Elemental Analysis of Edible Mountain Nettle (Obetia tenax) and the Influence of Soil on Its Chemical Composition

In developing countries, the dietary intake of essential elements is largely dependent on the consumption of edible fruits and leafy vegetables. The distribution of elements in the indigenous edible plant, Obetia tenax (mountain nettle), was investigated as a function of soil quality from eight sites in KwaZulu-Natal, South Africa. The results show concentrations of elements in the leaves to be in decreasing order of Ca?>?Mg?>?Fe?>?Mn?>?Zn?>?Cr?>?Cu?>?Ni?>?Pb?>?Co?>?As?>?Cd?>?Se, and in the stems and roots to be in decreasing order of Ca?>?Mg?>?Fe?>?Mn?>?Zn?>?Cu?>?Ni?>?As?>?Pb?>?Co?>?Cd?>?Cr?>?Se. The quality and pollution status of soil was evaluated by geoaccumulation indices and enrichment factors, which indicated moderate cadmium contamination at the Msinga location that was confirmed by the pollution index and ecological risk levels of single-factor pollution. An assessment of overall contamination of soil using Nemerow pollution index showed moderate pollution by cadmium, while the potential toxicity index indicated low-grade risk for all elements at all sites. Principal component and cluster analysis revealed two groups of elements with similarities, As, Cd, Co, Cr, Cu, Mn, Ni, and Fe, suggesting a lithogenic source and an anthropogenic source for Pb and Zn. Correlation analysis showed significantly positive correlations between As, Co, Cr, Cu, Fe, and Ni/Cd in the soil, confirming the elements’ common origin.     

Elemental bioaccumulators in air pollution studies

k₀-Based instrumental neutron activation analysis (k₀ INAA) was used to determine the concentrations of Cr, Fe, Co, Zn, Se, Sb and Hg in the vascular plantsCistus salvifolius andInula viscosa and in the lichenParmelia sulcata. The samples were collected in the neighbourhood of industrial complexes. The elemental accumulation in the vascular plants and the lichen are compared to optimize the choice of the bioaccumulator. It is concluded thatP. sulcata seems to be the best accumulator of the three species for the elements studied;Cistus salvifolius is sensitive to the contents of Zn, Fe, Cr and Sb in the air;Inula viscosa seems to accumulate Fe, Sb, Co, Cr and Zn. Nevertheless, it is concluded that lichen is a good air pollution indicator, while the vascular plants are not due to the large seasonal variations found in the elemental concentrations.     

Biomonitoring of the atmospheric pollution using lichens in the metropolitan area of São Paulo city,Brazil

The atmospheric pollution of São Paulo city is a serious problem due to the expansion of industrial area, increasing number of vehicles and population density. This work presents results obtained in the analysis of lichens collected in different sites of São Paulo city and in non-polluted areas of Atlantic Forest. Concentrations of twenty elements were determined in Canoparmelia texana species and comparisons were made between the results obtained in lichens from different sites. High concentrations of the elements As, Ba, Cd, Co, Cr, Fe, La, Mn, Sb and Zn were found for samples collected in sites located near industries and petrochemical plant. Br and Sb concentrations were also high in lichens from sites affected by vehicular emissions.     

Monitoring of inorganic species distribution in water and sediments of Aso river

Analytical results are reported for the determination of inorganic species in water and sediments sampled in the Aso river ecosystem. The species determined are Cd, Co, Cr, Cu, Fe, Mn, Ni, Zn, Hg, F-, NO3-, SO4--, Na, K, Ca, Mg, NH4+ in water, and Cd, Co, Cr, Cu, Fe, Mn, Ni, Zn, Hg in sediments. For all the elements, in addition to detection limits, precision and accuracy are given: the former, expressed as relative standard deviation (Sr), and the latter, expressed as relative error (e), were good, being in all cases lower than 6%.     

Spatial and temporal distribution of inorganic species in water and sediments of the Tronto River ecosystem

Analytical results are reported for the determination of inorganic species in water and sediments sampled in the Tronto river ecosystem. The species determined are Cd, Co, Cr, Cu, Fe, Mn, Ni, Zn, Hg, F, NO3-, SO4-, Na, K, Ca, Mg, NH4+ in integrated water, and Cd, Co, Cr, Cu, Fe, Mn, Ni, Zn, Hg in sediments. For all the elements, in addition to detection limits, precision and accuracy are given: the former, expressed as relative standard deviation (Sr), and the latter, expressed as relative error (e), were good, being in all cases lower than 5%.     

Metals and semi-metals in street soils of São Paulo city,Brazil

São Paulo is the largest city in Brazil and South America with about 20 million inhabitants in the metropolitan area, more than nine million motor vehicles and intense industrial activity, which are responsible for increasing pollution in the region. Nevertheless, little is known concerning metal and semi-metal content in the soils of this metropolitan region. This type of information could be extremely useful as a fingerprint of environmental pollution. The present study determined the elements As, Ba, Co, Cr, Sb, and Zn concentrations in soils adjacent to avenues of highly dense traffic in São Paulo city to assess their levels and possible sources. The analytical technique employed was Instrumental neutron activation analysis. The results showed, except for Co, concentration levels higher than the reference values for soils of São Paulo, according to the Environmental Protection Agency of the State of São Paulo guidelines. When compared to similar studies in other cities around the world, São Paulo soils presented higher levels, probably due to its high density traffic and industrial activity. The concentrations obtained for As and Cr indicate anthropogenic origin. The high levels of the traffic-related elements Ba, Sb, and Zn in soils nearby high density traffic avenues indicate they may originate from vehicular exhausts.     

Neutron activation as a routine method for the determination of trace elements in water

By freeze-drying the following elements can be determined in natural water except sea water: Au, Ba, Br, Ca, Ce, Co, Cr, Eu, Fe, K, La, Mo, Na, Sb, Sc, Se, U, Zn. Some problems may arise with respect to As and Hg. Cu, Cd and Ni can only be determined if present in high concentrations. Separation by adsorption on charcoal in presence of complexing agents gives yields between 75 and 100% for the following elements in sea water: Ag, Au, Cd, Ce, Co, Cr, Eu, Fe, Hg, La, Mo, Sc, Se, U, Zn (As 67%, Sb 56%). Activation or use of labelled ions and study of exchange give information about mobility of trace elements in suspended matter.     

Senio river ecosystem: characterization and distribution of inorganic species in water and sediments

Analytical results are reported for the determination of inorganic species in water and sediments sampled in the Senio river ecosystem. The species determined are Cu, Pb, Cd, Zn, Co, Cr, Ni, Fe, Mn, Hg, F-, Cl-, Br, NO3-, SO4-, Na+, K+, Ca++, Mg++, NH4+ in integrated water, and Cu, Pb, Cd, Zn, Co, Cr, Ni, Fe, Mn, Hg in sediments. For all the elements, in addition to detection limits, precision and accuracy are given: the former, expressed as relative standard deviation (sr), and the latter, expressed as relative error (e), were good, being in all cases lower than 6%. Limitedly to Cu, Pb, Cd and Zn a critical comparison with voltammetric measurements is also discussed.     

Assessment of the health of a river ecosystem due to the impact of pollution from industrial discharge using instrumental neutron activation analysis and inductively coupled plasma-mass spectrometry

Inductively coupled plasma-mass spectrometry (ICP-MS) and neutron activation analysis (NAA) were employed in the determination of heavy metal concentrations in water, plant and sediment samples to assess the extent of heavy metal pollution in a river system which is located within an industrial zone. Elemental concentrations of As, Pb, Hg, Cr, Cu, Cd, Ni and Zn were measured in the samples. Statistical analysis was performed on the data obtained to look for trends in the pollution pattern of these elements on the river system. The trend in concentrations of heavy metals pollution in water samples is in the order of Zn > Cu > Ni > Cr > As > Pb > Hg > Cd, whereas in plants the order is Zn > Cr > Cu > Pb > Ni > As > Hg > Cd and in sediments Zn > Cu > Pb > Ni > As > Hg.     

Co-precipitative pre-concentration with sodium diethyldithiocarbamate and ICP-AES determination of Se, Cu, Pb, Zn, Fe, Co, Ni, Mn, Cr and Cd in water

Sodium diethyldithiocarbamate in the presence of a weak oxidizing agent is used as a co-precipitative agent for the pre-concentration of Se, Cu, Pb, Zn, Fe, Co, Ni, Mn, Cr and Cd. A procedure was developed for ICP-AES determination of these elements after pre-concentration in river and waste water (an enrichment factor of 40). The recovery of all the elements tested for was more than 98%. The limits of determination (mg l⁻¹) (10 S.D. blank) are 0.001 (Cu, Co, Cr, Mn), 0.0007 (Zn, Cd), 0.003 (Se), 0.004 (Fe), 0.007 (Ni), and 0.01 (Pb).     

Nondestructive multi-element determination of air particulates in Hong Kong

Nondestructive neutron activation analysis employing reactor neutrons and a Ge(Li) gamma-spectrometer has been used to determine the trace element level of air particulates in various areas of Hong Kong. Comparison of the average concentrations of the trace elements of air particulates was made among industrial, heavy-traffic and residential areas. It was found that industrial areas have higher concentrations of Co, Cr, Hg, Mn and Zn, while heavy-traffic areas have very high concentrations of Br. Comparison of the pollution level of Hong Kong with other cities was also made. The average concentrations of Co, Cr, Hg, Zn and Br of air particulates in Hong Kong were found to have higher values than those of other cities. Finally, daily variation of the trace element level in a special area (Hung Hom) had been studied, but no significant variation was found.     

Metal levels and foraminifera occurrence in sediment cores from Guanabara Bay,Rio de Janeiro,Brazil

Summary Guanabara Bay, located at Rio de Janeiro, is an example of an impacted coastal environment due to the high influx of industrial and domestic effluents. Four sediment cores were sampled in areas with different levels of pollution and were analyzed for trace elements and foraminifera for abundance. Instrumental neutron activation analysis (INAA) was used to determine As, Ba, Co, Cr, Fe, Sb, Sc, and Zn. The effects of metal concentrations in the benthic foraminifera were studied. The low concentrations of the benthic foraminifera and the dominance of opportunistic species in coastal regions such as Ammonia may be correlated to natural stress or anthropogenic impact.     

Factor analysis in the geochemical studies along the Gediz river, Turkey

Water samples collected from 321 sampling points at 1 km intervalsat a site located close to the industrial and geological areas in the Gedizriver were analysed for U, Ra, Na, Mg, Mn, K, Ni, Cd, Co, Pb, Al, Fe, Cr,Zn, Cu and Ca. Heavy metal concentrations in the samples were determined byatomic absorption spectroscopy, laser excited fluorescence, and radon collectorchamber. Factor analysis was used to describe the relationship among 16 elements.Four factors were extracted and they account for 67% of the total variancein the data. These factors are named as industry, sea, agriculture and geology.According to this result, not only industrial plants but also geological structureand agricultural activities were seen to contribute in polluting of the riverwater. Beside, these factors have shown that a lot of agricultural activitiesand a sharp increase in the population of the Gediz basin, and industrialdevelopment related to above reasons speed up pollution of water sources andbecome a potential risk on the unpolluted sources.     

Major and trace elements in sediments of the upper course of Lerma river

Summary The Lerma is one of the most important rivers of Mexico, where it drains highly populated and industrialized regions. The concentration of six major and trace elements: titanium, manganese, iron, zinc, copper and lead in the surface sediments of the upper course of Lerma river was investigated, in order to identify its distribution along the river and to recognize the principal sites of pollution. The surface sediment samples were collected at 8 sites distributed following the stream flow direction of the river. Major and trace elements concentrations were determined by energy dispersive X-ray spectrometry. The results show that the metal concentrations in the sediments decrease in the sequence: Fe > Ti > Mn > Zn > Cu > Pb. Concentration of Fe, Mn and Ti were significantly higher than the other metals in site 8,200 meters downstream the Alzate Dam. The high concentrations and spatial variations of Zn, Cu and Pb in the middle sites of the upper course of the Lerma River indicate that the river pollution is probably associated with urban and industrial discharges.     

A comparative study of trace elements in water from various sources in surrounding areas of Nagpur city (India) by instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) has been used for the determination of 27 elements (Ag, Au, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Ga, Hg, Hf, K, La, Mn, Na, Sb, Sc, Se Sr, Th, P, Ta, Tb, Zn and Zr) in 15 water samples collected from different sources (reservoirs, well, borewell, sewage tank, river, rain) in and around Nagpur city (central India) including doubly distilled and a sea water sample from Bombay. Sample residues after evaporation were irradiated at a thermal neutron flux of 10¹²–10¹³ n·cm^–2·s^–1 for 10 min, 1d and 1wk and counted using a HPGe detector and an 4k MCA at different intervals. Several environmental standards from NIST (USA), NIES (Japan) and USGS rock were also analysed for quality assurance. Wide variations in elemental concentrations have been observed in water samples from different sources. Most elemental concentrations in drinking water from various sources, are within ISI/WHO limits. Sea water showed very high concentrations of Ba, Cr, Co, Fe, Hg, Sb, Se and Zn. For doubly distilled and rain waters, however, very low elemental concentrations of Ba, Ce, Fe, Sc, Hg, Se, Sr and Th were observed.     

Determination of trace elements in the water cycle by total-reflection x-ray fluorescence spectrometry

The determination of trace elements in the various stages of the water cycle is very important. Economic procedures for multi-element determinations of trace elements in various matrices are needed. The applications of total-reflection x-ray fluorescence spectrometry in this general area are reviewed briefly, with examples relating to rain, river and sea waters, sediments, particulate matter and manganese nodules and crusts, as well as mussel tissue. Up to 25 elements can be determined; these are S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Pb, Se, Rb, Sr, Y, Zr, Mo, Ag, Cd, Sb and Ba. Preliminary treatments of the various matrices are described. Accuracy checks by analysis of reference standards and by application of independent techniques are reported.     

Determination of trace elements in tree rings ofPinus by neutron activation analysis

The elemental composition of pine trees as a function of age was achieved by the tree-ring method. By using instrumental neutron activation analysis, trace elements were determined in individual rings ofPinus elliottii var.elliottii of 32, 14 and 9 years, from an implanted forest ofPinus sp., Buri, São Paulo, far away from industrial pollution. Different components of the system such as needles, pith, bark, soil and litter were also analyzed for 18 elements (As, Br, Ce, Co, Cs, Eu, Fe, Hf, K, La, Mn, Na, Rb, Sc, Sm, Yb, Zn, and Zr). Al, B, Ba, Ca, Fe, K, Mg, and P concentrations were determined by atomic absorption and/or emission spectrometry (AAS; ICP-AES). Some elements have showed similar radial distribution of the concentration for the three ages. Abrupt concentration changes in the pith and ring-bark boundary corresponding to the first and last growth rings were observed.     

Status of trace and toxic elements pollution in creek ecosystem using TXRF method

The economic development worldwide has brought in its wake many changes in the environment. Marine ecosystem which forms a part of this environment has been subjected to impact of industrialisation and urbanization. The study has been carried out in the creek ecosystem of Mumbai receiving the effluents from industrial and urban settlements. The trace elements such as P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb, As, Rb and Sr were analysed in the creek water collected from the side receiving industrial effluent and discharges from the urban settlements using total reflection X-ray fluorescence spectrometry. On comparing the concentration of the trace element from the mid stream water of the creek with the water samples collected from the industrial and city effluent receiving side, it was found that the concentration of P, Ca, Mn, Fe, Co, Cu, Zn, Pb and As were found higher in the industrial side of the creek whereas V, Cr and Ni concentration were found higher in the samples collected from the side receiving city effluent.     

Determination of trace elements in Wuxi fallen ice by INAA

The concentrations of 14 elements, including Ir, Au, Co, Cr, Fe, Sr, Rb, K, Ta, Zn, Sb, Ba, Sc and Se, in the Wuxi fallen ice were determined by neutron activation analysis. The experimental results show that the relative concentration ratios of Ir/Co, Ir/Cr and Ir/Sc etc. in the ice water (0.0069, 0.00024 and 0.11, respectively) are quite close to those of Type C1 chondrite (0.0102, 0.00021 and 0.092, respectively), which implies that the fallen ice might be a piece of extraterrestrial substance.     

57Fe Mössbauer spectroscopy of banded iron formations from eastern India

Samples of the mosses Hylocomium splendens and Pleurozium schreberi, collected in the summer of 1998, were used to study the atmospheric deposition of heavy metals and other toxic elements in the Chelyabinsk Region situated in the South Urals, one of the most heavily polluted industrial areas of the Russian Federation. Samples of natural soils were collected simultaneously with moss at the same 30 sites in order to investigate surface accumulation of heavy metals and to examine the correlation of elements in moss and soil samples in order to separate contributions from atmospheric deposition and from soil minerals. A total of 38 elements (Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Rb, Sr, Zr, Mo, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Hf, Ta, W, Au, Th, U) in soil and 33 elements Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Ag, Sb, Cs, Ba, La, Ce, Sm, Tb, Yb, Hf, Ta, W, Au, Th, U) were determined by epithermal neutron activation analysis. The elements Cu, Cd and Pb (in moss samples only) were obtained by atomic absorption spectrometry. VARIMAX rotated principal component analysis was used to identify and characterize different pollution sources and to point out the most polluted areas.