Background. There is increasing global concern over the health effects of heavy metals arising from various anthropogenic activities, especially mining. Mining activities in developing countries are often carried out at an artisanal level using a variety of extraction methods with human health and environmental consequences. Objectives. The broad objective of this study is to assess the chemical forms, distribution pattern, and health risks due to mining and processing techniques at a gold mining site in Igun, Osun State, Nigeria. Methods. Samples were collected from 28 active mine pits and sequentially extracted using standard methods. Extracts were analyzed for metals using inductively coupled plasma optical emission spectrometer (ICP/OES), while health risk was assessed using United States Environmental Protection Agency (USEPA) and Dutch methods. Chemical speciation of heavy metals and health risk assessment was calculated using mobile phase fraction summation. Results. Metals were exclusively present...

This study investigated the concentration of glyphosate in water (groundwater and surface), soil (top and sub) on cassava and maize farms within 3 farm settlements (Akufo, Ilora and Otiri Ipapo) from Ido, Oyo and Iseyin Local Government Areas of Oyo state, Nigeria. Samples of Top and sub soil were taken from the farms while water was collected from wells (groundwater) and streams (surface water) around each farm settlement using standard methods. Crops (cassava and Maize) samples were collected from each of the selected farm after harvest. The samples were collected over a six-month period to reflect seasonal variation. The glyphosate levels were determined using HPLC-FLD after liquid-liquid extraction technique for water and soxhlet extraction for soil crops The pH, electrical conductivity (EC), total dissolved solids (TDS) values for groundwater were within the WHO limits while values recorded for surface water were above the WHO limits. The phosphate and nitrate values were high in surface water compared to groundwater. High concentration of the exchangeable cations were recorded at the top soil for all the farms with values ranging from 4.0 ± 0.1 to 8.2 ± 0.0 for Ca²⁺, 2.9 ± 0.0 to 5.1 ± 0.1 for Mg²⁺, 0.3 ± 0.2 to 0.55 ± 0.0 for Na⁺, and 0.32 ± 0.0 to 8.2 ± 0.0 for K⁺. the residual concentration of glyphosate taken from wells and taps (groundwater) were within the maximum concentration of glyphosate in drinking water (0.7 mgL⁻¹). Glyphosate concentrations observed were higher in soil samples from all farm settlements during wet season compared to dry, higher concentrations were also observed in surface water during wet season (August) compared to dry, with Akufo farm settlement having the highest concentrations of 29.40 ± 0.83 mgL⁻¹. The glyphosate residues were also higher in cassava (0.3 ± 0.0 mgKg⁻¹) compared to maize (0.07 ± 0.08 mgKg⁻¹) across each farm settlement. Generally, the higher concentrations observed during wet season in both soil and water samples were as a result of active farm activities during wet season and run off respectively. If herbicide usage is not properly monitored within these settlements, it can pose a threat to aquatic animals and humans around the settlements, thus a sustainable and conservative farming is advised.

Breast milk is an essential source of nutrients and energy for infants. The study analyzed for the levels of essential, toxic and rare earth elements in the breast milk of lactating mothers within Abeokuta metropolis. Thirty-seven (37) breast milk samples were collected with consents of lactating mothers at Ogun State General Hospital in Abeokuta. The samples were digested using standard method and analyzed for essential, toxic and rare earth elements using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The data were subjected to descriptive analysis. The results showed higher concentrations of toxic elements than essential elements in the breast milk of lactating mothers, where five toxic metals: Ag, Ti, V, Pb and Ba were observed to be present in 11, 14, 15, 17 and 23 breast milk samples respectively. Two essential (P and S) and two toxic (Cd and Hg (except sample 19)) elements were observed to be present in all the breast milk samples. Rare Earth Elements (except Sr, U and Rb) were below the detection limit of the instrument. Though three breast milk samples (12, 14 and 17) were observed safe, they contained two toxic (Cd and Hg) and a rare earth trace (Rb) element. It could be concluded that despite the inherent benefits of human breast milk with essential elements to the infants, it can still be a source of toxic and trace earth metals contamination.

Groundwater from the communities adjoining Abule Egba (ABE), Epe (EPE), Ikorodu (IKR), Olushosun (OSH) and Solous (SOL) dumpsites in Lagos State, Nigeria, were collected and analyzed for polybrominated diphenyl ethers. Water samples were extracted using liquid-liquid extraction followed by Gas Chromatography/Mass Spectroscopy analysis using the already validated standard method. PBDEs concentrations ranged from 7 ± 10 (IKR) to 78 ± 109 µgL⁻¹ (ABE) for BDE-28; 5.4 ± 0.3 (OSH) to 31.5 ± 27.3 µgL⁻¹ (ABE) for BDE-47; 17 ± 24 (ABE) to 183 ± 226 µgL⁻¹ for BDE-100; 11.7 ± 16.5 (ABE) to 174 ± 217 µgL⁻¹(EPE) for BDE-99; 117 ± 166 (ABE) to 2034 ± 2819 µg L⁻¹ (EPE) for BDE −183; 296 ± 392 (IKR) to 4283 ± 1278 µg L⁻¹ (EPE) for BDE-209. BDE- 153 and BDE- 154 were not detected in all the water samples, while BDE- 28 was only detected in ABE and IKR water samples. The BDE- 209 was the most dominant congener in all the water samples. The cumulative Hazard Index (HI) values for children through ingestion route ranged from 4.95 E + 00 (SOL) to 4.53 E + 01 (EPE), while in adults, it ranged from 4.25 E + 00 (SOL) to 3.88 E + 01 (EPE). This study confirmed the presence of PBDEs at an elevated concentration in groundwater. Since there is no regular supply of pipe-borne water in the study area, residents consume the contaminated groundwater and may be exposed to endocrine-disrupting chemicals. Therefore, the government should provide pipe-borne water for the populace and discourage people from living close to the dumpsites.