The global cycle of mercury (Hg) is reasonably well-understood, as are some of the natural and anthropogenic sources of Hg to the atmosphere. Less well understood are the regional and local characteristics of Hg deposition and subsequent watershed-scale transport, important parameters for assessing human risk to various avenues of Hg exposure. This study employed a two-part strategy for understanding coupled deposition and transport processes in central Indiana (USA), including Indianapolis, a typical large city with multiple coal-fired electric utilities and other Hg emission sources. A spatial analysis of Hg concentrations in surface soils revealed elevated Hg proximal to many of the large emission sources, with a distribution aligned along a southwest-northeast axis corresponding to the mean wind direction in this region. This soil distribution suggests some local depositional impact from local utilities, with wind modification affecting the regional pattern. Post-depositional transport of Hg was assessed using a series of streambank sampling arrays as the White River and various tributaries travelled through the urban core of Indianapolis. Streambank sediments had peak Hg concentrations in the urban core, where several local sources are present and where a number of subwatersheds join the main trunk of the White River, suggesting local emission and/or rapid Hg transport from urban subwatersheds due to their relatively high proportion of impervious surfaces. High Hg values persist in White River sediments into rural areas tens of kilometers south of Indianapolis, raising concerns for anglers collecting fish in this apparently “pristine” environment.

The purpose of this study was to survey the distribution patterns of volatile organic compounds (VOCs) and formaldehyde in the various indoor environments using cluster analysis. We investigated VOCs and formaldehyde in subway stations, underground shopping areas, medical centers, maternity recuperation centers, public childcare centers, large stores, funeral homes, and indoor parking lots from June 2005 to May 2006 (9 p.m. to 6 a.m.). The concentration of total volatile compounds (TVOCs) in maternity recuperations was 2,605.7 μg/m3, which was higher than that stated in the guideline and other chosen facilities. TVOCs in public childcare centers were 1,951.6 μg/m3, which also exceeded the guideline. Moreover, the concentration of TVOCs in every facility exceeded the guideline of the Ministry of Environment, Korea. In the case of formaldehyde, the mean concentration of 336.5 μg/m3 found only in public childcare centers exceeded the 120 μg/m3 stated in the guideline. Finally, by applying cluster analysis, three patterns of the indoor air pollutions were distinguished. In the results of the analysis, concentrations of TVOCs and formaldehyde of cluster 3 were higher than clusters 1 and 2, which were 2,561.4 and 184.9 μg/m3, respectively.

Petroleum monoaromatics including benzene, toluene, ethylbenzene, and xylenes (BTEX) are among the notorious volatile organic compounds that contaminate water and soil. In this study, a surfactant- modified natural zeolite and its relevant granulated nanozeolites were evaluated as potential adsorbents for removal of petroleum monoaromatics from aqueous solutions. All experiments performed in batch mode at constant temperature of 20°C and pH of 6.8 for 48 h. The results revealed that the amount of BTEX uptake on granulated zeolites nanoparticles were remarkably higher than the parent micron size natural zeolite (in the order of four times). The isotherms data were analyzed using five models namely, Langmuir, Fruendlich, Elovich, Temkin, and Dubinin–Radushkevich models. It was concluded that the Langmuir model fits the experimental data. The measured adsorption capacities were 3.89 and 4.08 mg of monoaromatics per gram of hexadecyltrimethylammonium-chloride and n-cetylpyridinium bromide (CPB)-modified granulated nanozeolite, respectively. Considering the type of surfactant, adsorbents modified with CPB showed greater tendency for the adsorption of the adsorbates.

Achieving high productivity in agriculture is increasingly needed and requested; however, this activity should be performed in a sustainable and rational way. The use of micronutrients in the fertilization of the most diverse cultures is becoming a common practice on farms, but it is important to conduct studies in relation to fertilizers used for this supplement, including raw materials with which they are produced. Therefore, this study aimed to evaluate the phytoavailability of nutrients and toxic heavy metals Cd, Pb, and Cr; productivity; and yield components in wheat sown in soil with residue of N/P2O5/K2O + Zn-based fertilizer applied in previous crop. Treatments consisted of residual fertilization of five forms arranged in two doses (D1 = 300 kg ha−1 and D2 = 600 kg ha−1). The five types of fertilization were composed of formulated N/P2O5/K2O and the variation of different Zn sources. In the assessment of phytoavailability were determined levels of K, Ca, Mg, Cu, Mn, Zn, Fe, Cd, Pb, and Cr in wheat leaves. The results show that the residual effect of fertilization was not enough for there being difference between treatments at both doses used; however, it was found that the fertilizers used to Zn supply provided residual effect, providing significant levels of Pb and Cr for wheat plants.

The aggregate potential health impact due to ambient volatile organic compounds on the population living in the area nearby the petrochemical industrial complex in Thailand was evaluated using measured air contaminants concentration. Airborne volatile organic compounds were collected using canisters and were analyzed by gas chromatography/mass spectrophotometer following the US.EPA TO 15 procedure. Composite samples taken over a 24-h period were collected monthly. Concentrations of volatile organic compounds (VOCs) were analyzed for a suite of 24 compounds covering both carcinogenic and non-carcinogenic substances. Results were determined and analyzed in order to evaluate their spatial variability and their potential health risk. Comparison of data from each monitoring site indicated that patterns of VOCs across sites were different from their major species and their concentrations which might be influenced by nearest potential emission sources. Carcinogenic VOCs such as benzene, 1,3butadiene, and 1,2 dichloroethane were found to be higher than their annual national standards. A potential cancer risk map was drawn based on benzene concentration in order to illustrate the zone of impact and the number in the population likely to be exposed. Results indicated that 82% of the total area, and 89.6% of the total population were within the impact area. It was suspected that high concentrations of benzene and 1,3 butadiene might be attributed by both the mobile source and the point source of emissions while 1,2 dichloroethane was suspected to be emitted from factories located upwind from the monitoring sites. Hazard quotients and hazard indexes were applied to determine chronic health effects with non-cancer endpoints. Calculated values of hazard indexes for each of the target organ systems were lower than 1, which indicated that the non-cancer chronic risk due to level of volatile organic compounds in the study area was less.

In a warming climate, mercury (Hg) pathways in the Arctic can be expected to be affected. The Hg transport from the high arctic Zackenberg River Basin was assessed in 2009 in order to describe and estimate the mercury transported from land to the marine environment. A total of 95 water samples were acquired and filtered (0.4 μm pore size), and Hg concentrations were determined in both the filtered water and in the sediment. A range of other elements were also measured in the water samples. Hg concentrations in the filtered water were in general highest in the beginning of the season when the water came mainly from melted snow. THg concentrations in the sediment were in general relatively constant or slightly decreasing until mid-August, where after the concentrations increased. A principal component analysis separated the samples into spring, summer and autumn samples indicating seasonal characteristics of the patterns of element concentrations. The total amount of Hg in the sediment transported was estimated to 2.6 kg. Approximately 60% of the sediment-transported Hg occurred during a 24-h flood in the beginning of August caused by a glacial lake outburst flood. The total amount of transported dissolved Hg was estimated to 46 g, and 13% of this transport occurred during the 24-h flood. If it is assumed that the Hg transport by Zackenberg River is representative for the general glacial rivers in East Greenland, the total Hg transport into the North Atlantic from Greenland alone is approximately 4.6 tons year−1 with an estimated annual freshwater discharge of ∼440 km3.

Biological degradation rates of estrogen compounds and common pharmaceutical and personal care products (PPCPs) were examined in soils with a long history of exposure to these compounds through wastewater effluent and in soil not previously exposed. Biological degradation rates over 14 days were compared under aerobic and anaerobic conditions. Estrogen compounds including estrone, 17β-estradiol, estriol, and 17α-ethinylestradiol exhibited rapid degradation by soil microorganisms in both aerobic and anaerobic conditions. Rapid degradation rates for estrone, estriol, and 17α-ethinylestradiol occurred in pre-exposed soil under aerobic conditions; half-lives calculated under these conditions were 0.6, 0.7, and 0.8 day, respectively. Unexposed soil showed similar or slightly longer half-lives than pre-exposed soil under aerobic conditions. The exception was 17β-estradiol; in all treatments, degradation in unexposed soil resulted in a shorter half-life (2.1 versus 2.3 days). Anaerobic soils exhibited high biological degradation of estrogens as well. Half-lives of all estrogens ranged from 0.7 to 6.3 days in anaerobic soils. Triclosan degraded faster under aerobic conditions with half-lives of 5.9 and 8.9 days in exposed and unexposed soil. Under anaerobic conditions, triclosan half-lives were 15.3 days in unexposed and 28.8 days in exposed soil. Ibuprofen showed the least propensity toward biological degradation than other chemicals tested. Biological degradation of ibuprofen was only observed in unexposed soil; a half-life of 41.2 days was determined under anaerobic conditions and 121.9 days under aerobic conditions. Interestingly, unexposed soil exhibited a greater ability under anaerobic conditions to biologically degrade tested compounds than previously exposed soil.

In the last 10 years, the number of field applications of zero-valent iron differing from permeable reactive barrier has grown rapidly and at present are 112. This study analyzes and compares such field applications. By using statistical analysis, especially ANOVA and principal component analysis, this study shows that chlorinated solvent contamination can be treated efficiently by using zero-valent iron material singly or associated with other technologies. In the analyzed sample of case studies, the association with microbial dechlorination increased significantly the performances of nanoscale iron. This is likely due to the synergistic effect between the two processes. Millimetric iron was always used in association with source zone containment; therefore, it is not possible to distinguish the contributions of the two techniques. The comparison also shows that catalyst addition seems to not dramatically improve treatment efficiency and that such improvement is not statistically significant. Finally, the injection technology is correlated to the type of iron and to the soil permeability.

This paper focuses on the influence of uranium tailing piles on the contamination of their immediate surroundings. The monitoring was carried out on arable land near Pribram in Central Bohemia, Czech Republic. The monitored arable land is located 600 m northeast of the bottom of the piles. In addition, the high uranium (U) content in the topsoil ranged from 40 to 220 ppm. A former portion of it was found in an exchangeable fraction (49%). Both of these facts make this land unsuitable for agricultural use. The sequential extraction discovered a shift in the U content among sample spots situated in and outside the path of the predominant wind direction. In the first group, uranium binds mainly to Fe/Mn oxides, while in the other samples, U is accumulated in the more mobilizable fractions.

Constructed wetlands have been shown to achieve high chromium and organic matter removal efficiencies when treating tannery wastewaters. Further, findings suggested chromium was potentially binding to iron oxides and microbial surfaces on the wetland media. The purpose of the present study was to distinguish between physical–chemical and biologically mediated removal mechanisms operating on iron-containing media. A total of 12 small-scale reactors were used for testing three conditions: biotic, abiotic aerobic and abiotic anaerobic. All systems were operated in 3-day batches, with the biotic and abiotic aerobic systems operating for 11 batches and the abiotic anaerobic operating for five batches. The results show that biotic systems achieved significantly higher chromium removal efficiencies (83%) than both abiotic treatments (16%). Biotic reactors quickly lowered dissolved oxygen concentrations, removing an average of 53% of the influent organic matter in the process. Redox conditions were affected by microbial metabolism, favouring iron release from the media surface. Findings suggest that microbiological activity catalyses chromium removal from tannery wastewaters. Chromium removals achieved in sterile reactors illustrate that the media influences metal retention in constructed wetlands; however, microbial interactions with both the media and tannery effluent achieve overall greater chromium removal than achieved solely by physical–chemical mechanisms.