The aim of this article was to evaluate the influence and effects of chosen bioaccumulative substances i.e. heavy metals, pesticides, and polychlorinated biphenyls (PCBs) on fish, as well as provide information on time trends and potential threat to human health. Chemical substances which pollute water may affect living organisms in two ways. First of all, large amounts of chemical substances may cause sudden death of a significant part of the population of farmed fish, without symptoms (i.e. during breakdown of factories or industrial sewage leaks). However, more frequently, chemical substances accumulate in tissues of living organisms affecting them chronically. Heavy metals, pesticides, and polychlorinated biphenyls are persistent substances with a long-lasting biodegradation process. In a water environment they usually accumulate in sediments, which makes them resistant to biodegradation processes induced by, e.g., the UV light. These substances enter the fish through direct consumption of contaminated water or by contact with skin and gills. Symptoms of intoxication with heavy metals, pesticides, and PCBs may vary and depend on the concentration and bioavailability of these substances, physicochemical parameters of water, and the fish itself.

The aim of this article was to evaluate the influence and effects of chosen bioaccumulative substances i.e. heavy metals, pesticides, and polychlorinated biphenyls (PCBs) on fish, as well as provide information on time trends and potential threat to human health. Chemical substances which pollute water may affect living organisms in two ways. First of all, large amounts of chemical substances may cause sudden death of a significant part of the population of farmed fish, without symptoms (i.e. during breakdown of factories or industrial sewage leaks). However, more frequently, chemical substances accumulate in tissues of living organisms affecting them chronically. Heavy metals, pesticides, and polychlorinated biphenyls are persistent substances with a long-lasting biodegradation process. In a water environment they usually accumulate in sediments, which makes them resistant to biodegradation processes induced by, e.g., the UV light. These substances enter the fish through direct consumption of contaminated water or by contact with skin and gills. Symptoms of intoxication with heavy metals, pesticides, and PCBs may vary and depend on the concentration and bioavailability of these substances, physicochemical parameters of water, and the fish itself.

Objective: Heavy metals are serious environmental pollutants and their uptake and accumulation in the ecosystem, beyond safe limits, would cause direct consequences to food chain and ultimately to man. The present study was undertaken to ascertain the presence and levels of lead (Pb) in muscles and organs of slaughtered pigs at Nsukka agricultural zone, Nigeria. Materials and methods: From a total of 160 slaughtered pigs, liver, kidney and muscle of each pig were collected and processed for the detection of lead residue using Atomic Absorption Spectrophotometer. Results: A prevalence rate of 81.25% was recorded for Pb residue in Nsukka agricultural zone. There is a strong association (P<0.0001) between occurrence of Pb residue and the source of samples. Mean concentrations of 0.0758 mg/kg, 0.1050 mg/kg and 0.0985 mg/kg were recorded in kidney, mean concentrations of 0.1676 mg/kg, 0.1235 mg/kg and 0.1955 mg/kg were recorded in liver and mean concentrations of 0.0598 mg/kg, 0.0870 mg/kg and 0.1020 mg/kg in muscle samples in Nsukka, orba and Obollo slaughter houses respectively. There is no significant (P<0.05) difference between the mean concentrations of the Pb in the liver, kidney and muscle samples (Nsukka, Orba and Obollo) and its maximum permissible levels (MPL). Conclusion: More than half of the samples were positive for Pb and few samples that exceeded the MPL may pose human health threat to pork consumers in the study area. [J Adv Vet Anim Res 2016; 3(4.000): 392-398]