Assessment of chromium contamination in the soil and khat leaves (Catha edulis Forsk) and its health risks located in the vicinity of tannery industries; A case study in Bahir Dar City, Ethiopia

Industrial effluents containing trace metals can contaminate water, soil and plants, as well as can cause serious human health impacts. The aim of this study was to assess the concentration of chromium in the soil and khat leaves using spectroscopic methods and to evaluate its potential human health risk on the consumers. The average concentrations of total chromium in the soil samples ranged from 71.01 +/- 12.05 to 317.55 +/- 23.14 mg kg-1. These values were greater than the control (7.6 +/- 0.47 mg kg-1). The average concentrations of total Cr in the khat leaves ranged of 6.5 +/- 1.76 to 30.01 +/- 2.91 (mg kg-1). These values were higher than the maximum permissible Limits in vegetables 2.3 mg kg-1. The estimated daily intake (EDI) of an adult man weighing 70 kg and consuming on average 100 g of khat leaves per day was found in the range of 0.200-0.454 mg kg-1 body weight day-1. The target hazard quotient (THQ) of Cr from khat leaves consumption was found in the range of 0.001-0.076, which were <1, indicating no potential non-carcinogenic harmful health risk to the consumers in the society. Despite this, the regional EPA must pay close attention to controlling the use of irrigation water contaminated with tannery effluents in order to safeguard khat consumers. Furthermore, consumers must be aware of the health risks and refrain from consuming khat leaves cultivated in the study areas.