Population-based biomonitoring in the Czech Republic: urinary arsenic

The method of Guo et aL (AnaL Chim. Acta, 1997, 349, 313-318) for the determination of the toxicologically relevant arsenic in urine was verified and then used for the determination of arsenic in urine of the Czech population for monitoring purposes. Statistical evaluation at the level alpha = 0.05 did not prove any significant differences between industrial and agricultural regions, between males and females and smokers and nonsmokers. Likewise no differences were found among children in all the regions monitored. In the adult population small differences were found between some regions but these differences were not dependent on industrial pollution. The values of toxicologically relevant arsenic are low for all regions. The summarised value of the median for all groups together is 3.5 microg (g creatinine)(-1).     

Determining the global significance of local and regional mitigation strategies: Setting the scene with global integrated assessment models

Because of the importance and complexity of the processes involved in the response of land cover and land use to changing environmental conditions, other approaches are required to evaluate the effectiveness of mitigation options. One such approach is provided by the global integrated assessment model, IMAGE 2. This article presents the structure and some of the underlying assumptions of IMAGE 2, which illustrates the importance of feedback processes in evaluating the effectiveness of mitigation options with respect to land use. Although models such as IMAGE 2 are unsuitable for local and national mitigation evaluations, they can be used to define the regional and global constraints of the smaller scale assessments.     

TBT in California coastal waters: Monitoring and assessment

Butyltins were monitored at over eighty sites, primarily marinas, in surface waters and sediments of the California coast. Values of tributyltin (TBT) in marina waters ranged from 20 to 600 ppt while lower values were usually found in harbors and on the coast. The origin of the tributyltin is in its use as an antifouling agent in marine paints. In those marinas where the concentrations are greater than about 100 ppt, there is usually a conspicuous absence of native organisms, especially molluscs, which are among the most sensitive animals to the highly toxic TBT. The impact of TBT upon not-target organisms recalls the DDT episode of the 1970s. Increasing uses of TBT-containing antifouling paints in the future may have even more drastic effects on coastal organisms than those observed today. The conclusion is inescapable that TBT should be banned for use in commercially available marine paints.     

Chemical speciation in mining affected waters: the case study of Asarel-Medet mine

The inorganic chemical species in Maresh and Luda Yana rivers affected by the Cu– Mo Asarel-Medet mine, Bulgaria were determined during a low-flow and a high-flow period. The mining activities, the weathering and the oxidation processes strongly influenced the physicochemical processes in the whole water system. The main pollution source was a small lake receiving the acid effluents of the mining activities. High levels of SO₄ ^2???, Cu, Mg, Al, Mn and Fe were determined at the mining polluted and affected stations. Cu^2?+? and CuCO₃ ⁰ species (1:1) were present in the reference waters and Cu^2?+? and CuSO₄ ⁰ species (1:1) in the polluted and affected waters; Cu^2?+? species was dominating downstream. Me^2?+? followed by $\rm{MeSO}_{4}^{\kern3pt{0}}$ (Me = Mn, Zn, Cd and Pb), $\rm{PbCO}_{3}^{\kern3pt{0}}$ and $\rm{PbHCO}_{3}^{\kern3pt{+}}$ species as well as $\rm{Fe(OH)}_{2}^{\kern3pt{+}}$ , $\rm{Al(OH)}_{4}^{\kern3pt{-}}$ , $\rm{Al(OH)}_{2}^{\kern3pt{+}}$ , $\rm{Al(OH)}_{3}^{\kern3pt{0}}$ were prevailing in the system. $\rm{MeSO}_{4}^{\kern3pt{+}}$ and $\rm{Me(SO}_{4})_{2}^{\kern3pt{-}}$ (Me = Fe, Al), $\rm{Me(SO}_{4})_{2}^{\kern3pt{2-}}$ (Me = Zn, Cd and Pb), $\rm{Me(SO}_{4})_{3}^{\kern3pt{4-}}$ (Me = Zn, Cd) and $\rm{Cd(SO}_{4})_{4}^{\kern3pt{6-}}$ species polluted and affected waters. The major elements K and Na were mainly Me^?+? species, whereas Ca and Mg were Me^2?+? and $\rm{MeSO}_{4}^{\kern3pt{0}}$ species in different ratios. The concentration of concentration of $\rm{NO}_{2}^{\kern3pt{-}}$ , $\rm{NO}_{3}^{\kern3pt{-}}$ and $\rm{NH}_{4}^{\kern3pt{+}}$ species as well as complex phosphorous species such as H₂ $\rm{PO}_{4}^{\kern3pt{-}}$ , $\rm{FeHPO}_{4}^{\kern3pt{+}}$ , $\rm{HPO}_{4}^{\kern4pt{2-}}$ , $\rm{CaPO}_{4}^{\kern3pt{-}}$ , $\rm{CaHPO}_{4}^{\kern3pt{0}}$ and $\rm{MgHPO}_{4}^{\kern3pt{0}}$ were also calculated. The trace element concentrations decreased downstream due to dilution, sorption processes and precipitation, but the percentage of free metal species, which are more toxic, increased. An exception was iron and aluminum of which the dominant hydroxy colloidal and sulphate species were easily incorporated into the suspended phase.     

Revealing the pattern and evolution of global green development between different income groups: A global meta-frontier by-production technology approach

A clear understanding of the overall pattern of global green development and the green development discrepancies among countries has a bearing on how each country participates in global environmental governance, which is more conducive to promoting the process of global green development in the future. This study constructed a global meta-frontier by-production technology model to evaluate the green total-factor productivity (GTFP), and studied the discrepancies of green development process and their growth sources for a sample of 163 countries (or regions) during the period 1990–2017. The results indicate that global GTFP witnessed remarkable growth before financial crisis occurred in 2007, but showed a slow growth trend after a decline during the financial crisis. The performance of GTFP exhibits significant regional disparity and dynamic change disparity. GTFP was the highest in high-income group, while lower than 0.55 in the upper middle-income and lower middle-income group in all years. Technological gap between regions was the principal factor leading to this result. Dynamically, among all countries covered in this study, there are twenty-five countries (or regions) experienced GTFP decline. Technological gap enlargement was the most important factor causing their GTFP decline, followed by the resource allocation inefficiency.     

Dissolved organic iodine in marine waters: role in the estuarine geochemistry of iodine

Non-volatile dissolved organic iodine (DOI) can be a major, or even the dominant, species of dissolved I in coastal, inshore and estuarine waters. It can be converted to IO3- in the presence of an oxidizing agent and to I- by reacting it with a reducing agent. Depending on the exact experimental conditions, the yields of these reactions may not be quantitative. In previous analytical schemes for the determination of IO3-, I- and DOI in marine waters, if oxidation or reduction steps are involved and the concentrations of one or more species are estimated by difference, the presence of DOI can lead to an overestimation of the concentrations of the inorganic species determined by difference and an underestimation of the concentration of DOI. In two cruises covering the James River to the southern Chesapeake Bay and from the southern Chesapeake Bay to the Atlantic, above a salinity (S) of 2, the contribution of DOI to total I increased with decreasing salinity and reached a maximum of 80%. DOI, I- and IO3- were successively the dominant form of dissolved I at 0.1 < S < 15 in the James River estuary, 15 < S < 30 in the Southern Chesapeake Bay and S > 30 in the Atlantic Ocean at the Bay mouth, respectively. Total I behaved conservatively (i.e., no evidence of consumption or production) during estuarine mixing during both cruises. In the southern Chesapeake Bay, total inorganic I was also approximately conservative. The primary process affecting the speciation of dissolved I was the conversion of IO3- to I-. In the James River estuary, there were indications of the conversion of both IO3- and I- to DOI. The concentrations of total I, IO3-, I- and DOI in James River water were 0.121, undetectable, 0.068 and 0.053 microM, respectively. These concentrations of total I and I- are significantly higher while that of IO3- is noticeably lower than those used presently for estimating global riverine input of these I species to the oceans. The riverine flux of DOI to the oceans is presently unknown.     

Effect of fasting on the pattern of urinary arsenic excretion

Millions of people in some of the poorest regions of the world are exposed to high levels of arsenic through drinking contaminated water. It has been reported that development of cancer caused by arsenic exposure in such populations is dependent on dietary and nutritional factors which can modulate arsenic metabolism. Many people in arsenic exposed regions of Bangladesh and India practice fasting for at least one month every year when they refrain from consumption of food and fluid during daylight hours. How such practices may modulate arsenic metabolism has not been previously investigated. This study investigated this issue by determining total arsenic and its species in urine samples from a group of 29 unexposed volunteers at the beginning of the fasting and at the end of approximately 12 h of fasting period. Inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography (HPLC) coupled with ICP-MS was used to measure the total arsenic and arsenic speciation in the urine samples, respectively. The mean total levels of arsenic at the beginning of fasting (18.3 microg g(-1) creatinine) and at the end of approximately 12 h of fasting (17.7 microg g(-1) creatinine) did not differ significantly (p > 0.05). However, the percentages of urinary arsenic as the methylated arsenic species methylarsonate (MA) were found to be significantly different (p < 0.05) and this species was observed more frequently at the end of fasting, although its overall concentration was similar. There were no significant differences (p > 0.05) in both the concentrations and percentages of other urinary arsenic species detected, namely arsenobetaine (AB) and dimethylarsinate (DMA). Arsenite (As(III)) and arsenate (As(V)) were also analyzed, but were not detected. We conclude that fasting for a period of 12 h results in a significant increase in the percentage of urinary arsenic as MA, and its frequency of detection in the volunteers at the end of the fasting period is almost nine fold higher. This suggests that metabolism of arsenic is altered by fasting.     

Monoc programme: Scientific substantiation of the integrated global ocean ecological monitoring system

Man's exploitation of the World Ocean continues to increase both productively, i.e., utilization of fisheries and natural resources, and counterproductively, i.e., increased pollutant loading. This paper presents a scientific rationale for a global ecological monitoring programme which will address open as well as coastal waters.     

Appearance of aldehydes in the surface layer of lake waters

The paper presents results concerning the changes in the content of aldehydes in samples of lake water collected near the lake surface. The study of lake waters was undertaken to explain which physicochemical parameters of the environment have the greatest influence on the level of aldehydes, which of the aldehydes are most often met in surface water and in what concentrations. We observed that formaldehyde, acetaldehyde, propanal, glyoxal, methylglyoxal and acetone were commonly present in surface water samples, while semi-volatile and poorly soluble aldehydes such as nonanal and decanal were observed seasonally. The contents of total aldehydes varied in a wide range, from 55 to 670 μg/l, and the concentration of total organic carbon varied significantly from 3 to 18 mg /l, but there was no evident correlation between them in all of samples. The total content of aldehydes did not depend on the meteorological parameters such as air temperature, UV radiation and ozone concentration; however, it was noted that the level of carbonyl concentration is related to the period of intense precipitation: in the period of very low precipitations, the highest contents of total aldehydes were determined in all of the water samples, and in the periods of intense precipitations, the content of total aldehydes was drastically smaller.     

The 2007 crisis and Greek wildfires: a multivariate analysis of suppression times

Shifts in government priorities in response to the 2007 global recession have affected wildfire management and natural disaster funding arrangements, leading to a reduced effectiveness of fire suppression actions and increasing fire vulnerability. Our study investigates the role of local socioeconomic contexts on fire suppression effectiveness under economic expansion and recession in a Mediterranean region (Attica, Greece) strongly affected by 2007 crisis and displaying a persistently high density of peri-urban wildfires. Basic characteristics of wildfires (spatial distribution, intensity, and land use preferences) were investigated in the study area over two consecutive 8-year time intervals characterized by economic expansion (2000–2007) and recession (2008–2015). An integrated approach based on multivariate statistics and artificial neural networks was implemented to evaluate latent relationships between fire suppression time, wildfire characteristics, and socioeconomic dynamics. Controlling for wildfires’ characteristics over the two time intervals, fire time length increased under crisis—mainly for small and medium-sized fires—possibly as an indirect response to reduced effectiveness of forest land management. Local contexts and political decisions influenced by economic downturns are relevant factors shaping wildfires’ severity in the Mediterranean region. With recession, local contexts vulnerable to wildfires require more effective fire prevention measures, sustainable forest management, and regional planning.     

Statistical analysis of the physico-chemical data on the coastal waters of Cochin

Measurements of temperature, salinity, dissolved oxygen, nitrogen as ammonia, nitrate and nitrite, and phosphate along with chlorophyll were carried out at three stations on the coastal waters of Cochin, south west India, at two-levels of the water column over a period of five years. The data set has been factorised using principal component analysis (PCA) for extracting linear relationships existing among a set of variables. A graphical display of the scores generated from the PCA was done by means of boxplots and biplots, which helped in the interpretation of the data. The major factors conditioning the system are related to the input of fresh water from the estuary of the Periyar river and the high organic load of the bottom sediment in the coastal area which results in a reducing environment, as reflected in the parameters of dissolved oxygen, ammoniacal-nitrogen and nitrite-nitrogen. Another factor which contributes to the variation in the system is related to the unloading activity in the port area. The present approach presents a logical way to interpret the complex data of the physico-chemical measurements.     

From lake to estuary,the tale of two waters: a study of aquatic continuum biogeochemistry

The balance of fresh and saline water is essential to estuarine ecosystem function. Along the fresh-brackish-saline water gradient within the C-43 canal/Caloosahatchee River Estuary (CRE), the quantity, timing and distribution of water, and associated water quality significantly influence ecosystem function. Long-term trends of water quality and quantity were assessed from Lake Okeechobee to the CRE between May 1978 and April 2016. Significant changes to monthly flow volumes were detected between the lake and the estuary which correspond to changes in upstream management. and climatic events. Across the 37-year period, total phosphorus (TP) flow-weighted mean (FWM) concentration significantly increased at the lake; meanwhile, total nitrogen (TN) FMW concentrations significantly declined at both the lake and estuary headwaters. Between May 1999 and April 2016, TN, TP, and total organic carbon (TOC), ortho-P, and ammonium conditions were assessed within the estuary at several monitoring locations. Generally, nutrient concentrations decreased from upstream to downstream with shifts in TN/TP from values >?20 in the freshwater portion, ~?20 in the estuarine portion, and <?20 in the marine portion indicating a spatial shift in nutrient limitations along the continuum. Aquatic productivity analysis suggests that the estuary is net heterotrophic with productivity being negatively influenced by TP, TN, and TOC likely due to a combination of effects including shading by high color dissolved organic matter. We conclude that rainfall patterns, land use, and the resulting discharges of runoff drive the ecology of the C-43/CRE aquatic continuum and associated biogeochemistry rather than water management associated with Lake Okeechobee.     

non-lethal responses of the freshwater snail potamopyrgus antipodarum to dissolved arsenic

Two non-lethal responses, avoidance andimmobility, were observed for thefreshwater gastropod Potamopyrgusantipodarum on exposure to dissolvedarsenic (As) as arsenate (As(V)) orarsenite (As(III)). Two differentpopulations of P. antipodarum, onewith a long history of exposure todissolved As from geothermal fluids andthe other with minimal exposure, werecompared to test for adaptation to As. Both snail populations avoided dissolvedAs(III), the more toxic form, at lowerconcentrations than As(V). As(V), theless toxic form, was avoided by both snailpopulations at much lower concentrationsthan those at which the snails becameimmobile. In contrast, the concentrationsof As(III) which caused avoidance werealmost the same as those which causedimmobility, implying that avoidance may notbe an effective response to protect thesesnails from exposure to As(III). Snailsfrom the exposed population avoided As(V)at about 20% of the concentration thatwas avoided by the snails from theunexposed population. At higherconcentrations of As(V) which causedimmobility, this difference in sensitivitypersisted up to an exposure time of 48 hours. After 96 hours exposure, however,both populations showed similarsensitivity. Snails from the exposedpopulation were more sensitive to As(III),both avoiding the As and becoming immobileat lower concentrations than were observedfor the same responses in the snails fromthe unexposed population. We suggest thatthe differences in sensitivity between thetwo populations could have been the resultof the higher soft body As burden of theexposed snails at the start of thelaboratory experiments.     

global climate change: processes and products – an overview

Our knowledge of global climate change has many uncertainties.Whether global air temperature will increase, by how much, and when,are subject to debate, but there is little doubt that troposphericconcentrations of several trace gases are increasing. While possibleincreases in the average air temperature is a product of these changes,the increases in the trace gases alone will have an effect on agriculture.Increases in the ambient concentrations of carbon dioxide are expectedto have a positive net effect on crop production. In contrast, anyincreases in the penetration of surface-level ultraviolet-B (280–320 nm)radiation, and known increases in surface ozone concentrations, areconsidered to have adverse effects on certain crops. Our presentknowledge of the joint effects on crops of elevated levels of carbondioxide, ultraviolet-B radiation and ozone, and possible alterations in airtemperature and precipitation patterns, is virtually zero. Therefore, anypredictions of the effects of global climate change on agriculture aresubject to significant uncertainties. In contrast, coupling of climatechange (only temperature and precipitation) models to crop productionhas led to a number of future scenarios. In spite of theirpresent limitations, results from these efforts can be useful in planningfor future agriculture.     

Effect of domestic storage tanks on the quality of drinking waters

An investigation covering 12 districts of Baghdad city was conducted over 2 yr to monitor the effect of domestic storage practice on the quality of drinking water. Water storage tanks are widely used in Iraq as an additional water source. Tap and stored waters were tested for their chemical constituents i.e. Ca, Mg, Na, K, Cl, Zn, Fe, Pb, Cd, and total hardness (T.H.). All the tested elements were within the permissible limits. However, statistical analysis showed a significant variation between the different districts for T.H., Cu, Mg and chloride for both tap and stored waters. Seasonal variations have a significant effect on the levels of some elements. The quality of stored water was not affected by storage practice. Zinc, Pb and Fe were the only elements that showed some variation in the stored waters. This was attributed to the effects of corrosion of the tank metal and the migration of metals from the distribution system.     

Portable X-ray fluorescence in the characterisation of arsenic contamination associated with industrial buildings at a heritage arsenic works site near Redruth,Cornwall, UK

An investigation using in situ analysis by portable X-ray fluorescence (PXRF) has shown that contamination present on industrial buildings at a heritage arsenic works site near Redruth, Cornwall, UK results from the absorption of arsenic by porous and semi-porous building materials that were in contact with arsenic-rich flue gases. Results from a preliminary survey indicate that arsenic remains locked in these materials and is being gradually leached out by weathering processes. This weathering causes general contamination of the adjacent building surfaces averaging 1845 microg g(-1) arsenic, presumably caused by evaporation of leach solutions in contact with air at the surface of the building materials. More extensive crystalline deposits were found under arches protected from dissolution and further dispersion by rain water. These deposits appeared to comprise calcium sulfate (gypsum), associated with on average between 1.2 and 6.8% m/m As. In situ PXRF proved to be highly effective in locating sources of contamination at the site and in providing data that allowed a hypotheses for the origin of this contamination to be formulated and tested in the field.