Τρίτη, 16 Απριλίου 2019

Environmental Contamination and Toxicology

The Evaluation of Air Quality in Albania by Moss Biomonitoring and Metals Atmospheric Deposition

Abstract

The air quality of Albania is evaluated by trace metals atmospheric deposition using moss biomonitoring method. Bryophyte moss (Hypnum cupressiforme Hedw.) samples were collected during August and September 2015 from 55 sampling points distributed over the entire territory of Albania. The concentrations of Cr, Cu, Fe, Ni, Pb, V, and Zn in moss samples was determined by ICP-AES, ETAAS (As and Cd), and CVAAS (Hg) analysis. Spatial distribution and temporal trend of the moss elements is discussed in this study. Different variability was found in moss metal concentrations that may reflect their spatial distribution patterns and may identify the location of the areas with high contamination of each element. Compared with the measurements of moss collected in 2010, significant differences were found in the concentrations of As, Cr, Cu, Hg, Ni, Pb, and Zn. The differences between two moss surveys may reflect changes in the bioavailability of the elements resulting from wet and dry deposition respectively during 2015 and 2010 moss biomonitoring survey. The pollution loading index that was applied to judge the content of metal contamination indicated moderate pollution throughout Albania. Examination of the potential ecological risk found that As, Cd, Cr, Hg, Ni, and Pb pose the highest potential ecological risks particularly in the areas with high metal contents. Factor analysis applied to investigate the probable sources of metals in the environment suggested that Al and Fe likely originated from natural sources. As, Cd, Hg, Pb, Cu, Zn, Ni, and Cr likely originated from anthropogenic sources associated with long-range transport, transboundary pollution and local emission sources.



Biological Effects of Elevated Major Ions in Surface Water Contaminated by a Produced Water from Oil Production

Abstract

Produced water (PW) from oil and gas extraction processes has been shown to contain elevated concentrations of major ions. The objective of this study was to determine the potential effects of elevated major ions in PW-contaminated surface water on a fish (fathead minnow, Pimephales promelas) and a unionid mussel (fatmucket, Lampsilis siliquoidea) in short-term (7-day) exposures. The test organisms were exposed in 3 reconstituted waters formulated with 1, 2, and 4 times the major ions measured at a PW-contaminated stream site 1 month after a PW spill from an oil production wastewater pipeline in the Williston Basin, North Dakota. A reconstituted water mimicking the ionic composition of an upstream site from the spill was used as a reference water. Significant reductions in survival and growth of the fish were observed in the 4× treatment compared with the reference. The mussels were more sensitive than the fish, with significant reductions in survival in the 2× and 4× treatments, and significant reductions in length in the 1× and 2× treatments. Overall, these results indicate that elevated concentrations of major ions in PW-contaminated surface waters could adversely affect the fish and mussels tested and potentially other aquatic organisms.



Assessing Mercury Mobility in Sediment of the Union Canal, Scotland, UK by Sequential Extraction and Thermal Desorption

Abstract

The mobility of mercury (Hg) was assessed in sediment from the Union Canal, Scotland, UK. Samples collected from the vicinity of a former munitions factory that manufactured mercury fulminate detonators were subjected to sequential extraction followed by cold vapor atomic absorption spectrometry (CVAAS) and direct analysis using thermal desorption (TD). The sequential extraction indicated that > 75% of mercury (up to 429 mg kg−1) was in mobile forms, with < 12% semimobile and < 23% nonmobile species. In the TD method, > 67% of the total Hg content was desorbed in the temperature range 100–250 °C consistent with species weakly attached to the mineral matrix [tentatively identified as an iron (oxy)hydroxide-associated species]. This predominance of mobile mercury species may arise from a lack of association between Hg and either organic matter or sulfur in the sediments. Further investigation of Hg mobilization, transport, and assimilation/biomagnification is required both to determine whether there is a need for remediation of the sediment and to improve understanding of the biogeochemical cycling of Hg in shallow, oxic, freshwater systems.



A Review on the Status of Mercury Pollution in Pakistan: Sources and Impacts

Abstract

Mercury (Hg) contamination in environmental matrices and associated human exposure has been recognized as a critical long-lasting issue worldwide. However, studies are still elusive that summarized the overall status of Hg pollution and its impacts on public health in Pakistan. Hence, this review encompasses the environmental prevalence, potential sources, and human exposure tendencies to Hg contamination in Pakistan. Reviewed literature revealed jolting levels of Hg in various environmental samples, such as dust, soil, water, and air collected from the residential and industrial areas. Inhalation of Hg via dust particle was identified as the primary pathway for human exposure, while atmospheric deposition and gold mining are identified as the two primary sources of Hg contamination in the environment. Considering human exposure, the highest bioaccumulation of Hg was ranged from 5885 to 8698 µg/kg in hair samples collected from the residents of the Kashmir Valley, Pakistan. However, in the lower Himalayan regions, including Islamabad and Swabi, the concentration of Hg in hair samples was reported at 1085 µg/kg, slightly beyond WHO devised reference dose (RfD) of Hg (1000 µg/kg). This review revealed the worst scenario of Hg contamination in human biomatrices and environmental compartments in Pakistan, which needed immediate rehabilitation measures.



Metals Uptake from Particulate Matter Through Foliar Transfer and Their Impact on Antioxidant Enzymes Activity of S. robusta in a Tropical Forest, West Bengal, India

Abstract

Particulate matters deposition on the leaves of S. robusta were investigated during three different seasons in two tropical forests: Barjora forest, situated adjacent to heavy pollution sources, and the control, Ballavpur Wildlife Sanctuary, West Bengal, India. The purpose of this study is to measure the dust fall and foliar transfer of heavy metals (viz., Pb, Cd, Cu, Cr, Fe, Ni, Zn, and Mn) and antioxidant enzyme activities (peroxidase, catalase) in S. robusta, including the measurement of heavy metals present in the suspended particulate matter in ambient air. Dust fall on leaves and the total metal accumulation capacity of the plant were the highest during winter season with metal accumulation index of 9.82. Based on two-way ANOVA, it has been shown that there is a statistically significant difference in dust fall between the two forests and in different seasons. From cluster analysis, correlation results, and principal component analysis, it was suggested that heavy metals in Barjora may be due to the traffic emission and various industrial activities. Increased levels of peroxidase and catalase activities and the presence of high levels of reactive oxygen species in the leaves of the Barjora forest was an indication of stress state in this forest. On the basis of these findings, controlling the emission of pollutants from industrial and vehicular activities in that area is highly encouraged.



Multicompartment Mercury Contamination in Major Gold Mining Districts at the Department of Bolivar, Colombia

Abstract

Artisanal and small-scale gold mining is the main source of human exposure to mercury (Hg) in many countries. This study was designed to evaluate total Hg (T-Hg) concentrations in human hair, fish, soil, and air from two major gold-mining districts (GMDs) at the department of Bolivar, Colombia. Total Hg was analyzed using a direct Hg analyzer. The mean T-Hg concentration in hair samples was 3.07 ± 0.14 μg/g (range 0.15–25.1 μg/g; median 2.02 μg/g). The highest Hg level was observed in Mojana GMD, specifically at Achi-La Raya (9.2 ± 0.6 μg/g) and the lowest in Morales, at the Middle Magdalena GMD (1.50 ± 0.16 μg/g). Hair T-Hg values exceeded the U.S. Environmental Protection Agency reference level of 1.0 μg/g. Correlation between T-Hg in hair and stature was negative for the Mojana, but the opposite for Middle Magdalena, although for both GMDs hair T-Hg correlated positively with fish intake. The highest average T-Hg fish concentrations were observed in Caquetaia kraussii (0.37 ± 0.10 μg/g), Sorubim cuspicaudus (0.32 ± 0.16 μg/g), Plagioscion surinamensis (0.22 ± 0.02 μg/g), Trachelyopterus insignis (0.20 ± 0.02 μg/g), and Pseudoplatystoma magdaleniatum (0.20 ± 0.02 μg/g). Human health risk assessment of Hg based on fish consumption suggested that, with the exception of P. magdalenae, all economically important fish species are potentially harmful for the communities. Soil Hg levels in amalgam burning facilities were extremely high, and Hg in the air around mines and gold-processing shops exceeded international guidelines. In short, Hg pollution in GMDs of Bolivar is extensive, and this situation requires special attention to reduce environmental and human health problems.



Toxicity Assessment of Impacted Sediments from Southeast Coast of Tunisia Using a Biomarker Approach with the Polychaete Hediste diversicolor

Abstract

Toxicity caused by exposure to pollutants from marine sediments is a consequence of the interaction between biota and xenobiotics most frequently released by anthropogenic activities. The present work intended to characterize the toxicity of natural sediments putatively impacted by distinct human activities, collected at several sites located in the south of the Gulf of Gabes, Zarzis area, Tunisia. The selected toxicity criteria were analysed following ecologically relevant test conditions. Organisms of the polychaete species Hediste diversicolor were chronically exposed (28 days) to the mentioned sediments. Toxicity endpoints were biomarkers involved in the toxic response to common anthropogenic chemicals, namely neurotoxic (acetylcholinesterase), anti-oxidant (catalase, glutathione peroxidase), metabolic (glutathione S-transferases) enzymatic activities, and oxidative damage (lipid peroxidation, TBARS assay). The chemical characterization of sediments showed that the samples collected from the site near an aquaculture facility were highly contaminated by heavy metals (Cd, Cu, Cr, Hg, Pb, and Zn) and polycyclic aromatic hydrocarbons (fluorene, phenanthrene, anthracene, fluoranthene and pyrene). H. diversicolor individuals exposed to the sediments from this specific site showed the highest values among all tested biomarkers, suggesting that these organisms were possibly under a pro-oxidative stress condition potentially promoted by anthropogenic pollution. Moreover, it was possible to conclude that individuals of the polychaete species H. diversicolor responded to the chronic exposure to potentially contaminated sediments from the southeast coast of Tunisia, eliciting adaptive responses of significant biological meaning.



Dependence of urban air pollutants on morning/evening peak hours and seasons

Abstract

Traffic emission is a major source of air pollution in urban cities of developing world. This paper shows dependence of traffic-related air pollutants in urban cities on morning/evening peak hours and winter/summer seasons. This research also shows the meteorological impact, such as temperature (T), relative humidity (RH), and wind speed (WS), on traffic-related air pollutants in urban cites. Based on the research output, the elevated level of PM concentration was observed between 1.8 and 6.7 times at all nearby roadway locations compared with background (IIT [ISM] campus). We have found 2.3, 2.4, 2.6 (morning) and 2.0, 2.1, and 2.1 (evening) times higher average PM10, PM2.5, and PM1 concentrations, respectively, in the winter than summer monitoring periods across all locations, due to the stable boundary layer, lower mixing height, and lower friction velocity. It is indicated that urban meteorology plays a crucial role in increasing or decreasing exposed pollutant concentrations in various microenvironments. The analysis of PM2.5/PM10 ratios was lower during whole campaign due to higher contribution of coarser particles generated by vehicles. During winter and summer seasons, 0.57 and 0.33 was observed, respectively. It is indicated that 57% and 33% of PM10 makes up PM2.5 particle, respectively. PM concentrations have showed a negative linear relationship with T and WS and positive relationship with RH in winter/summer seasons. Therefore, traffic and meteorology play a big role to increase or decrease in traffic-related air pollutants in urban air quality.



Occurrence, Distribution, and Exposure Risk of Organophosphate Esters in Street Dust from Chengdu, China

Abstract

Street dust samples were collected from 31 sampling sites in urban area of Chengdu. The distribution characters of OPEs were analyzed in line with functional districts and industrial layout of the city. The results showed that the detection frequency was tris(2-carboxyethyl) phosphine (TCEP), trichloropropyl phosphate (TCPP), triphenyl phosphate (TPhP), and tributoxyethyl phosphate (TBEP) (100%) > tris(2-ethylhexyl) phosphate (TEHP) (93.5%) > tri-n-butyl phosphate (TnBP) (83.9%) > tridichloropropyl phosphate (TDCPP) (74.2%). The ∑7OPEs concentrations ranged from 94.0 to 1484.6 ng/g (mean 512.9 ± 417.5 ng/g), and TBEP was the predominant pollutant, accounting for 27.9% of the ∑7OPEs. The highest concentrations were observed in the center, west, and northwest sides of the city. Besides, compared with outer area, the higher concentration in the 1st Ring Road reflected that emissions of OPEs might be associated with the population and consumption of commercial products. The correlations between monomers were statistically significant (p < 0.05) for TnBP/TCPP (p = 0.002), TCEP/TCPP (p = 0.026), and TCEP/TPhP (p = 0.033). The exposure level in adults was 0.11 ng/(kg bw day), and in children was 0.20 ng/(kg bw day) while hand-to-mouth was the primary mode of transmission. The Risk Quotients (RQs) of OPEs were 5.35 × 10−10–1.46 × 10−5 and 4.99 × 10−10–2.82 × 10−5 for adults and children respectively, with no potential risk.



Influence of Anthropogenic Activities on Metals in Arctic Permafrost: A Characterization of Benchmark Soils on the Yamal and Gydan Peninsulas in Russia

Abstract

Permafrost-affected region in Russian Arctic is an important study area for investigating fate of trace metals in soils by geological processes and human-induced trace metals through atmospheric deposition. Two plots of soils in Yamal region were selected: Northern Trans-Urals area (PU1, PU2, PU3) adjacent to urban areas and Gydan Peninsula representing reference groups as natural landscapes (Yavai, Gyda, Enysei). The levels of most metals in Urals area were more than those in Gydan Peninsula. In soil profile, Histic horizon revealed the accumulation of most metals. Cd and Pb were classified as metals, which were transported by atmosphere from urban areas and accumulated in surficial organic layers. Gleying processes and cryogenic mass exchanges transported metals from bottom to top layers in mineral horizons. Moreover, gleying horizon functioned as a geochemical barrier for metal transporting below permafrost table. The levels of As, Mn, and Fe were obliviously higher than threshold limit values of Russian Siberia. However, these values cannot represent the natural hydromorphic soils in Arctic tundra. The Geoaccumulation Index (Igeo) were determined for assessing surface soil samples regarding to metals' pollution. The results suggested local geology pollution for Gydan Peninsula and atmospheric transport pollution for Urals area. More investigations with respect to trace metals behavior in permafrost-affected soil profile needed to be studied for understanding levels of trace metals with changes of active layer depth due to climate changing.



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