The mean concentrations of all metals were below the Canadian soil quality guidelines Low heavy metal concentrations in some samples compared to the other standards indicated that these sites were not affected seriously and the effect of pollutant sources can be ignored while high heavy metal concentrations indicated that the pollutants seriously influenced the soil environment 12
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Abstract The paper investigates the hypothesis that biotoxicities of trace metals depend not only on the concentration as expressed by the total amount, but also on their geochemical fractions and bioavailability.
The geochemical-based sequential extractions were performed on the particles using a series of increasingly stringent solutions selected to extract metals Cd, Cu, Cr, Ni, Pb, Zn, and Mn into four operational geochemical phases—exchangeable, reducible, organic, and residual—and then quantified using an Atomic Absorption Spectrophotometer.
However, most metals in the samples exist in nonmobile fractions: The pollution indices show ingestion as the leading route of metal exposure, with noncarcinogenic HQ and cancer risk HI for humans in the area being higher than 1. Introduction Dust is simply the finely divided particulate matter that can be readily lifted by wind from its place of origin and carried along by the turbulent atmospheric currents, finally settling either by gravity under calm condition or by being brought to the surface by precipitation [ 1 ].
Worldwide, nonoccupational exposure to dust especially in urban centres has aroused much attention because it is associated with some trace metals and diseases. Dust is generated during human activities such as sweeping, quarrying, and metals fabrication.
Once generated and released to the atmosphere, it travels long distances from the emission source. In the course of transportation, the particulate is bound to metals; hence, it creates a reserve pool of metals in urban atmosphere [ 2 ].
The presence of these metals in dust particles poses a significant environmental risk to the people. On breathing air containing metal absorbed into particulate matters, some of the smaller particles reach the wind pipe trachea and eventually dissolve in the blood stream.
According to [ 3 ], the two most serious health problems caused by dust are cancers of the lungs, throat, and nose and other lung conditions called chronic obstructive pulmonary disease COPD that includes chronic bronchitis and emphysema.
A report in gave a likely figure between 7 and 8, for cancers of the lung and the nose that are due to work exposure to dust [ 2 ]. Quite a lot of researchers have investigated elemental compositions of suspended particulate matters in cities worldwide: Monterrey, Mexico [ 4 ], Tehran, Iran [ 5 ], and Nigerian cities [ 6 — 10 ].
In most of these studies, elevated levels of heavy metals have been observed in atmospheric suspended dust in most cities. Meanwhile, Mafuyai et al.
Meanwhile, it has been hypothesized that the biotoxic effect of metals depends not only on the concentration as expressed by total amount but also on their bioavailability, origin, and properties [ 11 ]. To gain a deeper understanding of risk posed by individual metal, it is necessary to determine bioavailability of the metals in different geochemical phases.
A lot of investigators [ 71213 ] have employed sequential extractions to assess metal labiality and to characterize the speciation of metals in solid phases.
It has also been suggested that the most easily mobilized metals presented a risk to plants and animal [ 14 ].
However, in most cases the most abundant metals are not always the most mobile metals suggesting that other mechanisms are important in the uptake process. The city is situated in the rainforest zone of southwest Nigeria, with a population of about[ 15 ].
It is one of the fastest growing urban settlements in southwestern Nigeria, serving as transitory link to northern and eastern parts of the country, with many industrial plants. The climatic conditions of Nigeria and Akure have been described elsewhere.
The objectives of this study include i assessing the contamination level of the monitoring sites, ii determining the geochemical association of the studied metals along the various phases, iii investigating the mobility of metals found in airborne particles collected, and iv assessing the carcinogenic and noncarcinogenic toxicity potentials of the metals on the basis of relative content of the fractions.
It is envisaged that the data generated will stimulate environmental concerns on the impacts of airborne particulates and translate them into improved respiratory health among populace exposed to dust.[Nasser M.
Abdel-Latif and Inas A. Saleh. Heavy Metals Contamination in Roadside Dust along Major Roads and Correlation with Urbanization Activities in Cairo, Egypt.
J Am Sci ;8(6)]. Contamination of urban surface soils with heavy metals is one of the worrying problems owing to their extensive causes, resistant to biodegradation, toxic and accumulative properties.
Heavy metals and other pollutants in urban surface soils are usually originated from different sources of industrial activities, fossil fuel combustion. metals in the road dust of Gujrat city along with the transportation of sewage sludge, surface runoff from agricultural land and discharge of sewage water from drains.
Keywords: Industrialization, Heavy Metal, Traffic, Chromium, Lead, Sludge. May 26, · Distribution of heavy metals within road dust size fractions. Mean concentrations of metals in the five analyzed fractions are presented in Table Table3.
3. The finest fraction . Furthermore, size fraction and dominant urban activity are the main factors controlling metals concentrations in road dust. The contamination levels of the heavy metals in the road dust were evaluated on the basis of contamination factor (Cf).
As a major source of urban heavy metal contamination, the traffic area was carefully analyzed. Interelemental precipitation may wash away road dust, enabling heavy metals to enter water bodies as dissolved solids in data collection and Sample analySiS Study area.