Lead Concentrations In Soil Research Articles

The spatial distribution of lead concentrations in the agricultural soils and main crop plants in Poland

The spatial distribution of lead concentrations in the agricultural soils and main crop plants in Poland

Lead in New Orleans soils: New images of an urban environment

This paper describes a survey of lead in soil and computer generated maps that have been derived for New Orleans, Louisiana. The soil survey included streetside, houseside and open space samples. Because the survey covered every census tract in the metropolitan area it was possible to construct a computer-generated map of the distribution of lead dust in the soils of the urban environment. The data base consists of coordinates, site characteristics and lead analytical results of 3,704 soil samples. The resulting graphics show peaks of lead ranging from 600-1,200 μg per g in the streetside soil of the inner-city and a steeply declining slope to the suburban areas of the city where the lead content of streetside soils is less than 75 μg/g. In the inner-city, the amount of lead in soils found near building foundations is 10 to 20 times higher than the soils adjacent to streets where the median lead content of soils is over 300 μg g(-1). In areas surrounding the city core ("mid-city"), the amount of lead next to the foundation and adjacent to the street are equivalent with medians of 110 μg g(-1). In suburban locations, the median lead content of soil along streetsides is 86 μg g(-1). Soils adjacent to surburban foundations has a median Pb content of 50 μg g(-1). The lowest median lead content in soil is found in open spaces, ranging from 212 to 40 to 28 μg g(-1), respectively, for the inner-city, mid-city, and suburbs. These observations are consistent with the production and consumer use of lead-based paint and leaded-fuels within the modern city.

The spatial distribution of lead concentrations in the agricultural soils and main crop plants in Poland

This paper presents Pb concentrations in Poland's soils, in grain of cereal plants, and in roots or tubers of root plants, and examines the spatial distribution of these concentrations. The overall geometric means of Pb concentrations in the soils, cereals, and root plants were 16.4, 0.25 and 0.54 mg/kg, respectively. Spatial distribution of the data revealed that level of Pb in the soils in SW-W Poland was significantly higher than in the NE-E and central regiobs, apparently as a result of the impact of contamination from various sources. About 81% of the studied soils had natural concentrations of Pb; 16% had the metal concentratiobs higher than normal but lower than 100 mg/kg (limit concentration), and 3% of the soils had Pb concentrations over 100 mg/kg. Lead concentrations in the crops did not follow the pattern of the spatial distribution of Pb content of the soils, was also expressed by the lack of correlation between the metal content of the soils and plants. Around 10% of the samples of cereal plants and 30% of root plants were found to have elevated levels of Pb. The proportion of Pb cereal grain samples with elevated Pb concentrations was greater in the NE-E region of the century (23%) than in central and SW-W Poland (6–8%). In contrast, more root plant samples contaminated with lead were found in the SW-W than in the NE-E part of the country.

Relationship Between Soil Lead, Dust Lead, and Blood Lead Concentrations in Pets and Their Owners: Evaluation of Soil Lead Threshold Values

This paper reports the results of a study conducted in Granite City, Illinois during the months of August through October 1991. The study involved a subpopulation of 77 households having 106 dogs and cats which was a corollary to a major study conducted in humans by the Illinois Department of Public Health to evaluate lead exposure. A secondary lead smelter had been in operation in this town for almost 80 years and was shut down in 1982. Important soil contamination with lead was reported and this paper presents data regarding levels of soil and dust lead and associated blood lead concentrations in animals and their owners in a total of 77 households. Overall, blood lead concentrations (BLC) were low (0-13 μg/dl in the animal owners; 0-28 μg/dl in pets). There was no significant relationship between soil or dust lead and BLC in humans; however, the relationship was significant in animals. Odds ratios were computed to determine whether 500 or 1000 ppm lead in environmental samples was associated with increased risk of having a high BLC. We could not find any increased risk in humans, while the risk did increase in animals. It is concluded that animals are more at risk than their owners of having a high BLC when exposed to the same contaminated environment and can be used to monitor the bioavailability of lead.

Lead concentration in farmlands in southern Spain: influence of the use of sewage sludge as fertilizer.

Lead content in soils is closely linked to the nature of the parent materials, although this relation can change or even disappear due to other factors involved in soil formation. In addition, soil Pb content is also affected by biogeochemical cycles. Soil pH is another factor that influences Pb levels; in general, this element is more mobile in acid than in alkaline soils, and tends to form residual concentrations in the latter. The distribution of Pb varies in soil horizons of different depths, and is more abundant in more superficial horizons. This accumulation depends not only on the composition of the soil, but also on atmospheric contamination and the proximity of heavily transited roads or other sources of exhaust products from motor vehicles. An additional source of pollution is Pb in pesticides, and in sewage sludges used as fertilizers in farmlands. Within the ecosystem, soils retain a portion of the products that are applied to them, and thus behave as a reservoir of toxic substances, including Pb. These deposits represent an important route through which toxins are incorporated into subterranean and surface bodies of water, into plant tissues and into the human food chain. In this study we determined themore » degree of Pb contamination in farmlands on the Mediterranean coast of the province of Granada in southern Spain. The area studied is intensively cropped, contains industries, heavily-travelled highways and many small towns. Pesticides, fertilizers, and sewage sludge recovered from industrial and urban wastes is used. Correlations between the presence of Pb in different samples and their proximity to potential sources of pollution were considered and the influence of sewage sludge as a source of Pb in soils was examined. In addition, the geochemical characteristics of the area, their influence on Pb fixation and retention, and Pb availability to nearby vegetation and groundwater tables were analysed.« less

Lead in hair and urine of children and adults from industrialized areas.

The study of hair and urine lead concentrations in urban populations of various age groups exposed to contaminating effects of industry and transport and the corresponding analysis of lead in ambient air and soil have made it possible to determine the percentage of subjects showing evidence of elevated lead bioconcentrations. The highest lead concentrations among children were found among those who resided near a copper smelter (18.2 micrograms/g), a lead-cadmium plant (31.1 micrograms/g), and a storage battery factory (48.3 micrograms/g). In adults who resided in the same area, hair lead was lower; however, it exceeded the control group values by up to five times. Hair lead concentration in children correlated with lead content in air and soil (r = 0.7 and r = 0.74, respectively). In the majority of European countries and in the United States, legislative acts have been adopted recently to sharply reduce lead content in gasoline (i.e., from 0.4 to 0.15 g/l). Drastic measures need to be taken to diminish lead concentration in ambient air in Russia. Biomonitoring should be applied in preventive medicine, including medical inspection of industrial workers.

Effects of cadmium, copper, lead and zinc on growth, reproduction and survival of the earthworm Eisenia fetida (Savigny): Assessing the environmental impact of point-source metal contamination in terrestrial ecosystems.

The earthworm Eisenia fetida (Annelida: Oligochaeta) was exposed to a geometric series of concentrations of cadmium, copper, lead and zinc in artificial soil using the OECD recommended protocol. Mortality, growth and cocoon production were measured over 56 days to determine LC50 and EC50 values. No observed effect concentrations (NOECs) were also estimated. Furthermore, the percentage of viable cocoons and number of juveniles emerging per cocoon was recorded. Cocoon production was more sensitive than mortality for all the metals, particularly cadmium and copper for which NOEC reproduction values were an order of magnitude lower than those for NOEC mortality. However, there was no significant effect of metals on the viability of cocoons. The weights of earthworms declined in all treatments (including the controls) during the experiment. This was probably due to the lack of suitable food in the OECD standard soil medium used. It was concluded that future experiments should include animal manure in the test medium. The LC50, EC50 and NOEC values determined in this study were compared with concentrations of metals in soils in the vicinity of a smelting works at Avonmouth, southwest England. The 14-day LC50 for zinc in Eisenia fetida was exceeded in soils covering an area of 75 km2 around the works, compared to 4.2 km2 for copper and 4.7 km2 for lead. Soil values for cadmium did not exceed the LC50 value anywhere in the region. Similar estimates of relative effects on reproduction confirmed that zinc is most likely to be responsible for the absence of earthworms from sites close to the Avonmouth works. However, the OECD standard test overestimated the potential effects of metals on populations, since earthworms can be found as close as 1 km from the smelting works. The discrepancy between test and field observations was probably due to the greater availability of the metals in the artificial soil.

Lead Distribution in Grape Berries

Lead distribution in the outer part of the skin and in the three main parts of grape berry (skin, pulp, and seeds) was determined in different grape varieties in 33 locations of different geological origins (uranium-bearing, acid, and limestone soils). No lead assumed to be of atmospheric origin was found on the outsides of berries in 19 of the 33 plots. External lead in the remaining 14 plots formed 16.3% of total berry lead. Internal berry lead, assumed to be of soil origin, fluctuated between 27 and 127 µg/kg with an average of 58 µg/kg. The assumption correlated well with the average soil lead contents at each location. The different berry parts displayed considerable variation in lead concentrations: 352 µg/kg in seed, 90 µg/kg in skin, and 31 µg/kg in pulp. The findings enable better evaluation of the fate of lead in grape berries during winemaking.

Characteristics of residues at hazardous waste land treatment units

Soil cores and surface soil samples were taken from two hazardous waste land treatment (HWLT) units and analyzed for organics and metals. One HWLT site was in operation at the time the samples were taken and had been used for this purpose since 1958. The other site had been used for research purposes for 3 years and had been closed since 1979. Refinery process wastes had been applied at both sites. The soil samples were analyzed to understand the accumulation of waste residues that could occur at HWLT sites and the pattern of residue spatial variability that resulted from waste application. Such information is relevant to: (a) potential leachability of accumulated organics and metals and possible contamination of groundwater and (b) site closure decisions and subsequent site use. Volatiles and acid extractables were not found in the soils. Polynuclear aromatic hydrocarbon (PAH) compounds and freon extractables were the major organics found. In surface soils of these sites, the concentrations of the organics and metals were greater than in background soils. At depths below 60 cm, the concentrations of PAH compounds were below detection limits. For the sites at which metal concentrations could be compared to that in background soils, the concentrations of chromium and nickel in site soils at depths below 60 cm appeared greater than background soil concentrations whereas the concentrations of copper, lead and zinc in site soils at such depths appeared comparable to those in background soils.

Lead Pollution in Israel

The lead content of petrol used in Israel has been steadily decreasing over the past few years from 0.42 g/litre to 0.15 g/litre. Unleaded petrol has also been introduced. Blood lead levels measured in Israel suggest that some children may be above the 10 µg/dl threshold now considered to be hazardous. The lead contents of soils, food crops, water, and air in Israel are generally low compared with those in other developed countries, but measurements indicate that lead is still being added to surface soils. Further work in areas with heavy traffic shows that the reduced Pb level in petrol has so far not resulted in lower soil lead contents.

Determination of Zn, Pb, Cu, and Hg in soils of Ekpan, Nigeria

The concentrations of zinc, lead, copper, and mercury in soils in Ekpan were determined in order to assess the impact of petroleum-refining activities. Twenty soil samples were collected 100 m apart (10 topsoils 0 to 15 cm and 10 bottom soils 15 to 30 cm). Sample solutions prepared were analyzed using the atomic absorption spectrophotometry technique. Results show that top- soil samples contain as much as 7.13 to 13.10 μg/g zn, 55.13 to 65.50 μg/g Pb, 3.47 to 5.27 μg/g Cu, and 4.00 to 6.50 μg.g Hg. Bottom soil samples contain as much as 7.17 to 13.77 μg/g Zn, 54.97 to 63.23 μg/g Pb, 3.57 to 6.50 μg/g Cu, and 4.57 to 6.63 μg/g Hg. The levels reported had an abundance ratio in the order Pb>Zn>Hg>Cu in the soil samples. It is recommended that appropriate measures be put in place by the companies to treat waste effluent before discharging them to the immediate environment.

Impact of Lead Pollution on the Contamination of Water, Soil and Plants

Examines the effect of pollution along the agriculture highway between Cairo and Alexandria. Different samples of water, soil and plants (clover) were collected from nine variable locations along this highway. Results obtained revealed that the influence of lead precipitating from the atmosphere directly reflects the lead content of soil. Concentration of metals so far did not show any great significant effect.

Evaluation of lead concentrations in 18th-century Omaha Indian skeletons using ICP-MS.

The analysis of skeletal remains of Omaha Indians buried between AD 1780 and 1820 indicated that lead was incorporated in cortical bone. The diagenetic or biogenetic origin of the lead was evaluated by examination of lead isotope ratios of the bones and artifacts, and comparison of lead concentrations in burial soils with those of the bones. The isotopic values of the lead artifacts demonstrate that the lead was mined in the Missouri region. Although the isotope ratios in the bones are not identical with that from the lead artifacts, there is a strong relationship between them. This finding indicates that the lead in the bone was at least partly derived from the artifacts. Because lead artifacts rarely accompanied the burials but lead was ubiquitous in the bones, we suggest a biogenetic origin for the lead. There is also the possibility that some of the lead may have been derived from pigments applied to the corpse during mortuary ritual.

Lead in household dust

The lead content of 55 samples of dust collected from vacuum cleaner bags from various parts of Denmark has been determined. The concentrations found ranged from 1.5–48.9 ppm lead in the dry dust, the geometric mean being 9 ppm which is comparable to the mean concentration of lead in Danish arable soil. No correlation was found between traffic density and concentration of lead in the dusts.

Cadmium, copper, and lead in soils and garden produce near a metal smelter at Flin Flon, Manitoba

Towns in the vicinity of base metal smelters are subject to contamination from atmospheric fallout containing heavy metals. Many smelters have been in operation for decades, and have resulted in substantial accumulation of metals in the surrounding soils. Metal contamination of edible vegetation near mines and smelters has been the source of health concerns in a number of countries. One smelter that has operated for more than half a century is located at Flin Flon, Manitoba. Many Flin Flon residents utilize home vegetable gardens year after year. However little is known regarding heavy metal contamination of locally grown garden produce. Since food can contribute as much as 90% of total body uptake of metals it is important to identify any sources which may account for the disproportionate share. The objective of the present study was to examine concentrations of cadmium, copper and lead in soils and garden produce in the vicinity of the Flin Flon smelter.

Lead contamination in street soils of Nairobi City and Mombasa Island, Kenya

The advent of modern industrialization and, in particular, the motor vehicle has witnessed dramatic increases in lead usage both as a component of lead-acid storage battery and from 1923 as organic lead alkyl anti-knock additive in petroleum. Several workers have established a correlation between increasing lead concentration in roadside soils and vehicular traffic density. Although researchers studied the heavy metal content in Lake Victoria sediments, no urban roadside soils were investigated. Since lead is used as a petrol additive in Kenya, it is necessary to document the extent and magnitude of lead contamination of roadside soils in inland and coastal urban environments and evaluate its environmental implications.

Environmental cadmium, lead and nickel contamination: possible relationship between soil and vegetable content

The cadmium, lead and nickel content of soils of four agricultural areas exposed to different degrees of environmental pollution and vegetables grown there were measured by Atomic Absorption Spectrophotometry (AAS). In order to ascertain the possible relationship between the heavy metal content of soils (total and extractable) and of vegetables grown in them, the correlation between the two was calculated. The highest correlation values between metal content of soil and vegetables are these corresponding to nickel: the total metal content in soils and leaves-stems are linear (p<0.01). The extractable metal content of soils and leaves-stems are linear (p<0.1). Therefore, soil seems to be the main contributor to nickel content of plants (leaves-stems). In the case of cadmium a statistically significant linear correlation (p<0.01) was observed between total metal content in soil and in leaves-stems and a negative one between extractable metal content of soils and that of roots-bulbs. For lead a negative correlation was found between extractable metal content of soils and leaves-stems. In any case, the lead content of soils is not the main factor that influences the lead content of vegetables. Anthropogenic and environmental factors play a more important role than the lead in soils in the lead content of vegetables.

On the description of lead pollution in plants caused by traffic under application of robust statistics

Methods of robust statistics have successfully been applied to eliminate outliers, in the classical sense, in a number of cases. The least median squares regression has proved to be an advantageous method for the description of widely varying data sets which are often obtained as a result of analytically investigated environmental problems. The least median squares regression allows the computation of correlations between the plant lead contents and the soil lead contents, the traffic density or the distance from the road. These relations between the plant lead contents on the one hand and the soil lead contents or the traffic density on the other hand can help to interprete the uptake mechanisms, caused by lead immissions. The application of reweighted squares regression seems to be less useful. Because of the elimination of extreme measuring points, the statistical reliability of the regression models obtained is not as high as that of the least median squares regression. Robust estimations of the expected plant lead contents can be obtained by using the model of multiple least median squares regression.

Lead and cadmium contamination of soil and vegetables in the upper silesia region of Poland

Studies of the lead and cadmium content of soils and vegetables from 126 allotments in 12 towns in a polluted region of Poland are described. Metal concentrations in parsley, celery, carrots and red beet were determined using AAS. In most cases, metal concentrations in soils and vegetables exceeded accepted standards and concentrations found in rural regions. A total of 756 vegetable samples were studied and only 170 met the standard for lead and 17 for cadmium. The lowest lead content was found in parsley roots and the highest in celery leaves. Cadmium content between species did not differ greatly and the highest concentrations were recorded for celery. The metal intake by the consumer was also calculated using questionnaire data concerning vegetable consumption. In relation to the reference area, the metal intake in the polluted area was 2–5 times higher for lead and 2–16 times higher for cadmium. The main species responsible for the high metal concentrations were carrots and red beet. Replacing carrots and red beet with the same species grown in an unpolluted region would reduce the consumer's metal intake from vegetables considerably.

Assessing the contribution from lead in mining wastes to blood lead

Lead has been recognized for years as an environmental pollutant of concern for young children. Nonetheless, many children in the United States still experience high body burdens of lead. Reducing exposure to lead must include an assessment of all potential sources of lead and a definition of routes of exposure. In this paper, the relationships between soil lead and blood lead concentrations in residents in communities with high soil lead concentrations resulting from past mining and ore processing (milling) activities are compared to those derived from studies in urban communities or communities with operating smelters. The impact of mine waste-derived lead in soil (usually in the form of lead sulfide) on blood lead is less than that for lead in soil derived from smelter, vehicle, or paint sources. Possible reasons for a reduced impact of lead sulfide on blood lead in children in mining communities include the following: lead from mining sources contributes less to lead in the immediate environment of children than lead from other sources; mine wastes typically are of larger particle size, which decreases the bioavailability of lead in the gastrointestinal tract; and lead sulfide is absorbed less in the gastrointestinal tract compared to other lead species. A reduced impact of mine waste-derived lead on blood lead may be important from a regulatory point of view. Expensive cleanup actions for lead-contaminated soils in mining communities based on acceptable soil lead concentrations derived from smelter or urban communities may be questionable in terms of reducing blood lead in children.