Incidence of Heavy Metals in the Application of Fertilizers to Crops (Wheat and Rice), a Fish (Common carp) Pond and a Human Health Risk Assessment

Though manure has been used for centuries to enhance soil fertility and final agricultural yield, the overuse of fertilizers on the land can cause serious pollution issues, such as heavy metals and eutrophication, that can further lead to health problems. The current study aimed to assess the heavy metals in the most consumed crops (wheat and rice) and fish (common carp) and their risk to human health. Results revealed that there was an irregular trend of heavy metals in different sites of the study area; however, the general trend that was observed during the current research work was Pb>Cr>Cd>Mn in soil samples and crops, while in the case of fish muscle, the trend was Cr>Pb>Cd>Mn. Furthermore, after health index analysis, it was revealed that in some of the sites, the hazard index (HI) was above 1. Principal component analysis suggests a strong positive correlation of the heavy metals from the soil and water to the crops and fish muscles, respectively. Cd was highly bioaccumulated in the crops and fish muscles from different sites. There was an unusual increase in the metal concentration in the samples from the Sargodha. This result suggests a rapid increase in the metal concentration within the agricultural land and its products that can put human health at risk of developing multiple diseases related to the heavy metals, as indicated by the HI values. It is highly recommended that fertilizers should be used carefully so that human populations and animals can safely consume heavy-metal-free food.