Sampling and analysis for radon-222 dissolved in ground water and surface water

Radon-222 is a naturally occurring radioactive gas in the uranium-238 decay series that has traditionally been called, simply, radon. The lung cancer risks associated with the inhalation of radon decay products have been well documented by epidemiological studies on populations of uranium miners.The realization that radon is a public health hazard has raised the need for sampling and analytical guidelines for field personnel. Several sampling and analytical methods are being used to document radon concentrations in ground water and surface water worldwide but no convenient, single set of guidelines is available. Three different sampling and analytical methods-bubbler, liquid scintillation, and field screening-are discussed in this paper. The bubbler and liquid scintillation methods have high accuracy and precision, and small analytical method detection limits of 0.2 and 10 pCi/l (picocuries per liter), respectively. The field screening method generally is used as a qualitative reconnaissance tool.     

Comparison study of five analytical methods for the fractionation and subsequent determination of aluminium in natural water samples

Five methods for aluminium fractionation used in different laboratories in Norway and Finland were compared using six control, 75 soil water and 10 lake water samples. Different fractionation principles [cation exchange, formation of the Pyrocatechol Violet (PCV) or quinolin-8-ol (oxine) complex], types of cation exchanger [Amberlite (Na/H) or Bond Elut (H)], reaction time (from 2.3 s), flow systems (flow injection analysis or segmented flow) and determination principles (molecular absorption spectrometry or ICP-AES) were tested. Determination of the 'labile' fraction was strongly dependent on the method used and the largest differences were observed between the ICP-AES method with cation exchange (Bond Elut H form) and the 'quickly reacting' method (oxine, 2.3 s). Different flow systems, both using cation exchange and determination of the PCV complex but with different reaction times and an extra acidification step, resulted in large differences in the 'reactive' and 'non-labile' fractions determined. However, the determination of the labile fraction gave similar results with both these methods. The two different types of cation exchanger used (with and without pH buffering and with different counter ions) in the ICP-AES methods resulted in differences, mainly because of a smaller 'non-labile' fraction in the non-buffered system. The two flow injection systems (oxine and PCV complexation) showed common trends, which may be connected with the short reaction times used. Comparison with theoretical equilibrium calculations using the model ALCHEMI suggested that the best correlation for the determination of the 'labile' fraction were obtained with the ICP-AES method with an Amberlite column.     

Comparison of beach bacterial water quality indicator measurement methods

Three methods (membrane filtration, multiple tube fermentation, and chromogenic substrate technology kits manufactured by IDEXX Laboratories, Inc.) are routinely used to measure indicator bacteria for beach water quality. To assess comparability of these methods, quantify within-laboratory variability for each method, and place that variability into context of variability among laboratories using the same method, 22 southern California laboratories participated in a series of intercalibration exercises. Each laboratory processed three to five replicates from thirteen samples, with total coliforms, fecal coliforms or enterococci measured depending on the sample. Results were generally comparable among methods, though membrane filtration appeared to underestimate the other two methods for fecal coliforms, possibly due to clumping. Variability was greatest for the multiple tube fermentation method. For all three methods, within laboratory variability was greater than among laboratories variability.     

Use of cluster and principal component analyses to profile areas in California where ground water has been contaminated by pesticides

An empirical approach to profiling areas of ground water contamination by pesticides was devised that did not rely upon determining the level of vulnerability between land areas and that did not assume any particular pathway for ground water contamination. Climatic and soil data were obtained for 1-square mile sections of land in California where pesticide residues had been found in well water samples and the detection was attributed to legal agricultural applications. These sections were designated as known contaminated (KC) sections. Climate and soil data were also obtained for sections which lacked either well sampling data or a positive pesticide detection. These sections were designated as candidate sections. Statistical procedures were used to cluster groups of KC sections first with respect to climate characteristics and then with respect to soil characteristics. Principal components analysis (PCA) was used to construct a statistical profile of soil variables for each cluster of KC sections. A method based on the PCA was developed to compare the similarity of soil profiles derived for each KC section cluster to individual candidate sections. Since the profiling scheme was based only on data from KC sections, candidate sections that did not match any KC cluster profile could only be considered dissimilar to contaminated sections, receiving a status of not-classified. This profiling method is flexible and it can be revised to incorporate updated well sampling information.     

Siting analyses for water quality sampling in a catchment

Pollution loads discharged from upstream development or human activities significantly degrade the water quality of a reservoir. The design of an appropriate water quality sampling network is therefore important for detecting potential pollution events and monitoring pollution trends. However, under a limited budgetary constraint, how to site an appropriate number of sampling stations is a challenging task. A previous study proposed a method applying the simulated annealing algorithm to design the sampling network based on three cost factors including the number of reaches, bank length, and subcatchment area. However, these factors are not directly related to the distribution of possible pollution. Thus, this study modified the method by considering three additional factors, i.e. total phosphorus, nitrogen, and sediment loads. The larger the possible load, the higher the probability of a pollution event may occur. The study area was the Derchi reservoir catchment in Taiwan. Pollution loads were derived from the AGNPS model with rainfall intensity estimated using the Thiessen method. Analyses for a network with various numbers of sampling sites were implemented. The results obtained based on varied cost factors were compared and discussed. With the three additional factors, the chosen sampling network is expected to properly detect pollution events and monitor pollution distribution and temporal trends.     

Evaluation of preservation methods for nutrient species collected by automatic samplers

Automatic samplers are a common method of data collection for numerous monitoring projects in the South Florida region and elsewhere. Although total phosphorus (TP) is the primary parameter of interest within this region, nitrogen species such as ammonia nitrogen (NH₄-N), nitrate+nitrite nitrogen (NO_x-N), and total kjeldahl nitrogen (TKN) are also collected and analyzed. Federal and state quality assurance guidelines require nutrient samples to be preserved by acidification with H₂SO₄ to a pH < 2 and stored immediately at 4 °C. However, the remoteness of manysampling locations in South Florida makes it difficult to supplyelectricity for the refrigeration of samples collected by autosamplers. In addition, the use of propane-powered refrigerated autosamplers is a costly and ineffective solution in the South Florida climate. Consequently, while samples collected at these remote locations are routinely pre-preservedwith acid, they are not cooled to 4 °C for a period fromone to seven days. This study evaluated if a statistically significant difference ( = 0.05) existed between concentrations of nitrogen species from a common source samplethat was either: processed immediately; refrigerated to 4 °C for seven days; or not refrigerated for seven days.In all cases, the collected sample was pre-preserved by adding 1 mL of 50% H₂SO₄ to each 1 L discrete sample container before each 7 day testing period. Differences in concentrations of the calculated parameter total nitrogen (TN)were also investigated.Analyses using the Wilcoxon Signed-Rank Test showed no significant differences among the three treatment groups for NO_x-N, TKN, TN and TP. Significant differences were observedwhen the NH₄-N samples that were processed immediately werepaired with NH₄-N samples that were left unrefrigerated or refrigerated for seven days. Information from this study can be used by researchers and managers in evaluating the usefulness of nutrient water quality data that is collected when sample refrigeration is not available.     

Impact of poor solid waste management on ground water

Eight sediment cores recovered from Tamaki Estuary were analysed for Cu, Pb, Zn, and Cd using downward cored sub-samples. The results indicate a significant upward enrichment in heavy metals with the highest concentrations found in the uppermost 0–10 cm layer. Assessment of heavy metal pollution in marine sediments requires knowledge of pre-anthropogenic metal concentrations to act as a reference against which measured values can be compared. Pristine values for the cored sediments were determined from flat “base-line” metal trends evident in lower core samples. Various methods for calculating metal enrichment and contamination factors are reviewed in detail and a modified and more robust version of the procedure for calculating the degree of contamination is proposed. The revised procedure allows the incorporation of a flexible range of pollutants, including various organic species, and the degree of contamination is expressed as an average ratio rather than an absolute summation number. Comparative data for normalized enrichment factors and the modified degree of contamination show that Tamaki Estuary sediments have suffered significant systematic heavy metal contamination following catchment urbanization. Compared to baseline values the uppermost sediment layers show four-fold enrichment averaged across eight cores and four analysed metals.     

Sensitive spectrophotometric methods for the assessment of nitrite in water sample

Two spectrophotometric methods have been developed for the determination of nitrite using dapsone (DAP) with alpha-naphthol and 4-amino-5-hydroxynapthalene-2,7-disulphonic acid monosodium salt (AHNDMS) as chromogenic reagents with maximum absorbance wavelength at 540 and 520 nm respectively. For the method that utilizes dapsone with alpha-naphthol (DAP-alpha-naphthol), the beer's law range is obeyed between 0.05-0.8 microg ml(-1) with molar absorptivity of 5.749 x 104 l mol(-1) cm(-1). The second method that uses dapsone with AHNDMS (DAP-AHNDMS), the beer's law is valid over the range 0.2-1.4 mug ml(-1) and molar absorptivity 2.44 x 104 l mol(-1) cm(-1). The common interfering ions in the analytical procedures have been studied. This proposed methods are reliable, reproducible and have been successfully applied to determine nitrite in various water sources of environmental interest.     

Statistical analyses of coastal water quality for a port and harbour region in India

A long-term study of temperature, pH, turbidity, suspended solid, salinity, dissolved oxygen, biochemical oxygen demand and ammonia nitrogen has been performed in a port and harbour region in India for four years from December 1996 to November 2000. Marine water quality results showed no regular trend. The mean monthly values of temperature, pH, turbidity, suspended solid, salinity, dissolved oxygen, biochemical oxygen demand and ammonia nitrogen were in the range of 22.64 ± 0.4 to 29.05 ± 1.37 °C; 7.65 ± 0.04 to 7.81 ± 0.13; 28.8 ± 14.7 to 64.2 ± 32.0 NTU; 283.5 ± 81.8 to 356.0 ± 159.7 mg/L; 29.78 ± 7.18 to 29.78 ± 1.04 ppt; 4.67 ± 0.50 to 6.01 ± 1.02 mg/L; 5.41 ± 1.92 to 7.56 ± 2.1 mg/L; and 0.25 ± 0.07 to 0.63 ± 0.49 mg/L, respectively. The results of correlation analysis showed that biochemical oxygen demand (BOD) was inversely correlated dissolved oxygen (DO) and poorly correlated with all other parameters. Turbidity and suspended solid were moderately correlated with each other while salinity was moderately correlated with other water quality parameters. In factor analysis, four factors were drawn out of the eight variables, which represented 74% of the variance of the original data. Factor I was related to suspended solid and turbidity. Factor II represented mainly temperature and DO showing inverse relation between these two. Factor III implied the degree of pollution at any monitoring station. Factor IV included pH and salinity. It could be concluded that the factor model represented almost all the variables.     

Organochlorine insecticide residues in drinking and ground water in and around Delhi

A multiresidue method was developed for the estimation of 15organochlorine pesticides in water. 50 samples of drinking watersupplied by the Municipal Corporation to the residential areasof Delhi and 20 ground water samples from nearby villages usedfor irrigation were monitored for the presence of organochlorineinsecticides by the method developed. Although, organochlorinepesticides were detected in the ground water and irrigationwater samples, the levels of pesticides were below the MaximumContaminant Level as prescribed by WHO. No organochlorineinsecticides were detected in any of the drinking water samples.     

Multi-criteria decision analysis with probabilistic risk assessment for the management of contaminated ground water

Traditionally, environmental decision analysis in subsurface contamination scenarios is performed using cost–benefit analysis. In this paper, we discuss some of the limitations associated with cost–benefit analysis, especially its definition of risk, its definition of cost of risk, and its poor ability to communicate risk-related information. This paper presents an integrated approach for management of contaminated ground water resources using health risk assessment and economic analysis through a multi-criteria decision analysis framework. The methodology introduces several important concepts and definitions in decision analysis related to subsurface contamination. These are the trade-off between population risk and individual risk, the trade-off between the residual risk and the cost of risk reduction, and cost-effectiveness as a justification for remediation. The proposed decision analysis framework integrates probabilistic health risk assessment into a comprehensive, yet simple, cost-based multi-criteria decision analysis framework. The methodology focuses on developing decision criteria that provide insight into the common questions of the decision-maker that involve a number of remedial alternatives. The paper then explores three potential approaches for alternative ranking, a structured explicit decision analysis, a heuristic approach of importance of the order of criteria, and a fuzzy logic approach based on fuzzy dominance and similarity analysis. Using formal alternative ranking procedures, the methodology seeks to present a structured decision analysis framework that can be applied consistently across many different and complex remediation settings. A simple numerical example is presented to demonstrate the proposed methodology. The results showed the importance of using an integrated approach for decision-making considering both costs and risks. Future work should focus on the application of the methodology to a variety of complex field conditions to better evaluate the proposed methodology.     

Comparison of macroinvertebrate sampling methods for nonwadeable streams

Bioassessment of nonwadeable streams in the United States is increasing, but methods for these systems are not as well-developed as for wadeable streams. In this study, we compared six macroinvertebrate field sampling methods for nonwadeable streams adapted from those used by three major programs: the U.S. Environmental Protection Agencys Environmental Monitoring and Assessment Program-Surface Waters, the U.S. Geological Surveys National Water Quality Assessment Program, and the Ohio Environmental Protection Agency, Division of Surface Water Biocriteria Program. We performed all six methods at 60 sites across four rivers and measured water chemistry and physical habitat at each site to assess abiotic conditon. Sites were divided into two groups: those influenced by navigational lock and dam structures (restricted flow, or RF) and those free-flowing or with lowhead dams (run-of-the-river, or ROR). Metrics based on passive Hester-Dendy artificial substrate samplers differed greatly from active sampling methods (i.e., using nets) but represented abiotic conditions well in both ROR and RF sites. Although metric values were similar across certain sampling methods, the metrics significantly correlated with abiotic variables varied among methods and between ROR and RF sites. These results emphasize that methods are not interchangeable, and the ability to detect certain stressors depends on sampling method.The U.S. Governments right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

Influence of geology on arsenic concentrations in ground and surface water in central Lesvos, Greece

The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos-Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range <0.7-88.3 microg L(-1) in groundwater, 41.1-90.7 microg L(-1) in thermal spring water and 0.4-13.2 microg L(-1) in stream water, whereas As concentrations in stream sediments varied between 2.0-21.9 mg kg(-1). Four out of 31 groundwater samples exceeded the EC standard of 10 microg L(-1). The survey revealed an enrichment in both surface and groundwater hydrological systems in the northern part of the area (average concentrations of As in groundwater, stream water and stream sediment: 8.0 microg L(-1), 8.8 microg L(-1) and 15.0 mg kg(-1) respectively), in association with the volcanic bedrocks, while lower As concentrations were found in the eastern part (average concentrations in groundwater, stream water and stream sediment: 2.9 microg L(-1), 1.7 microg L(-1) and 5.9 mg kg(-1) respectively), which is dominated by ophiolitic ultramafic formations. The variation of As levels between the different parts of the study area suggests that local geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos-Lisvori does not affect the presence of As in groundwater and streams.     

Statistical analyses of regional surface water quality in southeastern Ontario

Historical records from Ontario's Provincial Water Quality Monitoring Network (PWQMN) for rivers and streams were analyzed to assess the feasibility of mapping regional water quality patterns in southeastern Ontario which spans two major geologic zones, the Precambrian Shield and the St. Lawrence Lowlands, thus serving as a paradigm for much of Ontario. Despite biases toward the populated Lowlands and associated pollution problems, general spatial trends are evident via the analysis of intervariable relations, individual parameter maps and multivariate analysis. Using a robust algorithm designed to identify outliers and abstract underlying bivariate relations, a linear regional hardness-alkalinity relation was derived, where most anomalies proved to be mine drainage impacted sites. Regionally, multivariate ordination reveals that central tendencies of common indicators of ionic strength and nutrient richness correlate positively and that site clusters broadly reflect the transition from oligotrophic Shield waters to eutrophic conditions of heavily agricultural Lowland streams. Results suggest that on the Shield more precisely delineated aquatic regions may be realized by applying GIS to integrate river and synoptic lake survey data. Further synthesis with bedrock and surficial geology, physiography, pedology and other temporally invariant spatial attributes should yield regional patterns of background quality from which locally attainable water objectives might be defined. Additional synoptic surveys of sedimentary Lowland streams may be required as most available sites relflect anthropogenic pollution.     

Comparison of methods of preserving tissues for pesticide analysis

Formalin preservation, freezing, spoiling followed by freezing, and phenoxyethanol were compared in terms of concentrations of DDT, DDD, DDE, endrin, and heptachlor epoxide measured in brain, liver and carcass of birds fed dietary dosages of pesticides and in spiked egg homogenate. Phenoxyethanol proved to be an unsatisfactory preservative; the amount of extractable lipid was excessive, and measurements of concentrations in replicates were erratic. Concentrations of residues in formalin-preserved and frozen samples did not differ significantly in any tissue. Percentage lipid in brains and eggs, however, were significantly lower in formalin-preserved samples. Samples of muscle and liver that had been spoiled before freezing yielded less DDD, and muscle samples yielded more DDT than formalin-preserved samples. We conclude that formalin preservation is a satisfactory method for preservation of field samples and that the warming and spoiling of samples that may occur unavoidably in the field will not result in misleading analytical results.     

Comparison of three sampling and analytical methods for the determination of airborne hexavalent chromium

A field study was conducted with the goal of comparing the performance of three recently developed or modified sampling and analytical methods for the determination of airborne hexavalent chromium (Cr(VI)). The study was carried out in a hard chrome electroplating facility and in a jet engine manufacturing facility where airborne Cr(VI) was expected to be present. The analytical methods evaluated included two laboratory-based procedures (OSHA Method ID-215 and NIOSH Method 7605) and a field-portable method (NIOSH Method 7703). These three methods employ an identical sampling methodology: collection of Cr(VI)-containing aerosol on a polyvinyl chloride (PVC) filter housed in a sampling cassette, which is connected to a personal sampling pump calibrated at an appropriate flow rate. The basis of the analytical methods for all three methods involves extraction of the PVC filter in alkaline buffer solution, chemical isolation of the Cr(VI) ion, complexation of the Cr(VI) ion with 1,5-diphenylcarbazide, and spectrometric measurement of the violet chromium diphenylcarbazone complex at 540 nm. However, there are notable specific differences within the sample preparation procedures used in three methods. To assess the comparability of the three measurement protocols, a total of 20 side-by-side air samples were collected, equally divided between a chromic acid electroplating operation and a spray paint operation where water soluble forms of Cr(VI) were used. A range of Cr(VI) concentrations from 0.6 to 960 microg m(-3), with Cr(VI) mass loadings ranging from 0.4 to 32 microg, was measured at the two operations. The equivalence of the means of the log-transformed Cr(VI) concentrations obtained from the different analytical methods was compared. Based on analysis of variance (ANOVA) results, no statistically significant differences were observed between mean values measured using each of the three methods. Small but statistically significant differences were observed between results obtained from performance evaluation samples for the NIOSH field method and the OSHA laboratory method.     

Comparison of SFE with Soxhlet in the analyses of PCDD/PCDFs and PCBs in sediment

The efficiency of supercritical fluid extraction (SFE) for the isolation of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) from sediments was investigated by comparing SFE with Soxhlet. Five sediments obtained from an international interlaboratory study were used as a test material. SFE was performed with an automatic system where extracted analytes were collected by solid-phase trapping using carbon mixed with Celite as an adsorbent. For the first time, SFE of the most toxic PCBs, coplanar PCBs, was studied with real sediment samples. The majority of PCBs investigated, a total of 38 congeners from tri- to decachlorinated, were quantitatively extracted from sediment by SFE with pure CO2 at pressure 400 atm and temperature 100 degrees C. Under these conditions a successful extraction was obtained also for PCDD/PCDFs except for hepta- and octachlorinated congeners. Copper powder added to the sediment efficiently prevented the transfer of sulfur from the sample during SFE. The TEQs of both PCDD/PCDFs and PCBs obtained by SFE corresponded well with those obtained by the Soxhlet-based method. The reproducibility of SFE was high for both groups.     

Organochlorine pesticide residues in ground water of Thiruvallur district, India

Modern agriculture practices reveal an increase in use of pesticides and fertilizers to meet the food demand of increasing population which results in contamination of the environment. In India crop production increased to 100% but the cropping area has increased marginally by 20%. Pesticides have played a major role in achieving the maximum crop production, but maximum usage and accumulation of pesticide residues was highly detrimental to aquatic and other ecosystem. The present study was chosen to know the level of organochlorines contamination in ground water of Thiruvallur district, Tamil Nadu, India. The samples were highly contaminated with DDT, HCH, endosulfan and their derivatives. Among the HCH derivatives, Gamma HCH residues was found maximum of 9.8 μg/l in Arumbakkam open wells. Concentrations of pp-DDT and op-DDT were 14.3 μg/l and 0.8 μg/l. The maximum residue (15.9 μg/l) of endosulfan sulfate was recorded in Kandigai village bore well. The study showed that the ground water samples were highly contaminated with organochlorine residues.     

Monitoring of the three organophosphate esters TBP,TCEP and TBEP in river water and ground water (Oder,Germany)

The behaviour of the three organophosphate esters tributyl phosphate (TBP), tris(2-chloroethyl)phosphate (TCEP) and tris(2-butoxyethyl)phosphate (TBEP) during infiltration of river water to ground water has been investigated. The monitoring site is the Oder River and the adjacent Oderbruch aquifer. From March 2000 to July 2001, 76 ground water samples from monitoring wells located close to the Oder River and nine river water samples were collected. Additionally, influent and effluent samples from local waste water treatment plants, one sample of rain water and samples of roof runoff were collected. All samples were analysed by solid-phase-extraction followed by gas chromatography/mass spectrometry. TBP, TCEP and TBEP were detected at mean values of 622 ng l(-1), 352 ng l(-1), and 2955 ng l(-1), respectively in municipal waste water effluents. This points to a major input of these compounds into the Oder River by municipal waste water discharge. The concentrations of TBP and TBEP decreased downstream the Oder River possibly due to aerobic degradation. TBP, TCEP and TBEP were detected in ground water influenced predominantly by bank-filtered water. This demonstrates a transport of organic compounds by river water infiltration to ground water. TBP, TCEP and TBEP were also detected in rain water precipitation, roof runoff and ground water predominantly influenced by rain water infiltration. This hints to an input of these compounds to ground water by dry and wet deposition after atmospheric transport. Organophosphate esters were also detected in parts of the aquifer at 21 m depth. This demonstrates low anaerobic degradation rates of TBP, TCEP and TBEP.     

Comparison of static and mineralogical ARD prediction methods in the Nordic environment

Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Commonly used tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods.