The contamination of heavy metals in various environmental matrices is a major concern to many researchers and requires attention due to their detrimental impacts on the environment and humans as well. This research w...The contamination of heavy metals in various environmental matrices is a major concern to many researchers and requires attention due to their detrimental impacts on the environment and humans as well. This research was carried out to investigate heavy metal levels in soils of some selected sites along the Vaisigano river in Upolu, Samoa. The soil samples were also analysed for physicochemical parameters such as pH, Electrical Conductivity, Moisture Factor, Cation Exchange Capacity (CEC), Organic Carbon, Nitrogen, Phosphorus, and Soil texture. The mean concentrations of heavy metals at the Lelata site were 0.19 ± 0.05 mg/kg (Pb), 0.37 ± 0.45 mg/kg (Mn), 0.15 ± 0.02 mg/kg (Zn) and 0.56 ± 0.42 mg/kg (Cu). The mean concentrations of heavy metals at the Alaoa site were 0.13 ± 0.03 mg/kg (Pb), 0.42 ± 0.51 mg/kg (Mn), 0.16 ± 0.03 mg/kg (Zn) and 0.45 ± 0.43 mg/kg (Cu). The heavy metal concentrations from both sites were lower than the permissible levels given by the World Health Organization (WHO). The Geo-accumulation pollution index (I(geo)) of heavy metals in the Lelata site was Cu > Mn > Pb > Zn and from the Alaoa site was Cu > Pb > Zn > Mn.展开更多
This study investigates the temporal and spatial variations of phosphate concentrations in riverine systems,highlighting their relationship with precipitation patterns and temperature.Monthly climate data reveal disti...This study investigates the temporal and spatial variations of phosphate concentrations in riverine systems,highlighting their relationship with precipitation patterns and temperature.Monthly climate data reveal distinct wet and dry seasons,with precipitation peaking in December and January at over 450 mm and 525 mm,respectively,and reaching its lowest levels in June and July at approximately 75 mm.Maximum and minimum temperatures remain stable,averaging 30℃ and 25℃,respectively.Phosphate concentrations follow a seasonal pattern,with low levels(1.0-1.3 mg/L)recorded from July to November.Peaks occur in December(3.50±0.63 mg/L)and June(4.00±1.34 mg/L),coinciding with periods of heavy rainfall.Increased precipitation likely contributes to runoff from agricultural and residential areas,introducing higher phosphate loads into water bodies.Site-specific analysis reveals statistically significant differences(p<0.05),in phosphate levels,influenced by land use,vegetation cover,and human activities.The lower stream,subject to cumulative upstream runoff,exhibits the highest variability,while the upper stream shows reduced concentrations due to minimal human interference and better vegetation cover.This study provides critical insights into the interplay between climatic variables and nutrient dynamics,offering valuable implications for water quality management and the preservation of aquatic ecosystems in Samoa.展开更多
文摘The contamination of heavy metals in various environmental matrices is a major concern to many researchers and requires attention due to their detrimental impacts on the environment and humans as well. This research was carried out to investigate heavy metal levels in soils of some selected sites along the Vaisigano river in Upolu, Samoa. The soil samples were also analysed for physicochemical parameters such as pH, Electrical Conductivity, Moisture Factor, Cation Exchange Capacity (CEC), Organic Carbon, Nitrogen, Phosphorus, and Soil texture. The mean concentrations of heavy metals at the Lelata site were 0.19 ± 0.05 mg/kg (Pb), 0.37 ± 0.45 mg/kg (Mn), 0.15 ± 0.02 mg/kg (Zn) and 0.56 ± 0.42 mg/kg (Cu). The mean concentrations of heavy metals at the Alaoa site were 0.13 ± 0.03 mg/kg (Pb), 0.42 ± 0.51 mg/kg (Mn), 0.16 ± 0.03 mg/kg (Zn) and 0.45 ± 0.43 mg/kg (Cu). The heavy metal concentrations from both sites were lower than the permissible levels given by the World Health Organization (WHO). The Geo-accumulation pollution index (I(geo)) of heavy metals in the Lelata site was Cu > Mn > Pb > Zn and from the Alaoa site was Cu > Pb > Zn > Mn.
文摘This study investigates the temporal and spatial variations of phosphate concentrations in riverine systems,highlighting their relationship with precipitation patterns and temperature.Monthly climate data reveal distinct wet and dry seasons,with precipitation peaking in December and January at over 450 mm and 525 mm,respectively,and reaching its lowest levels in June and July at approximately 75 mm.Maximum and minimum temperatures remain stable,averaging 30℃ and 25℃,respectively.Phosphate concentrations follow a seasonal pattern,with low levels(1.0-1.3 mg/L)recorded from July to November.Peaks occur in December(3.50±0.63 mg/L)and June(4.00±1.34 mg/L),coinciding with periods of heavy rainfall.Increased precipitation likely contributes to runoff from agricultural and residential areas,introducing higher phosphate loads into water bodies.Site-specific analysis reveals statistically significant differences(p<0.05),in phosphate levels,influenced by land use,vegetation cover,and human activities.The lower stream,subject to cumulative upstream runoff,exhibits the highest variability,while the upper stream shows reduced concentrations due to minimal human interference and better vegetation cover.This study provides critical insights into the interplay between climatic variables and nutrient dynamics,offering valuable implications for water quality management and the preservation of aquatic ecosystems in Samoa.
