Comparatively Study and Analysis of Heavy Metal in the Cultivated Wetland of Baien Stream, Shakargarh, Pakistan

Abstract

Heavy metal pollution of soil has increased globally in recent years. In many dry and semi-arid locations throughout the world, wastewater is seen as a novel and unusual supply of water for agricultural development. As a result, soil and plant monitoring for a variety of factors, including heavy metals and hazardous contaminants, is necessary. The farmers in Shakargarh use wastewater and tube wells for crop production, however workers and customers are concerned about the possible public health hazards linked with the use of wastewater. This investigation aimed to determine the health threats of using wastewater for crop production by estimating heavy metal concentrations in vegetable crops. Vegetables samples (radish and turnip), soil and irrigation water were collected from critical points and examined for the detection of heavy metals (copper, chromium, cadmium, cobalt, and arsenic) by atomic absorption spectrophotometer. Vegetable parts were collected at the growing stage and at the time of harvesting from farmers’ fields. Three soil sampling campaigns were carried out from the radish and turnip plots. Irrigation water samples were collected from different water bodies including wastewater and the tube well water. The following metals were detected: copper, chromium, cadmium, cobalt, and arsenic in the tested samples. It was observed that the high concentration of these metals in the roots of radish at fruiting stage: Cu (39 mg kg^-1), Cr (201 mg kg^-1), Cd (1.3 mg kg^-1), Co (54 mg kg^-1), and As (17.3 mg kg^-1). It was found that mean concentration of these metals in the roots of turnip at fruiting stage: Cu (34 mg kg^-1), Cr (178 mg kg^-1), Cd (2.1 mg kg^-1), Co (49 mg kg^-1), and As (14.1 mg kg^-1). The general pattern for the distribution of heavy metals in different parts of the plant was roots > stem > leaves > fruits. The incidence of heavy metals in soil samples was highest for chromium followed by copper, arsenic, cobalt and cadmium. The incidence of heavy metals in irrigation water samples was highest for chromium followed by copper, cadmium, arsenic, and cobalt. These concentrations were significantly greater than the permissible level recommended by FAO / WHO. It can be inferred that the health threats associated with the consumption of vegetables are currently very significant. Therefore, it is recommended that irrigation water, soil, and vegetables be monitored on a regular basis to safeguard the health of workers and consumers.