Evaluation of diffusive samplers and photoionisation detectors for measuring very short peak exposures in the workplace

The extent to which very short peak widths, peak frequency, sampling time and post-sampling/pre-capping time impact upon occupational exposure measurements of toluene has been investigated using diffusive tubes. Additionally, the effect of the width of the peak on the estimation of peak maximum concentration and time-weighted average (TWA) concentration from real-time instruments (photoionisation detectors-PIDs) was also studied, and their responses modelled. No clear differences were perceived between diffusive and pumped tube results. Mean biases of -5 to +6% were recorded but no trend could be distinguished with respect to any of the variables examined; the main source of uncertainty was attributed to analytical uncertainty. The diffusive tubes can therefore be used to measure short term transient toluene concentrations (e.g. 5 s duration) over short (15 min) exposure periods. The two slower responding PIDs (t50 = 4 s) underestimated the maximum concentration of short term peaks having durations less than 10 s. The other three PIDs (t50 < or = 2 s) only significantly underestimated the maximum concentration of short term peaks having durations of 2 s and below. Pulse duration appeared to affect the PID's estimation of peak height more than peak area (TWA concentration).     

A positive chemical ionization GC/MS method for the determination of airborne ethylene glycol and propylene glycols in non-occupational environments

An analytical method for ethylene glycol and propylene glycols has been developed for measuring airborne levels of these chemicals in non-occupational environments such as residences and office buildings. The analytes were collected on charcoal tubes, solvent extracted, and analyzed by gas chromatography-mass spectrometry using a positive chemical ionization technique. The method had a method detection limit of 0.07 microg m(-3) for ethylene glycol and 0.03 microg m(-3) for 1,2- and 1,3-propylene glycols, respectively, based on a 1.44 m3 sampling volume. Indoor air samples of several residential homes and other indoor environments have been analyzed. The median concentrations of ethylene glycol and 1,2-propylene glycol in nine residential indoor air samples were 53 microg m(-3) and 13 microg m(-3) respectively with maximum values of 223 microg m(-3) and 25 microg m(-3) detected for ethylene glycol and 1,2-propylene glycol respectively. The concentrations of these two chemicals in one office and two laboratories were at low microg m(-3) levels. The maximum concentration of 1,3-propylene glycol detected in indoor air was 0.1 microg m(-3).     

Solid-phase microextraction to monitor the sonochemical degradation of polycyclic aromatic hydrocarbons in water

Solid-phase microextraction (SPME) coupled with GC-MS has been used to monitor the degradation of polycyclic aromatic hydrocarbons (PAHs) by ultrasound treatment. Immersion SPME sampling enabled the fast and solventless extraction of target contaminants at the low microg l(-1) concentration level. The developed protocol was found to be linear in the concentration range from 0.1 to 50 microg l(-1) for most target analytes, with the limits of detection ranging between 0.01 and 0.70 microg l(-1) and the relative standard deviations between 4.31 and 27%. The developed SPME protocol was used to follow concentration profiles of aqueous solutions containing 16 PAHs, which were subject to low frequency ultrasonic irradiation. At the conditions employed in this study (80 kHz of ultrasound frequency, 130 W l(-1) of applied electric power density, 30 microg l(-1) of initial concentration for each of the 16 PAHs), sonochemical treatment was found capable of destroying the lower molecular weight PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) within 120-180 min of irradiation. The higher molecular weight PAHs were more recalcitrant to ultrasound treatment.     

Approaches to systematic assessment of environmental exposures posed at hazardous waste sites in the developing world: the Toxic Sites Identification Program

In the developing world, environmental chemical exposures due to hazardous waste sites are poorly documented. We describe the approach taken by the Blacksmith Institute's Toxic Sites Identification Program in documenting environmental chemical exposures due to hazardous waste sites globally, identifying sites of concern and quantifying pathways, populations, and severity of exposure. A network of local environmental investigators was identified and trained to conduct hazardous waste site investigations and assessments. To date, 2,095 contaminated sites have been identified within 47 countries having an estimated population at risk of 71,500,000. Trained researchers and investigators have visited 1,400 of those sites. Heavy metals are the leading primary exposures, with water supply and ambient air being the primary routes of exposure. Even though chemical production has occurred largely in the developed world to date, many hazardous waste sites in the developing world pose significant hazards to the health of large portions of the population. Further research is needed to quantify potential health and economic consequences and identify cost-effective approaches to remediation.     

Evaluation of exposure to the airborne asbestos in an asbestos cement sheet manufacturing industry in Iran

Iran imports nearly 55,000 tons of Chrysotile asbestos per year and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, airborne asbestos concentrations during AC sheet manufacturing were measured. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM), with energy-dispersive X-ray analysis. Airborne total fiber concentrations of 45 personal samples were analyzed by phase contrast microscopy. The results have highlighted that 15.5% of samples exceed the threshold limit value (TLV) established the American Conference of Governmental Industrial Hygienists, which is 0.1 fiber per milliliter (f/ml). Personal monitoring of asbestos fiber levels indicated a ranged from 0.02?±?0.01 to 0.16?±?0.03 f/ml. The geometrical mean was 0.05?±?1.36 f/ml, which is considerably lower than the TLV. SEM data demonstrate that the fibrous particles consisted, approximately, of Chrysotile (55.89%) and amphiboles (44.11%). We conclude that the industrial consumption of imported Chrysotile asbestos is responsible for the high airborne amphibole asbestos levels in the AC sheet industry. More research is needed to improve characterization of occupational exposures by fiber size and concentration in a variety of industries.     

Chlorobiphenyl contaminants at Pladda and Garroch Head in the Firth of Clyde in relation to sewage sludge input

Sewage sludge dumped at Garroch Head in the Firth of Clyde contains significant quantities of chlorinated hydrocarbons, such as polychlorinated biphenyls (CBs). These compounds are lipophilic and resistant to degradation. They accumulate in the biota either from the water column or through the food chain, particularly in tissue with a high lipid content. Bottom dwelling fish, such as plaice, in the vicinity of the dump site will accumulate CBs from their environment. Eighteen of the 209 CBs were measured in plaice livers from the Garroch Head dump site and from Pladda, a site reasonably remote from the dump site but also in the Clyde, over a 7 year period prior to the cessation of dumping in December 1998. Concentrations of the congeners in the liver of fish caught at the dump site were, in general, higher than those in the liver of fish caught at Pladda. Concentrations in the plaice livers for the sum of 18 CBs ranged from 1611 to 8471 micrograms kg-1 lipid for Garroch Head samples and from 336.9 to 2635 micrograms kg-1 lipid for samples from Pladda. The data were evaluated using principal component analysis (PCA). Pattern analysis was undertaken by normalising to the recalcitrant CB 153. Livers from the dump site were found to have a higher proportion of the lower chlorinated CBs. CB patterns were similar at the Garroch Head dump site from year to year, but multivariate techniques showed that there were differences in pattern when normalised to CB 153.     

Speciation/fractionation of nickel in airborne particulate matter: improvements in the Zatka sequential leaching procedure

Modifications are reported to the sequential leaching analytical method for nickel speciation/fractionation specified by Zatka so that larger sample masses can be analyzed. Improvements have been made in the completeness of the sulfide/metallic separation during the peroxide-citrate leach step by use of a larger volume of leachant, a longer leach duration and an orbital shaker. Minimal extraction of metallic nickel in this prolonged sulfidic nickel extraction has been confirmed. An increase in the number of samples analyzed simultaneously using these modifications has resulted in substantial productivity improvements and concomitant lower costs. It is critical for practitioners of sequential leaching techniques to recognize potential limitations and to use professional judgment when interpreting results. For example, results obtained may not be biologically relevant in assessing health risks; the acts of sampling and storage may result in changes in fractionation with time; surface coatings/films may alter the ability of a leachant to react with the target compound; and leaching behaviours may be different for samples differing only in particle size distributions.     

Magnetic susceptibility measurements as proxy method to monitor soil pollution: the case study of S. Nicola di Melfi

The development of in situ, cheep, noninvasive, and fast strategies for soil monitoring is a crucial task for environmental research. In this paper, we present the results of three field surveys carried out in an industrial area of Southern Italy: S. Nicola di Melfi. The monitoring procedure is based on soil magnetic susceptibility measurements carried out by means of experimental protocols that our research group developed during the last years. This field surveys is supported by both geological characterization of the area and analytical determinations of metal concentrations in soils. Magnetic studies were carried out not only in situ but also in laboratory. Results show that, taking into account the influence due to the geomorphologic difference, soil magnetic susceptibility is an optimal indicator of the anthropogenic impact. So, our monitoring strategy discloses that the combined use of magnetic susceptibility measurements and soil geomorphology information may be used as a useful tool for the temporal monitoring of pollution evolution and for a fast screening of polluted zones.     

Using ecological memory as an indicator to monitor the ecological restoration of four forest plantations in subtropical China

A large area of plantations has been established worldwide and especially in China. Evaluating the restoration status of these plantations is essential for their long-term management. Based on our previous work, we used an ecological memory (EM) approach to evaluate four 26-year-old plantations that represent four common kinds of plantations in subtropical China, i.e., mixed broad-leaved plantation (MBP), mixed coniferous plantation (MCP), eucalyptus plantation (EP), and mixed legume plantation (MLP). Comparing them with the regional climax community, i.e., monsoon evergreen broad-leaved forest (BF), all four plantations accumulated nearly the same pattern of EM during succession. EM was >50 % for soil minerals, light conditions, soil age, soil animals, and soil microbes. EM was about 25 % for soil pollen and 10 % for birds, soil seed bank, and plant species. The total EM value of the four plantations ranged from 50.96 to 52.54, which indicated that all four plantations were in the regional, natural trajectory of succession and between the early and medium successional stages. The results indicated that natural succession processes are unlikely to be accelerated by planting late-stage tree species without sufficient EM. The results also demonstrated that all four plantations were in positive successional trajectories, and the positive succession dynamics were greater in the MLP and MCP. We suggest that the entire natural succession trajectory be used to evaluate the restoration of a site and that the ultimate restoration target be divided into several milestones along the reference trajectory to monitor progress. Forest restoration may be accelerated by starting with a minimum dynamic unit supporting sufficient EM.     

红外法测定不同行业废水中石油类/动植物油

用红外光度法和非分散红外光度法对几种有代表性水样的石油类/动植物油进行了测定,对GB/T16488-1996标准中一些步骤的可操作性及必要性进行了分析,并提出相应建议。     

Design to monitor trend in abundance and presence of American beaver (Castor canadensis) at the national forest scale

Wildlife conservationists design monitoring programs to assess population dynamics, project future population states, and evaluate the impacts of management actions on populations. Because agency mandates and conservation laws call for monitoring data to elicit management responses, it is imperative to design programs that match the administrative scale for which management decisions are made. We describe a program to monitor population trends in American beaver (Castor canadensis) on the US Department of Agriculture, Black Hills National Forest (BHNF) in southwestern South Dakota and northeastern Wyoming, USA. Beaver have been designated as a management indicator species on the BHNF because of their association with riparian and aquatic habitats and its status as a keystone species. We designed our program to monitor the density of beaver food caches (abundance) within sampling units with beaver and the proportion of sampling units with beavers present at the scale of a national forest. We designated watersheds as sampling units in a stratified random sampling design that we developed based on habitat modeling results. Habitat modeling indicated that the most suitable beaver habitat was near perennial water, near aspen (Populus tremuloides) and willow (Salix spp.), and in low gradient streams at lower elevations. Results from the initial monitoring period in October 2007 allowed us to assess costs and logistical considerations, validate our habitat model, and conduct power analyses to assess whether our sampling design could detect the level of declines in beaver stated in the monitoring objectives. Beaver food caches were located in 20 of 52 sampled watersheds. Monitoring 20 to 25 watersheds with beaver should provide sufficient power to detect 15–40% declines in the beaver food cache index as well as a twofold decline in the odds of beaver being present in watersheds. Indices of abundance, such as the beaver food cache index, provide a practical measure of population status to conduct long-term monitoring across broad landscapes such as national forests.     

Biomarkers of environmental contaminants in the coastal waters of Estonia (Baltic Sea): effects on eelpouts (Zoarces viviparus)

The eastern Baltic Sea near the Estonian coast is heavily navigated by numerous cargo ships and oil tankers. Hundreds of accidents and oil spills happen yearly in this area. Yet, there is a lack of data concerning the distribution and effects of the environmental contaminants, especially polycyclic aromatic hydrocarbons (PAHs). Different parts of the Baltic Sea have different levels of contamination; therefore a wide range of monitoring stations in coastal areas in the Gulf of Finland and Gulf of Riga were chosen. The aim of the present research was to document the responses of chosen biomarkers of environmental contaminants in different unstudied areas of the Estonian coastal sea. During 2009 and 2010 we measured PAH metabolites, EROD activities, geno- and cytotoxicity, histology, parasites and other biomarkers from the eelpout (Zoarces viviparus), a resident benthic fish species. The results showed that fish from the Gulf of Riga emitted lower levels of fluorescence in fixed wavelength analyses (representing equivalents of PAH metabolites in bile and urine), and consistently, showed less geno- and cytotoxicity and parasite infection, higher liver somatic index (LSI) and a higher condition factor (CF) than fish inhabiting areas close to the Baltic proper and in the Gulf of Finland. The results point to the effect of long-range contaminant transportation, whether atmospheric or hydrodynamic, and also to the intensive shipping activity in international routes. This study fills the gap of knowledge in this area that has persisted until now. Nevertheless, more studies in this area on the different groups of contaminants are necessary, to specify the factors that are responsible for observed biological effects.     

Ammonia emissions from a broiler farm: spatial variability of airborne concentrations in the vicinity and impact on adjacent woodland

Agricultural NH₃ emissions affect air quality and influence the nitrogen cycle. In the subject study, NH₃ emissions from a broiler farm and the resulting atmospheric concentrations in the immediate vicinity during three growing cycles have been quantified. Additionally, vegetation along a transect in an adjacent woodland was analysed. The emissions were as high as 10 kg NH₃ h⁻¹ and the atmospheric concentrations ranged between 33 and 124 μg NH₃ m⁻³ per week in the immediate vicinity. Measurements of the atmospheric concentrations over 7 weeks showed a substantial decline of mean concentrations (based on a 3-week average) from ∼13 to <3 μg NH₃ m⁻³, at 45- and 415-m distance from the farm. Vegetation surveys showed that nitrophilous species flourished when they grew closest to the farm (their occurrence sank proportionately with distance). A clearly visible damage of pine trees was observed within 200 m of the farm; this illustrated the significant impact of NH₃ emissions from agricultural sources on the sensitive ecosystem.     

Strategies used to Guide the Design and Implementation of a National River Monitoring Programme in South Africa

This article explores the strategies that were, and are being, used to facilitate the transition from scientific developmentto operational application of the South African River Health Programme (RHP). Theoretical models from the field of the management of technology are used to provide insight into the dynamics that influence the relationship between the creation and application of environmental programmes, and the RHP in particular. Four key components of the RHP design are analysed,namely the (a) guiding team, (b) concepts, tools and methods, (c) infra-structural innovations and (d) communication. These key components evolved over three broad life stages of the programme, which are called the design, growth and anchoring stages.     

The use of marine sponge, Haliclona tenuiramosa as bioindicator to monitor heavy metal pollution in the coasts of Gulf of Mannar, India

The results of the present research study indicate that the heavy metal accumulation in the marine sponges provide evidence as an excellent bioindicators for monitoring heavy metal pollution between near and offshore environments of Mandapam coast of "Gulf of Mannar (GoM), India". The heavy metal concentrations in sea water and accumulation in the tissues of Haliclona tenuiramosa were analyzed by ICP-MS (inductively coupled plasma-mass spectrometry). The concentrations of metals in the coastal waters of nearshore (< 0.5 km from shore) were always higher than those in the offshore waters (2-5 km away from shore). Likewise, sponges living in the nearshore accumulated greater concentrations of heavy metals (As, Cd, Co, Cu, Fe, Mn and Ni) ranging from 2 to 17 times higher concentration than the sponges located away from the shore. A positive correlation between concentration levels in water and bioaccumulation in tissues was observed. The bioaccumulation of heavy metals in sponge tissue were in order of Fe > Mn > Ni > Cu > As > Co > Cd in both the near and offshore stations. The present results justified that a more comprehensive monitoring of presence of heavy metals in H. tenuiramosa of surrounding GoM, is necessary to help a better mitigation of the problem.     

Application of a battery of biomarkers in mussel digestive gland to assess long-term effects of the Prestige oil spill in Galicia and the Bay of Biscay: lysosomal responses

In order to assess the long-term lysosomal responses to the Prestige oil spill (POS), mussels, Mytilus galloprovincialis, were collected in 22 localities from Galicia and the Bay of Biscay (North Iberian peninsula) in July, and September 2003, April, July, and October 2004-2005 and April 2006. Lysosomal membrane stability (labilisation period, LP) and lysosomal structural changes (lysosomal volume density, Vv(L) and lysosomal surface-to-volume ratio, S/V(L)) were measured as general stress biomarkers. The most remarkable long-term effects after the POS were drastic changes in lysosomal size (lysosomal enlargement) and membrane stability (extremely low LP values) up to April-04. Later on, a recovery trend was envisaged all along the studied area after July-04, albeit membrane stability continued to be below 20 min throughout the studied period up to April-06, which indicates a "distress-to-moderate-stress" condition. Lysosomal Response Index (LRI) revealed that environmental stress was more marked in Galicia than in the Bay of Biscay, mainly in the first sampling year, although a "moderate-to-high-stress" condition persisted until July-05. Overall, although lysosomal size returned to reference values, membrane stability was not fully recovered indicating a stress situation throughout the studied period.     

Application of the positive matrix factorization approach to identify heavy metal sources in sediments. A case study on the Mexican Pacific Coast

During the last two decades, sediments collected in different sources of water bodies of the Tehuantepec Basin, located in the southeast of the Mexican Pacific Coast, showed that concentrations of heavy metals may pose a risk to the environment and human health. The extractable organic matter, geoaccumulation index, and enrichment factors were quantified for arsenic, cadmium, copper, chromium, nickel, lead, vanadium, zinc, and the fine-grained sediment fraction. The non-parametric SiZer method was applied to assess the statistical significance of the reconstructed metal variation along time. This inference method appears to be particularly natural and well suited to temperature and other environmental reconstructions. In this approach, a collection of smooth of the reconstructed metal concentrations is considered simultaneously, and inferences about the significance of the metal trends can be made with respect to time. Hence, the database represents a consolidated set of available and validated water and sediment data of an urban industrialized area, which is very useful as case study site. The positive matrix factorization approach was used in identification and source apportionment of the anthropogenic heavy metals in the sediments. Regionally, metals and organic matter are depleted relative to crustal abundance in a range of 45–55 %, while there is an inorganic enrichment from lithogenous/anthropogenic sources of around 40 %. Only extractable organic matter, Pb, As, and Cd can be related with non-crustal sources, suggesting that additional input cannot be explained by local runoff or erosion processes.     

Magnesium hydroxide bulk and colloid-associated 152Eu in an alkaline environment: colloid characterisation and sorption properties in the presence and absence of carbonate

The distribution of 152Eu between magnesium hydroxide bulk, colloids and solution has been assessed under alkaline conditions, such as those in nuclear fuel storage ponds. The colloidal phase has been characterised by two complementary methods: coupled ultrafiltration-ICP-AES and scanning electron microscopy. The quantity and the size distribution of the colloidal phase is strongly ionic strength-dependent. A decrease of the quantity of colloids, in particular the larger size ranges, has been observed with increasing ionic strength. Small colloids (1 kDa-10 kDa fraction) are predominant at all ionic strengths. The morphology of colloids, observed by field-emission gun scanning electron microscopy, appears to change from hexagonal prismatic (characteristic to the mineral) to spherical (energetically more favourable) as size decreases. The distribution of 152Eu between the solid and liquid/colloidal phases has been investigated at carbonate concentrations ranging from 0 to 10(-2) M by coupled ultrafiltration and gamma-spectrometry. Mg(OH)2 bulk appears to be a very strong sorbent for 152Eu, since complete sorption onto the bulk happens for carbonate concentrations as high as 10(-3) M. Scavenging of 152Eu by Mg(OH)2 colloids is negligible in the presence of Mg(OH)2 bulk. The distribution of 152Eu between liquid and colloidal phases has been investigated in the absence of bulk at various carbonate concentrations. A significant uptake of 152Eu by the colloids in solution has been observed, which decreases with increasing carbonate concentration. 152Eu appears to be mainly associated to the smallest colloids (1 kDa-10 kDa fraction). There is a strong correlation between the sorption properties and the surface area of the colloids.