Health Risk Assessment of Heavy Metals in Sediment of Tropical Freshwater Stream

An investigation of the heavy metals in the bed sediment of Asunle stream was carried out to assess how seriously the sediment is polluted using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The potential health risk assessment was calculated for a lifetime exposure (ingestion) based on the United State Environmental Protection Agency (USEPA) models to determine the carcinogenic and noncarcinogenic risks for children and adults. The range of values (mg/kg) of heavy metals in bed sediment were: Fe (2850 – 7260), Mn (58 – 209), Co (0.7 – 33), Ti (21.6 – 67), Ba (1.61 – 9.81), Zn (7.5 – 79), Cu (5.6 – 25), As (8 – 137), Al (273 – 2160), Y (24 – 49), and Sr (0.10 – 5.3). As and Sr, values were below the background values for typical soil. The health risk assessment of heavy metals in the bed sediments revealed that carcinogenic risk was almost insignificant while the non-carcinogenic risk was significant since their values were above the recommended minimal risk level. The results also revealed that children are more vulnerable to hazards than adults. The chronic hazard quotient index for exposure to these metals through ingestion exceeded the acceptable USEPA value of 1.0

Heavy Metals in Over-the-Counter Pediatric Drugs Locally Produced in Uganda: A Stare at Manganese, Lead, and Cadmium: Heavy metals in OTC pediatric drugs

This study evaluated the amounts of lead (Pb), cadmium (Cd), and manganese (Mn) in pediatric over-the-counter medications made in Uganda. Twelve distinct brands from four categories of pediatric medications (antihistamine, cough expectorant, antipyretic and analgesic, and cold and flu medication) were chosen at random from Kampala's drug stores. Before acid digestion, the syrups were washed with concentrated HNO3:HClO4 (5:1), and the metals were measured using FAAS AAnalyst 400. The average values (µg/mL) found were as follows: antihistamine (Cd, 0.89±0.122; Pb, 7.01±10.0); cold and flu (Cd, 0.89±0.073; Pb, 1.69±0.718); cough expectorant (Cd, 0.14±0.0196; Pb, 1.55±1.332); and antipyretics and analgesic (Cd, 0.16±0.774; Pb, 1.76±1.123). Antihistamines and medications for the cold and flu were not detectable in sample codes (A1 and B1), respectively. In every sample examined, manganese levels were below the non-detectable threshold. The different coefficient of variation (CV) values found in this investigation demonstrated that the metals in pediatric medications came from a wide variety of sources. According to total metal content, each brand of pediatric medication contains Antihistamine (56%), Antipyretic and analgesic (15%), Cold and flu (15%), and Cough expectorant (14%). Uganda's pediatric medicine producers should be closely watched by the National Drug Agency

Detection of Organochlorine Pesticide (OCPs) Residues and Trace Metals in Some Selected Malt Drinks in Nigeria

In this study we evaluated the trace metals and toxic residues of pesticides in commercial malta drinks sold in Nigeria markets. Residual concentrations of seventeen (17) chlorinated hydrocarbons and trace metals were determined in fifteen samples of three batches each of five selected brands of Malta drink sold in Nigeria markets. Gas Chromatograph-Electron Capture Detector (GC-ECD) and Atomic Absorption Spectrophotometry (AAS) were employed in quantitative analysis. The results revealed that all the malt drink analyzed have one or more OCPs detected. The presence of eleven (11) OCPs residue were detected at varying concentrations. The total burden of OCPs in the samples was in the following order: AMS > DUB > MAG > HIM > MLT. Trace metals results revealed that Cd was below detection limit in all the samples while Pb; Ni and Cr were above World Health Organization and United State Environmental Protection Agency (WHO/USEPA) limits for drinking water

Concentrations of Polybrominated Diphenyl Ethers (PBDEs) in Water from Asunle Stream, Ile-Ife, Nigeria

This study assessed the concentrations of polybrominated diphenylethers (PBDEs) in stream water obtained from Asunle stream, an adjoining stream of the Obafemi Awolowo University dumpsite. Water samples were collected for a period of eight months from six different locations comprising of a spot upstream in an uphill area relative to the refuse dumpsite and five others downstream along the stream course. The sampled waters were extracted with dicholoromethane using liquid-liquid extraction method and cleanup was carried out with silica gel. The final extracts after concentration were analyzed using GC-MS/MS. The recovery experiments were adequate (105%–110%). The mean levels of Ʃ6PBDEs compounds analyzed ranged from 0.03 to 0.45 ng/mL. Seasonal variability of PBDEs indicated that higher levels were found during the wet season. The levels of PBDEs recorded in this work were relatively lower compared to the values reported in the literature from other developed nations

Assessment of two persistent bioaccumulative toxicants in the UNESCO protected river of Osun-Osogbo, Nigeria

Abstract Introduction Osun River dissecting the Osun-Osogbo Sacred Grove, though inscribed on the World Heritage List, has been rarely assessed for biodiversity values or ecotoxicology. In this study, we investigated the concentrations of Cu and Zn in the benthic sediments and two dominant gastropod species (Melanoides tuberculata and Lanistes varicus) of the Osun River. Benthic sediment and gastropod samples were collected on quarterly basis from June 2015 to March 2016 along the longitudinal stretch of the river. Dry samples were digested and analysed for Cu and Zn using the atomic absorption spectrophotometry. Results With the exception of September sampling period, the two metals recorded higher values in the animals than in the sediments. Cu (1.23 ± 0.81 μg/g) was much lower (p < 0.01) than zinc (6.29 ± 2.15 μg/g) in the benthic sediments. In the same vein, Cu was significantly lower (p < 0.01) than Zn in both species. Both metals recorded much lower values than their average concentrations in the Earth’s crust as well as the recommended limits for freshwater life. Comparatively, L. varicus recorded higher bioaccumulation factor than M. tuberculata. Conclusions Findings from this study suggest that both metals posed no toxicological risk to the freshwater system of Osun River. Concentrations of both metals in the sediments as well as their accumulation factors in both gastropod species were indicative of an unimpacted freshwater system

Assessment of polybrominated diphenyl ethers in sediment of Asunle stream of the Obafemi Awolowo University, Ile-Ife, Nigeria

Assessment of levels of polybrominated diphenyl ethers (PBDEs) from the sediment of Asunle stream, an adjourning stream of the Obafemi Awolowo University dumpsite, has been carried out. Sediment samples were collected from the stream at six locations for a period of 8 months, composed of 4 months each of wet (May–Aug) and dry (Nov–Feb) seasons. Soxhlet extraction was employed for the isolation of all the target compounds from the sediment samples. Extracts were further subjected to multi-layer column chromatography employing different forms of silica gel. The prepared samples were analyzed using GC-MS. The overall mean concentrations of the total PBDEs ranged from 1.80 to 9.46 ng/g. The results showed that the concentrations of the PBDEs were slightly higher during the wet season than those during the dry season. In all the studied locations, BDE28, BDE47, BDE99, BDE100, BDE153, and BDE154 were detected in all the sediment samples at concentrations that ranged from 0.73 to 10.43 ng/g. Results of this study indicated that BDE153 was the major pollutant of the Asunle stream sediments

Effectiveness of termite hill as an economic adsorbent for the adsorption of alizarin red dye

The adsorption of alizarin red (AR) dye onto termite hill sample (THs) was investigated. Prior to the adsorption studies, the elemental, morphological, surface and structural properties of THs were examined by modern analytical methods. Instrumental analysis showed that the homogenous micro-structured THs are comprised of iron oxide, silica oxide, and alumina as major components. Experiments showed that the adsorption capacity of AR decreases with increasing pH and initial AR concentrations, and increases with increasing contact time, stirring speed and temperature. The equilibrium study obeyed the Langmuir adsorption model and the kinetics followed the pseudo-second-order model. About 95.0% AR reduction (1.425 mg/g) was achieved when 0.8 g of THs was mixed with 30 mL of 40 mg/L AR solution for 120 min at 400 rpm and a pH of 2. Thermodynamic study suggested that AR adsorption onto THs is spontaneous at higher temperatures of 323 K and above (ΔGo values are negative). However, ΔGo are positive at lower temperatures of 293–313 K, which implies that the adsorption process is not spontaneous at these temperatures. This study showed that THs could be used as alternative, low-cost, natural adsorbents for the removal of dyes from wastewater

Interventions to reduce pesticide exposure from the agricultural sector in Africa: a workshop report

Despite the fact that several cases of unsafe pesticide use among farmers in different parts of Africa have been documented, there is limited evidence of which specific interventions are effective in reducing pesticide exposure and associated risks to human health and ecology. The overall goal of the African Pesticide Intervention Project (APsent) study is to better understand ongoing research and public health activities related to interventions in Africa through the implementation of suitable target-specific situations or use contexts. A systematic review of the scientific literature on pesticide intervention studies with a focus on Africa was conducted. This was followed by a qualitative survey among stakeholders involved in pesticide research or management in the African region to learn about barriers to and promoters of successful interventions. The project was concluded with an international workshop in November 2021, where a broad range of topics relevant to occupational and environmental health risks were discussed such as acute poisoning, street pesticides, switching to alternatives, or disposal of empty pesticide containers. Key areas of improvement identified were training on pesticide usage techniques, research on the effectiveness of interventions targeted at exposure-reduction and/or behavioral changes, awareness-raising, implementation of adequate policies, and enforcement of regulations and processe