BIOACCUMULATION AND EFFECTS OF LEAD (PB) ON METABOLIC PROCESSES AT CELLULAR AND TISSUE LEVEL OF TILAPIA (Oreochromis niloticus)

Abstract

Aquaculture environments have faced major problems due to the accumulation of various contaminants and pollutants due to various industrial activities. Lead (Pb) is one of the heavy metals that is very dangerous for the sustainability of the food chain. Early producers and consumers are the chains most vulnerable to being directly affected by heavy metal exposure in aquatic environments. Their large numbers in the ecological pyramid allow heavy metal accumulation to occur in higher consumers due to chain processes and food webs. Tilapia (Oreochromis niloticus) is an omnivore species of fish that feeds on various early producers and consumers in the ecological pyramid. When fish consume foods that contain toxic substances, the substances will accumulate and settle for a long time in fish cells and tissues. Pb can also enter the body of fish through gills, then will be carried by blood flow through arteries to all organs involved in fish blood circulation. In the end, Pb will be deposited in the liver of the fish for a long time. O. niloticus exposed to heavy metals in the environment is reported to cause damage to several vital organs of fish such as gills, kidneys, and liver. Organ failure will cause chronic pain, make it easier for pathogens to enter the tissues, weaken the body's immune system and death in fish. Exposure to Pb is reported to inhibit active transport processes, suppress oxidation-reduction reactions, and protein synthesis. Other reports suggest that PB residues can cause hematological, neural, and gastrointestinal dysfunctions in fish. Exposure and accumulation of Pb in fish is in fact very dangerous for the survival of fish. A dangerous threat is food security for humans. We, humans who consume tilapia as a source of protein must consume food that is free from various exposures to harmful heavy metals that generally manifest as hazardous waste in industry. In the future, factories and industries must thoroughly manage industrial waste so that it is completely safe and free of various heavy metals before being discharged into the aquatic environment.