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PubMed2006

Microbial activity in weathering columns.

The aim of the present work was to evaluate the metabolic activity of the microbial population associated with a pyritic tailing after a column-weathering test. For this purpose, a column 150cm high and 15cm diameter was used. The solid was a tailing with 63.4% pyrite and with minor amounts of Cu, Pb and Zn sulfides (1.4, 0.5 and 0.8%, respectively). The column model was the habitual one for weathering tests: distilled water was added at the top of the column; the water flowed down through tailings and finally was collected at the bottom for chemical and microbiological analysis. Weathering was maintained for 36 weeks. The results showed a significant presence of microbial life that was distributed selectively over the column: sulfur- and iron-oxidizing aerobic bacteria were in the more oxygenated zone; anaerobic sulfur-reducing bacteria were isolated from the samples taken from the anoxic part of the column. Activity testing showed that (oxidizing and reducing) bacteria populations were active at the end of the weathering test. The quality of the water draining from the column was thus the final product of biological oxidation and reduction promoted by the bacteria consortia.

Bacteria, Aerobic↗
PubMed2005

Image analysis for quantification of bacterial rock weathering.

A fast, quantitative image analysis technique was developed to assess potential rock weathering by bacteria. The technique is based on reduction in the surface area of rock particles and counting the relative increase in the number of small particles in ground rock slurries. This was done by recording changes in ground rock samples with an electronic image analyzing process. The slurries were previously amended with three carbon sources, ground to a uniform particle size and incubated with rock weathering bacteria for 28 days. The technique was developed and tested, using two rock-weathering bacteria Pseudomonas putida R-20 and Azospirillum brasilense Cd on marble, granite, apatite, quartz, limestone, and volcanic rock as substrates. The image analyzer processed large number of particles (10(7)-10(8) per sample), so that the weathering capacity of bacteria can be detected.

Agriculture↗
PubMed1998

Comparison of oil composition changes due to biodegradation and physical weathering in different oils.

The well-characterized Alberta Sweet Mixed Blend oil and several other oils which are commonly transported in Canada were physically weathered and then incubated with a defined microbial inoculum. The purpose was to produce quantitative data on oil components and component groups which are more susceptible or resistant to biodegradation, and to determine how oils rank in relation to each other in terms of biodegradation potential. The biodegraded oils were characterized by quantitative determination of changes in important hydrocarbon groups including the total petroleum hydrocarbons, total saturates and aromatics, and also by quantitation of more than 100 individual target aliphatic, aromatic and biomarker components. The study reveals a pattern of distinct oil composition changes due to biodegradation, which is significantly different from the pattern due to physical or short-term weathering. It is important to be able to distinguish between these two forms of loss, so that loss due to weathering is not interpreted as loss due to biodegradation in the laboratory or in the field. Based on these findings, the oil composition changes due to biodegradation can be readily differentiated from those due to physical weathering. To rank the tested oils with respect to biodegradability, losses in total petroleum hydrocarbons and aromatics were used to calculate biodegradation potential indices, employing equations proposed by Environment Canada and the US National Oceanic and Atmospheric Administration. The different methods produced very similar biodegradation trends, confirming that patterns of oil biodegradability do exist.

Bacteria↗
PubMed2000

Short-term natural weathering of MSWI bottom ash.

The release of heavy metals from MSWI bottom ash has been the key concern in the management of this material. The leaching distribution values obtained from 100 freshly quenched bottom ash samples, according to the German DIN 38414-S4 procedure test, showed the release of lead, zinc and copper to be the main hazards associated with bottom ash utilisation as a secondary building material. Currently, natural weathering of MSWI bottom ash, for an estimated period of 1-3 months, is the most economic treatment available to ensure the eventual utilisation of this material. The leaching of natural weathered bottom ash in the short-term (up to 9 months) was studied. The most significant changes in the bottom ash were found to occur in the first 90 days. At pH values greater than 12, lead, zinc and copper were the main heavy metals to be released from the MSWI freshly quenched bottom ash samples studied. Natural weathering for a period of about 90 days reduced the leaching of heavy metals, stabilising the bottom ash pH to minimise the solubility of metal hydroxides, and enabled the residue to be used as secondary building material. The profile of the pH neutralisation curve is similar to that described by carbonates, which would suggest that the reaction is controlled by CO(2). The formation of insoluble oxides as well as carbonates control the immobilisation of certain heavy metals, e.g. lead and zinc. The leaching of aluminium increases during this short natural weathering stage due to elemental metal oxidation. Aluminium solubility is controlled by the precipitation of gibbsite or other aluminium-sulphate neoformations. The latter may contribute to the immobilisation of heavy metals.

Air Pollutants↗
PubMed2003

Short-term natural weathering of MSWI bottom ash as a function of particle size.

The chemical and material composition of MSWI bottom ash depends on the particle size; this suggests that the mechanisms and kinetics of natural weathering are also a function of particle size. This paper reports the effects of short-term natural weathering on the leaching of heavy metals (mainly Pb, Cu and Zn) from MSWI bottom ash. Initial concentrations of heavy metals were higher for the smallest particle size fractions, but these levels fell dramatically during the first 50 days of weathering before levelling off. The main differences between size fractions were in the pH and the solubility of calcium and aluminium. For the initial stages of weathering and small size fractions, portlandite solubility seemed to control the pH. In contrast, for fractions bigger than 6 mm, the formation of ettringite was the reaction controlling the pH and the solubility of sulphates, aluminium and calcium.

Carbon↗
PubMed2003

Subspecies-level variation in the phytoextraction of weathered p,p'-DDE by Cucurbita pepo.

Previous studies indicate that Cucurbita pepo can phytoextract highly weathered persistent organic pollutants (POPs) from soil and translocate large quantities to aerial tissues. To investigate intraspecific variability in uptake potential, a field study was conducted to quantify the phytoextraction of weathered p,p'-DDE by 21 cultivar varieties of summer squash from two distinct subspecies, C. pepo ssp texana and C. pepo ssp pepo. Significant differences exist between the two subspecies, with average root and stem to soil bioconcentration factors (BCF, dry weight ratio of contaminant concentration in the vegetation to that in the soil) of 7.22 and 5.40 for ssp pepo and of 2.37 and 0.454 for spp texana, respectively. The amounts of weathered p,p-DDE extracted from the soil by ssp pepo and ssp texana were 0.301 and 0.065%, respectively, with maximum values within each subspecies of 0.780 and 0.182%, respectively. The quantities of 14 inorganic elements were determined in both the soil and tissues (roots, stems, leaves, and fruit) of all 21 cultivar varieties. Phosphorus concentrations in the tissues of ssp pepo were 14 (fruit)-73% (stems) greater than those of ssp texana. These data support our hypothesis that the unique ability of certain cultivars of C. pepo to phytoextract highly weathered POPs from soil is the result of low molecular weight organic acid exudation as a unique phosphorus acquisition mechanism.

Biodegradation, Environmental↗
PubMed2002

Mycorrhizal weathering of apatite as an important calcium source in base-poor forest ecosystems.

The depletion of calcium in forest ecosystems of the northeastern USA is thought to be a consequence of acidic deposition and to be at present restricting the recovery of forest and aquatic systems now that acidic deposition itself is declining. This depletion of calcium has been inferred from studies showing that sources of calcium in forest ecosystems namely, atmospheric deposition and mineral weathering of silicate rocks such as plagioclase, a calcium-sodium silicate do not match calcium outputs observed in forest streams. It is therefore thought that calcium is being lost from exchangeable and organically bound calcium in forest soils. Here we investigate the sources of calcium in the Hubbard Brook experimental forest, through analysis of calcium and strontium abundances and strontium isotope ratios within various soil, vegetation and hydrological pools. We show that the dissolution of apatite (calcium phosphate) represents a source of calcium that is comparable in size to known inputs from atmospheric sources and silicate weathering. Moreover, apatite-derived calcium was utilized largely by ectomycorrhizal tree species, suggesting that mycorrhizae may weather apatite and absorb the released ions directly, without the ions entering the exchangeable soil pool. Therefore, it seems that apatite weathering can compensate for some of the calcium lost from base-poor ecosystems, and should be considered when estimating soil acidification impacts and calcium cycling.

Apatites↗
PubMed2006

Developing space weathering on the asteroid 25143 Itokawa.

Puzzlingly, the parent bodies of ordinary chondrites (the most abundant type of meteorites) do not seem to be abundant among asteroids. One possible explanation is that surfaces of the parent bodies become optically altered, to become the S-type asteroids which are abundant in the main asteroid belt. The process is called 'space weathering'-it makes the visible and near-infrared reflectance spectrum of a body darker and redder. A recent survey of small, near-Earth asteroids suggests that the surfaces of small S asteroids may have developing stages of space weathering. Here we report that a dark region on a small (550-metre) asteroid-25143 Itokawa-is significantly more space-weathered than a nearby bright region. Spectra of both regions are consistent with those of LL5-6 chondrites after continuum removal. A simple calculation suggests that the dark area has a shorter mean optical path length and about 0.04 per cent by volume more nanophase metallic iron particles than the bright area. This clearly shows that space-weathered materials accumulate on small asteroids, which are likely to be the parent bodies of LL chondrites. We conclude that, because LL meteorites are the least abundant of ordinary (H, L, and LL) chondrites, there must be many asteroids with ordinary-chondrite compositions in near-Earth orbits.

Journal Article↗
PubMed2005

Weathering trials of Amulet cue-lure and Amulet methyl eugenol "attract-and-kill" stations with male melon flies and oriental fruit flies (Diptera: Tephritidae) in Hawaii.

Amulet C-L (cue-lure) and Amulet ME (methyl eugenol) molded paper fiber "attract-and-kill" dispensers containing fipronil were tested under Hawaiian weather conditions against Bactrocera cucurbitae (Coquillett) (melon fly) and Bactrocera dorsalis (Hendel) (oriental fruit fly), respectively. In paired tests (fresh versus weathered), C-L dispensers were effective for at least 77 d, whereas ME dispensers were effective for at least 21 d. Thus, C-L dispensers exceeded, whereas ME dispensers did not meet the label interval replacement recommendation of 60 d. Addition of 4 ml of ME to 56-d-old ME dispensers restored attraction and kill for an additional 21 d. This result suggested the fipronil added at manufacture was still effective. By enclosing and weathering ME dispensers inside small plastic bucket traps, longevity of ME dispensers was extended up to 56 d. Fipronil ME and C-L dispensers also were compared, inside bucket traps, to other toxicants: spinosad, naled, DDVP, malathion, and permethrin. Against B. dorsalis, fipronil ME dispensers compared favorably only up to 3 wk. Against B. cucurbitae, fipronil C-L dispensers compared favorably for at least 15 wk. Our results suggest that fipronil C-L dispensers can potentially be used in Hawaii; however, fipronil ME dispensers need to be modified or protected from the effects of weathering to extend longevity and meet label specifications. Nonetheless, Amulet C-L and ME dispensers are novel prepackaged formulations containing C-L or ME and fipronil that are more convenient and safer to handle than current liquid insecticide formulations used for areawide suppression of B. dorsalis and B. cucurbitae in Hawaii.

Animals↗
PubMedDate not supplied

Leachate chemistry of field-weathered spent mushroom substrate.

Passive leaching by rainfall and snowmelt is a popular method to treat piles of spent mushroom substrate (SMS) before its reuse. During this field weathering process, leachate percolates into the underlying soils. A field study was conducted to examine the chemistry of SMS leachate and effects of infiltration. Two SMS piles were deposited (90 and 150 cm in height) over a Typic Hapludult and weathered for 24 mo. Leachate was collected biweekly using passive capillary samplers. The SMS leachate contained high concentrations of dissolved organic carbon (DOC; 0.8-11.0 g L(-1)), dissolved organic nitrogen (DON; 0.1-2 g L(-1)), and inorganic salts. The pH, electrical conductivity, and acid neutralizing capacity were 6.6 to 9.0, 21 to 66 ds m(-1), and 10 to 75 mmolc L(-1), respectively. Inorganic chemistry of the leachate was dominated by K+, Cl-, and SO24-. Leachate DOC was predominantly low molecular weight (<1000 Da) organic acids. During 2 yr of weathering, the 90-cm SMS pile released (per cubic meter of SMS) 3.0 kg of DOC, 1.6 kg of dissolved N, and 26.6 kg of inorganic salts. The 150-cm pile released (per cubic meter of SMS) 2.8 kg of DOC, 0.7 kg of dissolved N, and 13.6 kg of inorganic salts. The 150 cm pile retained more water and exhibited lower net nitrification compared with the 90-cm pile. The top 90 cm of soil retained 20 to 89% of the leachate solutes. Weathering of SMS in piles of 90 cm depth or greater may adversely affect ground water quality.

Agaricales↗
PubMed2005

Accelerated weathering of biosolid-amended copper mine tailings.

Application of municipal biosolids to mine tailings can enhance revegetation success, but may cause adverse environmental impacts, such as increased leaching of NO3- and metals to ground water. Kinetic weathering cells were used to simulate geochemical weathering to determine the effects of biosolid amendment on (i) pH of leachate and tailings, (ii) leaching of NO3- and SO4(2-), (iii) leaching and bioavailability (DTPA-extractable) of selected metals, and (iv) changes in tailing mineralogy. Four Cu mine tailings from southern Arizona differing in initial pH (3.3-7.3) and degree of weathering were packed into triplicate weathering cells and were unamended and amended with two rates (equivalent to 134 and 200 Mg dry matter ha(-1)) of biosolids. Biosolid application to acid (pH 3.3) tailings resulted in pH values as high as 6.3 and leachate pH as high as 5.7, and biosolids applied to circumneutral tailings resulted in no change in tailing or leachate pH. Concentrations of NO3--N of up to 23 mg L(-1) occurred in leachates from circumneutral tailings. The low pH of the acidic tailing apparently inhibited nitrification, resulting in leachate NO3--N of <5 mg L(-1). Less SO4(2-)-S was leached in biosolid-amended versus unamended acid tailings (final rate of 0.04 compared with 0.11 g SO4(2-)-S wk(-1)). Copper concentrations in leachates from acidic tailings were reduced from 53 to 27 mg L(-1) with biosolid amendment. Copper and As concentrations increased slightly in leachates from biosolid-amended circumneutral tailings. Small increases in DTPA-extractable Cu, Ni, and Zn occurred in all tailings with increased biosolid rate. Overall, there was little evidence of potential for adverse environmental impacts resulting from biosolid application to these Cu mine tailings.

Biological Availability↗
PubMed2005

Rhizospheric mobilization and plant uptake of radiocesium from weathered micas: II. Influence of mineral alterability.

Acute K depletion in the rhizosphere can lead to increased root uptake of radiocesium. Two processes can govern this increase: the very low uptake of potassium and the weathering of Cs-fixing clay minerals. Their respective importance is, however, unknown. We investigated the effects of these processes on radiocesium mobilization by roots of willow (Salix viminalis L.) from three micas: muscovite, biotite, and phlogopite. Willows were grown in a mixed quartz-mica substrate with the three respective (134)Cs-contaminated micas as sole sources of potassium and radiocesium. After 7 wk of plant growth, the micas were partially weathered. The degree of mica weathering and the prevalent potassium concentration in the solution increased in the order muscovite (5-11 microM K) < biotite (25-32 microM K) < phlogopite (25-35 microM K). The mobilization and root uptake of radiocesium were negligible with muscovite but increased in the same order. These results show that mica weathering directly and chiefly governs the mobility of radiocesium in K-depleted rhizosphere soil. The low mobility of trace Cs in the muscovite rhizosphere is linked with the dioctahedral character of this mica, and hence to its very low alterability.

Cesium Radioisotopes↗
PubMedDate not supplied

Anuria secondary to hot weather-induced hyperuricaemia: diagnosis and management.

BACKGROUND: There is little information on the management of anuria secondary to severe volume depletion or as a rare manifestation of heat stroke in areas of the world with very hot summers. We present our experience with hot weather-induced hyperuricaemia in Kuwait. PATIENTS AND METHODS: Patients presenting to our urology unit as an emergency during the hot summer months of April to October (average temperature 40-55 oC) were suspected of having hot weather-induced anuria secondary to hyperuricemia if they had a history of working in the sun for 6 to 8 hours per day and a progressive decrease in urine output to complete anuria. The diagnosis was confirmed by demonstration of elevated serum creatinine and uric acid, ultrasound findings of normal kidneys, ureters, and bladder (KUB) or mild to moderate hydronephrosis, but no features of chronic renal disease and little or no urine in the bladder. Management consisted of emergency cystoscopy, retrograde pyelogram, ureterorenoscopy (URS), and J stents followed by rehydration, oral allopurinol and urinary alkalinization. RESULTS: Twenty-nine patients (27 males and 2 females, mean age, 44.52A +/- 8.3 years) satisfied the diagnostic criteria for anuria secondary to hot weather-induced hyperuricaemia. Twentyeight (97%) patients worked outdoors on construction sites. Six patients had small radiopaque calculi on plain KUB X-ray. During cytoscopy and URS, uric acid crystals were encountered in all patients in the ureters and bladder. Recovery of renal function was complete in 23/29 (79.3%) patients, while 4/29 (13.8%) had partial recovery and 2/29 (6.9%) had no renal recovery. CONCLUSION: Hot weather-induced anuria secondary to hyperuricaemia is a complication of severe dehydration. Effective treatment will result in successful resolution of this rare but reversible cause of acute renal failure in about 80% of cases. Ancillary treatment methods like haemodialysis or the use of PCN can be safely avoided in the majority of the patients. However, rehydration alone may be insufficient treatment in these patients.

Journal Article↗
PubMedDate not supplied

[Bronchial asthma, atmospheric pollution, and weather conditions. Guadalajara, Jal].

BACKGROUND: In the last year it has been an increase in the prevalence of asthma, as well as in the air pollution. The effect of air pollution on the respiratory health is still controversial. OBJECTIVE: To determine the relationship between the income to the Emergency Room for asthmatic crisis and the air pollution or weather conditions. MATERIAL AND METHOD: An observational, descriptive, retrospective survey was made with children and adult patients who had an income to the Emergency Room of the Dr. Valentín Gómez Farías Regional Hospital due to an asthmatic crisis, during period between January 1st and December 31 the of 1994, being related to weekly measures of ozone, nitrogen dioxide, carbon monoxide, sulfur dioxide and particulate matter as air pollution, and minimal temperature, minimal percentage of humidity and wind speed, as weather conditions. They was related by autoregression technique using the Epi Info 5 computing system. RESULTS: An amount of 406 incomes to the Emergency Room for asthmatic crisis was recorded, observing an increase during the period between September and November. When compared to the air pollutants and weather conditions measurement, it has found a moderate relation between the increase of income and the nitrogen dioxide quantification, as the highest value. CONCLUSIONS: Air pollution and weather conditions by themselves seem to have a minimal to moderate influence on the incidence of incomes to the Emergency Room for asthmatic crisis.

Adult↗
PubMed1999

[Effect of weather on the occurrence of cerebral stroke].

In this paper a set of medical and meteorological data for the period of years 1985-1987 is elaborated and statistically evaluated in order to find correlations between daily occurrence of ischemic and haemoragic forms of cerebral stroke and particular biotropic types of weather. For tracing we gathered clinical medical data from eight health-service institutions in Bratislava. We compared both annual and seasonal courses of biometeorological types of weather in the investigated period with annual and seasonal courses of the followed sickness rate. We have found that the most unfavourable weather type is the central low pressure area with transition of the frontal system. The most favourable atmospheric type is a sunny weather in the warm high pressure area without surface inversion. (Tab. 2, Fig. 4, Ref. 10.)

Cerebrovascular Disorders↗
PubMed2003

Mechanical transmission of porcine reproductive and respiratory syndrome virus throughout a coordinated sequence of events during warm weather.

Mechanical transmission of porcine reproductive and respiratory syndrome virus (PRRSV) throughout a coordinated sequence of events that replicated common farm worker behavior during warm weather (10 degrees C to 16 degrees C) was assessed using a field-based model. The model involved fomites (boots and containers), vehicle sanitation, transport, and personnel movement. In a previous study, the model successfully demonstrated mechanical transmission of PRRSV in 8 out of 10 replicates during cold weather. A field strain of PRRSV was inoculated into carriers consisting of soil samples, which were adhered to the undercarriage of a vehicle. The vehicle was driven approximately 50 km to a commercial truck washing facility where the driver's boots contacted the carriers during washing, introducing the virus to the vehicle interior. The vehicle was then driven 50 km to a simulated farm site, and the driver's boots mechanically spread virus into the farm anteroom. Types of containers frequently employed in swine farms contacted drippings from the footwear on the anteroom floor. The truck wash floor, vehicle cab floor mats, boot soles, anteroom floor, and the ventral surface of containers were sampled to track the virus throughout the model. Ten replicates were conducted, along with sham-inoculated controls, and control replicates. In 2 replicates, infectious PRRSV was detected on the anteroom floor and in 1 replicate, infectious PRRSV was detected on the surface of the container by swine bioassay. All sham-inoculated controls and protocol controls were negative. These results indicate that mechanical transmission of PRRSV throughout a coordinated sequence of events in warm weather can occur, but in contrast to data from studies conducted during cold weather, it appears to be a relatively infrequent event.

Animal Husbandry↗
PubMedDate not supplied

[Correlation between weather factors and the number of premature and yearly births].

In a retrospective study for a period of five years, a total of 41,760 births in Sarajevo were analysed. For the same period, also meteorological data, such as air temperature, humidity, rain, cloudiness, barometric pressure, were gathered, by determining the weather type for each day. Using computer analyses, daily weather types with the number of births were compared. On the basis the statistical method of Friedman's test it is concluded that there is a significant correlation (p less than 0.05) between the weather types and the daily number of births. By comparing the daily number of births with the weather type of the preceding day the same conclusion was drawn. A cyclic fluctuation was also observed in the number of human births: the increased number of births in the December-January period and the decreased number of births in the August-September period. Premature births did not show any cyclic pattern.

Birth Rate↗
PubMed1999

Does the weather influence dementia admissions?

BACKGROUND: There is currently no literature on the relationship between weather parameters and admissions of organic brain syndromes such as dementias. In this present study we aimed to examine the effect of weather parameters such as relative humidity, sunshine hours, diurnal variations in temperature and rainfall on dementia admissions in North Cheshire. METHOD: Daily number of hospital admissions of dementias and other diagnoses in North Cheshire was analysed in relation to meteorological data, which were measured at the nearest meterological office to the study population. RESULTS: The study found no evidence of any statistically significant association between weather parameters and dementia admissions. There was a weak, lagged inverse relationship between dementia admissions and relative humidity and a positive association with diurnal variations in temperature within a week of admission. However, neither finding achieved statistical significance. CONCLUSION: The study is the first in currently available literature on the subject and may therefore provide a base reference for future studies. The interesting observation relating to relative humidity and diurnal variations in temperature is unexpected and may suggest further research.

Adolescent↗