No abstract

The aim of this study is to ascertain the level of some heavy metals namely; Arsenic, Cadmium, Chromium, Cobalt and Lead in baby milk or infant formulas used in the country and evaluate the health risk associated with their consumption. Five (5) brands of popularly consumed and most preferred or recommended infant formula foods for children in Nigeria were bought from the main (Watt) market in Calabar, Cross River State, Nigeria and were coded and labeled V, W, X, Y and Z respectively. The samples were digested in the fume cupboard using aqua regia and analyzed for heavy metals using Flame Atomic Absorption Spectrometer (AAS). The results showed that the concentration of Arsenic was less than 0.001mgkg-1 across all the five (5) brands. Cadmium concentration ranged between 0.010 - 0.052 mgkg-1 , and it was detected in all the samples. Cobalt ranged between 0.002 - 0.010 mgkg-1 , and it was detected in 3 out of the 5 samples. Chromium concentration ranged between 0.002 - 0.004 mgkg-1 was detected in 4 out of the 5 samples or brands of infant formula studied. Lead amount ranged between 0.080 - 0.014 mgkg-1 and was less than 0.001 mgkg-1 in 2 brands out of the five brands sampled. These results are low and within the permissible limits of WHO. The Target Hazard Quotients (THQ) of these metals were all less than 1 except for Cadmium in brand V that was 1. This indicates that there is no health danger associated with the imgestion of the infant formulas at the moment Keywords: Health risk, Heavy metals, Infant formula, Calabar-Nigeria

Owing to the fact that the use of 2,2-dichlorovinyldimethylphosphate (DDVP) as an agrochemical has become a matter of concern due to its persistence and potential harm to the environment and human health. Detecting and addressing DDVP contamination is crucial to protect human health and mitigate ecological impacts. Hence, this study focuses on harnessing the properties of fullerene (C60) carbon materials, known for their biological activities and high importance, to develop an efficient sensor for DDVP. Additionally, the sensor's performance is enhanced by doping it with gallium (Ga) and indium (In) metals to investigate the sensing and trapping capabilities of DDVP molecules. The detection of DDVP is carefully examined using first-principles density functional theory (DFT) at the Def2svp/B3LYP-GD3(BJ) level of theory, specifically analyzing the adsorption of DDVP at the chlorine (Cl) and oxygen (O) sites. The adsorption energies at the Cl site were determined as − 57.894 kJ/mol, − 78.107 kJ/mol, and − 99.901 kJ/mol for Cl_DDVP@C60, Cl_DDVP@Ga@C60, and Cl_DDVP@In@C60 interactions, respectively. At the O site, the adsorption energies were found to be − 54.400 kJ/mol, − 114.060 kJ/mol, and − 114.056 kJ/mol for O_DDVP@C60, O_DDVP@Ga@C60, and O_DDVP@In@C60, respectively. The adsorption energy analysis highlights the chemisorption strength between the surfaces and the DDVP molecule at the Cl and O sites of adsorption, indicating that the O adsorption site exhibits higher adsorption energy, which is more favorable according to the thermodynamics analysis. Thermodynamic parameters (∆H and ∆G) obtained from this adsorption site suggest considerable stability and indicate a spontaneous reaction in the order O_DDVP@Ga@C60 > O_DDVP@In@C60 > O_DDVP@C60. These findings demonstrate that the metal-decorated surfaces adsorbed on the oxygen (O) site of the biomolecule offer high sensitivity for detecting the organophosphate molecule DDVP.

This study is evaluated the concentration of some toxic heavy metals present in selected cosmetics sold and used in Calabar, Cross River State, Nigeriausing aFlame Atomic Absorption Spectrophotometer (AAS), VGP 210 (BUCK Scientific) Model. The result revealed that the average  concentration of the metals in mg/L ranged thus: Cadmium (0.012- 0.046), Chromium (0.002- 0.022), Lead (0.004- 0.024) and Nickel (0.140- 0.416). The concentration of Arsenic and Mercury was not detected, and were considered string variables in this study. From the results, the concentration of the metals detected were within the permissible limit of the World Health Organization (WHO) except Cadmium that was slightly above the WHO limit in one of the samples with a value of 0.046 mg/L. These results indicate that the selected cosmetics used in Calabar contains low amounts of the heavy metals analyzed in this study and may not pose any health risk for now, except that the accumulation of such little amounts over timedue to prolonged use of these cosmetics may cause harm. Keywords: Concentration, Heavy metals, Cosmetics, Calabar

The soil and edible vegetable samples were collected from Obanliku Urban Area of Cross River State and were digested and analyzed for the cadmium (Cd), chromium (Cr), iron (Fe) and mercury (Hg) (heavy metals) concentration using Flame Atomic Absorption Spectrometer (AAS) in Chemistry Laboratory, University of Calabar. The eight vegetables were considered such as Amaranthus spp., Corchorus olitorius, Murraya koenigii, Ocimum grattissimum, Solanum melongena, Talinum triangulare, Telfaira occidentalis and Vernonia amygdalina. The results revealed that the mean concentration of the metals in the soil in mgkg-1 ranged from (0.003-0.017) and (0.003-0.015) for Cd, (0.005-0.040) and (0.004-0.038) for Cr, and (0.052-1.541) and (0.050-1.511) for Fe in rainy and dry seasons respectively. Also, the mean concentration of the metals accumulated by the vegetables in mgkg-1 ranged from (0.002-0.010) for Cd, (0.003-0.018) and (0.003-0.016) for Cr, and (0.013-0.175) and (0.013-0.150) for Fe in rainy and dry season respectively. The concentration of Hg was not detected in the soil or vegetables. The mean concentration accumulated by the vegetables and that present in the soil was in the order: Fe > Cr > Cd > Hg. These results showed that there is no significant difference between the amount of metals in the soil or that accumulated by the vegetables in rainy and dry seasons of the year. Also the amount of metals accumulated by most of the vegetables was directly proportional to the amount present in the soil where they are planted. The bioaccumulation ratios and Target Hazard Quotients (THQ) were all less than 1. The results indicate that the concentration of Cd, Cr, Fe & Hg in the soil and vegetables were still low and within the permissible limits of WHO/FAO. Thus, the consumption of the vegetables in the area at the time when this study was carried out may not pose any health risk.