HEAVY METAL LEVELS OF SOME FISH SPECIES (CLARIAS GARIEPINUS AND SCOMBER SCOMBRUS) SOLD AT EKE AWKA MARKET, AWKA, AWKA SOUTH L.G.A, ANAMBRA STATE.

A study was conducted to determine the levels of heavy metals in two fish species, Clarias gariepinus and Scomber scombrus, sourced from Eke Awka Market. Samples were collected over several days from various vendors and analyzed at the Spring Board laboratory. The fish were tested for Copper, Zinc, Manganese, Mercury, and Arsenic in their tissues. Results indicated that most heavy metal concentrations were within the acceptable limits set by regulatory bodies, with a few exceptions. Copper levels remained stable below the 10 mg/kg threshold, registering values of 0.105 ± 0.039 mg/kg on Day 1, 0.101 ± 0.026 mg/kg on Day 2, and 0.135 ± 0.051 mg/kg on Day 3. Catfish also had copper levels below this limit, ranging from 0.239 ± 0.061 mg/kg on Day 1 to 0.388 ± 0.050 mg/kg on Day 2, then dropping to 0.242 ± 0.026 mg/kg on Day 3. Zinc levels decreased over the sampling period, from 0.396 ± 0.039 mg/kg on Day 1 to 0.273 ± 0.063 mg/kg on Day 2 and 0.211 ± 0.014 mg/kg on Day 3, all remaining significantly under the 150 mg/kg limit. Catfish showed zinc levels that started at 0.133 ± 0.049 mg/kg on Day 1, increased to 0.269 ± 0.106 mg/kg on Day 2, and then fell to 0.176 ± 0.028 mg/kg on Day 3. Manganese levels also declined from 0.055 ± 0.016 mg/kg on Day 1 to 0.026 ± 0.025 mg/kg on Day 2 and 0.025 ± 0.011 mg/kg on Day 3, well within the 12.7 mg/kg limit. Catfish manganese levels were low as well, ranging from 0.016 ± 0.009 mg/kg on Day 1 to 0.037 ± 0.030 mg/kg on Day 2, dropping to 0.010 ± 0.012 mg/kg on Day 3, again below the limit. Mercury levels were of particular concern, initially exceeding the 0.5 mg/kg limit at 0.517 ± 0.482 mg/kg on Day 1, but decreasing to 0.113 ± 0.034 mg/kg on Day 2 and 0.074 ± 0.017 mg/kg on Day 3; in catfish, mercury levels were below this limit, starting at 0.035 ± 0.005 mg/kg on Day 1 and falling to 0.012 ± 0.013 mg/kg on Day 2 before rising slightly to 0.060 ± 0.016 mg/kg on Day 3. Arsenic concentrations were also below the 0.01 mg/kg limit, with values starting at 0.019 ± 0.014 mg/kg on Day 1, dropping to 0.002 ± 0 mg/kg on Day 2 and 0.0015 ± 0.007 mg/kg on Day 3. However, catfish arsenic levels surpassed the 0.01 mg/kg level on Day 1 at 0.033 ± 0.027 mg/kg, decreasing to 0.008 ± 0.002 mg/kg on Day 2 and further to 0.007 ± 0.005 mg/kg on Day 3. The elevated mercury levels in mackerel and high arsenic levels in catfish on Day 1 raise serious concerns, highlighting the urgent need for stricter monitoring and regulation of heavy metal contamination in fish to protect consumer health.