Evaluation of geothermal water and assessment of corrosive and scaling potential of water samples in Tulsishyam Geothermal Region, Gujarat, India.

The purpose of this study was to evaluate and analyse the water quality in the Tulsishyam region in terms of corrosive and scaling properties. Thermal water samples (TWS), groundwater samples (GWS), and riverwater samples (RWS) were collected and analysed for a variety of geochemical parameters in various locations throughout the Tulsishyam region. The pH of such thermal springs ranges between 7.1 and 7.4, suggesting that they are neutral, and the temperature ranges between 39 and 42 °C. To determine the corrosive and scaling properties of water, various indices such as the Langelier Saturation Index (LSI), the Puckorius Scaling Index (PSI), the Ryznar Stability Index (RSI), and the Larson Index (LaI) are used. According to the indices described previously, all water samples are extremely corrosive to intolerably corrosive with a significant abrasion rate. The chemical composition of the fluids is also investigated in relation to the weathering processes. Sulphate has a significant negative link with chlorine and a weak correlation with bicarbonate, whereas chlorine has a moderate correlation with bicarbonate, according to multivariate analysis. Industrial usage of water samples from the study area should be limited due to the aggressive nature of the water samples.

Three-dimensional visualization of planta clathrin-coated vesicles at ultrastructural resolution.

Biological systems are the sum of their dynamic three-dimensional (3D) parts. Therefore, it is critical to study biological structures in 3D and at high resolution to gain insights into their physiological functions. Electron microscopy of metal replicas of unroofed cells and isolated organelles has been a key technique to visualize intracellular structures at nanometer resolution. However, many of these methods require specialized equipment and personnel to complete them. Here, we present novel accessible methods to analyze biological structures in unroofed cells and biochemically isolated organelles in 3D and at nanometer resolution, focusing on Arabidopsis clathrin-coated vesicles (CCVs). While CCVs are essential trafficking organelles, their detailed structural information is lacking due to their poor preservation when observed via classical electron microscopy protocols experiments. First, we establish a method to visualize CCVs in unroofed cells using scanning transmission electron microscopy tomography, providing sufficient resolution to define the clathrin coat arrangements. Critically, the samples are prepared directly on electron microscopy grids, removing the requirement to use extremely corrosive acids, thereby enabling the use of this method in any electron microscopy lab. Secondly, we demonstrate that this standardized sample preparation allows the direct comparison of isolated CCV samples with those visualized in cells. Finally, to facilitate the high-throughput and robust screening of metal replicated samples, we provide a deep learning analysis method to screen the "pseudo 3D" morphologies of CCVs imaged with 2D modalities. Collectively, our work establishes accessible ways to examine the 3D structure of biological samples and provide novel insights into the structure of plant CCVs.

Decreased hearing levels at frequencies for understanding speech in tannery workers exposed to a high level of trivalent chromium in Bangladesh.

Hexavalent chromium [Cr(VI)], which has a strong corrosive effect, has been reported to cause perforation of the eardrum. Trivalent chromium [Cr(III)] also has a weak corrosive effect. However, there has been no study on the effects of exposure to Cr, either Cr(VI) or Cr(III), on hearing levels in animals or humans. In this study, the effect of Cr(III) exposure on hearing levels was determined in a human study. Then the reproducibility of the results obtained in the human study and the etiology were investigated in an animal study. The mean levels of total chromium (t-Cr) in hair and toenails from 100 Bangladeshi tannery workers were >20-fold and >360-fold higher, respectively, than those in hair and toenails from 49 Bangladeshi non-tannery workers (office workers). Multivariate analysis revealed decreases of hearing levels (DHLs) at 1 k and 4 k Hz, frequencies that are crucial for understanding language, but not at 8 k and 12 k Hz, in the tannery workers. Since >99.99% of t-Cr in the wastewater that the workers were in direct contact with in the tanneries was Cr(III), the epidemiological results suggest Cr(III)-mediated DHLs in the tannery workers. The results of animal experiments in this study further showed that treatment with eardrops but not intraperitoneal injection with the same amount of Cr(III) that tannery workers might be exposed to resulted in DHL with a damaged eardrum in mice. Previous studies suggested that Cr(III) can directly reach the eardrums of tannery workers via droplets in the air. Cr(III) could also reach the eardrum via picking an ear canal with a finger contaminated with tannery wastewater including Cr(III). Taken together, the results of both human and animal studies suggest the risk of DHLs caused by damage of the eardrum through external exposure to Cr(III) via the ear canal.

The pH of lye and no-lye hair relaxers, including those advertised for children, is at levels that are corrosive to the skin.

BACKGROUND: Hair relaxers are used by up to 70% of females of black African ancestry. Occupational safety regulations list a pH ≥10.5 as irritant and a pH ≥11.50 as corrosive to the skin. OBJECTIVES: To determine the pH of all relaxers sold on the South African market and whether it is lower in no-lye relaxers and those marketed for children. METHODS: Relaxers were purchased from retailers in Cape Town, but more than half (54%) of the 39 brands tested were international. The pH was determined using a benchtop pH meter with an electrode for emulsions. Three pH readings were done over 3 consecutive days for each sample, and the average was used for data analysis. Differences between relaxers were analysed using Kruskal-Wallis, Wilcoxon rank-sum (Mann-Whitney) and two-sample t-tests (p<0.05). RESULTS: The median pH of all relaxers (calcium hydroxide, lithium hydroxide and sodium hydroxide) was 12.36 (interquartile range 12.10 - 12.62). The active ingredient was sodium hydroxide (lye or caustic soda) in 63% of the total of 121 relaxers (6/76 (7.9%) of these marketed for children). Lithium hydroxide and calcium hydroxide (no-lye) relaxers comprised 17% and 20%, respectively. No difference in pH was found between relaxers marketed for adults and those for children (sodium hydroxide p=0.2703, lithium hydroxide p=0.6787 and calcium hydroxide p=0.1048) or between lye (sodium hydroxide) and no-lye (calcium hydroxide) relaxers (p=0.2740). Furthermore, 64/70 (91%) of sodium hydroxide relaxers for adults and 4/6 (67%) of those for children were sold packaged without a neutralising shampoo. CONCLUSIONS: The pH of all the relaxers tested was at levels deemed corrosive to the skin and may contribute to the high prevalence of alopecia in females with afro-textured hair. A review of permissible safe pH levels for cosmetic use is warranted.

Repeated attempted homicide by administration of drugs documented by hair analysis.

Attempted murder by repeated poisoning is quite rare. The authors describe the case of a 62-year-old man who was admitted to an intensive care unit (ICU) for neurological disturbances complicated by inhalation pneumopathy. He presented a loss of consciousness while his wife was visiting him at the ICU (H0). Forty-eight hours later (H48), police officers apprehended the patient's wife pouring a liquid into his fruit salad at the hospital. Toxicological analyses of a blood sample and the infusion equipment (H0), as well as the fruit salad and its container (H48), confirmed the attempted poisoning with cyamemazine (H0) and hydrochloric acid (H48). In order to evaluate the anteriority of poisonings, hair analysis was requested and the medical records of the 6 previous months were also examined. Two 6-cm brown hair strands were sampled and the victim's medical record was seized in order to determine the treatments he had been given during the previous six months. Segmental hair testing on two 6-cm brown hair was conducted by GC-MS, LC-DAD and LC-MS/MS (0-2/2-4/4-6 cm; pg/mg). Haloperidol (9200/1391/227), amitriptyline (7450/1850/3260), venlafaxine (332/560/260), that had never been part of the victim's treatment were detected, as well as some benzodiazepines (alprazolam, bromazepam, nordazepam); cyamemazine was also detected in all the segments (9960/1610/2367) though only a single dose administration was reported in the medical records. The toxicological analyses performed at H0 and H48 confirmed the homicide attempts in the ICU. In addition, comparison of the results in hair analysis with the medical records confirmed repeated poisoning attempts over the previous six months, and thus explain the origin of the disorders presented by the victim. This case serves to remind us that repeated attempted murder can be difficult to diagnose and that hair analysis can be an effective way to detect such attempts.

Hazardous substances in frequently used professional cleaning products.

BACKGROUND: A growing number of studies have identified cleaners as a group at risk for adverse health effects of the skin and the respiratory tract. Chemical substances present in cleaning products could be responsible for these effects. Currently, only limited information is available about irritant and health hazardous chemical substances found in cleaning products. We hypothesized that chemical substances present in cleaning products are known health hazardous substances that might be involved in adverse health effects of the skin and the respiratory tract. METHODS: We performed a systematic review of cleaning products used in the Swiss cleaning sector. We surveyed Swiss professional cleaning companies (n = 1476) to identify the most used products (n = 105) for inclusion. Safety data sheets (SDSs) were reviewed and hazardous substances present in cleaning products were tabulated with current European and global harmonized system hazard labels. RESULTS: Professional cleaning products are mixtures of substances (arithmetic mean 3.5 +/- 2.8), and more than 132 different chemical substances were identified in 105 products. The main groups of chemicals were fragrances, glycol ethers, surfactants, solvents; and to a lesser extent, phosphates, salts, detergents, pH-stabilizers, acids, and bases. Up to 75% of products contained irritant (Xi), 64% harmful (Xn) and 28% corrosive (C) labeled substances. Hazards for eyes (59%) and skin (50%), and hazards by ingestion (60%) were the most reported. CONCLUSIONS: Cleaning products potentially give rise to simultaneous exposures to different chemical substances. As professional cleaners represent a large workforce, and cleaning products are widely used, it is a major public health issue to better understand these exposures. The list of substances provided in this study contains important information for future occupational exposure assessment studies.

Accidental potassium dichromate poisoning. Toxicokinetics of chromium by ICP-MS-CRC in biological fluids and in hair.

Intoxications by chromium (Cr) compounds are very life threatening and often lethal. After oral ingestion of 2 or 3g of hexavalent Cr (Cr(VI)), gastrointestinal injury, but also hepatic and renal failure, often occurs which each leads to a fatal outcome in most patients. Cellular toxicity is associated with mitochondrial and lysosomal injury by biologically Cr(VI) reactive intermediates and reactive oxygen species. After Cr(VI) has been absorbed, there is not much that can be done except to control the main complications as the treatment is only symptomatic. The biotransformation of Cr(VI) to Cr(III) reduces the toxicity because the trivalent form does not cross cellular membranes as rapidly. In fact, more than 80% of Cr(VI) is cleared in urine as Cr(III). We report the case of a 58-year-old male patient who was admitted to hospital after accidental oral ingestion of a 30 g/L potassium dichromate (the estimated amount of ingested Cr is about 3g). ICP-MS equipped with a collision/reaction cell (CRC) and validated methods were used to monitor plasma (P), red blood cells (RBCs), urine (U) and hair chromium. For urine the results were expressed per gram of creatinine. After 7 days in the intensive care unit, the patient was discharged without renal or liver failure. P, RBC and U were monitored during 49 days. During this period Cr decreased respectively from 2088 µg/L to 5 µg/L, 631 µg/L to 129 µg/L and 3512 µg/g to 10 µg/g. The half-life was much shorter in P than in RBC as the poison was more quickly cleared from the P than from the RBC, suggesting a cellular trapping of the metal. Hair was collected 2 months after the intoxication. We report a very rare case of survival after accidental Cr poisoning which has an extremely poor prognosis and usually leads to rapid death. For the first time, this toxicokinetic study highlights a sequestration of chromium in the RBC and probably in all the cells.

Progress in understanding the sources, deposition and above-ground fate of trichloroacetic acid.

AIM AND SCOPE: This paper is a companion to the recent review paper by Laturnus et al. (2005) on TCA in soils, presenting a complementary review of knowledge gaps in the sources and fate of trichloroacetic acid (TCA) in plants. MAIN FEATURES: The review considers the various sources of TCA precursors, including the question of how much atmospheric TCA comes from naturally-produced precursors, and addresses the implications of climate change on atmospheric TCA formation. Models of the conversion of precursors to TCA in the atmosphere are critically compared with field measurements of concentrations, deposition and budgets; data on the quantitative relationships between gas-phase TCA, particulate TCA, and TCA dissolved in rain and clouds are reviewed. Methods for quantifying TCA are summarised, along with a description of what the different techniques measure, and how results can be compared. A distinction is made between 'extractable' TCA and 'total' TCA in vegetation. Evidence for the various pathways by which TCA enters plants is given, including the in situ production of TCA in leaves. This leads to a better understanding of how plant tissue concentrations depend on uptake, production and removal rates. Finally, knowledge of the toxic effects of TCA on plants and TCA metabolism in plant tissues is summarised. RESULTS AND DISCUSSION: The discussion highlights knowledge gaps, and is intended to aid the reader in interpreting previously published results through identifying where different ways of expressing data have been used, and the consequent conclusions that can be drawn. CONCLUSION AND FURTHER RESEARCH DIRECTIONS: Recommendations are given for future research directions--in identifying precursor sources, quantifying heterogeneous atmospheric processes, recognising and quantifying uptake pathways, and elucidating the biochemical mechanisms involved in sequestering and degrading TCA inside leaves.

Urinary excretion half life of trichloroacetic acid as a biomarker of exposure to chlorinated drinking water disinfection by-products.

AIMS: To measure accurately urinary elimination half life of trichloroacetic acid (TCAA). METHODS: A longitudinal pilot exposure/intervention study measured the elimination half life of TCAA in urine. Beverage consumption was limited to a public water supply and bottled water of known TCAA concentration, and ingestion volume was managed. The five participants limited fluid consumption to only the water provided. Consumption journals were kept by each participant and their daily first morning urine (FMU) samples were analysed for TCAA and creatinine. TCAA elimination half life curves were generated from a two week washout period using TCAA-free bottled water. RESULTS: Individual elimination half lives ranged from 2.1 to 6.3 days, for single compartment exponential decay, the model which fit the data. CONCLUSION: Urinary TCAA is persistent enough to be viable as a biomarker of medium term (days) exposure to drinking water TCAA ingestion within a range of realistic concentrations.

Fluxes and reservoirs of trichloroacetic acid at a forest and moorland catchment.

The concentrations and input/output fluxes of trichloroacetic acid (TCA) were measured in all relevant media for one year at a 0.86 km2 upland conifer plantation and moorland catchment in SW Scotland (n > 380 separate samples analyzed). Annual wet precipitation to the catchment was 2.5 and 0.4 m for rain and cloud, respectively. TCA input to the catchment for the year was 2100 g, predominantly in rainwater (86%), with additional input via cloudwater (13%) and gas plus particle dry deposition (1%). There were no seasonal trends in TCA deposition, and cloudwater concentration was not enhanced over rainwater. TCA in precipitation exceeded concentrations estimated using currently accepted routes of gas-phase oxidation from anthropogenic chlorinated hydrocarbon precursors, in agreement with previous studies. Export of TCA from the catchment in streamwater totalled 1970 g for the year of study. The TCA concentration in streamwater at outflow (median 1.2 microg L(-1)) was significantly greater than that before the stream had passed through the conifer plantation. To well-within measurement uncertainties, the catchment is currently at steady-state with respect to TCA input/output. The catchment reservoir of TCA was dominated by soils (approximately 90%), with the remainder distributed in forest litter (approximately 9%), forest branchwood and stemwood (approximately 0.7%), forest foliage (approximately 0.5%), and moorland foliage (approximately 0.1%). Although TCA is clearly taken up into foliage, which consequently may be important for the vegetation, this was a relatively minor process for TCA at the catchment scale. If it is assumed, on the basis of laboratory extraction experiments, that only approximately 20% of "whole soil" TCA measured in this work was water extractable, then total mass of TCA in the catchment is reduced from approximately 13 to approximately 3.5 kg. Comparing the latter value with the annual flux yields an average steady-state residence time for TCA in the catchment of approximately 1-2 y, if all TCA is involved in catchment turnover. Considering that other evidence indicates the lifetime of TCA in soil and biota is considerably shorter than this (weeks rather than years), the magnitude of the TCA reservoir is suggested to be strong evidence for net natural TCA production in soils and/or that the majority of TCA in the reservoir is not involved with external fluxes.

Chloroacetic acids in European soils and vegetation.

Trichloroacetic acid (TCA) and dichloroacetic acid (DCA) are possible minor atmospheric degradation products of perchloroethylene and trichloroethylene, respectively. These acids may be wet- or dry-deposited from the atmosphere to land surfaces and hence possibly affect plant growth. However, the existing database on TCA levels in soil is limited to a few studies carried out in the late 1980's and the early to mid-1990's and it was concluded that there is a need for further measurements of concentrations of TCA and DCA in soils. In this study soil samples from 10 locations in 5 European countries, as well as vegetation samples, and a limited number of rainwater and air samples were collected and analysed for DCA and TCA to determine the concentrations of these compounds. An isotope dilution method using GC-MS was used for the determination of these acids in the samples. The method was briefly validated and the performance characteristics are presented. The results of the analysis of the soil samples show that the DCA and TCA concentrations in soil from different sites in Europe are more or less comparable, with the exception of Germany, especially Freudenstadt, where significantly higher TCA concentrations (up to 12 microg kg(-1) dw) were found. The average DCA and TCA concentrations in soil in this study were 0.25 +/- 0.12 and 0.64 +/- 1.40 microg kg(-1) dw, respectively. Generally, the concentration in soils from forest areas are about twice those from open-land areas. The DCA and TCA concentrations in vegetation samples ranged from 2.1 to 73 microg kg(-1) dw for DCA and from 4.7 to 17 microg kg(-1) dw for TCA. Thus, the concentrations in vegetation samples are 10-20 times higher than the soil concentrations. DCA and TCA concentrations in wet deposition samples and air samples collected in The Netherlands were 0.14 and 0.15 microg l(-1) for wet deposition samples and <0.5 and 0.7 ng m(-3) for air samples respectively. For these samples taken in The Netherlands, the estimated values for soil and air concentrations calculated from the wet deposition concentrations are in agreement with the concentrations measured in this study.

Urinary levels of trichloroacetic acid, a disinfection by-product in chlorinated drinking water, in a human reference population.

Trichloroacetic acid (TCAA), a known mouse liver carcinogen and a possible human carcinogen, is found in chlorinated drinking water. We measured TCAA in archived urine samples from a reference population of 402 adults using isotope-dilution high-performance liquid chromatography-tandem mass spectrometry. TCAA was detected in 76% of the samples examined at concentrations ranging from < 0.5 micro g TCAA/L to more than 25 micro g/L; the 90th percentile concentration was 23 micro g/L (22 micro g TCAA/g creatinine); and the geometric mean and median concentrations were 2.9 micro g/L (2.6 micro g/g creatinine) and 3.3 micro g/L (3.2 micro g/g creatinine), respectively. The frequency of detection of TCAA in urban areas was higher than in rural areas (p = 0.00007), and sex and place of residence (i.e., urban vs. rural) were found to have a significant interaction in modulating the levels of TCAA (p = 0.012). Urban residents had higher mean levels of TCAA (men, 5.3 micro g/L, 3.8 micro g/g creatinine; women, 2.9 micro g/L, 2.8 micro g/g creatinine) than did rural residents (men, 2.2 micro g/L, 1.7 micro g/g creatinine; women, 2.6 micro g/L, 2.7 micro g/g creatinine). The higher frequency of detection of TCAA in urban than in rural areas and higher levels of TCAA among urban than among rural residents may reflect the fact that urban residents use primarily chlorinated water from public water supplies, whereas those in rural areas are more likely to obtain water from private wells, which typically are not chlorinated.

Highly enhanced photoreductive degradation of perchlorinated compounds on dye-sensitized metal/TiO2 under visible light.

This study reports an example of visible-light photocatalyst based on TiO2 modified by ruthenium-complex sensitizers and noble metal deposits. The photodegradation of trichloroacetate (TCA) and carbon tetrachloride was used as a probe reaction for evaluating the visible light activity of the photocatalyst under the illumination of lambda > 420 nm. Photodeposition of platinum nanoparticles on dye-sensitized TiO2 (Pt/TiO2/Ru(II)L3) drastically enhanced the degradation rate of TCA and CCl4. The visible light reactivity of Pt/TiO2/Ru(II)L3 was optimal with [Ru(II)L3] = 10 microM, [TiO2] = 0.5 g/L, and Pt loading of about 0.2 wt %. Although no electron donors to regenerate the oxidized Ru-sensitizers were added in the aqueous suspension, the photoreductive dechlorination of perchlorinated compounds proceeded far beyond the stoichiometric limit of the initial sensitizer concentration. Water acted as an electron donor to regenerate the sensitizer with a concurrent production of dioxygen. On the other hand, Pt/TiO2/Ru(II)L3 was completely inactive in the presence of dissolved oxygen and the in-situ generated dioxygen gradually decelerated the dechlorination rate. Conduction band electrons transferred to O2 in preference to CCl4 and TCA on Pt deposits. Other noble metals (Ag, Au, and Pd) deposited on TiO2 showed a better oxygen-tolerance but less visible-light reactivity than PtTiO2/Ru(II)L3. Effects of metal loading on the visible light activity and its implications for the efficientvisible-light photocatalyst development are discussed.

Trichloroacetic acid as a biomarker of exposure to disinfection by-products in drinking water: a human exposure trial in Adelaide, Australia.

We addressed the need for a biomarker of ingestion exposure to drinking water disinfection by-products by performing a human exposure trial. We evaluated urinary excretion of trichloroacetic acid (TCAA) as an exposure biomarker using 10 volunteers who normally consume their domestic tap water. We recruited the volunteers at a water quality research laboratory in Adelaide, Australia. Participants maintained a detailed consumption and exposure diary over the 5-week study. We also analyzed tap water and first morning urine (FMU) samples for TCAA, and tap water for chloral hydrate (CH). We documented both interindividual and intraindividual variability in TCAA ingestion and urinary excretion, and both were substantial. With a TCAA-free bottled water intervention, we used creatinine-adjusted urinary TCAA levels to estimate urinary TCAA excretion half-lives for three of the participants. We observed correspondence over time between estimated TCAA excretion, calculated from TCAA + CH ingestion levels, and measured TCAA urinary excretion. This study demonstrates the merits and feasibility of using TCAA in FMU as an exposure biomarker, and reveals remaining concerns about possible alternate sources of TCAA exposure for individuals with low drinking water ingestion exposure.

Trichloroacetic acid in the environment.

Suppositions that the trichloroacetic acid (TCA, CCl3C(O)OH) found in nature was a consequence solely of the use of chlorinated hydrocarbon solvents prompted this critical review of the literature on its environmental fluxes and occurrences. TCA is widely distributed in forest soils (where it was rarely used as an herbicide) and measurements suggest a soil flux of 160 000 tonnes yr(-1) in European forests alone. TCA is also produced during oxidative water treatment and the global flux could amount to 55 000 tonnes yr(-1) (from pulp and paper manufacture, potable water and cooling water treatments). By contrast, the yields of TCA from chlorinated hydrocarbon solvents are small: from tetrachloroethene 13 600 tonnes yr(-1) and from 1,1,1-trichloroethane 4300 tonnes yr(-1) on a global basis, at the atmospheric burdens and removal rates typical of the late 1990s. TCA is ubiquitous in rainwater and snow. Its concentrations are highly variable and the variations cannot be connected with location or date. However, there is no significant difference between the concentrations found in Chile and in eastern Canada (by the same analysts), or between Malawi and western Canada, or between Antarctica and Switzerland, nor any significant difference globally between the concentrations in cloud, rain and snow (although local enhancement in fog water has been shown). TCA is present in old ice and firn. At the deepest levels, the firn was deposited early in the 19th century, well before the possibility of contamination by industrial production of reactive chlorine, implying a non-industrial background. This proposition is supported by plume measurements from pulp mills in Finland. TCA is ubiquitous in soils; concentrations are very variable but there are some indications that soils under coniferous trees contain higher amounts. The concentrations of TCA found in plant tissue are region-specific and may also be plant-specific, to the extent that conifers seem to contain more than other species. TCA is removed from the environment naturally. There is abundant evidence that soil microorganisms dehalogenate TCA and it is lost from within spruce needles with a half-life of 10 days. There is also recent evidence of an abiotic aqueous decarboxylation mechanism with a half-life of 22 days. The supposedly widespread effects of TCA in conifer needles are not shown in controlled experiments. At concentrations in the needles of Scots pine similar to those observed in needles in forest trees, changes consequent on TCA treatment of field laboratory specimens were almost all insignificant.

Simplified analysis of contaminant rejection during ground- and surface water nanofiltration under the information collection rule.

A simple, closed-form analytical expression based on the homogenous solution diffusion model is derived for contaminant removal during nanofiltration (NF) of ground and surface water. Solute permeation and back-diffusion coefficients were used as fitting parameters to model rejection characteristics of four thin-film composite NF membranes under conditions typical of drinking water NF. Nonlinear fits of the model to experimental data suggests that the United States Environmental Protection Agency's (USEPA)'s Information Collection Rule protocol for bench-scale studies could be improved to obtain greater precision of the mass transfer coefficients. The model was found to fit rejection data for several water treatment contaminants including total organic carbon, precursors to total organic halide, four trihalomethanes and nine haloacetic acids containing chlorine and bromine, calcium and total hardness, alkalinity and conductivity. The simplified approach to mass transfer calculations from multisolute systems suggests that feed water recovery has a stronger influence on contaminant rejection than permeate flux. Evidence for coupled transport of divalent inorganic ions is also presented. Even though the model developed does not account for ion coupling and cannot be applied in a purely predictive mode, it can assist in the better design and interpretation of data obtained from site-specific pilot-scale water treatment NF studies conducted in support of plant design.

A new method for the determination of trichloroacetic acid in spruce foliage and other environmental media.

Trichloroacetic acid (TCAA) is a phytotoxic chemical, present throughout the environment. The majority of methods for analysis of TCAA require chemical derivatisation and multiple extraction steps prior to analysis by gas-chromatography. Here, a new analytical method for TCAA determination in environmental matrices is reported. The method is based on a modified Nielsen-Kryger steam distillation that combines into one 1 h reflux the thermal decarboxylation of TCAA to CHCl3 and the partitioning and concentration of the CHCl3 into 5 ml of hexane, which is analysed by GC. Sample preparation is minimal and no matrix standard additions are required. The background CHCl3 in the sample is removed prior to extraction by degassing the solution for 1 h with nitrogen. Optimisation of the method gave recoveries from three separate solutions of 0.31 ppb aqueous TCAA standards of 93 +/- 15% (n = 9), 110 +/- 9% (n = 9) and 105 +/- 11% (n = 6). The extraction method has been compared with a decarboxylation and headspace GC method for determination of TCAA in Sitka spruce needles. No significant difference in TCAA concentration or replicate precision between the two methods was observed.

Childhood injuries from artificial nail primer cosmetic products.

BACKGROUND: Methacrylic acid-containing primers used in artificial nail cosmetic products are typically not contained in child-resistant packaging, although they are sold to the general public. OBJECTIVE: To analyze the type and severity of childhood poisoning injuries involving methacrylic acid-containing artificial nail primers. DESIGN: Secondary analysis of 2 national, population-based injury data sets. SETTING: The 1991 through 1993 National Electronic Injury Surveillance System data on emergency department visits compiled by the Consumer Product Safety Commission and the 1993 through 1995 Toxic Exposure Surveillance System data on calls to poison control centers compiled by the American Association of Poison Control Centers. SUBJECTS: Children younger than 6 years with injuries associated with exposures to nail primers. RESULTS: In the National Electronic Injury Surveillance System, there were 769 exposures to nail preparations, 32 (4.2%) of which involved nail primers. Twenty-eight (87.5%) of 32 nail primer exposures involved children younger than 6 years. Of the severe nail primer injuries, 80% involved preschoolers; most of the injuries were dermal burns. In the Toxic Exposure Surveillance System data set, there were 759 methacrylic acid-containing nail product exposures, of which 567 (74.7%) occurred in children younger than 6 years. Of exposures in preschool children, 56 (9.9%) resulted in moderate severity injuries and 3 (0.5%) in "major" injuries; there were no deaths. CONCLUSIONS: Artificial nail primers containing methacrylic acid represent a corrosive hazard to young children and have been associated with severe injuries. New product labeling and packaging regulations and public education measures that recognize this hazard are recommended.

Acute poisoning due to alkalis used during industrial cleaning of soft drinks' glass containers: a case report.

Corrosive alkalis are used in the soft drink and beer industries for the cleaning of the non-disposable glass containers using several different methods. It is well understood that complete cleaning of these vessels by multiple and well-organized rinsing is an absolute necessity. In cases of disturbance of this process, some residuals of alkaline agents may be retained in the glass containers, causing severe health risks to consumers. This case of acute poisoning due to caustic alkalis concerns a young woman who consumed carbonated lemonade from a non-disposable glass container. Clinical signs and symptoms and the treatment of the affected woman are described. Toxicological analysis of the soft drink consumed led to the detection, identification and quantitative determination of the presence of the alkalis.