Microbial extracellular enzyme activities in Humex Lake Skjervatjern

Two microbial extracellular enzyme activities (MEEA) were studied in HUMEX Lake Skjervatjern: acid phosphatase (APHA) and leucine aminopeptidase (LeuAMPA). Both enzyme activities varied in the vertical and horizontal scale in both lake sites. APHA varied in the acidfied Basin A between 945–1706 nmol L⁻¹ h⁻¹ and LeuAMPA between 3.7–25 nmol L⁻¹ h⁻¹. Both MEEA reached maxima in 0.5 m depth. In the control site (Basin B), APHA was lower by a factor of two, and varied between 156–669 nmol L⁻¹ h⁻¹. LeuAMPA reached similar values as in Basin A and varied between 7.8–34.8 nmol L⁻¹ h⁻¹. Maxima of APHA were found in the upper layer (0–2 m), while LeuAMPA had only one distinct maxima at 2–2.5 m depth. The number of bacteria (AFDC) varied between 4.4–8.8 10⁶ cells mL⁻¹ and was not significantly different in either side, but both had maxima in the thermocline. Highest specific LeuAMPA activities were found in the thermocline (3.2–4.5 fmol L⁻¹ h⁻¹ cell⁻¹) in both sides and varied between 0.4–4.5 fmol L⁻¹ h⁻¹ cell⁻¹ in both water columns. The main contributor (60–70%) to LeuAMPA was found in the microplankton fraction, retained on Nuclepore filters with pore sizes between 2.0-0.2 μm. APHA was retained less even on a filter with pore size smaller than 0.2 μm. About 50–70% of APHA passed through 0.2 μm-0.1 μm Nuclepore filters and could be found in the dissolved organic matter (DOM) fraction. APHA and bacteria counts (AFDC) showed a distinct gradient from the littoral zone to the pelagial in the surface water samples (0.2 m depth). APHA and LeuAMPA are regarded as important regulators for nutrient availability to microplankton. However, all data from vertical as important regulators for nutrient availability to microplankton. However, all data from vertical and horizontal samples showed that Lake Skjervatjern is a strongly gradient-dominated aquatic ecosystem. Watershed-littoral effects are more pronounced in the shallow, acidified Basin A than in the control side, Basin B.     

Screening of household products for the emission of volatile organic compounds

10 household products, eight waxes or polishes, and two detergents have been screened by a headspace technique for the emission of volatile organic compounds (VOC). Using Tenax sampling and analysis by combined gas chromatography-mass spectrometry (GC-MS) more than 80 single compounds or groups of isomers have been identified, and semiquantitative data on the initial emission rates (emission rate immediately after application) have been obtained. Products fall into two groups: those containing water as a main (80 to 90%) constituent and those without water. The initial emission rate of the first group ranged from 0.2 to 2 μg cm⁻²min⁻¹, whereas the second group had higher emission rates of up to 430 μg cm⁻²min⁻¹. Products of the second group emit essentially hydrocarbons (alkanes, alkenes, and terpenes), whereas most products of the first group emit oxygenated compounds including terpene alcohols and their acetates, aliphatic alcohols and esters, and alkoxy-alcohols.     

Determination of phthalate ester plasticizers in the aquatic environment of Southwestern Nigeria

Water from the Lagos, Oyo, Osun, Ondo, and Delta states of Nigeria and the cities' water treatment plants had been analized for the presence of ubiquitous phthalate esters using liquid chromatography. Extraction with CH₂Cl₂ and liquid chromatography was used for compound separation. Several phthalate esters, dimethyl- (DMP), diethyl- (DEP), and di-n-butyl- (DBP) were found present at levels of 10 mg L⁻¹ to 1472 mg L⁻¹ in river water and 91 mg L⁻¹ to 1219 mg L⁻¹ in tap water from the cities' water treatment plants. A study of uncontaminated water was done to establish blank levels.     

Present status of Rn in groundwater in Extremadura

Radon-222 was measured in groundwater sources of Extremadura (Spain), analyzing 350 samples from private and public springs, wells, and spas by liquid scintillation counting (LSC) and gamma spectrometry. The ²²²Rn activity concentrations ranged from 0.24 to 1168 Bq L⁻¹. The statistical analysis showed a log-normal distribution with a mean of (111 ± 7) Bq L⁻¹ and a median of (36 ± 3) Bq L⁻¹. A hydrogeological study revealed correlations between the activity concentration and the aquifer material's characteristics. A map of ²²²Rn in groundwater was elaborated and compared with the natural gamma radiation map for this region. About 35% of the samples showed ²²²Rn activity concentrations above the Euratom recommended limit of 100 Bq L⁻¹. Three uranium series radionuclides (²³⁸U, ²³⁴U, and ²²⁶Ra) were also assayed by alpha-particle spectrometry, estimating the annual effective dose due to the presence of these natural radionuclides in drinking water.     

Mercury in algae of the Canary Islands littoral

The concentrations of Hg in three groups of algae (Phaeophyta, Chlorophyta, and Rhodophyta) found in the Canary Islands littoral were determined. The mean concentrations found were, respectively: Phaeophyta: 0.13 mg kg⁻¹ (range 0.01 to 2.30 mg kg⁻¹); Chlorophyta: 0.13 (range 0.025 to 0.36 mg kg⁻¹); Rhodophyta: 0.11 mg kg⁻¹ (range 0.02 to 0.28 mg kg⁻¹). There are no relevant differences in the contents of Hg at group level and at species level, only a sample of Phaeophyta presents an abnormally high concentration (>1 mg kg⁻¹), corresponding to a sampling station nearby an urban drain.     

Growth response of Scenedesmus to different concentrations of copper, cadmium, nickel, zinc, and lead

The fresh water alga Scenedesmus was cultured in graded concentration of Cu, Cd, Ni, Zn, and Pb to evaluate the effect of these cations on the growth response of Scenedesmus. The effective concentration of metal which depressed the Scenedesmus growth for Cu was 0.5 mg l⁻¹, for Cd 0.5 mg l⁻¹, for Ni 2 mg l⁻¹, and for Zn 2 mg l⁻¹. The alga exhibited tolerance for high Pb concentrations up to 30 mg l⁻¹. Exposure of a Scenedesmus cell to each metal revealed anatomical changes and chloroplast disruption especially at high metal concentrations.     

Applying mass transfer models for controlling organic compounds in ozonation process

Mass transfer plays a significant role in the ozonation process. The prediction models associated with the volumetric overall mass transfer coefficient (K_La) and initial fractional ozone absorption (FOA₀) during the ozonation process were developed through the use of dimensional analysis. It was found that the volumetric overall mass transfer coefficient is the function of diffusivity, agitation speed, and gas flow rate, and the parameters in the K_La equation are determined. Application of the prediction models for K_La and FOA₀ would yield information to choose the most practically feasible operating parameters. The removability of total organic carbon (TOC) can be estimated based on the mass balance relationship and kinetic expression of TOC oxidation, during continuous laboratory ozonation of humic acid solution. The reaction rate constant averaged 0.0291 L/mg·min. The developed model in combination with the mass transfer and reaction kinetics can be used successfully in forecasting the most efficient agitation speed to control the formation of organic compounds. Also, the critical value of ozone partial pressure to achieve the highest TOC removability can be determined through the use of the above developed model.     

Application of a “closed-can” technique for measuring radon exhalation from mine samples of Punjab, Pakistan

Using the closed-can technique, radon exhalation rate measurements have been carried out for shale and coal samples collected from various mines located in the Chakwal and Makarwal areas of Pakistan. For the two areas, the measured average values of the exhalation rates from shale are 1.45±0.13 and 0.67±0.25 Bq m⁻² h⁻¹ and for coal are 1.0±0.03 and 0.65±0.32 Bq m⁻² h⁻¹, respectively. These values are much lower than the measured exhalation rates from alum-shale-based Nordic concrete which has values in the 50–200 Bq m⁻² h⁻¹ range. The lower values of the measured exhalation rates from the shale and coal deposits in the Chakwal and Makarwal areas are indicative of their lower uranium contents and mine workers in these areas do not face any abnormal health hazard due to radon since the exhalation rates have been found to be on the low side.     

Chemical and biological evaluation of a reaction mixture of R-(+)-limonene/ozone: Formation of strong airway irritants

The airway irritation of a reaction mixture of R-(+)-limonene and ozone was evaluated by a mouse bioassay in which sensory irritation, bronchoconstriction and pulmonary irritation were measured. Significant sensory irritation (33% reduction of mean respiratory rate) was observed by dynamic exposure of the mice, during 30 min, to a ca. 16 s old reaction mixture of ozone and limonene. The initial concentrations were nominally 4 ppm O₃ and 48 ppm limonene. After reaction, the residual O₃ was <0.03 ppm. Conventional analytical chemical methods were used to measure the formation of readily identified and stable products. Besides the expected products, 1-methyl-4-acetylcyclohexene (AMCH), 3-isopropenyl-6-oxoheptanal (IPOH), formaldehyde and formic acid, autooxidation products of limonene and a series of compounds (i.e., acetone, acrolein and acetic acid), which may or may not be artefacts, were identified. Addition of the sensory irritation effects of the residual reactants and all the identified compounds could not explain the observed sensory irritation effect. This suggests that one or more strong airway irritants were formed. Since limonene is common in the indoor air, and ozone is infiltrated from outdoors and/or produced indoors (e.g., by photocopiers), such oxidation reactions may be relevant for indoor air quality.     

Isotope tracing of submarine groundwater discharge offshore Ubatuba, Brazil: results of the IAEA–UNESCO SGD project

Results of groundwater and seawater analyses for radioactive (³H, ²²²Rn, ²²³Ra, ²²⁴Ra, ²²⁶Ra, and ²²⁸Ra) and stable (D and ¹⁸O) isotopes are presented together with in situ spatial mapping and time series ²²²Rn measurements in seawater, direct seepage measurements using manual and automated seepage meters, pore water investigations using different tracers and piezometric techniques, and geoelectric surveys probing the coast. This study represents first time that such a new complex arsenal of radioactive and non-radioactive tracer techniques and geophysical methods have been used for simultaneous submarine groundwater discharge (SGD) investigations. Large fluctuations of SGD fluxes were observed at sites situated only a few meters apart (from 0 cm d⁻¹ to 360 cm d⁻¹; the unit represents cm³/cm²/day), as well as during a few hours (from 0 cm d⁻¹ to 110 cm d⁻¹), strongly depending on the tidal fluctuations. The average SGD flux estimated from continuous ²²²Rn measurements is 17 ± 10 cm d⁻¹. Integrated coastal SGD flux estimated for the Ubatuba coast using radium isotopes is about 7 × 10³ m³ d⁻¹ per km of the coast. The isotopic composition (δD and δ¹⁸O) of submarine waters was characterised by significant variability and heavy isotope enrichment, indicating that the contribution of groundwater in submarine waters varied from a small percentage to 20%. However, this contribution with increasing offshore distance became negligible. Automated seepage meters and time series measurements of ²²²Rn activity concentration showed a negative correlation between the SGD rates and tidal stage. This is likely caused by sea level changes as tidal effects induce variations of hydraulic gradients. The geoelectric probing and piezometric measurements contributed to better understanding of the spatial distribution of different water masses present along the coast. The radium isotope data showed scattered distributions with offshore distance, which imply that seawater in a complex coast with many small bays and islands was influenced by local currents and groundwater/seawater mixing. This has also been confirmed by a relatively short residence time of 1–2 weeks for water within 25 km offshore, as obtained by short-lived radium isotopes. The irregular distribution of SGD seen at Ubatuba is a characteristic of fractured rock aquifers, fed by coastal groundwater and recirculated seawater with small admixtures of groundwater, which is of potential environmental concern and has implications on the management of freshwater resources in the region.     

Pulmonary function changes in Chinese hamsters exposed six months to diesel exhaust

Chinese hamsters were exposed for eight hours per day to automotive diesel exhaust emissions which were diluted with air (18 to 1) and had a particulate level of 6.4 mg/m³. Pulmonary function measurements were made after six months exposure. Body weight (BW), lung weight (LW), vital capacity (VC), residual volume by water displacement (RV_w) and by gas dilution (RV_D), alveolar volume (V_A), and carbon monoxide transfer factor (D_LCO) were measured. LW showed a significant increase in the diesel exposed animals (P < 0.01) while VC, RV_W, and D_LCO showed decreases (P < 0.01). Static deflation volume-pressure curves showed depressed deflation volumes for diesel exposed animals when volumes were corrected for body weight and even greater depressed volumes when volumes were corrected for lung weight. However, when volumes were expressed as percent vital capacity, the diesel exposed animals had higher lung volumes at 0 and 5 cm H₂O. Results of the pathological examination of the lung tissue will be necessary for final analysis of our findings. However, preliminary interpretation indicates possible emphysematous changes which are compatible with the observed decrease in D_LCO.     

Activities of Po and Pb in the water column at Kuala Selangor, Malaysia

Natural radionuclides, such as ²¹⁰Po and ²¹⁰Pb were measured in the water samples collected from six stations at Kuala Selangor, Malaysia. Results for ²¹⁰Po and ²¹⁰Pb in dissolved and particulate phases have showed the difference in distribution and chemical behavior. The fluctuation activities of ²¹⁰Po and ²¹⁰Pb depend on wave action, geology and degree of fresh water input occurring at study areas and probably due to different sampling dates. The distribution coefficient, K_d, values of ²¹⁰Po and ²¹⁰Pb ranged from 2.0 × 10³ l g⁻¹ to 265.15 × 10⁵ l g⁻¹, and from 3.0 × 10³ l g⁻¹ to 558.16 × 10⁵ l g⁻¹, respectively. High K_d values of ²¹⁰Po and ²¹⁰Pb indicated that a strong adsorption of ²¹⁰Po and ²¹⁰Pb onto suspended particles, and the sinking of both nuclides on the seabed at study locations were controlled by the characteristics of suspended particles.     

Ra and Ra in scale and sludge samples and their correlation with the chemical composition

In order to contribute to a future waste management policy related to the presence of technologically enhanced natural occurring radioactive material (TENORM) in the Brazilian petroleum industry, the present work presents the chemical composition and the ²²⁶Ra and ²²⁸Ra content of sludge and scales generated during the offshore E and P petroleum activities in the Campos Basin, the primary offshore oil production region in Brazil.The ²²⁶Ra and ²²⁸Ra content on 36 sludge and scales samples were determined by gamma-spectrometry. Based on X-ray diffractometry results, a chemical analysis schema for these samples was developed. The results have shown that scales are 75% barium and strontium sulfates, with a mean ²²⁶Ra and ²²⁸Ra content of 106 kBq kg⁻¹ and 78 kBq kg⁻¹, respectively. On the other hand, sludge samples have a much more complex chemical composition than the scales. The ²²⁶Ra and ²²⁸Ra content in sludge also varies much more than the content observed in the scales samples and ranged from 0.36 to 367 kBq kg⁻¹ and 0.25 to 343 kBq kg⁻¹, respectively.     

Solid partitioning and solid-liquid distribution of Po and Pb in marine anoxic sediments: roads of Cherbourg at the northwestern France

A sequential extraction protocol has been used to determine the solid-phase partition of ²¹⁰Po and ²¹⁰Pb in anoxic marine sediment from the roads of Cherbourg (France) in the central English Channel. Measurements were also obtained in pore waters, in which ²¹⁰Po activities range between 1 and 20 mBq L⁻¹ and ²¹⁰Pb activities between 2.4 and 3.8 mBq L⁻¹, with highest activities in the topmost layer. These activities are higher than in seawater, suggesting that sediment act as a source of both ²¹⁰Po and ²¹⁰Pb for overlying water. The ²¹⁰Po profile in the pore waters is apparently correlated with those obtained for Fe, Mn and SO₄²⁻, suggesting an influence of early diagenetic processes on the ²¹⁰Po solid-liquid distribution. In the sediment, ²¹⁰Po is predominantly bound to organic matter or chromium reducible sulphides, and residuals (clay minerals and refractory oxides). Our results indicate that ²¹⁰Po is not significantly bound to AVS, i.e. acid volatile sulphides: bioturbation could play a role by the early redistribution of ²¹⁰Po bound to acid volatile sulphides in the sediment. ²¹⁰Po, ²¹⁰Pb and Pb exhibit differences in terms of distribution, probably due to a different mode of penetration in the sediment. This work provides information on solid and liquid distribution of ²¹⁰Po and ²¹⁰Pb in marine sediment. These data are very scarce in the litterature.     

A quantitative integrated assessment of pollution prevention achieved by Integrated Pollution Prevention Control licensing

This paper presents an innovative, quantitative assessment of pollution avoidance attributable to environmental regulation enforced through integrated licensing, using Ireland's pharmaceutical-manufacturing sector as a case study. Emissions data reported by pharmaceutical installations were aggregated into a pollution trend using an Environmental Emissions Index (EEI) based on Lifecycle Assessment methodologies. Complete sectoral emissions data from 2001 to 2007 were extrapolated back to 1995, based on available data. Production volume data were used to derive a sectoral production index, and determine ‘no-improvement’ emission trends, whilst questionnaire responses from 20 industry representatives were used to quantify the contribution of integrated licensing to emission avoidance relative to these trends. Between 2001 and 2007, there was a 40% absolute reduction in direct pollution from 27 core installations, and 45% pollution avoidance relative to hypothetical ‘no-improvement’ pollution. It was estimated that environmental regulation avoided 20% of ‘no-improvement’ pollution, in addition to 25% avoidance under business-as-usual. For specific emissions, avoidance ranged from 14% and 30 kt a^− 1 for CO₂ to 88% and 598 t a^− 1 for SO_x. Between 1995 and 2007, there was a 59% absolute reduction in direct pollution, and 76% pollution avoidance. Pollution avoidance was dominated by reductions in emissions of VOCs, SO_x and NO_x to air, and emissions of heavy metals to water. Pollution avoidance of 35% was attributed to integrated licensing, ranging from between 8% and 2.9 t a^− 1 for phosphorus emissions to water to 49% and 3143 t a^− 1 for SO_x emissions to air. Environmental regulation enforced through integrated licensing has been the major driver of substantial pollution avoidance achieved by Ireland's pharmaceutical sector — through emission limit values associated with Best Available Techniques, emissions monitoring and reporting requirements, and performance targets specified in environmental management plans. This compliant sector offers a positive, but not necessarily typical, case study of IPPC effectiveness.     

137Cs in marine samples from the Brazilian southeastern coastal region

The present work presents the results of ¹³⁷Cs concentration in seawater, fish and sediments samples collect in 11 sampling points, crossing the Brazilian Southeastern coastal region, from Vitória (ES) to Santos (SP), on a routine basis from 1997 to 2002. This monitoring program was carried out by the Instituto de Radioproteção e Dosimetria (IRD/CNEN/MCT), in cooperation with the Instituto de Estudos do Mar Almirante Paulo Moreira (IEAPM/Brazilian Navy), aiming at determining artificial radionuclides in marine samples. Additionally to the ¹³⁷Cs results, ⁹⁰Sr concentrations in fish samples from 1998 to 2002 are also reported.The ¹³⁷Cs in seawater follows a lognormal distribution, with a geometric mean of 1.8 Bq m^-3 and a geometric standard deviation of 1.4 (n=54), decay corrected to June/2002. For ¹³⁷Cs levels in fish samples a geometric mean of 0.19 Bq kg⁻¹ and a geometric standard deviation of 2.9 (n=39), decay corrected to June/2002, with a range of 0.03 to 1.7 Bq kg⁻¹, were obtained. Based on the ¹³⁷Cs mean concentration in fish as well as in seawater, a transfer factor of 1 × 10² was calculated, which is quite in agreement with the recommended value found in the Safety Report Serie 19.     

Mineral content of drinking water in lowland papua

This study presents concentration of nine minerals (Na, K, Mg, Ca, Cl, Mn, Zn, Cd, Pb) in 31 drinking water samples collected in the Papua New Guinea lowland, where coastal villagers draw water from artificial wells blended with sea water, riverside villagers utilize brackish river water, and inland villagers fetch creek or swamp water whose chemical composition is close to rain water. During the dry season, the coastal well water contains 500 mgL⁻¹ of sodium and 50–90 μgL⁻¹ of lead. The inland creek or swamp water contains very small amount of minerals; on the average, for instance, 0.64 mgL⁻¹ of magnesium, 0.84 mgL⁻¹ of calcium, and 4.78 mgL⁻¹ of water hardness (as CaCO₃). From some epidemiological evidence in industrialized countries, these mineral concentrations are judged to be indicative of high risk of cardiovascular disorders.     

Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar – Iran

Plants are unique in their ability to serve as in situ monitors for environmental genotoxins. We have used the alkaline comet assay for detecting induced DNA damage in Allium cepa to estimate the impact of high levels of natural radiation in the soils of inhabited zones of Ramsar. The average specific activity of natural radionuclides measured in the soil samples for ²²⁶Ra was 12,766 Bq kg⁻¹ whereas in the control soils was in the range of 34–60 Bq kg⁻¹. A positive strong significant correlation of the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas with ²²⁶Ra specific activity of the soil samples was observed. The results showed high genotoxicity of radioactively contaminated soils. Also the linear increase in the DNA damage indicates that activation of repair enzymes is not triggered by exposure to radiation in HBRA.     

Effects of radionuclide and rainfall characteristics on field loss parameters of grass

The decrease of foliar activity in vegetation after its initial contamination by foliar deposition is termed “field loss” (Chamberlain, 1970). This work investigated further laboratory data concerning field loss of ¹³⁴Cs, ¹³⁷Cs, ⁸⁵Sr, ¹³³Ba and ^123mTe deposited on grassland (Madoz-Escande et al., 2005). Treatments consisted in rainfall scenarios cumulating 14 mm per week, combining two levels of intensity (8 or 30 mm/h) and two levels of frequency/precocity (late once or early twice-a-week). The time course of field loss was monitored in the edible tissues which were sampled by mowing between the rainfalls. Data were analyzed with an offset exponential loss model which is applicable to chronic contamination and is consistent with approaches adopted in radiological assessment models. Its parameters were estimated by the maximum-likelihood method, and their accuracy was determined by nonparametric boostrap. Radionuclide and rainfall conditions significantly affected the estimated rate (λ₁) and extent (A₁) of field loss. Field loss rate (λ₁) and nonentrainable fraction (1 − A₁) varied by a factor 1.5–3. Cesium was very mobile but persistent. On the contrary Tellerium was found less labile, but eventually was almost completely eliminated. Strontium and Barium had intermediate behaviors. Field loss was more efficient for moderate late once-a-week rainfalls (8 mm/h). Higher rainfall intensity reduced more the radionuclides losses than higher rainfall frequency/precocity. This paper reports statistically relevant effects that should be considered for more realistic assessments.     

Doses of external exposure in Jordan house due to gamma-emitting natural radionuclides in building materials

The use of building materials containing naturally occurring radionuclides as ⁴⁰K, ²³²Th, and ²³⁸U and their progeny results in external exposures of the residents of such buildings. In the present study, indoor dose rates for a typical Jordan concrete room are calculated using Monte Carlo method. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling are assumed.Using activity concentrations of natural radionuclides typical for the Jordan houses and assuming them to be in secular equilibrium with their progeny, the maximum annual effective doses are estimated to be 0.16, 0.12 and 0.22 mSv a⁻¹ for ⁴⁰K, ²³²Th- and ²³⁸U-series, respectively. In a total, the maximum annual effective indoor dose due to external γ-radiation is 0.50 mSv a⁻¹. Additionally, organ dose coefficients are calculated for all organs considered in ICRP Publication 74. Breast, skin and eye lenses have the maximum equivalent dose rate values due to indoor exposures caused by the natural radionuclides, while equivalent dose rates for uterus, colon (LLI) and small intestine are found to be the smallest. More specifically, organ dose rates (nSv a⁻¹ per Bq kg⁻¹) vary from 0.044 to 0.060 for ⁴⁰K, from 0.44 to 0.60 for radionuclides from ²³⁸U-series and from 0.60 to 0.81 for radionuclides from ²³²Th-series.The obtained organ and effective dose conversion coefficients can be conveniently used in practical dose assessment tasks for the rooms of similar geometry and varying activity concentrations and local-specific occupancy factors.