Level Of Pb Pollution Research Articles

Recent lead deposition trends in the Czech Republic as recorded by peat bogs and tree rings

Abstract The lead (Pb) content and 206 Pb/ 207 Pb ratio were studied in three peat profiles dated by 210 Pb from the border-area mountains of the Czech Republic and in the tree rings of spruce trees located in their immediate vicinity. Both archives document a similar progress in Pb pollution levels and Pb accumulation in the 1950’s–1990’s. The deposition rate (DR) of Pb in peat bogs attained maximum values of 40 mg Pb m −2 y −1 in the “Black Triangle” area and 15 mg Pb m −2 y −1 in more distant areas in this period. The Pb isotopic record of both archives from the contaminated area exhibit a similar trend in the presence of the individual sources of Pb, in which Pb derived from combustion of coal predominates. The peat cores in more distant areas document well the effect of automobile Pb in the atmosphere and its substantial reduction after 2000. The two archives differ in individual patterns following from the differences in the rates of formation of their biomass and different means of deposition of Pb in the two archives.

Diversity and metal tolerance of nematode-trapping fungi in Pb-polluted soils

The diversity of nematode-trapping fungi (NTF) in two lead (Pb) mines in Yunnan Province, China was investigated in 2004. In total, 20 species belonging to five genera were identified from 500 samples collected at the Lanping and the Huize mines. Pb concentrations ranged from 216 approximately 7,150 mg/kg for the former and 132 approximately 13,380 mg/kg for the latter, respectively. The fungi were divided into five groups based on different trapping mechanisms. The trapping-net producer group contained the largest number of species, with nine. Two predators, Dactylellina ellipsosporum and Arthrobotrys oligospora, were found at frequencies of 32.85% and 15.41%, respectively. The diversity indexes of NTF were positively correlated with Pb pollution levels in both the Lanping Mine (r=0.66) and the Huize Mine (r=0.72), suggesting that the distribution of NTF was not negatively affected by Pb contamination. For most strains of a given species, there was no significant difference (P>0.01) in the Pb tolerance between the strains isolated from habitats with low or high Pb concentrations. However, Pb toxicity exerted adverse effects on trap formation and predacious capability of fungi. We discuss the possible metal tolerance mechanisms and their relationships to the survival strategy of NTF in Pb-polluted environments.

Characteristics and sources of lead pollution after phasing out leaded gasoline in Beijing

A 5-year long-term programme of Pb-monitoring from 2000 to 2004 was carried out at three representative urban sites (a traffic, an industrial, and a residential site), and a suburban site to evaluate the pollution level of Pb in Beijing. For comparison, aerosol samples were also collected in four other cities, Shanghai, Qingdao, Duolun, and Yulin in China. Pb pollution in Beijing has been very serious when compared with other sites over the world, as the concentration of Pb in Beijing remained as high as ∼100–300 ng m −3 in fine particles (PM 2.5). Significant spatial variation of Pb in summer with the highest concentration at the industrial site was observed, while relatively even spatial variation was found in winter in urban area, although much heavier in the urban area than at suburban site. Strong seasonal variation of ∼2–3 times higher Pb concentration in winter than that in summer was found. Pb exhibited a unimodal size distribution with most of it in fine fraction. Pb in fine particles was enriched by a factor of 200–1600 relative to its abundance in crust. Besides industry emission, motor vehicle emission, and coal burning, long-range transported dust from outside Beijing and the re-suspended soil containing the deposition of those from previously emitted leaded gasoline could be the important sources of Pb in Beijing.

Seasonal Fluctuation in Heavy Metal Pollution in Iran´s Siahroud River - A Preliminary Study (7 pp)

The management of its available water resources has become a key issue for Iran. During the last few decades, the water quality of Siahroud River in the coastal plain of the Caspian Sea in Gilan Province in Northern Iran has significantly degraded. The scarcity of water has been compounded by rapid population growth and increasing pollution from fertilizers, pesticides, and municipal and industrial wastes. One of the sources of this degradation is the movement of heavy metals from the river's watershed into the various water systems supported by the river, including the water system for Rasht City. To study the magnitude of heavy metal pollution in the Siahroud River, seven heavy metals including Zn, Cu, Pb, Cd, Mn, Fe, and Ni were measured in duplicate from replicated water samples collected over five consecutive seasons and analyzed by Atomic Absorption Spectrometry. In situ measurements of pH were taken with the samples and total organic carbon (TOC) was analyzed by IR gas measurement. The results demonstrated that four of the seven heavy metals including Pb, Fe, Cd, and Mn exceeded permissible safe levels as established by the United States Environmental Protection Agency. Multivariate factor analysis suggested that industrial land-use was the main contributing factor for the high levels of Fe and Mn in the Siahroud River, whereas, Cd was principly from agricultural activities in the watershed. The data also suggested that pH and TOC had an important role in the behaviour of Pb and Mn, and that the elevated levels of these two heavy metals in Siahroud River was the consequence of other anthropogenic sources. Only negligible levels of Zn, Cu and Ni were detected. Finally, all the sampling stations were subjected to cluster analysis. The results indicated that three different zones could be distinguished according to the levels of pollution. In addition, it was shown that the urban areas did not have a significant impact on the heavy metal pollution in the river. This observation stems from the fact that the data from the sampling stations before and after Rasht City were not significantly different. Preventive measures need to be undertaken in the land-use systems and watersheds of the Siahroud River to reduce the pollution levels of Pb, Cd, Mn and Fe.Cd, Mn and Fe.

Heavy metal tolerance of nematode-trapping fungi in lead-polluted soils

A study was conducted to establish whether the diversity of nematode-trapping fungi in Pb-polluted soils increases or decreases with increasing degree of soil contamination, and whether the fungi from polluted soils exhibit higher tolerance to Pb toxicity than those from unpolluted soils. Five genera containing 28 nematode-trapping fungi were recorded in total from five collection sites highly contaminated by Pb, with the concentration ranging from 306 to 4907 mg kg −1. These fungi fell into seven groups according to their trapping mechanisms. In this area, the most frequent group was the net former of which 16 species were recorded and its occurrence frequency (61.15%) was higher than those of the others. Fungal diversity of NTF was slightly positively correlated with the Pb pollution levels ( r = 0.29), which suggested the distribution of nematode-trapping fungi was not restricted by the heavy metal at these sites. The mycelial growth of nematode-trapping fungi which derived from either Pb-polluted soils or from unpolluted soils was completely inhibited by 1.8 mmol of Pb. At the Pb concentration of 1.2 mmol, the inhibition growth rates varied between 18.50 and 22.57% and there was no significant difference in the Pb tolerance of nematode-trapping fungi as to whether the strains derived from Pb pollution soils or unpolluted soils.

Radial Distributions of Ph in Stems of 6-Year-Old Spruce Trees (Picea Abies (L.) Karst.) Grown for 2 Years in Ph- Contaminated Soil}

Concentrations and total quantities of Pb in annual growth rings of 6-year-old Picea abies trees were determined after two years of growth in Pb-contaminated soil. Xylem rings grown after Pb addition to the soil did not show highest Pb concentrations. Peak concentrations of Pb were found in inner, older rings. Radial distribution patterns of total Pb quantities in the rings were different from those of Pb concentrations in the rings. Relatively small quantities were found near the pith and in the outermost rings whereas larger amounts occurred in rings grown in the years just before or after the Pb treatment started. The results were compared to data of a previous harvest of spruce trees from the same experiment after one year of treatment. Radial distributions of Pb concentrations did not change in the period of one year between the first and the second harvest but concentration levels varied. The radial distributions of Pb concentrations were no chronological records of temporal variations in soil Pb levels. Neither concentrations nor quantities of Pb in growth rings were reliable indicators of the year when Pb was added to the soil. The results question the use of such data for biomonitoring of historical changes in environmental Pb pollution levels.

An Assessment of Lead Pollution from Vehicle Emissions Along Selected Roadways in Harare (Zimbabwe)

Abstract Vehicle emissions where Pb containing gasoline is used contributes to toxic metal urban air pollution and is still a matter of concern. An assessment of the extent of roadside Pb pollution in Harare (Zimbabwe) was undertaken. Pb was measured in soil and vegetation roadside samples. For busy roads Pb levels in soil and vegetation indicated a significant level of Pb pollution in the environment nearby the road. The Pb levels at the kerb of busy roads (Simon Mazorodze Road) were 1480 and 23.3 μg.g−1 in soil and vegetation, respectively, and the levels found for less busy roads (Mutare Road) were 404 and 8.0 μg.g−1 in soil and vegetation samples respectively. The gradual phasing out of the level of Pb in leaded gasoline is suggested.

Stable lead isotopes ratios in major french rivers and estuaries

Lead isotopes ratios have been determined in suspended matter and water samples collected from major rivers and estuaries in France to assess their present level of Pb pollution. Most of the anthropogenic Pb found in the environment comes from Pb alkyls added to petrol. In France most petrol Pb comes from imported Pb ores which mainly have very characteristic Pb isotopes ratios (for example, a low 206Pb/ 207Pb ratio). Indeed, the 206Pb/ 207Pb ratio of aerosols sampled in France near a highway and a carpark was found to be very low (1.09-1.11). Despite not being so important with respect to atmospheric and water pollution, anthropogenic Pb produced by the iron, steel and copper production industries has also been considered and a slightly higher 206Pb/ 207Pb ratio (1.141) has been found from measurements made in the north of France near industrial plants. Conversely, higher 206Pb/ 207Pb ratios (1.197-1.206) were found in the pre-industrial sediments discharged by the rivers studied. These ratios are considered to be representative of local natural Pb during pre-industrial times. The measured Pb isotopes ratios in the suspended particulate matter compared with the two end-members show that the most polluted river is the Seine, followed by the Rhône and then the Garonne and the Loire. It is shown that anthropogenic Pb pollution is more easily detected when the solid discharge is low, such as in the Seine river. Conversely, a high particulate load can dilute the level of pollution by anthropogenic Pb and in this case Pb isotopes ratios are very similar to the natural level. As far as estuaries are concerned (the Seine estuary was not studied), variations of Pb isotopes ratios are generally observed and are attributed either to natural geochemical processes (Gironde estuary) or to man's influence (Loire and Rhône estuaries).

Heavy metals in the sediments of Cockburn Sound, Western Australia, and its surrounding areas

Some physical properties (pH and Eh), heavy metal concentrations (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and organic and carbonate concentrations of the calcareous marine sediments of Cockburn Sound, Western Australia, are reported. The results failed to show up the widespread Cd pollution that is known to exist in the biota as a result of the discharges of Cd-contaminated gypsum: carbonates seem to discriminate against the accumulation of Cd in oxidising conditions. Lead, on the other hand, although not a major problem, is concentrated in the carbonate sediments, giving a distorted view of the level of Pb pollution in oxidising conditions. The elevated concentrations of Cr at a few sites did, however, reflect the discharge of Cr in tannery waste. Significant correlation coefficients between metals suggest that the elevated concentration of metal in sediments adjacent to the industrialised zone of the Sound are due to anthropogenic activity; however, the overall use of marine calcareous sediments as indicators of heavy metal pollution in oxidising conditions is not recommended.

Retrospective Study of Lichen Lead Accumulation in the Northeastern United States

Retrospective Study of Lichen Lead Accumulation in the Northeastern United States