Heterotrophic Nano- and Microplankton under Conditions of Anthropogenic Eutrophication of the Bay of Novorossiisk

Seasonal and long-term dynamics of heterotrophic plankton in the Bay of Novorossiisk are discussed. It is shown that specific variation in the biomass of nanoheterotrophs and infusoria is associated with the processes of anthropogenic water eutrophication. The biomass of infusoria has increased ten times and that of zooflagellates two times since 1985–1986. Infusoria of the genera Strombidium, Strobilidium, and Mesodiniumare dominant in the protozoan plankton. The annual average level of Oligotrichadevelopment in the bay is characteristic of eutrophic water bodies (112–417 mg/m³); in the spring–summer season, however, it may increase to 500–1034 mg/m³. In the part of the bay near the port, which is exposed to a strong anthropogenic impact, the biomass of ciliate protozoa can reach 2 g/m³.     

Greenhouse gases emissions from a closed old landfill cultivated with biomass crops

Closed landfills need after-closure rehabilitation. The chosen option should ensure greenhouse gases release, from the landfill, is not promoted once settled. The objective of this study was to estimate and confront, during different seasons, CH₄, CO₂ and N₂O emissions under three vegetation covers in a closed landfill in Buenos Aires, Argentina. CH₄ (methane), CO₂ (carbon dioxide) and N₂O (nitrous oxide) emissions from landfill’s technosol under spontaneous vegetation (control), Pennisetum purpureum and Miscanthus giganteus (biomass crops), were quantified with non-steady-state non-flow-through chambers, in July 2014 and from February to July 2015. A linear regression analysis was performed to relate the variables “flux of a gas” and “concentration of that gas” from the 3 treatments and 6 dates, separating the 5 sampling times. A high correlation between concentrations and fluxes of CO₂ and N₂O was found, but no correlation was established for CH₄. Mean emissions (2014–2015) varied from: ?2.3 to 639.41 mgCH₄ m^?2 day^?1, 3884 to 46,365 mgCO₂ m^?2 day^?1 and 0.40 to 14.59 mgN₂O m^?2 day^?1. Vegetation covers had no significant effect on CH₄ and N₂O concentration in time, but they had on CO₂ concentration. Season of the year had a significant effect on concentration of the three gases. This is the first study on CH₄, CO₂ and N₂O emissions from a landfill closed 27 years ago covered with biomass crops.     

Effect of sample conditioning and chamber loading on rate of formaldehyde release from wood products in a desiccator test

Several variables may influence the observed rate of formaldehyde (CH₂O) offgassing from wood products in a small static test chamber. We studied the effect of sample conditioning at ≈100% relative humidity and chamber loading (sample size) on CH₂O release rate from particle board (PB) and plywood (PW). Samples of PB and PW were placed in glass desiccators with reservoirs of water at a loading of 21 m²/m³ (sample surface area per chamber volume). The rate of CH₂O offgassing from the PB did not change over several weeks under these conditions (0.24 μg/cm²/day), but the overall release rate from the PW decreased after 8 days. In another experiment, the loading of the desiccator had a major effect on the rate of CH₂O offgassing from PB over a loading range of 1 to 42 m²/m³. The same phenomenon was observed with different loadings of PW. The inverse of the observed release rate varied linearly with the chamber loading of PB or PW. At a loading which may be encountered in a house (0.25 m²/m³), the release rate coefficient for PB calculated from the above inverse relation was 22-fold higher than that measured at a more conventional test load of 21 m²/m³. These results indicate that great care should be exercised when using desiccator tests for assessing and comparing the potential strength of materials as sources of CH₂O in the indoor environment.     

Characteristics of PM10, PM2.5, CO2 and CO monitored in interiors and platforms of subway train in Seoul, Korea

This study was performed to investigate the concentration of PM₁₀ and PM_2.5 inside trains and platforms on subway lines 1, 2, 4 and 5 in Seoul, KOREA. PM₁₀, PM_2.5, carbon dioxide (CO₂) and carbon monoxide (CO) were monitored using real-time monitoring instruments in the afternoons (between 13:00 and 16:00). The concentrations of PM₁₀ and PM_2.5 inside trains were significantly higher than those measured on platforms and in ambient air reported by the Korea Ministry of Environment (Korea MOE). This study found that PM₁₀ levels inside subway lines 1, 2 and 4 exceeded the Korea indoor air quality (Korea IAQ) standard of 150 μg/m³. The average percentage that exceeded the PM₁₀ standard was 83.3% on line 1, 37.9% on line 2 and 63.1% on line 4, respectively. PM_2.5 concentration ranged from 77.7 μg/m³ to 158.2 μg/m³, which were found to be much higher than the ambient air PM_2.5 standard promulgated by United States Environmental Protection Agency (US-EPA) (24 h arithmetic mean: 65 μg/m³). The reason for interior PM₁₀ and PM_2.5 being higher than those on platforms is due to subway trains in Korea not having mechanical ventilation systems to supply fresh air inside the train. This assumption was supported by the CO₂ concentration results monitored in tube of subway that ranged from 1153 ppm to 3377 ppm. The percentage of PM_2.5 in PM₁₀ was 86.2% on platforms, 81.7% inside trains, 80.2% underground and 90.2% at ground track. These results indicated that fine particles (PM_2.5) accounted for most of PM₁₀ and polluted subway air. GLM statistical analysis indicated that two factors related to monitoring locations (underground and ground or inside trains and on platforms) significantly influence PM₁₀ (p < 0.001, R² = 0.230) and PM_2.5 concentrations (p < 0.001, R² = 0.172). Correlation analysis indicated that PM₁₀, PM_2.5, CO₂ and CO were significantly correlated at p < 0.01 although correlation coefficients were different. The highest coefficient was 0.884 for the relationship between PM₁₀ and PM_2.5.     

Introduction to and experimental conditions during the first year of the GMR chronic inhalation studies of diesel exhaust

A chronic exposure study was initiated to determine the effects of diesel exhaust on the health of experimental animals. For this purpose, test atmospheres of clean air (control) or freshly diluted diesel exhaust at concentrations of 250, 750, and 1500 μg/m³ were supplied to four 12.6 m³ inhalation chambers which housed rats and guinea pigs. Diesel aerosol size and concentration, as well as chamber temperature and relative humidity, were continually monitored and controlled to maintain the exposure dose levels and an environment of 22±2°C and 50%±20% relative humidity. The concentrations of CO and NO_x were found to be 5.8±1.0 mg/m³ and 7.9±1.0 mg/m³ above ambient in the chamber containing 1500 μg/m³ of particulate. Animals were supplied from the chambers, on a random basis, for both intramural and extramural studies throughout the exposure period. The experiment ran uninterrupted for over twelve months with mean diesel particle mass concentrations within 2% of the target values.     

Plutonium isotopes in surface air of Prague in 1986–2006

Monitoring of ^239,240Pu in surface air of Prague started in 1986 in connection with the Chernobyl accident. Measurable activities of 10–28 μBq m⁻³ were found from 29 April 1986 to 5 May 1986. In the most of the monitoring periods of 1987–1996, activities of ^239,240Pu in air were not measurable. Positive values for ^239,240Pu and ²³⁸Pu in air could be obtained after installation of an aerosol sampler with higher flow-rate in 1997. Activity concentrations of ^239,240Pu and ²³⁸Pu in Prague air in the most of quarters of 1997–2006 were in the range 0.53–5.06 and <0.16–1.10 nBq m⁻³, respectively. Seasonal fluctuations can be found in content of ^239,240Pu in air. Activity ratios of ²³⁸Pu/^239,240Pu in air are higher than those in top soil, so it can be supposed that ²³⁸Pu is coming to air of Prague also from other sources than resuspension of fallout from atmospheric nuclear tests.     

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.     

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.     

The Potential of Soil Carbon Sequestration Through Improved Management Practices in Norway

The study was conducted to assess the potential of Norwegian agricultural ecosystems to sequester carbon (C) based on the data from some long-term agronomic and land use experiments. The total emission of CO₂ in Norway in 1998 was 41.4 million metric ton (MMT), of which agriculture contributed only 0.157 MMT, or <0.4% of the total emissions. With regards to methane (CH₄) and nitrous oxide (N₂O) gases, however, agricultural activities contributed 32.5% and 51.3% of their respective emissions in Norway. The soil organic carbon (SOC) losses associated with accelerated soil erosion in Norway are estimated at 0.475 MMTC yr^–1. Land use changes and soil/crop management practices with potential for SOC sequestration include conservation tillage methods, judicious use of fertilizers and manures, use of crop residues, diverse crop rotations, and erosion control measures. The potential for SOC sequestration is 0.146 MMTC yr^–1 for adopting conservation tillage, 0.011–0.035 MMTC yr^–1 for crop residue management, 0.026 MMTC yr^–1 for judicious use of mineral fertilizer, 0.016–0.135 MMTC yr^–1 for manure application, and 0.036 MMTC yr^–1 for adopting crop rotations. The overall potential of these practices for SOC sequestration ranges from 0.591 to 1.022 MMTC yr^–1 with an average value of 0.806 MMTC yr^–1. Of the total potential, 59% is due to adoption of erosion control measures, 5.8% to restoration of peat lands, 21% to conversion to conservation tillage and residue management, and 14% to adoption of improved cropping systems. Enhancing SOC sequestration and improving soil quality, through adoption of judicious land use and improved system of soil and crop management, are prudent strategies for sustainable management of soil, water and environment resources.Readers should send their comments on this paper to: bhaskarn ath@aol.com within 3 months of publication of this issue.     

Air infiltration measurements in a home using a convenient perfluorocarbon tracer technique

Using miniature perfluorocarbon tracer (PFT) sources and miniature passive samplers, both about the size of a cigarette, tests conducted in the laboratory and in a typical home successfully demonstrated the utility of the PFT kit as a means for implementing wide-scale infiltration measurements in homes. The PFT diffusion plug source, an elastomer containing a dissolved perfluorocarbon compound, was shown to emit vapors at the rate of about 0.1 to 5 nL/min, providing steady-state concentrations in a home of about 1 to 10 pL/L, i.e., parts per trillion by volume, when one source is deployed for each 300–500 ft² (28–46 m²) of living space. The emission rate from the diffusion source was predictable, but its dependence on both temperature and time suggested the development of alternative approaches. One such alternative, a liquid PFT permeation source, had emission rates which could be tailored over the range 10–20 nL/min, were independent of age for as long as the liquid remained ( 5 yr), and had significantly lower temperature dependence. A number of passive adsorption tube samplers performed reproducibly and identically (to within ±2%–3%) in laboratory tests. Together with a programmable tracer sampler, the miniature diffusion sources and samplers were deployed in a typical home; six PFT sources were uniformly deployed, three on each level of a two-story house. Multiple location sampling, as well as sampling in rooms with and without a miniature source, demonstrated that even in a house without forced-air circulation, a well-mixed modeling approach is justified. Analyses of the tracer samplers were performed back in the laboratory with an automatic electron-capture gas-chromatography system. The effects of the inside/outside temperature differential, as well as that of an open fireplace compared with a wood-burning stove, on the measured air infiltration rates were clearly demonstrated. Comparisons of the PFT tracer method with that of the SF₆ tracer decay approach showed the results of the two methods to be identical within experimental precision. With this miniature source and sampling tracer kit, infiltration rates in the range 0.2–5 air changes per hour can be measured over time-averaged periods of as little as 1 day up to several years.     

Investigation of equilibria involving carbon dioxide, carbonates and water

Several laboratory techniques are reviewed in this paper, which yield reliable data on carbonate equilibria. In particular, it is emphasized that pco₂ variation is necessary in order to potentiometrically distinguish between hydrogen carbonato and caronato complexes. The essential features of reliable solubility measurements of carbonate phases are summarized. A neglected autoclave technque is described which has been successfully applied for the synthesis of pure, crystalline, MnCO₃, FeCO₃ and CoCO₃. Details of a continuously operating solubility cell for experiments at 5–95°C are also given.Solubilty constants for different ionic media are related by the respective equilibrium vapor pressure of H₂O and the standard potentials of the respective metal electrodes. It is shown that a thermodynamic cycle can be exploited for an indirect determination of the Fe²⁺/Fe standard potential. The application of solubility data is discussed using the pco₂ control in the recent geologic past an an example.     

The influence of ventilation on indoor/outdoor air contaminants in an office building

The air quality in a newly built preschool was investigated in a longitudinal study. Typical air contaminants emanating from building materials were determined, their variation over time (0–18 months) was measured, and the influence of the ventilation system (81%–91% recirculation of return air) on contaminant concentrations was studied. Volatile organic compounds were sampled by adsorption on porous polymer, analysed by a GC/FID system, and identified by MS. A spatial build-up in concentration (ppb or μg/m³ levels) is evident for all the organic compounds, as well as for CO₂, from the outdoor air, through the ventilation system, and through the rooms to the exhaust air. The longitudinal comparison over time shows that all the organic compounds decline in concentration mainly within the first 6 months of occupancy: 1-butanol 4–14 times, toluene and pentanal + hexanal 2–4 times, while formaldehyde remained at a constant low level of 90 ppb (110 μg/m³). It is difficult to believe that the problems of poor air quality in 100 preschools in Stockholm are caused by the organic compounds alone unless interactions occur. A preschool building needs to be gassed off during the first 6 months after its construction with no recirculation of return air allowed (outdoor air rate approx 4–5 ach). During at least 1–2 additional years, it is desired that the recirculation rate of return air is restricted, perhaps to 50%.     

Development of a personal exposure monitor for two sizes of inhalable particulates

Measurement of personal exposure to ambient level particulate concentrations is often extremely difficult because of a lack of personal exposure monitors capable of collecting measurable quantities within a meaningful sampling period. A new personal exposure monitor for two fractions of inhalable particulates (i.e., the 3–15 μm aerodynamic diameter and the < 3 μm or respirable fraction) has been developed and characterized. This monitor is capable of collecting a sample of each fraction that is quantifiable with ambient concentrations of inhalable/respirable particulates as low as 25 μg/m³ in a 24-h sampling period. Wind tunnel tests have been made on the particulate personal exposure monitor to determine sampling efficiency as a function of relative wind speed and orientation with respect to the sampler.     

Two-year follow-up study of nonregulatory recommendations for better air quality in indoor ice arenas

A standardized questionnaire was used in a two-year follow-up study to test the effectiveness of non-regulatory recommendations to improve indoor air quality of 103 ice arenas in Finland. In addition, the performance of a state-of-the-art emission control technology (ECT) on propane-fueled resurfacers was evaluated by measuring the one-week average nitrogen dioxide (NO₂) concentration in a small sample of arenas. The number of retrofitted ECT on propane-fueled resurfacers increased from 6 to 37 (8% to 37% of ice arenas) and the number of electric resurfacers from 7 to 9 (both 9% of arenas) in 1994–1996. At the same time, the prevalence of inadequate ventilation increased among the most susceptible small arenas (volume <30 000 m³) from 11 (31%) to 19 (38%). Combustion-powered resurfacers (88%) and inadequate ventilation (24%) were prevalent also among the 17 new arenas built in 1994–1996. ECT resurfacers significantly decreased the mean indoor NO₂ concentration of eleven arenas from 650 μg/m³ to 147 μg/m³. Thus, retrofitting resurfacers with ECT seems to be a feasible mitigation option to improve indoor air quality in ice arenas, but the ultimate solution is an electric ice resurfacer. Non-regulatory recommendations seem to be partially effective in abatement against the air quality problems, but additional regulatory measures are needed for full compliance in all arenas.     

Population exposure to airborne thorium at the high natural radiation areas in India

High natural radiation areas in the coastal and peninsular India were studied for airborne thorium and resultant population exposure due to inhalation. Four locations covering three states viz., Ayiramthengu and Neendakara in Kerala, Kudiraimozhi in Tamil Nadu and Bhimilipatnam in Andhra Pradesh were investigated. External gamma radiation fields 1 m above the monazite ore bodies ranged from 200 to 3000 nGy h^-1. Soil samples showed ²³²Th specific activity varying from 0·1 to 1·5 Bq g^-1 with surface alpha activity in the range of 1·0–12·5 Bq cm^-2. Suspended particulates in the samples ranged from 60–140 μg m^-3 with ²³²Th showing a wider variation of <0·03–0·3 mBq m^-3. There was poor correlation between suspended particulates and long-lived alpha airborne activity . The resuspension factors for ²³²Th were in the range of 1·5×10^-8–7·9×10^-7 cm^-1. Higher resuspension was correlated with dry sand dunes. The upper limits for Committed Effective Dose (CED) due to inhalation of airborne ²³²Th at the respective high natural radiation areas were estimated to range from 50±30 to 300±130 μSv (5–30 mrem) per year per adult member of public assuming an activity median aerodynamic diameter of 1 μm for the airborne particulates.     

Application of Remote Sensing and GIS in the Management of Mangrove Forests Within and Adjacent to Kiunga Marine Protected Area, Lamu, Kenya

The status of mangroves within and adjacent to Kiunga Marine Protected Area (MPA) were assessed by means of aerial photographs and intensive ground truthing. Vegetation maps (1 : 25,000) were produced on GIS environment making it possible to store, retrieve and analyze various types of information very quickly. The maps together with the digitized information provide important tools to the management of mangroves of Kiunga MPA since various proposed treatments can now be entered and summarized thus providing useful overviews for planning, implementation and monitoring.The present inventory revealed that the existing mangrove forests within and adjacent to Kiunga MPA have a net standing volume of 2,354,004.85 m³ in 16,035.94 ha. There are eight species of mangrove trees, of which Rhizophora mucronata and Ceriops tagal are dominant. The standing volume ranges between 6.85 to 710.0 m³ ha^–1 for stem with diameter above 5.0 cm. The average volume of the entire study area was 145.88 m³ ha^–1, which corresponds to a stocking rate of 1736 stems per ha. Given its high potential productivity and regeneration, mangroves within and adjacent to Kiunga MPA have excellent prospects for sustainable exploitation.     

Collection characteristics of a double stage scrubber to eliminate the paint mist from a spray booth

A 4.5 m³/min laboratory paint spray booth was built adopting a double-stage scrubber with heavy oil as the scrubbing liquid. The relationship between the collection efficiency E and the pressure drop ΔP was studied using a cylindrical paper tilter and a Digital Dust Counter. Experimental results indicated that the collection efficiency in this system is in accordance with the collection efficiency equation based on the theory of inertial impaction. With water used as the scrubbing liquid, the factor K is about 0.5 for single-stage scrubbing, while it is 0.6 for double-stage scrubbing. At a pressure drop of 60 mm of H₂O, heavy oil used as the scrubbing liquid gained about 2.0% more in collection efficiency than water. The zigzag baffler equipped for removing heavy oil mist was also effective for the paint mist collector, and 99.1% of E was gained at a pressure drop of 135 mm H₂O.     

Concentrations and determinants of outdoor, indoor and personal nitrogen dioxide in pregnant women from two Spanish birth cohorts

Determinants of outdoor, indoor and personal concentrations of nitrogen dioxide (NO₂) were assessed in a subset of pregnant women of the Spanish INMA (Environment and Childhood) Study. Home indoor and outdoor NO₂ concentrations were measured during 48 h with passive samplers for 50 and 58 women from the INMA cohorts of Valencia and Sabadell, respectively. Women from Sabadell also carried personal NO₂ samplers during the same period. Data on time–activity patterns, socio-economic characteristics, and environmental exposures were obtained through questionnaires. Multiple linear regression models were developed to predict NO₂ levels.In Valencia, median outdoor NO₂ levels (42 µg/m³) were higher than median indoor levels (36 µg/m³). In Sabadell, personal NO₂ showed the highest median levels (40 µg/m³), followed by indoor (32 µg/m³) and outdoor (29 µg/m³) levels. Personal exposure to NO₂ correlated best with the indoor NO₂ levels. Temporal and traffic-related variables were significant predictors for outdoor NO₂ levels. Thirty-two percent of the indoor NO₂ variability in the two cohorts was explained by outdoor NO₂ levels and the use of the gas appliances. The model for personal exposure accounted for 59% of the variance in NO₂ levels in Sabadell with four predictor variables (outdoor and indoor NO₂ levels, time spent in outdoor environments and time exposed to a gas cooker). No significant association was found between personal or indoor NO₂ levels and exposure to environmental tobacco smoke (ETS) at home.Personal NO₂ levels were found to be strongly influenced by indoor NO₂ concentrations. The study supports the use of time–activity patterns along with indoor measurements to predict personal exposure to traffic-related air pollution.     

A study of diesel emissions on Drosophila

A sex-linked recessive lethal test was performed on male fruit flies of the species Drosophila melanogaster, (Oregon-R strain), exposed to an approximate five-fold dilution of exhaust from a diesel engine. The eight hour exposure was achieved by drawing diluted diesel exhaust from a three cubic meter stainless steel exposure chamber housing laboratory animals through a two liter reaction flask modified for use with Drosophila. A preconditioned sampling bag was used to collect the emissions after passing through the exposure chamber containing the flies. Results of analyses performed on the diesel exhaust mixture showed the following: carbon dioxide—0.17%, carbon monoxide—12.2 ppm, hydrocarbons—11.6 ppm, nitrogen oxide—3.8 ppm, nitrogen dioxide—2.9 ppm, sulphur dioxide—1.0 ppm, and particulates—2.18 mg/m³. Two broods of the F₂ generation were investigated for the occurrence of recessive lethal events. These broods approximated the developing gametogenic stages of mature sperm (P₁ matings on days 2 and 3 postexposure) and spermatocytes (P₁ matings on days 8 and 9). Additionally, the F₃ generation was evaluated for the occurrence of mosaic recessive lethal events which might escape detection in the F₂ generation. An equal number of F₂ and F₃ flies for both broods served as concurrent controls. Results indicate that, under the conditions tested, the diesel exhaust did not increase the mutation frequency of the exposed flies (F₂ rate = 0.30%, F₃ rate = 0%) when compared to the concurrent controls (F₂ rate = 0.37%, F₃ rate = 0.15%).     

Effect of cigarette smoking on residential NO2 levels

Two studies evaluating the levels and sources of nitrogen dioxide in approximately 90 employee homes in the Richmond area with continuous sampling during the weeks of August 5, 1980, and February 9, 1981, were performed using samplers in the living room, bedroom, kitchen, and outdoors. Additional data were collected concerning appliance usage, heating/cooling plant, ventilation and cigarette smoking. Results were analyzed using BMDP routines. The largest contributor to NO₂ concentration was found to be gas-fired kitchen appliances. The mean kitchen level for homes with gas appliances during the winter study was 188 μg/m³. Excluding participants with gas kitchens, incremental influence due to cigarette smoking was detected. The 7-day, 3-room average level of NO₂ in the homes of nonsmokers and smokers without gas-fired appliances was 12 and 15 μg/m³, respectively, in the summer. The corresponding winter values were 19 and 22 μg/m³. Furthermore, the individual levels of NO₂ in the homes of smokers were generally below both the adjacent outdoor level and the National Ambient Air Quality Standard limit for annual exposure.