Public health threats of heavy metals due to the consumption of Achachatina marginata (African Giant Land Snail) from a partially remediated site in Ikot Ada Udo, Akwa Ibom State, South-South Nigeria.

The risk of oral intake of metals from the ingestion of contaminated Achachatina marginata was carried-out. Snail samples (n = 48) were hand-picked, preserved in ice, then analyzed for zinc (Zn), nickel (Ni), chromium (Cr) using inductively coupled plasma-atomic emission spectrometry (ICP-AES, Yobin Yvon JY-24), then cadmium (Cd), lead (Pb) using graphite furnace atomic absorption spectrometry (GF-AAS, 4110 ZL PerkinElmer). The mean levels of metals in snail from each sampling point were higher compared to the control site. SP 1 had the highest significant levels (p < 0.05) of Pb, Zn, Ni, Cd, while SP 3 had the highest significant levels (p < 0.05) of Cr compared to the control site. The mean heavy metals in the snail were 3.280 ± 0.995 mg/kg (Cd), 8.906 ± 2.079 mg/kg (Zn), 0.896 ± 0.401 mg/kg (Cr), 1.867 ± 0.921 mg/kg (Ni), 1.998 ± 0.781 mg/kg (Pb). The mean Cd, Cr, Ni, and Pb in A. marginata were above WHO acceptable limits for food. Heavy metals level in A. marginata had a decreasing trend of Zn > Cd > Pb > Ni > Cr. The estimated daily intake (EDI) of Cd (5.61 × 10 mg/kg/day) was higher than the reference oral dose (RfD) value of 0.001 mg/kg/day. The target hazard quotient (THQ) of Cd (5.61) and the hazard index (HI) of metals (6.80) were greater than 1. The carcinogenic risk (CR) of Ni (5.43 × 10) and Cd (2.13 × 10) from contaminated snails intake were higher than the safe range of 10 to 10. The THQ, EDI of Cd, HI of the metals, and the CR values of Ni and Cd in snails from the contaminated site reveals a potential future health challenge to consumers and a possibility of contracting cancer over a 70 year lifetime. Furthermore, the findings revealed that the site requires a thorough clean-up for the total restoration of the environment.