scholarly journals CONTAMINATION BY HEAVY METALS AND ITS CONSEQUENCES: REFLECTIONS

2020 ◽  
Vol 3 (1) ◽  
pp. 101
Author(s):  
Gabrielle Diniz dos Santos ◽  
Gil Dutra Furtado ◽  
Cíntia Cleub Neves Batista
Keyword(s):  
Heavy Metals ◽  
Urban Areas ◽  
Memory Loss ◽  
Trophic Levels ◽  
Low Fertility ◽  
Free Form ◽  
Dissolved Metals ◽  
Physiological Factors ◽  
The Central Nervous System ◽  
Anthropic Influence

Nowadays, the vast majority of aquatic bodies suffer some kind of anthropic influence due to the great expansion of urban areas and consequently industrial areas, with the pollution coming into such environments. One of the types of pollutants present in the environment are heavy metals, which are found naturally in water bodies due to the weathering of rocks and volcanic activities. The present work is of bibliographic nature, based on searches in the bibliography pertinent to the theme. It is possible to state that with anthropic intervention, such metals become common and are found in greater quantities in the environment in a free form. Thus, some of the most common sources of release of heavy metals into the environment are fertilizers, pesticides, coal and oil combustion, vehicular emissions, mining, smelting, refinement and incineration of urban and industrial waste. Thus making contamination of humans with heavy metals more and more common, one of the most common and easy forms of contamination is through food. The absorption of metals by animals can occur in two ways, bioaccumulation and biomagnification. The first occurs through the diffusion or ingestion of the dissolved metals in the water, which occur through the gills or the digestive tract and then lodges in the animals' tissues, so that the organism cannot absorb it, thus obtaining a bioaccumulative character. In the trophic biomagnification or magnification, the concentration of metals in the organism occurs gradually through the trophic levels. The transfer of contaminants through the food chain characterizes such a process that passes from producers to consumers and the longer the chain, the greater the concentration on the final consumer. Therefore, we can emphasize that the concentration and absorption content of such substances are relative and depend on several environmental and physiological factors that vary between species of beings. Metal poisoning can cause serious damage, such as low fertility, decreased immune defenses, reduced growth rate and pathologies that can lead to senescence. Metals can cause different problems in humans, most of which are of a motor nature, as they directly affect the central nervous system (CNS), and can cause memory loss, uncontrolled limb tremors, muscle atrophy, kidney injuries, among others.

scholarly journals METAIS PESADOS E QUALIDADE DA AGUA DO RIO SÃO FRANCISCO NO SEGMENTO ENTRE TRÊS MARIAS E PIRAPORA - MG: ÍNDICE DE CONTAMINAÇÃO

2012 ◽  
Author(s):  
Elizêne Veloso Ribeiro ◽  
Antônio Pereira Magalhães Junior ◽  
Adolf Heinrich Horn ◽  
Wallace Magalhães Trindade
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Heavy Metal ◽  
Urban Areas ◽  
Heavy Metal Concentration ◽  
Icp Oes ◽  
Dissolved Metals ◽  
Contamination Index ◽  
Sao Francisco River ◽  
São Francisco River

Este trabalho apresenta resultados da avaliação da qualidade da água na secção do Rio São Francisco no segmento entre Três Marias e Pirapora. Foram monitorados parâmetros físico-químicos e os elementos Zn, Cd, Pb, Cr, Co, Cu, Ba, Ni, Al, Mn, Ca, Mg e Fe durante um ano; as concentrações dos metais foram obtidas por leitura em ICP-OES. Vários elementos apresentaram altos níveis de contaminação nas áreas urbano-industriais de Três Marias e Pirapora. No segmento de influência rural entre os dois centros urbanos e a jusante de Pirapora, foram observadas alterações para os metais pesados (Cd, Cu, Cr, Co e Ni), que evidenciam a necessidade de um estudo de contaminação dos solos agrícolas, principalmente irrigados, na região. A variação sazonal marca a diferença da qualidade da água no segmento no que se refere aos metais em suspensão com maiores concentrações na estação chuvosa. O Índice de Contaminação foi definido pela razão entre a concentração encontrada e os limites ambientais da Resolução Conama 357/2005. Os resultados evidenciam a degradação da qualidade da água nos centros urbano-industriais, cujos altos Ic decorrem das elevadas concentrações de Zn, Cd, Cu, Cr e Ni. Chamam atenção principalmente os valores que foram obtidos para os metais dissolvidos devido à maior possibilidade de efeitos tóxicos.. Ressalta-se a necessidade de intervenção nas áreas de maior Ic adjacentes aos centros urbano-industriais visando a melhorar a qualidade da água e responder à população local que tem forte relação com o Rio São Francisco.Palavras-chave: Metais Pesados, Qualidade da Água, Índice de Contaminação, Rio São Francisco e Uso do Solo. ABSTRACT: HEAVY METALS AND WATER QUALITY OF THE SÃO FRANCISCO RIVER IN SEGMENT BETWEEN TRÊS MARIAS AND PIRAPORA –MG: INDEX OF CONTAMINATION. This work presents heavy metal concentration measurements taken across a section of the São Francisco River, between Três Marias and Pirapora, to evaluate water quality. The physicochemical parameters and the elements Zn, Cd, Pb, Cr, Co, Cu, Ba, Ni, Al, Mn, Ca, Mg and Fe were monitored during a one year period; the concentration levels of metals were determined by ICP-OES. High contamination levels were found for many elements in Três Marias and Pirapora urban-industrial areas. The section under rural influence, located between the two urban areas and downstream from Pirapora, presented anomalous heavy metal (Cd, Cu, Cr, Co and Ni) readings. That indicates that soil contamination studies are needed, especially on irrigated soil, in agricultural areas within the region. The index is defined by the ratio between the concentrations found which results from environmental limits established by Resolution CONAMA 357/2005. The results show the degradation of water quality in urban-industrial centers, which high rates of contamination result from high concentrations of Zn, Cd, Cu, Cr and Ni. The values obtained for dissolved metals are especially worth of attention, due to the greater risk of toxic effects caused by them. We stress the need for intervention in the areas showing the highest contamination index - which are located next to urban-industrial centers - to improve water quality and meet the expectations of the locals, whose lives are strongly intertwined with the São Francisco River.Keywords: Heavy Metals, Water Quality, Contamination Index, São Francisco River and Soil Use

Fish tissue metals and zooplankton assemblages of northeastern U.S. lakes

1998 ◽  
Vol 55 (2) ◽  
pp. 339-352 ◽  
Author(s):  
Richard S Stemberger ◽  
Celia Y Chen
Keyword(s):  
Heavy Metals ◽  
Urban Areas ◽  
Regression Models ◽  
Forest Cover ◽  
Geographic Location ◽  
Fish Tissue ◽  
Significant Negative Correlation ◽  
Structural Features ◽  
Trophic Levels ◽  
Structural Variables

Temperature, chlorophyll a, proportion of forest cover on the watershed, and fish tissue Pb, Zn, and Hg concentrations were the primary gradients that best explained the patterns of distribution of zooplankton assemblages in 38 northeastern U.S. lakes. Different zooplankton assemblages were associated with lakes that contained trout or cool-water species of minnows and systems dominated by a variety of warmwater fish species. Heavy metals in fish varied widely with geographic location and proximity to urban areas. Regression models indicated that Zn and Hg in fish were significantly and positively associated with chain length of the zooplankton web. In contrast, these metals and As showed a significant negative correlation with the number of feeding links between species. Structurally complex pelagic webs, comprising many lateral links, may significantly attenuate the transfer of heavy metals to higher trophic levels. Stepwise regression models that included structural variables significantly improved the amount of explainable variance in the fish metal concentrations over those with only physicochemical and land use variables. This study suggests that the high variability of metals in fish observed between adjacent lakes and across the region is explained in part by the structural features of the zooplankton web.

Aging of rural population in Yugoslavia

Stanovnistvo ◽  
1999 ◽  
Vol 37 (1-4) ◽  
pp. 73-92
Author(s):  
Jelena Antonovic
Keyword(s):  
Age Structure ◽  
Rural Population ◽  
Urban Areas ◽  
Age Groups ◽  
Population Ageing ◽  
Low Fertility ◽  
Demographic Ageing ◽  
Substantial Impact ◽  
Mass Migration ◽  
Rural And Urban

Mass migration to urban areas constitutes the basic direct factor of the decline in rural population of Yugoslavia in the second half of the 20th century. Due to the characteristic migration patterns by age and sex, they have had a substantial impact on the change in age structure of rural population towards rapid demographic ageing. By inducing decline in fertility and an increase in mortality, the newly formed age structure is increasingly becoming one of the basic factors to further decline in population, or even the major factor to rural depopulation in the majority of regions. The paper analyzes changes in age structure of rural population in the FR of Yugoslavia and across its republics and provinces during the period from 1961 to 1991. The conditions prevailing during the last census (1991) are particularly highlighted. The author points to distinct differences in ageing of urban versus rural populations, and considerable regional differences at the achieved level of demographic age. Based on the main demographic age indicators (the share of five-year and larger age groups, average age, ageing index and movement in major age-specific contingents), the author concludes that the process of population ageing had taken place in both rural and urban populations, but was more intensive in villages (higher share of the aged, higher index of ageing and higher average age) during the period under review. The author points to distinct ageing of rural population in all republics and provinces. It was most prominent in central Serbia and Vojvodina, while being quite slow in Kosovo and Metohia and recorded mainly in between the last two censuses (1981-1991). Likewise, Kosovo and Metohia constitute the only major region of Yugoslavia in which rural population in 1991 is still demographically younger than the population in urban settlements. Rural versus urban population ageing was much more intensive in other major regions of the country, both from the base and from the apex of the age pyramid. In view of the minimal differences in fertility and mortality levels by type of settlement (particularly in central Serbia and Vojvodina), the author argues that the inherited age structure constitutes the main cause of rapid acceleration in rural population ageing in low fertility regions.

scholarly journals Ecological variation in wealth–fertility relationships in Mongolia: the ‘central theoretical problem of sociobiology’ not a problem after all?

2014 ◽  
Vol 281 (1796) ◽  
pp. 20141733 ◽  
Author(s):  
Alexandra Alvergne ◽  
Virpi Lummaa
Keyword(s):  
Urban Areas ◽  
Market Integration ◽  
Low Fertility ◽  
Theoretical Problem ◽  
Economic Returns ◽  
Trade Offs ◽  
Mass Privatization ◽  
Using Data ◽  
Socioeconomic Success ◽  
Status Enhancement

The negative wealth–fertility relationship brought about by market integration remains a puzzle to classic evolutionary models. Evolutionary ecologists have argued that this phenomenon results from both stronger trade-offs between reproductive and socioeconomic success in the highest social classes and the comparison of groups rather than individuals. Indeed, studies in contemporary low fertility settings have typically used aggregated samples that may mask positive wealth–fertility relationships. Furthermore, while much evidence attests to trade-offs between reproductive and socioeconomic success, few studies have explicitly tested the idea that such constraints are intensified by market integration. Using data from Mongolia, a post-socialist nation that underwent mass privatization, we examine wealth–fertility relationships over time and across a rural–urban gradient. Among post-reproductive women, reproductive fitness is the lowest in urban areas, but increases with wealth in all regions. After liberalization, a demographic–economic paradox emerges in urban areas: while educational attainment negatively impacts female fertility in all regions, education uniquely provides socioeconomic benefits in urban contexts. As market integration progresses, socio-economic returns to education increase and women who limit their reproduction to pursue education get wealthier. The results support the view that selection favoured mechanisms that respond to opportunities for status enhancement rather than fertility maximization.

Lightweight aggregates to reduce heavy metal pollution in green infrastructure for urban stormwater management

2021 ◽  
Author(s):  
Concepcion Pla ◽  
Javier Valdes-Abellan ◽  
Miguel Angel Pardo ◽  
Maria Jose Moya-Llamas ◽  
David Benavente
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Green Infrastructure ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Urban Areas ◽  
Stormwater Management ◽  
Lightweight Aggregates ◽  
Urban Stormwater ◽  
Runoff Water

<p>The impervious nature of urban areas is mostly responsible for urban flooding, runoff water pollution and the interception of groundwater recharge. Green infrastructure and sustainable urban drainage systems combine natural and artificial measures to mitigate the abovementioned problems, improving stormwater management and simultaneously increasing the environmental values of urban areas. The actual rate of urban growth in many urban areas requires the enhancement and optimization of stormwater management infrastructures to integrate the territorial development with the natural processes. Regarding the quality of runoff stormwater, heavy metals are critical for their impact on human health and ecological systems, even more if we consider the cumulative effect that they produce on biota. Thus, innovative stormwater management approaches must consider new solutions to deal with heavy metal pollution problems caused by runoff. In this study, we propose the employment of Arlita<sup>®</sup> and Filtralite<sup>®</sup>, two kind of lightweight aggregates obtained from expanded clays, to remove heavy metal concentration from runoff stormwater. Laboratory experiments were developed to evaluate the removal rate of different heavy metals existent in runoff stormwater. The lightweight aggregates acted as filter materials in column experiments to quantify their removal capacity. In addition, batch tests were also developed to evaluate the exhaustive capacity of the materials. Results from the study confirmed the efficiency of the selected lightweight aggregates to reduce the heavy metals concentration by up to 90% in urban stormwater runoff.</p>

Can management improve the lawn’s functioning in the conditions of multiple anthropogenic stressors?

2021 ◽  
Author(s):  
Olga Gavrichkova ◽  
Dario Liberati ◽  
Viktoriya Varyushkina ◽  
Kristina Ivashchenko ◽  
Paolo De Angelis ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Soil Respiration ◽  
Green Infrastructure ◽  
Urban Areas ◽  
Ecosystem Respiration ◽  
Heterotrophic Respiration ◽  
Sand Mixture ◽  
Anthropogenic Stressors ◽  
Unplanted Soil ◽  
The Impact

<p>Release of heavy metals, salts and other toxic agents in the environment is of increasing concern in urban areas. Contaminants not solely decline the quality of the local environment and affect the health of human population and urban ecosystems but are also spread through runoff and leaching into non-contaminated areas. Urban lawns are the most distributed green infrastructure in the cities. Management of lawn system may either exacerbate the negative effects of contaminants on lawn functioning either help to withstand the toxic effects and maintain the lawn ecosystem health and the efficient release of ecosystem services.  </p><p>The aim of this study was to evaluate the interactions between the lawn management, the lawn functioning, and the release into the soil of typical urban contaminants. For this purpose, <em>Festuca arundinacea</em> grass was planted in a turf-sand mixture with and without amendment addition (zeolite + vermicompost). To reproduce the impact of traffic-related contaminants in proximity of the road, pots were treated with a solution containing de-icing salt (NaCl) and 6 heavy metals (Zn, Cd, Pb, Cr, Cu, Ni), imitating road runoff solution. After contamination, half of pots was maintained at optimum soil water content (Smart irrigation), another half was left to periodical drying in order to simulate conditions with discontinuous watering (Periodical irrigation). The same experimental scheme was reproduced for unplanted soil. CO<sub>2</sub> net ecosystem exchange (NEE), soil and ecosystem respiration as well as flux from unplanted soil (heterotrophic respiration) were measured shortly after the treatment (short-term) and up 3 months since the treatment start (long-term).</p><p>Soil amendment stimulated plant productivity and increased the efficiency of the system in C uptake (+56% NEE). A relevant reduction of NEE was observed from 14 to 40 days after the application of traffic-related contaminants in both amended and non amended pots. During this period the contaminants had the greatest impact on lawn NEE subjected to Periodic irrigation (-49% and -66% in amended and non amended pots, respectively), while lawn under Smart irrigation was less affected (-35% and -26% in amended and non amended pots, respectively). Different respiration sources (ecosystem respiration, soil respiration, heterotrophic respiration) were characterized by different sensitivity to management and contamination. Heterotrophic flux was not sensitive to soil amending but declined with contamination with enhanced negative effect under Smart irrigation. Response of ecosystem respiration to contamination was less pronounced in confront to soil respiration suggesting leaf-level buffering.    </p><p>Three months later,  the effect of contaminants on lawn gas exchange ceased for all treated pots. Instead, the irrigation effect persisted depending on whether pots were amended or not. In non amended pots NEE was reduced by 18% under Periodic irrigation, while this effect was not present in amended pots. We conclude, that performance of such green infrastructure as lawns in terms of C sequestration under multiple anthropogenic stressors could be efficiently improved through soil amending and irrigation control.</p><p>Current research was financially supported by RFBR No. 19-29-05187 and RSF No. 19-77-30012.</p>

Effect of feeding with bilberry fruit on the expression pattern of αCaMKII in hippocampal neurons in normal and diabetic rats

2017 ◽  
Vol 20 (2) ◽  
pp. 313-319 ◽  
Author(s):  
M. Matysek ◽  
S. Mozel ◽  
R. Szalak ◽  
A. Zacharko-Siembida ◽  
K. Obszańska ◽  
...  
Keyword(s):  
Cognitive Processes ◽  
Hippocampal Neurons ◽  
Negative Impact ◽  
Expression Patterns ◽  
Memory Loss ◽  
Diabetic Rats ◽  
Control Group ◽  
Neuroprotective Effects ◽  
The Central Nervous System ◽  
And Control

Abstract αCaMKII, widely occurring in the central nervous system, plays a significant role in cognitive processes. It is well known that diabetes is a risk factor that may trigger brain atrophy, cognitive dysfunction and finally lead to memory loss. Antioxidants richly present in bilberry fruits are believed to have significant effects on diabetes-related brain dysfunctions mainly due to their abilities to modulate neurotransmitter release that lead to reduction of the negative impact of free radicals on cognitive processes. The aim of the present research was to immunohistochemically investigate the expression patterns of αCaMKII in hippocampal neurons from non-diabetic, diabetic and diabetic rats fed with an extract of bilberry fruit. The obtained results show that in comparison to the control group, in diabetic rats hippocampal neurons immunoreactive (ir) to αCaMKII were swollen and the lengths of the neuronal fibres were reduced. Further study shows that in diabetic rats fed with bilberry fruit, αCaMKII-positive nerve fibres were significantly longer when compared to the groups of diabetic and control rats. Additionally, we observed statistically significant changes in the average larger diameter of αCaMKII-ir hippocampal neurons between groups of diabetic rats (with vs. without supplement of bilberry fruit). The results of the present work suggest that antioxidants present in bilberry fruits influence the morphology of and possibly exhibit beneficial and neuroprotective effects on hippocampal neurons during diabetes. It is likely that changes in the appearance of αCaMKII-expressed hippocampal neurons may reflect the diabetes-evoked rise in Ca2+ level in the cerebral nerve terminals. The present research extends our knowledge of preventive mechanisms for cognitive dysfunctions occurring in the brain during diabetes.

Sign in / Sign up

Export Citation Format

Share Document