Heavy metals in vegetables: screening health risks involved in cultivation along wastewater drain and irrigating with wastewater

Abstract

Irrigation of agricultural land with wastewater leads to continuous buildup of metals at these sites which gets accumulated in the vegetables and crops growing on these sites. Not just the crops irrigated with wastewater are hazardous, in present study, we have found that vegetables growing in vicinity of wastewater drain are also not safe for human consumption. The risk associated with consumption of vegetables was assessed by calculating hazard quotient and results revealed that the hazard quotient for leafy and tuberous vegetables was higher than the safe limits in all the sites irrespective of mode of irrigation. Spinach was the most hazardous among all as the hazard quotient with respect to cobalt and copper was highest in spinach. Uptake trend of metals in all vegetables: Iron > Cobalt > Copper > Cadmium > Lead. Cadmium, a potential carcinogen was found in concentrations higher than permissible limits in many vegetables from all sites. Highest level of cadmium (1.20 mg/kg) and copper (81.33 mg/kg) was reported in site which was in vicinity of waste water drain but irrigated with ground water. Concentration of copper and lead in vegetable samples from different sites exhibited no statistically significant difference with respect to different sites.

Effects of wastewater quality on Henna (Lawsonia inermis L.) germination and seedling growth: a case study, Tunisia

“…Reuse of treated wastewater for irrigation may have many beneficial effects such as the increase of the organic matter content of the soil and the positive effects on growth and yield of different plant species [5,6]. Taking into account the benefits and drawbacks of the irrigation with treated wastewater leads to consider that some crops are more prone to contamination than other by Metal Trace Elements (MTE) and pathogens which may still remain in the treated wastewater [7] such as crops with the edible parts exposed to the contaminated soil after wastewater irrigation like leafy and tuberous vegetables [8,9]. The World Health Organization (WHO) guidelines for the safe use of wastewater in agriculture recommended restrictions for crops, especially those eaten raw [10].…”

Temporal Heavy Metals Variation in Vegetables Sampled at Kasu

“…Industrial and sewage wastewater are disposed in open drains whose water is used for irrigation (Su et al 2014;Sharma et al, 2016). These wastes contain huge amount of heavy metals e.g.…”

“…Thus, the carcinogenic effects generated by continuous consumption of fruits and vegetables loaded with heavy metals such as Cd, Pb or even Cu and Zn are known. There are already published works related to the incidence of gastrointestinal cancer (Gupta et al, 2015), and cancer of the pancreas, urinary bladder or prostate (Sharma et al, 2016). There are, in Romania, three areas (CopşaMică-Sibiu County, Zlatna -Alba County and Baia Mare -Maramures County) very strongly polluted with heavy metals, caused by nonferrous ores extraction and metallurgical processing.…”

Copper Toxicity and Prediction Models of Copper Content in Leafy Vegetables

“…Cadmium (Cd), zinc (Zn), lead (Pb) and copper (Cu) are the main elements that accumulate in staple foods, fruits and vegetables in mining areas or industrial-polluted fields [9][10][11][12]. Recent publications increasingly focus on vegetables as healthy foods, but vegetables still face exposure to toxic metal contamination [9,11,[13][14][15][16][17]. Most of these studies quantify multiple toxic metals in vegetables, but few of them mention the negative effects of copper upon growth and production in leafy vegetables [9,13,14,16].To improve food safety from toxic metal contamination, it is an efficient strategy to predict the toxic metal contamination of crops by using the toxic metal information in the soil.…”

“…Recent publications increasingly focus on vegetables as healthy foods, but vegetables still face exposure to toxic metal contamination [9,11,[13][14][15][16][17]. Most of these studies quantify multiple toxic metals in vegetables, but few of them mention the negative effects of copper upon growth and production in leafy vegetables [9,13,14,16].To improve food safety from toxic metal contamination, it is an efficient strategy to predict the toxic metal contamination of crops by using the toxic metal information in the soil. The transportation of metals from the soil to the crops could be affected by the dissolved, exchangeable, structural components of soil and insoluble precipitation [18,19].…”