scholarly journals Seasonal study of contamination by metal in water and sediment in a sub-basin in the southeast of Brazil

2011 ◽  
Vol 71 (4) ◽  
pp. 833-843 ◽  
Author(s):  
WAC. Chiba ◽  
MD. Passerini ◽  
JAF. Baio ◽  
JC. Torres ◽  
JG. Tundisi
Keyword(s):  
Rainy Season ◽  
Principal Component ◽  
Dry Season ◽  
Seasonal Differences ◽  
Sediment Samples ◽  
Fluorescent Lamps ◽  
Water And Sediment ◽  
Temporal Occurrence ◽  
Bodies Of Water ◽  
Water And Sediment Samples

The spatial and temporal occurrence of heavy metals (Al, Cd, Pb, Zn, Cr, Co, Cu, Fe, Mn and Ni) in water and sediment samples was investigated in a sub-basin in the southeast of Brazil (São Carlos, SP). All samples were analysed using the USEPA adapted metal method and processed in an atomic absorption spectrophotometer. The discriminant analysis demonstrated that there are significant seasonal differences of metal distribution in the water data, but there are no differences to sediment. The basin studied has high levels of contamination by toxic metals in superficial water and sediment. The superficial water, in the rainy season, presented high levels of Cr, Ni, Pb and Cd, while in the dry season it presented high levels of Zn and Ni. The Principal Component Analysis demonstrated that the season has a huge influence on the levels, types and distribution of metals found in water. The source of contamination was probably diffuse, due to products such as batteries and fluorescent lamps, whose dump discharge can contaminate the bodies of water in the region in the rainy season. Due to fires from the harvest of sugar cane, high levels of Zn were found into the environment, in the dry season.

scholarly journals Contamination Levels of Organochlorine and Organophosphorous Pesticide Residues in Water and Sediment from River Owena, Nigeria

2019 ◽  
pp. 1-11
Author(s):  
Yetunde A. Adeshina ◽  
Akinnawo Solomon ◽  
Aiyesanmi F. Ademola
Keyword(s):  
Water Samples ◽  
Pesticide Residues ◽  
Rainy Season ◽  
Negative Impact ◽  
Fish Farming ◽  
Dry Season ◽  
Sediment Samples ◽  
Water And Sediment ◽  
Organophosphorous Pesticide ◽  
Contamination Levels

River Owena functions as the source of water for the Owena dam which supplies drinking water to the communities in the region, the river also plays an important economic role in irrigation and fish farming in the region. But there has been an indiscriminate used of pesticide because residents of the study area are not well orientated concerning the negative impact of pesticide in the environment. Analysis of organochlorine and organophosphorous pesticide residues was carried out in water and sediment from river Owena, the objective of the research is to determine the contamination levels of organochlorine and organophosphorous pesticide in the water and sediment of river Owena. Analysis was carried out using gas chromatography coupled with electron capture detector in order to identify and quantify the concentration of organochlorine and organophosphorous pesticide in the water and sediment samples from river Owena. Analysis revealed the contamination of water and sediment with organophosphorous pesticide residues at different contamination levels in both dry and rainy season, while a low levels of organochlorine pesticide residues only during the dry season. The TOPP for sediment samples ranges from 1.045mg/L during the dry season and 2.279mg/L during the rainy season, while the TOPP for water samples ranges from 7.163mg/L during the dry season to 7.83mg/L during the rainy season. The TOCP values ranges from 1.288mg/L to 0.015mg/L for sediment and water samples respectively during the dry season, while organochlorine pesticides were not detected during the rainy season. The occurrence and seasonal variation of organophosphorous pesticide residues in river Owena can be attributed to the intense agricultural and urban activities in the vicinity of river Owena. 

scholarly journals Heavy Metals Analysis and Health Risk Assessment of Three Fish Species, Surface Water and Sediment Samples in Ogbaru Axis of River Niger, Anambra State, Nigeria

2021 ◽  
pp. 64-81
Author(s):  
Opeyemi F. Ojaniyi ◽  
Patrice A. C. Okoye ◽  
Daniel O. Omokpariola
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Surface Water ◽  
Fish Species ◽  
Dry Season ◽  
Sediment Samples ◽  
Anambra State ◽  
Water And Sediment ◽  
River Niger ◽  
Water And Sediment Samples

Human activities on environmental resources have negatively affected floras and faunas in maintaining fair balance. In this research study, selected heavy metals (Al, As, Cd, Cr, Cu, Fe, Hg, Pb, Ni, Zn) concentration in three fish species (Clarias gariepinus, Heterotis niloticus and Anguilla labiate), surface water and sediment samples in Ogbaru axis of River Niger, Anambra State, Nigeria. We evaluated the samples using atomic absorption spectrophotometer (AAS). The result of heavy metals (Cu, Fe, Zn, Ni, Pb, Cd, Al, Cd) analysis in fish samples showed that Cr was detected in Clarias garipinus and Anguilla labiate with a concentration of 0.001mg/kg in both species but was not detected in Heterotis niloticus. Hg and Al were not detected in Anguilla labiate but both metals were detected in the other fish species with a mean concentration of 0.311mg/kg and 0.019mg/kg respectively for Clarias garipinus and 0.001mg/kg and 0.005mg/kg respectively for Heterotis niloticus. In decreasing order, the heavy metal concentration in Clarias garipinus in increasing order of Cu >Fe > Ni > Hg > Pb > Zn > As > Cd > Al > Cr, while Heterotis niloticus followed the order Cu > Zn > Fe > Ni > Pb > Cd > Al > As > Hg > Cr, and  Anguilla labiate followed the pattern of Cu > Fe > Zn > Ni > Pb > Cd > Cr > As > Hg > Al. For surface water, As (0.005mg/l), Cd (0.032 mg/l), Cr (0.099 mg/l), Cu (0.186 mg/l), Fe (2.308 mg/l), Hg (1.501 mg/l) and Pb (0.724 mg/l) showed high concentration for the raining season compared to dry season, as Al (0.246 mg/l), Ni (0.773 mg/l) and Zn (2.903 mg/l) were dominant during dry season, while sediment samples of Cr (0.112 mg/kg), Cu (0.029 mg/kg), Ni (0.945 mg/kg) and Pb (0.039 mg/kg) concentration in raining season were higher than dry season and vice versa for other As, Cd, Fe, Hg, Zn. Correlation matrices showed positive value showing that heavy metals were from a similar source with migration route and vice versa for negative correlation. Health and exposure risk assessment was conducted for carcinogenic and non-carcinogenic exposure in adults and children, where the cumulative cancer risk was within USEPA regulatory standard (1.0E-6 – 1.0E-04) and cumulative hazard index were above 1 for adults (2.02) and children (4.93), implying that children are at risk of having adverse health issues compared to adults. Therefore, there is a need for regulatory advocacy and special care to mitigate anthropogenic release and safeguard the environment.

Taking the pulse of Mother Ganga - Revealing the visible and invisible water pollution crisis along the Ganges River

2021 ◽  
Author(s):  
Stefan Krause ◽  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Land Use ◽  
Surface Water ◽  
River Network ◽  
Ganges River ◽  
Sediment Samples ◽  
Water And Sediment ◽  
The Ganges ◽  
Water And Sediment Samples

<p>It is probably hard to overestimate the significance of the River Ganges for its spiritual, cultural and religious importance. As the worlds’ most populated river basin and a major water resource for the 400 million people inhabiting its catchment, the Ganges represents one of the most complex and stressed river systems globally. This makes the understanding and management of its water quality an act of humanitarian and geopolitical relevance. Water quality along the Ganges is critically impacted by multiple stressors, including agricultural, industrial and domestic pollution inputs, a lack and failure of water and sanitation infrastructure, increasing water demands in areas of intense population growth and migration, as well as the severe implications of land use and climate change. Some aspects of water pollution are readily visualised as the river network evolves, whilst others contribute to an invisible water crisis (Worldbank, 2019) that affects the life and health of hundreds of millions of people.</p><p>We report the findings of a large collaborative study to monitor the evolution of water pollution along the 2500 km length of the Ganges river and its major tributaries that was carried out over a six-week period in Nov/Dec 2019 by three teams of more than 30 international researchers from 10 institutions. Surface water and sediment were sampled from more than 80 locations along the river and analysed for organic contaminants, nutrients, metals, pathogen indicators, microbial activity and diversity as well as microplastics, integrating in-situ fluorescence and UV absorbance optical sensor technologies with laboratory sample preparation and analyses. Water and sediment samples were analysed to identify the co-existence of pollution hotspots, quantify their spatial footprint and identify potential source areas, dilution, connectivity and thus, derive understanding of the interactions between proximal and distal of sources solute and particulate pollutants.</p><p>Our results reveal the co-existence of distinct pollution hotspots for several contaminants that can be linked to population density and land use in the proximity of sampling sites as well as the contributing catchment area. While some pollution hotspots were characterised by increased concentrations of most contaminant groups, several hotspots of specific pollutants (e.g., microplastics) were identified that could be linked to specific cultural and religious activities. Interestingly, the downstream footprint of specific pollution hotspots from contamination sources along the main stem of the Ganges or through major tributaries varied between contaminants, with generally no significant downstream accumulation emerging in water pollution levels, bearing significant implications for the spatial reach and legacy of pollution hotspots. Furthermore, the comparison of the downstream evolution of multi-pollution profiles between surface water and sediment samples support interpretations of the role of in-stream fate and transport processes in comparison to patterns of pollution source zone activations across the channel. In reporting the development of this multi-dimensional pollution dataset, we intend to stimulate a discussion on the usefulness of large river network surveys to better understand the relative contributions, footprints and impacts of variable pollution sources and how this information can be used for integrated approaches in water resources and pollution management.</p>

scholarly journals What are the main local drivers determining richness and fishery yields in tropical coastal fish assemblages?

2018 ◽  
Vol 35 ◽  
pp. 1-12
Author(s):  
Cynthia Diniz Souza ◽  
Vandick S. Batista ◽  
Nidia Noemi Fabré
Keyword(s):  
Wind Speed ◽  
Rainy Season ◽  
Fish Assemblages ◽  
Principal Component ◽  
Dry Season ◽  
Community Diversity ◽  
Tropical Species ◽  
Coastal Fish ◽  
Wide Range ◽  
Diversity Profiles

Seasonal ecological effects caused by temperature and photoperiod are typically considered minimal in the tropics. Nevertheless, annual climate cycles may still influence the distribution and abundance of tropical species. Here, we investigate whether seasonal patterns of precipitation and wind speed influence the structure of coastal fish assemblages and fishing yields in northeast Brazil. Research trips were conducted during the rainy and dry seasons using commercial boats and gear to sample the fish community. Diversity was analyzed using abundance Whittaker curves, diversity profiles and the Shannon index. Principal Component Analysis (PCA) was used to analyze associations between the abundance of species and various environmental variables related to seasonality. A total of 2,373 fish were collected, representing 73 species from 34 families – 20 of which were classified as both frequent and abundant. Species richness was greater and more equitable during the rainy season than the dry season – driven by changes in the precipitation rather than to wind speed. Species diversity profiles were slightly greater during the rainy season than the dry season, but this difference was not statistically significant. Using PCA was identified three groups of species: the first associated with wind speed, the second with precipitation, and the third with a wide range of sampling environments. This latter group was the largest and most ecologically heterogeneous. We conclude that tropical coastal fish assemblages are largely influenced by local variables, and seasonally mediated by annual changes related to precipitation intensity and wind speed, which in turn influences fishery yields.

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