Environmental Health Science and Technology

Assessment of the level of selected heavy metals (Hg and Pb) in water, sediment, and fish muscle from gold mining sites: A case study in Dima district, Gambela, Southwest Ethiopia

Sun, 06 Jul 2025 00:00:00 GMT

Assessment of the level of selected heavy metals (Hg and Pb) in water, sediment, and fish muscle from gold mining sites: A case study in Dima district, Gambela, Southwest Ethiopia Okuch Abwola Ongom; Gutama Haile; Higemengist Astatkie Background Artisanal small scales gold mining is a common economic activity in many developing regions, providing livelihoods for local communities. However, this practice often comes at a significant environmental cost. Gold mining in the stud y areas potentially contaminates the aquatic environment since the mining tailings from the amalgamation process are directly discharged into the water body. Due to these practices, mining and agricultural activity in the catchment area of the Akobo River are suspected of adding to the streams connected to the river’s heavy metal load. However, no previous study has been done on the levels of selected heavy metals in the Akobo River. Objectives. The study aimed to assess the level of selected heavy metals Hg and Pb in water, sediment, and the muscles of six fish species collected from the gold mining site. Methods. This study was conducted in the Dima district of Gambela, Ethiopia, specifically at the Akobo River and gold mining sites. It utilized a cross-sectional research design. A total of thirty samples were collected from July 18 to 19, 2022, which included twelve water samples, twelve sediment samples, and six distinct fish samples. The levels of lead (Pb) and mercury (Hg) were determined using Inductively Coupled Plasma Mass Spectrometry (ICP MS). The results were analyzed and compared across sites using a one-way analysis of variance (ANOVA) Results. The finding indicated that Hg was below the detected limit in the water, while Pb ranges 0.52±0.006 to 0.58±0.010 mg/L. In sediments ranges between 0.177±0.002 to 0.272±0.002 mg/kg, and Hg ranges between 0.034±0.001 to 0.084±0.001 mg/kg dry weight, respectively. In the fish samples range between 2.313±0.002 to 3.306±0.002 mg/kg, And Pb ranges 0.195±0.002 to 0.247±0.015 mg/kg dry weight, respectively. Therefore, in the water sample was above the WHO (2011) permissible limits. While Pb and Hg in sediment were below TEL and (ERL) set by CCME and NOAA. Hg and Pb in the fish sample were above the threshold limit by FAO/WHO. The highest Hg and Pb levels were reported in B. docmak, 3.306±0.002 mg/kg and 0.247±0.015 mg/kg, followed by S. filamentosus, 2.313±0.002 mg/kg and 0.206±0.002 mg/kg dry weight, respectively, where both fish were collected at the same station, ST-3 (downstream). Conclusion: Therefore, Akobo River fish and water are not suitable for food, Drinking and other domestic purposes, such as cooking and washing, since the level of heavy metals Hg and Pb level, which are known to be carcinogens, were exceeded the safe limit set by the Ethiopian standard (ESA, 2013) and (FAO/WHO, 2011). Recommendation: Regional and local authorities should aware communities on the health and environmental risks of heavy metal exposure. Stakeholder must regularly monitor fish, water, and sediment quality to track pollution levels. Regulatory bodies should enforce strict waste control measures for mining facilities. Sustainable mining and agricultural practices must be promoted to protect the Akobo River and public health.

Quality Assessment of Raw and Treated Milk Samples Collected From Food and Drink Establishments and Milk Distribution Centers of Jimma City, Southwest Ethiopia

Wed, 11 Jun 2025 00:00:00 GMT

Quality Assessment of Raw and Treated Milk Samples Collected From Food and Drink Establishments and Milk Distribution Centers of Jimma City, Southwest Ethiopia Fikreselam Wubeshet; Temima Jemal; Tizita Teshome; Alemayew Haddis Background: Milk is an important source of nutrition but is also highly susceptible to microbial contamination and adulteration if not handled with hygiene. In Ethiopia, raw milk has been studied extensively, but little is known about the microbial safety of treated milk (boiled or steamed) consumed in urban establishments such as cafes and hotels. Objective: To assess the quality of raw and treated milk samples collected from food and drink establishments and milk distribution centers of Jimma city, southwest Ethiopia. Method: A cross-sectional study was conducted among 201 milk samples collected from food and drink establishments and milk distribution centers from September to October 2024. Stratified systematic random sampling was used, with one milk sample collected per establishment. Laboratory analyses assessed total bacterial count (TBC), total coliform count (TCC) and specific gravity for adulteration. Structured questionnaires and observational checklists captured milk handling practices. Quality assurance included negative controls (uninoculated media, sterile water) were performed. Data were analyzed using Kruskal-Wallis tests, logistic regression and adjusted odds ratios (AOR). Result: A total of 15 raw, 68 boiled, and 118 steamed milk samples were analyzed. Both raw and treated milk frequently exceeded Ethiopian Standards for TBC and TCC, with Staphylococcus aureus and Escherichia coli as dominant isolates. Adulteration was detected in >40% of samples, particularly from steamed milk establishments. Hygiene practices were poor: none of the handlers used personal protective equipment (PPE) and only 22.9% had received training. Observed hygiene did not always align with self-reported practices. Multivariate analysis identified milk adulteration and cooler temperature management as significant predictors of poor milk quality. Conclusion and recommendation: Milk sold in Jimma City is compromised by microbial contamination and adulteration due to poor milk handling practice. Strengthened regulatory enforcement, improved cold chain infrastructure and mandatory handler training are recommended to safeguard consumer health.

Level of Indoor Air Pollutants Concentration, Self-Reported Health Problems, and Associated Factors among Woodworking Enterprises in Jimma City, Oromia Region, Ethiopia

Thu, 18 Sep 2025 00:00:00 GMT

Level of Indoor Air Pollutants Concentration, Self-Reported Health Problems, and Associated Factors among Woodworking Enterprises in Jimma City, Oromia Region, Ethiopia Eyerusalem Gurmessa; Gudina Terefe Tucho; Debela Hinsermu; Mulunesh Deti Background: Woodworking is a labor-intensive occupation that plays a vital role in the economies of developing countries, including Ethiopia. However, workers are often exposed to occupational hazards such as wood dust, volatile organic compounds (VOCs), and poor indoor air quality, which can adversely affect their health. Despite these risks, limited research has examined health problems and contributing factors among woodworkers in Ethiopia, particularly in small-scale enterprises. This study Page | iii aimed to assess the prevalence of self-reported health problems, indoor air pollutant concentrations, and associated factors among woodworkers in Jimma City. Methods: A cross-sectional study was conducted among 130 randomly selected woodworkers. Self- reported health problems were assessed using a modified ATS questionnaire by reviewing different literatures. PM₂.₅ and PM₁₀ were measured with a Hold Peak 5800D dust detector, while TVOCs and CO₂ were measured using an Aeroqual Series 500. Temperature and humidity were recorded with a digital thermo-hygrometer. Bivariate and multivariable logistic regression analyses were used to identify independent predictors of health problems, with statistical significance set at p < 0.05. Results: The prevalence of self-reported health problems among woodworkers was 88.5%. Among enterprises, 41.5% had PM₂.₅ ≥3 mg/m³, 43.8% had PM₁₀ ≥10 mg/m³, and 25.4% had TVOCs >1000 µg/m³. Workers above the age of 35 years old were more likely to report health problems (AOR = 3.10; p = 0.041), whereas workers having higher education, income, and greater than 3 years of experience reported lower health issues. Workers working in sanding, painting, and assembling department showed the risk of exposure by about two-folds (AOR = 1.8–3.9). Similarly, workers working more than 8 hours/day, lack of safety training, smoking, use alcohol, khat chewing, and physical inactive are more likely reported health problems (AOR = 2.9–3.8). Elevated PM₂.₅, PM₁₀, TVOCs, CO₂, high temperature, and humidity were all significantly associated with increased health problems. Conclusion: This study found a high prevalence (88.5%) of self-reported health problems among woodworkers in Jimma City, significantly associated with occupational exposures to PM₂.₅, PM₁₀, TVOCs, CO₂, elevated temperature, and relative humidity. Additional risk factors included working in sanding, painting, and assembling departments, prolonged working hours, and unhealthy personal behaviors. These findings emphasize the need for targeted workplace interventions to enhance air quality, ensure consistent use of personal protective equipment, and promote health education to reduce occupational health risks.

Effects of Stream Sediment and Water Quality on Macro invertebrate Abundance and Diversity in Gilgel Gibe Watershed, Southwestern Ethiopia F Stream Sediment and Water Quality on Macro Invertebrate Abundance and Diversity in Gilgel Gibe Watershed, Southwestern Ethiopia

Sat, 06 Dec 2025 00:00:00 GMT

Effects of Stream Sediment and Water Quality on Macro invertebrate Abundance and Diversity in Gilgel Gibe Watershed, Southwestern Ethiopia F Stream Sediment and Water Quality on Macro Invertebrate Abundance and Diversity in Gilgel Gibe Watershed, Southwestern Ethiopia Amelework Derseh; Mahmud Ahmednur; Kassahun Ebba Background: Freshwater ecosystems face intense anthropogenic pressure, threatening water quality and biodiversity. Benthic macroinvertebrates are key bioindicators of ecosystem health, yet their response to multiple stressors from water and sediment pollution in tropical watersheds remains poorly understood. Study on sediment and water quality is helpful for integrated water resource management. This study investigated the individual and combined effects of stream sediment and water quality on macroinvertebrate abundance and diversity in the Gilgel Gibe watershed, Southwestern Ethiopia, in 2024. Methods: A cross-sectional study was conducted from October to November 2024 across 30 sampling sites in the Gilgel Gibe watershed. Macroinvertebrates were sampled using a rectangular kicking net (15 × 25 × 40 cm) with a mesh size of 300 m and identified to the family level with a stereomicroscope and standard guides. Physicochemical water quality parameters were measured onsite and analyzed in the laboratory using standard methods. Sediment samples were collected and their physicochemical quality was analyzed. Diversity indices (Shannon Wiener, Simpson and Margalef) were calculated. Multivariate analysis; Canonical Correspondence Analysis were applied to examine relationships between sediment and water quality with macroinvertebrate assemblages. Variance Partitioning Analysis quantified the relative contributions of water and sediment quality variables to community variation. Results: A total of 3,370 macroinvertebrates belonging to 7 orders and 36 families were collected; dominated by Ephemeroptera (34.12%), Trichoptera (27.24%), and Odonata (13.73%). Collector-gatherers dominated functional feeding groups (26.47%). Principal Component Analysis explained 37.08% of environmental variation differentiating urban, semi urban and rural sites. Canonical correspondence Analysis showed Water pH, Water Electrical Conductivity, Water Turbidity, Water depth, Sediment Electrical Conductivity, Sediment Organic Carbon and Water width were significant variables which influence the macroinvertebrate assemblage. Water Electrical Conductivity, Water depth, Biological Oxygen Depth5, Sediment Electrical Conductivity, Water pH and Sediment Available Phosphorous were the significant factors which influence the diversity of macroinvertebrates. Variance Partitioning Analysis revealed shared water and sediment variables explained largest proportion of macroinvertebrates assemblage variation. Water quality explained more the assemblage variation than sediment quality. Conclusion: The study revealed that macroinvertebrate abundance and diversity regulated jointly by water and sediment quality, and their combined effect is larger than their individual inputs. The shared effects of water and sediment variables explained a notable portion of community variation; highlighting the need for integrated ecosystem assessment. Water exerted a stronger separate influence on the assemblage than sediment quality. Therefore, effective biomonitoring and conservation of such ecosystems need a concerted approach with a priority for water quality management within the framework of sediment quality.