ASSESSMENT OF HUMAN HEALTH RISK FOR LEAD, COPPER, NICKEL, MERCURY AND ZINC IN FISH COLLECTED FROM LAKE GERIYO, ADAMAWA STATE.

Abstract

Fishes are constantly exposed to aquatic system and exposure of metals through fish consumption may lead to health risks, especially for high-fish consumption populations. This study determined levels of Pb, Cu, Hg, Ni, and Zn in muscle tissues of fish from lake geriyo wetland and estimated the health risk posed by fish ingestion. The levels of heavy metals were below the permissible limits issued by JECFA of FAO/WHO. The tolerable intake of As, Cu, Hg, Ni, and Zn as PTWI (Provisional Tolerable Weekly Intake) and PTDI (Provisional Tolerable Daily Intake) was calculated and presented. To estimate the human health risk, the target hazard quotient (THQs), was calculated, THQs for individual metals were lower than USEPA guideline value of 1. However, the hazard index of lead, copper, mercury, nickel and zinc mixture for Clarrias was marginally high. The target cancer risk (TR) of lead and nickel for intake of the Clarrias,  nilotica and Tilapa  was 1.5x10^-4 and 5.8x10^-4, 7.7x10^-5 and 3.0x10^-4, 4.7x10^-5 and 5.4x10^-4, respectively, with the average of 8.6 x 10^-5 and 4.7 x 10^-4, respectively.