Terrestrial snails as quantitative indicators of environmental metal pollution

Concentrations of cadmium, lead, copper and zinc were measured in individuals of Arianta arbustorum from different urban sampling sites. In comparison to snails from a reference site, the animals collected in the city showed higher concentrations of cadmium, lead, and copper, indicating elevated levels of metal pollution. The most pronounced difference in tissue concentrations between control animals and contaminated snails was observed for lead. Within the city, metal levels in snails differed significantly, even between adjacent populations. Arianta arbustorum is a suitable species for biomonitoring, because it is widespread, resident and easy to collect; it has a high capacity for metal accumulation and shows different concentrations depending on metal contamination of the sampling area. An interspecific comparison of metal concentrations in terrestrial gastropods was conducted to define background levels and classes of burden. Three pollution levels are distinguished on the basis of the snails' metal burden: no pollution (class 1: reference sites), moderate (class 2: traffic and other human activities in urban areas), and high pollution (class 3: mining and heavy industry).     

Heavy metals in Patella caerulea (Mollusca, Gastropoda) in polluted and non-polluted areas from the Iskenderun Gulf (Mediterranean Turkey)

The concentrations of Cd, Cu, Zn, Fe, Pb, Ni, and Co were measured in gastropod mollusks Patella caerulea in the Mediterranean area. The organisms were collected at two coastal sites in Iskenderun Gulf during winter, spring, summer, and autumn 2008. Samples of the digestive gland, gill, and muscle were analyzed for heavy metals. The aim of study is to determine heavy metal levels in tissues of P. caerulea in different locations. Tissues of P. caerulea from the polluted site showed metal concentrations appreciably higher than unpolluted organisms. The highest metal levels were registered in the digestive gland of P. caerulea. Generally, digestive gland and gills showed higher metal concentrations than muscle. The average concentrations of heavy metals analyzed exhibited the following decreasing order: Fe > Zn > Cu > Ni > Cd > Pb > Co for both stations 1 and 2. Seasonal changes in metal concentrations were observed in the tissues of P. caerulea from a polluted and an unpolluted population.     

Heavy metal pollution across sites affecting the intestinal helminth communities of the Egyptian lizard, Chalcides ocellatus (Forskal, 1775)

This study aimed to investigate the possible effects of heavy metal pollution across sites and some biological factors on helminth communities infecting the lizard, Chalcides ocellatus. The possibility of heavy metal accumulation by such helminths was also investigated. A total of 202 C. ocellatus were collected from three different sites (industrial, rural, and urban systems) in Ismailia governorate, Egypt, during summer 2009. The lizards were classified according to their sex and size and were examined for the intestinal helminths. Heavy metal levels were detected in the intestinal tissue of the lizards and the recovered helminths. Species richness was 6, 5, and 3 in rural, urban, and industrial systems, respectively. Significant site variations regarding infection prevalence, intensity, and abundance were encountered at different levels. Some noticeable effects of the host size were found. The significant differences found between the metal levels of the intestinal tissues and the recovered helminths and the other relations found in this study may be indications for a possible metals accumulation capacity by helminths. The cestode Oochoristica tuberculata could be a promising biomonitor for Cu and Pb, while the intestinal nematodes were less sensitive to the pollution. Differences in the accumulation capacity may be attributed to the intensity of infection, parasite species, and metal. The observed patterns of distribution and occurrence of helminths and the metals accumulation capacity reflect the need for more studies since this study proposes the model intestinal helminth/C. ocellatus as another promising bioindication system in the terrestrial habitat, especially in areas where the lizard C. ocellatus are available.     

Pollution in the urban soils of Lianyungang,China, evaluated using a pollution index,mobility of heavy metals,and enzymatic activities

Soil samples from 16 urban sites in Lianyungang, China were collected and analyzed. A pollution index was used to assess the potential ecological risk of heavy metals and a sequential extraction procedure was used to evaluate the relative distribution of Cu, Zn, Pb, Cd, Cr, and As in exchangeable, carbonate, Fe/Mn oxide, organic/sulfide, and residual fractions. The mobility of heavy metals and urease (URE) activity, alkaline phosphatase (ALP) activity, and invertase (INV) activity of soils was determined. The results showed that the average concentrations of Cu, Zn, Pb, Cd, Cr, and As in Lianyungang soils were much higher than those in the coastal city soil background values of Jiangsu and China. Among the five studied regions (utilities, commercial, industrial, tourism, and roadside), the industrial region had the highest metal concentrations demonstrating that land use had a significant impact on the accumulation of heavy metals in Lianyungang soils. Compared to the other metals, Cd showed the highest ecological risk. According to chemical partitioning, Cu was associated with the organic/sulfides and Pb and Zn were mainly in the carbonate and the Fe/Mn oxide phase. The greatest amounts of Cd were found in exchangeable and carbonate fractions, while Cr and As were mainly in the residual fraction. Cd had the highest mobility of all metals, and the order of mobility (highest to lowest) of heavy metals in Lianyungang soils was Cd > Zn > Pb > Cu > As > Cr. Soil urease activity, alkaline phosphatase activity, and invertase activity varied considerably in different pollution degree sites. Soil enzyme activities had the lowest levels in roadside and industrial regions. Across all the soil data in the five regions, the total Cu, Zn, Pb, Cd, Cr, and As level was negatively correlated with urease activity, alkaline phosphatase activity, and invertase activity, but the relationship was not significant. In the industrial region, alkaline phosphatase activity had significant negative correlations with total Cu, Pb, Cr, Zn, Cd, and heavy metal fractions. This showed that alkaline phosphatase activity was sensitive to heavy metals in heavily contaminated regions, whereas urease and invertase were less affected. The combination of the various methods may offer a powerful analytical technique in the study of heavy metal pollution in street soil.     

Determination of heavy metal levels in water, sediment and tissues of tench (Tinca tinca L., 1758) from Beyşehir Lake (Turkey)

In the present study, some heavy metals (Cu, Fe, Zn and Mn) were seasonally determined in water, sediment and some tissues of fish Tinca tinca from Bey?ehir Lake, which is an important bird nesting and visiting area, a water source for irrigation and drinking. In the water, Fe has the highest concentrations among the studied metals. Generally, the metal concentrations increased in the hottest period decreased in warm seasons. Results for levels in water were compared with national and international water quality guidelines, as well as literature data reported for the lakes. Fe was the highest in sediment samples, also Cu and Zn were the highest in spring, while Fe and Mn were in autumn. Among the heavy metals studied, Cu and Mn were below the detection limits in some tissues. Generally, higher concentrations of the tested metals were found in the summer and winter, compared with those during the autumn and spring seasons. High levels of heavy metals were found in liver of T. tinca, while low levels in muscle samples. Metal concentrations in the muscle of examined fish were within the safety permissible levels for human consumption. The present study shows that precautions need to be taken in order to prevent further heavy metal pollution.     

Comparison of the suitability of two lichen species and one higher plant for monitoring airborne heavy metals

We compared the capacity to accumulate airborne heavy metals of two lichens (Flavoparmelia caperata and Parmotrema chinense) and one higher plant (Nerium oleander) at a very densely populated urban site near Naples. After 15, 45, 75, and 120 days of exposure at four sites with different levels of air pollution, equal portions of thalli and 20 leaves were collected, and four environmentally significant elements, Fe, Cu, Zn, and Pb, were measured by inductively coupled plasma analysis. To compare the accumulation rates of lichens and the vascular plant, we determined an index of relative accumulation rate of pollutants during time and the ratio between the concentrations of each element in exposed samples to that of control samples (exposed-to-control ratio). Our data indicate F. caperata as being the most suitable bioaccumulator, followed by P. chinense. N. oleander was also found to be a useful heavy metal biomonitor though not suitable as a bioaccumulator.     

Determination of selected heavy metals in air samples from the northern part of Jordan

In this work, the atmospheric concentrations of selected heavy metals including lead (Pb), iron (Fe), cadmium (Cd), copper (Cu), nickel (Ni), manganese (Mn), and zinc (Zn) were measured for two different sampling sites (urban and rural) in the northern part of Jordan (Irbid city). Samples were collected according to a certain schedule for 1 year. High volume air samplers and glass fiber filters were used to collect the samples. Collected samples were digested using a mixture of analytical grade nitric acid and analytical grade hydrochloric acid, and analyzed to evaluate the levels of heavy metals by atomic absorption spectrophotometry. Six heavy metals (Pb, Fe, Cu, Ni, Mn, and Zn) were measured in all samples; the concentrations of Cd and Co were not detected in Irbid atmosphere by atomic absorption spectroscopy. The results were used to determine the levels of heavy metal pollutants in air, possible sources, and to compare the levels of selected heavy metals in the two studied sites. Aerosols from the rural site have lower concentrations for all the metals compared to those from the urban site. The daily and monthly variations of the elements were investigated. All heavy metals in urban and rural sites reached maximum concentrations in June, July, and August. This is consistent with the increased activities leading to particulate matter emission during the summer period. The enrichment factors with respect to earth crust and correlation coefficients of heavy metals were investigated to predict the possible sources of heavy metals in air.     

Heavy Metal Load Of Soil, Water And Vegetables In Peri-Urban Delhi

Peri-urban lands are often used for production of vegetables for better market accessibility and higher prices. But most of these lands are contaminated with heavy metals through industrial effluents, sewage and sludge, and vehicular emission. Vegetables grown in such lands, therefore, are likely to be contaminated with heavy metals and unsafe for consumption. Samples of vegetables i.e., spinach (Spinacia oleracea L.) and okra (Abelmoschus esculentus L.); soil and irrigation water were collected from 5 peri-urban sites of New Delhi to monitor their heavy metal loads. While heavy metal load of the soils were below the maximum allowable limit prescribed by the World Health Organization (WHO), it was higher in irrigation water and vegetable samples. The spinach and okra samples showed Zn, Pb and Cd levels higher than the WHO limits. The levels of Cu, however, were at their safe limits. Metal contamination was higher in spinach than in okra. Spatial variability of metal contamination was also observed in the study. Bio-availability of metals present in soil showed a positive relationship with their total content and organic matter content of soil but no relationship was observed with soil pH. Washing of vegetables with clean water was a very effective and easy way of decontaminating the metal pollution as it reduced the contamination by 75 to 100%.     

Heavy metal accumulation and ecosystem engineering by two common mine site-nesting ant species: implications for pollution-level assessment and bioremediation of coal mine soil

The present study focuses on the abundance, heavy metal content, and the impact of ecosystem engineering activities of two coal mine site-inhabiting ant species, Cataglyphis longipedem and Camponotus compressus. The abundance of Ct. longipedem increased while that of C. compressus decreased, with increasing soil pollution. Correspondence analysis reveals a close association between soil heavy metal concentrations and Ct. longipedem abundance, but this association is lacking in the case of C. compressus. Cataglyphis ants which occupy stress-characterized niches appear to be pre-adapted to tolerate heavy metal pollution. Higher concentrations of Zn and Mn in Ct. longipedem may contribute to the strengthening of the cuticular structures, necessary for nest excavation in the hard, arid soil and for single load carrying. C. compressus ants appear to be pollution sensitive. Their higher Fe content may be related to metal uptake via plant-derived liquids and species-specific regulatory mechanisms. The metal pollution index and biota-to-soil accumulation factors, calculated by using the ant body metal content of the two species, indicate an overall decrease of soil heavy metal concentrations with increase of the site age, which reflects the degree of pollution related to the mine site age. The concentrations of total and available heavy metals (Fe, Zn, Mn, Pb, and Cu) were significantly lower in the ant nest debris soil as compared to the reference soil. The results of the present study highlight the role of ants as bioindicators and in bioremediation of contaminated soil.     

Analysis of acidic components, heavy metals and PAHS of particulate in the Changwon–Masan area of Korea

This study is an analysis of the concentrations and components of heavy metals in PM_2.5 and the total suspended particulate (TSP) collected at a mechanical industrial complex (IC) site in Changwon and at a residential site in Masan, Korea. Particulate was collected during two sampling periods, from the late summer to the early fall and from the middle to late fall, at the IC site and one sampling period, from the middle fall to the early winter, at the residential site. PM_2.5 and TSP samples were taken by an annular denuder system and a hi-volume air sampler, respectively. The authors also identified the concentrations and components of heavy metals extracted from the PM_2.5 and TSP filters, the acidic components extracted from the PM_2.5 filters, and the polycyclic aromatic hydrocarbons (PAHs) extracted from polyurethane foam (PUF) plug. The average concentrations of the PM_2.5 collected at the IC and residential sites were very similar. Major sources of PM_2.5 at the study sites, however, were air emissions from vehicles and industry as well as emissions from residential heating and soil origins, respectively. The higher concentrations of the TSP at the IC site, as compared to those at the residential site, were due to either increased suspended dust from vehicle emissions or re-suspended road dust because of increased vehicle speeds near the IC site. Heavy metal concentrations in the TSPs were higher than those in the PM_2.5. The heavy metal concentrations in the PM_2.5 and TSP at the IC site with heavy traffic were substantially greater than those at the residential site. The concentrations of TSP and heavy metals and PAHs in PM during the period of the middle to late fall was much higher than those during the period of the late summer to early fall at the IC site. This is because of the difference in meteorological characteristics and energy uses between two periods. The residential site also showed higher concentrations of acidic anions while the IC site showed higher concentrations of acidic cation. Secondary aerosols or particulates, such as ammonium nitrate or ammonium nitrite, might have been important constituents of the PM_2.5 at the residential site. The PAHs in the TSP collected at the IC site was greatly affected by traffic and industry emissions consisting mostly of high molecular weight PAHs with two to four rings. PAHs in the TSP at the site, however, were affected by residential heating and air emissions from small chemical plants having higher concentrations of low molecular weight PAHs with five to six rings.     

The responses of the hepatosomatic index (HSI), 7-ethoxyresorufin-O-deethylase (EROD) activity and glutathione-S-transferase (GST) activity in sea bass (Dicentrarchus labrax, Linnaeus 1758) caged at a polluted site: implications for their use in environmental risk assessment

The present study investigates the response of three hepatic biomarkers in adult sea bass (Dicentrarchus labrax, Linnaeus 1758) caged at a wastewater outlet of an oil refinery with fish caged at a pristine site used as controls. The biomarkers that were investigated were the hepatosomatic index (HSI), 7-ethoxyresorufin-O-deethylase (EROD) activity and glutathione-S-transferase (GST) activity. In addition, we have measured the levels of polycyclic aromatic hydrocarbons (PAHs) and selected heavy metals (lead, cadmium, mercury, copper and zinc) in sediment samples at the polluted site. Although the polluted site had high environmental levels of PAHs and heavy metals, there was no difference in hepatic EROD activity and HSI between fish caged at the polluted site and controls. On the other hand, GST activity was significantly lower in fish caged at the polluted site compared to controls. Our results point out that the studied biomarkers have limited use in environmental risk assessment studies, at least when caged adult sea bass is used as the sentinel species and complex toxicant mixtures are involved.     

Heavy metals contamination in water and three species of most consumed fish sampled from Caspian Sea, 2011

The present study is an attempt to evaluate the heavy metal contamination in the marine environment of the Caspian Sea of Iran. The concentrations of zinc, chromium, cadmium, and lead were measured in water and dorsal muscle of fish sampled from 10 selected stations along Gorgan coast using atomic absorption spectrophotometry during summer of 2011. The average concentrations of lead in water and fish samples (115.29?±?14.78 and 113.23?±?27.01 μg/L) were significantly higher than that of cadmium and chromium (P?<?0.05). The highest heavy metals content was observed in Cyprinus carpio samples. The heavy metals concentrations in the samples were within the acceptable recommended standards. But, elevating levels of heavy metals in water and fish made a serious concern about ecosystem and food chain contamination. It is recommended that protective authorities should carry out a continual assessment on the levels of pollutants in the sea.     

Biomonitoring of Lead, Zinc, and Cadmium in Streams Draining Lead-Mining and Non-Mining Areas, Southeast Missouri, USA

We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish, and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001, near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring studies.     

Multiple approaches to assess the safety of artisanal marine food in a tropical estuary

In this study, metal and metalloid concentrations and pathogens were measured in shellfish at different locations in a tropical estuary, including sites impacted by sewage and industry. Oyster, mangrove snails and mud snails did not exceed Australian and New Zealand Food Standards maximum levels for copper, lead or estimated inorganic arsenic at any site although copper concentrations in oysters and mud snails exceeded generally expected levels at some locations. Bacterial community composition in shellfish was species-specific regardless of location and different to the surrounding water and sediment. In the snails Telescopium telescopium, Terebralia palustris and Nerita balteata, some bacterial taxa differed between sites, but not in Saccostrea cucullata oysters. The abundance of potential human pathogens was very low and pathogen abundance or diversity was not associated with site classification, i.e. sewage impact, industry impact and reference.     

An investigation of arsenic contamination in Peninsular Malaysia based on Centella asiatica and soil samples

The first objective of this study was to provide data of arsenic (As) levels in Peninsular Malaysia based on soil samples and accumulation of As in Centella asiatica collected from 12 sampling sites in Peninsular Malaysia. The second objective was to assess the accumulation of As in transplanted C. asiatica between control and semi-polluted or polluted sites. Four sites were selected which were UPM (clean site), Balakong (semi-polluted site), Seri Kembangan (semi-polluted site) and Juru (polluted site). The As concentrations of plant and soil samples were determined by Instrumental Neutron Activation Analysis. The As levels ranged from 9.38 to 57.05 μg/g dw in soils, 0.21 to 4.33 μg/g dw in leaves, 0.18 to 1.83 μg/g dw in stems and 1.32–20.76 μg/g dw in roots. All sampling sites had As levels exceeding the CCME guideline (12 μg/g dw) except for Kelantan, P. Pauh, and Senawang with P. Klang having the highest As in soil (57.05 μg/g dw). In C. asiatica, As accumulation was highest in roots followed by leaves and stems. When the As level in soils were higher, the uptake of As in plants would also be increased. After the transplantation of plants to semi-polluted and polluted sites for 3 weeks, all concentration factors were greater than 50 % of the initial As level. The elimination factor was around 39 % when the plants were transplanted back to the clean sites for 3 weeks. The findings of the present study indicated that the leaves, stems and roots of C. asiatica are ideal biomonitors of As contamination. The present data results the most comprehensive data obtained on As levels in Malaysia.     

Energy-dispersive X-ray fluorescence analysis of moss and soil from abandoned mining of Pb-Zn ores

This research investigates heavy metal pollution around one of the most important mining areas in Turkey, the Sebinkarahisar (Giresun) lead–zinc mining, by means of analyzing moss and soil samples collected in the neighborhood of the copper mining at different distances. Energy dispersive X-ray fluorescence spectrometry (Epsilon 5, PANalytical, Almelo, The Netherlands) is utilized in the experiments. The results have indicated that the both moss and soil samples contain aluminum, vanadium, chromium, manganese, iron, nickel, copper, zinc, arsenic, barium, cerium, tungsten, and lead. The comparison of the heavy metal concentrations with the typical measurements in the world and with the limit values for the human health has revealed the critical heavy metal pollution levels in the region. The possible consequences of these results are briefly discussed from the point of potential hazards to ecology and human health.     

Acetylcholinesterase activity in Corbicula fluminea Mull., as a biomarker of organophosphate pesticide pollution in Pinacanauan River, Philippines

Organophosphates are known to inhibit the enzyme acetylcholinesterase. In this study, the AChE activity from the total soft tissues of Corbicula fluminea Mull. was used as a biomarker of organophosphate pollution in Pinacanauan River. Clams were collected from two different sites and at different seasons of the year. A colorimetric assay on the total soft tissues of the clams showed a directly proportional relationship between enzyme activity and condition of the riverine system. In vitro experiments on the total soft tissue, adductor muscles, digestive glands, and gills were conducted to assess the degree of localization of AChE as well as the sensitivity and tolerance of the enzymes in these tissues to varying concentrations of malathion. The degree of enzyme localization from highest to lowest is as follows: adductor muscle > gills > digestive gland whereas sensitivity to OP from greatest to least is: gills > adductor muscles > digestive gland.     

Microbial activities and trace element contents in an urban soil

Soil biological properties are influenced by trace metals. The main sources of these pollutants in the urban areas are industrial plants, power stations, domestic heating systems and motor vehicles. The aim of this work was to evaluate, in relation to distance from urban roads, soil trace metal concentrations (Pb, Cu, Cr, Cd and V) and their influence on C-microbial biomass as well as on soil respiration and enzyme activities (phosphatase glucosidase, galactosidase, xylanase, cellulase, trealase, protease and invertase). The samplings were carried out at four sites, along a route that goes from Giannone Street to Passionisti Street, two heavily travelled roads at two different times of the year (spring and autumn). Heavy metal contents and microbial activities were highest at the sites near the roads. The highest values of microbial activities were found in the inner site; here, on the contrary, the lowest concentrations of heavy metals were measured. Significant and negative correlations were found between microbial activity and heavy metal contents.     

徽县铅锌冶炼区土壤中重金属的空间分布特征

采集甘肃省徽县铅锌冶炼区域土壤样品,分析该区域内重金属污染分布规律及污染特征。结果表明,表层土壤中Pb、Cd、Cu、Zn的平均含量分别为214、3.12、25.8、79.5 mg/kg。研究区域内重金属的分布特征显示,污染浓度由冶炼厂中心向四周递减。纵向0~30 cm范围内重金属含量逐渐降低,大部分重金属污染物集中在土壤表层的0~20 cm区域,其中0~2 cm区域内含量较高,Pb和Cd的最高含量分别达到3 877、24.8 mg/kg,与国家土壤环境质量二级标准(p H 6.5~7.5)(GB 15618—1995)相比,分别超标13、82倍,属于重度污染。重金属元素的分布与土壤有机碳含量及p H相关。冶炼厂周围的重金属污染应引起有关部门的高度重视,严格控制污染源,尽快采取措施以防止污染范围进一步扩大。