SOUTHERN JOURNAL OF SCIENCES

Introduction: The detection of methanol in alcoholic beverages represents a critical public health issue, particularly in light of the recent outbreak of poisonings in Brazil, which registered 58 confirmed cases and 15 deaths through October 2025. Methanol's toxicity, with an estimated lethal dose ranging from 0.5 to 1.5 g/kg, requires reliable analytical methods for health surveillance. Brazilian legislation establishes a maximum limit of 20 mg/100 mL of anhydrous alcohol; however, the need for accessible screening methods in field settings remains an important challenge. Objective: To critically compare three analytical methods for methanol determination: classical qualitative methods (Lucas Test and dichromate/Schiff), Brazilian colorimetric method, and gas chromatography with flame ionization detector (GC-FID), evaluating their performance and applicability in resource-limited contexts. Methods: Theoretical-comparative approach through critical analysis of specialized literature and normative technical documentation. Methods were evaluated according to: operational principle, sensitivity (LOD/LOQ), selectivity, operational complexity, analysis time, and practical applicability. Results: The Lucas Test is not applicable for methanol detection. Colorimetric methods showed moderate sensitivity (LOD ~20-160 mg/100 mL), a 10-30-minute execution time, low operational complexity, and excellent portability. The Brazilian method presented chemical equivalence with international standards, differing only in the type of reading performed. GC-FID has shown superior sensitivity (LOD ≤ 1 mg/100 mL) and high specificity, but it requires extended time (~45-60 minutes), complex laboratory infrastructure, and specialized operators. Sugars interfere with colorimetric methods. Conclusions: The methods are complementary within a hierarchical system. Colorimetric methods enable rapid field screening, while GC-FID serves as the confirmatory method for forensic analyses. We recommend implementing integrated protocols that combine in situ colorimetric screening with GC-FID confirmation in accredited laboratories for effective health surveillance.

Background: The lack of comprehensive baseline data on raw sewage pollution in Minna, Nigeria's Niger State capital, represents a significant gap in public health information. This deficiency necessitates a systematic study to establish a database documenting sewage pollution patterns in Minna's urban environment. Aim: To employ georeferencing tools and descriptive observations for identifying and mapping potential mosquito breeding sites related to sewage discharge within Minna's built-up areas and to develop an interactive Geographic Information System (GIS) map as an environmental audit tool for public health officials. Methods: The study area was divided into five sectors: Greater Bosso, Minna Central, Greater Maitumbi, Tunga, and Greater Chanchaga. Following initial site familiarization and GIS equipment testing, systematic surveys were conducted. Field teams documented locations of household sewage discharge points, collecting geographic coordinates, temporal data (date, time, weather conditions), and site characteristics. Each identified location was photographed and recorded in standardized data sheets, including household information where available. Results: Using ArcGIS®10.8 software, comprehensive sewage pollution layers were created for each sector by integrating collected field data with Minna's township built-up and settlement shapefiles. The mapping revealed distinct pollution patterns and clusters across different neighborhoods. Discussion: Analysis of the spatial distribution showed a clear correlation between socioeconomic status and sewage management practices, with higher concentrations of improper sewage discharge in low-income areas. Conclusions: This database serves as a valuable resource for public health interventions targeting mosquito breeding grounds. Regular monitoring through periodic sewage pollution audits and expanded geographical coverage is recommended for improved urban health management.

Background: Dams are one of the biggest threats to aquatic biodiversity. They restrict the movement of migratory fish. The construction of barriers can cause the complete extinction of some species from the rivers. When a dam can no longer perform its function or research will determine the need to demolish it, dams are often removed. In the lower part of the Enguri River, Georgia, an irrigation weir is currently non-functional. Aims: This research aims to prove the need to demolish the dam construction on the 44th km of the Enguri River, as it negatively impacts biodiversity and creates an artificial barrier in the river. Methods: Visual inspection was used as a method to assess the morphology and habitat of the dam where it is located. The conversation method was used with Engurhesi LTD representatives to understand the current function of the dam. The Questions were related to the current function of the dam. Results: Based on the conservation with Engurhesi LTD representatives, the study has shown that there is no reason that an irrigation weir might be left in its current state on the Enguri River. Based on the studies, the damage to biodiversity is real and disturbing. Discussion: The irrigation weir on the Enguri River was left untended because of the construction of the Enguri dam. Currently, there is no reason to divert the river Enguri with the help of an irrigation weir as there is no excess water in this river. Conclusions: In conclusion, it can be said that it is necessary to remove the irrigation weir on the Enguri River to restore habitat and mitigate the threats to biodiversity.