was observed. Fe concentration in edible parts of carrot (C = 888.00 ppm, S = 524.80 ppm), radish (C = 139.69 ppm, S = 123.60 ppm), turnip (C = 195.00 ppm, S = 121.37 ppm), and fenugreek (C = 1054.93 ppm, S = 461.77 ppm) were also decreased by sewerage water treatment while spinach leaves had accumulated higher Fe (C = 1560.33 ppm, S = 1682.67 ppm) in sewerage water treatment. The highest bioaccumulation factor value was 4.17 for Cd in carrots irrigated with sewerage water. The maximum value of bioconcentration factor was 3.11 for Cd in turnip under control, and the highest value of translocation factor was 4.82 in fenugreek irrigated with sewerage water. Daily intake of metals and health risk index (HRI) calculation indicated that HRI for Cd was more than 1, suggesting toxicity in these vegetables while HRI for Fe and Zn is still under safe limit. Correlation analysis among different traits of all vegetables under both treatments revealed valuable information for selecting traits in the next crop breeding programs. It is concluded that untreated sewerage-irrigated vegetables, highly contaminated with Cd, are potentially toxic for human consumption and should be banned in Pakistan. Furthermore, it is suggested that the sewerage water should be treated to eliminate toxic compounds, particularly Cd, before irrigation usage and non-edible/phytoremediation crops might be grown in contaminated soils.

Evaluation of Antimicrobial Effect of Silver Nanoparticle Based Whey Emulsions and Edible Films for the Extension of Shelf Life of Fruits and Vegetables.

The purpose of this study was to develop and assess the antimicrobial properties of silver nanoparticles (AgNPs)-based whey emulsions and edible films for extending the shelf life of fruits and vegetables. The AgNPs were synthesized using a biological method, and their morphological and topographical characteristics were evaluated using scanning electron microscopy (SEM). The AgNPs were incorporated into the emulsions and films to increase their antimicrobial efficacy. Bacterial and fungal strains were identified by DNA regions, including 16S and 18S rRNA, TEF-1α, and RPB2 to evaluate antimicrobial activity. AgNPs-based emulsions and films were used to extend the shelf life of fruits and vegetables for up to 15 days. The results showed that the use of AgNPs in the coated samples significantly increased their effectiveness against bacterial and fungal strains. SEM analysis revealed the presence of AgNPs of varying sizes, ranging from 21 to 62 nm. The zones of inhibition were measured against Staphylococcus aureus, Escherichia coli, Salmonella enterica, Aspergillus flavus, Aspergillus tamari, and Aspergillus niger. The total viable count (log cfu/ml) decreased from 6.423 in the control group to 3.301 in the treated samples. The antioxidant activity of the treated fruits and vegetables was also significantly improved, with values of 56.12, 23.36, 26.10, 7.6, 36.04, and 33.81% for strawberry, taro root, guava, peas, green chili, and carrot, respectively (p < 0.05). The AgNPs-based whey protein emulsions were found to exhibit the highest antimicrobial activity and are therefore a promising approach to extend the shelf life of fruits and vegetables.