global evaluation of potentially harmful elements (phes) in potato and carrot irrigated by wastewater: a systematic review, meta-analysis, and health risk assessment

Background: we aimed to conduct a metaanalysis on the concentration of potentially harmful elements (phes) in carrots and potatoes irrigated by wastewater and estimate noncarcinogenic health risks among adult and children consumers. methods: the health risk of phes concentration, including pb, cd, total cr, ni, zn, cu, and fe, in the edible parts of carrot and potato irrigated by wastewater was investigated by a metaanalysis using a randomeffects model (rem). accordingly, the related articles were screened from international databases such as scopus, medline, and embase. results: the metaanalysis of 32 papers (38 studies) revealed that the rank order of the most accumulated phes in potato was fe (86.54 mg/kg wet weight) > zn (30.9 mg/kg wet weight) > cu (13.7 mg/kg wet weight) > ni (8.42 mg/kg wet weight) > pb (5.56 mg/kg wet weight) > cr (3.45 mg/kg wet weight) > cd (0.58 mg/kg wet weight). this ranking for carrot was fe (43.36 mg/kg wet weight) > zn (36.29 mg/kg wet weight) > ni (13.49 mg/kg wet weight) > cu (9.79 mg/kg wet weight) > pb (1.84 mg/kg wet weight) > cr (1.05 mg/kg wet weight) > cd (0.28 mg/kg wet weight). total hazard quotient (thq) of phes was higher than 1 for potato and carrot; its rank order for potato and carrot was cu > pb > cd > ni > fe > zn > cr and cd > pb > cu > ni > fe > zn > cr, respectively. the cd, pb, and cu had also a considerable role for consumer health risk. conclusion: according to the results, continuous monitor and control of wastewater treatment plants are necessary.