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PubMed1977

Myocardial infarction and weather.

The association of meterological factors with acute myocardial infarction was studied within a one-year period in Helsinki. Seasonal variation was found with the lowest incidence in summer and the highest in late autumn. Environmental temperature was not significantly correlated with the incidence of myocardial infarction but the case fatality rate was higher on coldest days. Atmospheric pressure turned out to be the meteorological variable with the highest correlation with the occurrence of myocardial infarction. Rapid decrease in atmospheric pressure was also associated with increased incidence of acute myocardial infarction. Relative humidity had little independent effect. The weather types with highest and lowest risk of heart attack were determined by the combined use of factor and cluster analysis. The most unfavourable turned out to be a relatively cold and moist weather with low atmospheric pressure, common in Helsinki during early winter and late autumn. The incidence of infarction did not increase on typical cold and dry winter days. The most favourable weather was warm, dry and stable summer weather. The difference in incidences between most and least favourable weather types was three-fold.

Acute Disease↗
PubMed1995

Acknowledging the weather-health link.

The impact of weather on health is generally overlooked by physicians. Possible reasons for this include lack of training and insufficient awareness of the significant body of research on human biometeorology. The authors argue that, in the absence of clearly demonstrable causal connections, statistical associations between weather phenomena and health problems should be enough to influence clinical practice. Physicians in Germany make use of daily bulletins from the national weather service to advise patients on the management of common health problems that seem to be exacerbated by certain weather conditions. The authors urge Canadian doctors to follow the lead of their European colleagues by increasing their awareness of the relation between weather and health.

Canada↗
PubMed1997

Elderly suicide and weather conditions: is there a link?

BACKGROUND: Studies of the effect of meteorological factors on suicide have yielded inconclusive and often contradictory results. This may be due to a variety of methodological problems including small numbers and variability in the definition of suicide. The relationship has not been examined in the elderly. OBJECTIVES: To study the effect of weather conditions on suicide rate in an elderly population of 40,000 of North Cheshire aged 65 and above. In this study, coroner's verdicts of suicide and open verdict which were recorded in a specified period were included. METHOD: Five-year data of deaths resulting from suicide within North Cheshire were analysed in relation to meteorological data, which were measured at the nearest Met office to the study population. RESULTS: Significant positive association was demonstrated between suicide in the elderly and hours of sunshine (p < 0.01) and relative humidity (p < 0.05). These effects were independent of sex. CONCLUSIONS: Weather may influence suicide in the elderly, probably interacting with biological and social variables. The rate of reported suicide appears to be positively related to fine weather conditions, during early summer, and not to extreme weather conditions as previously reported. Method of death appears to be also associated with weather conditions.

Aged↗
PubMedDate not supplied

Secondary and backscattered electron imaging of weathered chromian spinel.

Secondary (SE) and backscattered electron (BSE) imaging as well as x-ray microanalysis have demonstrated that the weathering of chromian spinel occurs as a progressive form of alteration. Numerous chemical discriminant analysis methods based on the composition of chromian spinel are used to locate valuable deposits of minerals. These methods will be misleading if the correct interpretation of the weathering of chromian spinel and the subsequent pattern of changes in its mineral chemistry are not properly assessed using scanning electron microscopy. This assessment is vital in understanding the geological processes involved and the economic potential of any indicated deposit. Minerals such as chromian spinel, pyrope garnet, and picroilmenite are considered to be highly resistant to weathering and abrasion and are therefore useful in the search for associated valuable deposits of diamond, nickel, platinum, and gold. Known as indicator minerals, they are usually present in relatively large concentrations compared with the target mineral (e.g., diamond) and form large and often subtle dispersion anomalies adjacent to the deposit. Chromian spinel has long been regarded as a stable indicator mineral; however, detailed SE and BSE imaging indicates that many of the chromian spinels that are routinely examined using scanning electron microscopes (SEM) and microprobes are extensively altered. Secondary electron and BSE imaging of weathered chromian spinel in a normal SEM provides valuable data on the form and chemical style of the alteration. Secondary electron imaging of weathered chromian spinel in the environmental SEM (ESEM) not only enhances the difference in atomic number between unaltered and altered areas but also allows high-resolution imaging of these very fine replacement textures.

Journal Article↗
PubMed2004

Statistical evaluation of potash-lime-silica glass weathering.

Two potash-lime-silica model glasses with compositions similar to those of medieval stained glass were exposed at 26 test sites all over Europe and in North America for 3-6 years. The objectives of this large-scale field exposure programme were: (a) a qualitative analysis of the weathering products formed on the surface of the samples in the (environmental) scanning electron microscope in combination with energy dispersive X-ray microanalysis (ESEM/EDX or SEM/EDX, respectively); (b) a statistical evaluation of the weathering phenomena by applying a multiple linear regression (MLR) analysis to find correlations between the degree of weathering, which was measured in terms of surface coverage with reaction products, and environmental parameters such as the concentration (c) of the acidifying gases SO(2), NO(2) and O(3), the temperature (T) and the relative humidity (RH); and (c) the calculation of a time-dependence function of the weathering process of these glasses. Mainly sulfates of calcium and potassium such as gypsum (CaSO(4).2 H(2)O), arcanite (K(2)SO(4)) and syngenite (CaSO(4).K(2)SO(4).H(2)O) could be identified in the SEM and ESEM. Carbonates, nitrates and many particles deposited on the glass surface were found as well. MLR calculations exhibit significant dependencies of the degree of weathering on T, RH, c(NO(x)), c(SO(2)) and c(O(3)). Applying a time-dependence function of the general form y= a. t(b) (t=time) results in a value of approximately 0.42 for the exponent b, which comes close to values expected from various studies in the literature.

Calcium Compounds↗
PubMed2005

Toxicity of emerging energetic soil contaminant CL-20 to potworm Enchytraeus crypticus in freshly amended or weathered and aged treatments.

We investigated the toxicity of an emerging polynitramine energetic material hexanitrohexaazaisowurtzitane (CL-20) to the soil invertebrate species Enchytraeus crypticus by adapting then using the Enchytraeid Reproduction Test (ISO/16387:2003). Studies were designed to develop ecotoxicological benchmark values for ecological risk assessment of the potential impacts of accidental release of this compound into the environment. Tests were conducted in Sassafras Sandy Loam soil, which supports relatively high bioavailability of CL-20. Weathering and aging procedures for CL-20 amended into test soil were incorporated into the study design to produce toxicity data that better reflect soil exposure conditions in the field compared with the toxicity in freshly amended soils. Concentration-response relationships for measurement endpoints were determined using nonlinear regressions. Definitive tests showed that toxicities for E. crypticus adult survival and juvenile production were significantly increased in weathered and aged soil treatments compared with toxicity in freshly amended soil, based on 95% confidence intervals. The median effect concentration (EC50) and EC20 values for juvenile production were 0.3 and 0.1 mg kg-1, respectively, for CL-20 freshly amended into soil, and 0.1 and 0.035 mg kg-1, respectively, for weathered and aged CL-20 soil treatments. These findings of increased toxicity to E. crypticus in weathered and aged CL-20 soil treatments compared with exposures in freshly amended soils show that future investigations should include a weathering and aging component to generate toxicity data that provide more complete information on ecotoxicological effects of emerging energetic contaminants in soil.

Aniline Compounds↗
PubMed2001

Contribution of different sources to the pollution of wet weather flows in combined sewers.

Experiments performed on "Marais" catchment, in central Paris, aimed to follow up the quality of wet weather flows from the entry to the exit of a combined sewer network. SS, VSS, COD, BOD5, Cd, Cu, Pb, Zn concentrations were measured for an important number of rain events in roof, yard, street runoff, as well as in dry and wet weather flows at the catchment outlet. Mass entry-exit totals, at the scale of the catchment, were calculated over 31 rain events in order to evaluate the contribution of different types of runoff, of sanitary sewage and of sewer sediments to the total wet weather pollutant loads at the catchment outlet. The erosion of in-sewer pollutant stocks was found to be the main source of particles and of organic matter in wet weather flows, whereas heavy metal loads mainly originated from roof runoff, due to the corrosion of metallic roofs. Particles eroded inside the sewer during rain events were found to be quite different from the particles constituting the main part of sewer sediments: they are organic and biodegradable, with rather important settling velocities and seem to accumulate during dry weather periods. A change of the chemical form of heavy metals was noticed during the transport in the sewer and it is suspected that a fraction of the dissolved metals from the runoff is adsorbed on sewer sediments.

Cadmium↗
PubMed2000

Photoenhanced toxicity of weathered oil to Mysidopsis bahia.

The toxicity of a water-accommodated fraction (WAF) prepared from weathered oil was assessed in a 7-day static renewal test with Mysidopsis bahia. Weathered oil was collected from the 5x monitoring well at the Guadalupe oil field. Solar ultraviolet and visible light intensities were measured in various habitats in the vicinity of the weathered oil sample collection site, and the resultant measurements were used to produce laboratory light treatments that were representative of the on-site quality and intensity of natural solar radiation. Each of five WAF dilutions and a control without WAF was tested under three different simulated solar radiation intensities. During the test, survival and growth of the mysids, irradiance, and total petroleum hydrocarbon (TPH) concentrations in the test treatments were measured. Significant increases (P</=0.05) in mortality occurred among mysids exposed to 0.57 and 1.30 mg TPH/l and the effects were potentiated as irradiance increased. Seven-day LC50 (0.92-0.42 mg TPH/l) and LC20 (0.58-0.15 mg TPH/l) values decreased as the simulated solar irradiance increased. Calculated EC20 and EC50 values for mysid growth indicate that surviving mysids exposed to 0.1-1.0 mg TPH/l would incur significant reductions (P</=0.05) in productivity (biomass). Results of the present study indicate that effects elicited through the interaction of WAF of weathered oil and solar radiation will substantially increase the toxicity of weathered oil. Further, the photomediated effects of petroleum compounds measured as TPH on mysid survival and growth demonstrate a need to consider the interactions of ultraviolet light and contaminant to avoid under estimating toxicity that might occur in the environment.

Journal Article↗
PubMed1990

Pesticide decontamination from fabric by laundering and simulated weathering.

This laboratory study investigated the effectiveness of selected detergents and the phenomenon of simulated environmental conditions (weathering) on the removal of a commercial-grade mixture of parathion and methyl parathion from a three-layer laminated fabric. The weathering treatment consisted of exposure and non-exposure to simulated environmental conditions of heat, light, and humidity. Contaminated fabric samples were laundered in one of three detergents containing an anionic, a nonionic, and a combined anionic and nonionic surfactant. The test fabric, a three-layer fabric containing an impermeable microporous film laminated between two layers of nylon, was pipette-contaminated with 400 microliters of field strength pesticide solution and allowed to dry. Half of the contaminated samples were weathered in an Atlas Fade-Ometer. All of the contaminated samples were subsequently laundered in a Launder-Ometer. Percent of pesticide residue was determined by gas chromatography. Weathering did significantly reduce both parathion and methyl parathion residues remaining in the test fabric. No statistically significant difference was found among the three detergents. High amounts of both parathion and methyl parathion remained in the test fabric after weathering and laundry treatments. Before the test fabric can be recommended for use in protective garments further research is needed to develop more effective decontamination procedures.

Detergents↗
PubMed2006

Ectomycorrhizal weathering of the soil minerals muscovite and hornblende.

Ectomycorrhizal fungi are hypothesized to enhance mineral weathering in forest soils. Several studies have shown an increased uptake of mineral-derived nutrients by trees when in symbiosis with ectomycorrhizal fungi. However, it is difficult to determine from these studies if the improved nutrient uptake is the result of increased weathering or better exploitation of the substrate by the ectomycorrhizal fungi. In a pot experiment, Pinus sylvestris (Scots pine) seedlings were grown with or without ectomycorrhizal fungi, and with or without the mineral muscovite as the only potassium (K) source or the mineral hornblende as the only magnesium (Mg) source. After 27 wk, all pools of non-mineral-bound K or Mg were determined. The ectomycorrhizal fungus Paxillus involutus increased weathering of muscovite but not hornblende. The other ectomycorrhizal fungi tested, Piloderma croceum and Suillus bovinus, did not increase weathering of either muscovite or hornblende compared with the nonmycorrhizal trees. The P. involutus-mediated mobilization of K from muscovite resulted in increased K content of root plus adhering hyphae, but not of shoots. In conclusion, ectomycorrhizal fungi may increase weathering of minerals in response to nutrient deficiencies, but this response is species specific.

Minerals↗
PubMedDate not supplied

A joint TEM-HLEM geophysical approach to borehole sitting in deeply weathered granitic terrains.

The accurate location of aquiferous fracture zones in granite beneath a > 50 m thick weathered mantle in semi-arid regions is a major hydrogeological problem. It is expected that the zone of intensive fracturing will be more susceptible to weathering and thus be characterized by the thickest development of saprolite, a good electrically conductive target for deep-probing electromagnetic systems. The single-loop transient electromagnetic (TEM) technique is well known to have the capability for detecting concealed steep mineralized targets in mining environments and can be adapted to this hydrogeological problem. We propose that combining the conventional frequency-domain horizontal-loop electromagnetic (HLEM) and single-loop TEM is an effective practical approach to locating concealed aquiferous fracture zones. In the supporting case studies presented here, we deployed multifrequency HLEM profiling (with 50 m transmitter-receiver separation) and TEM soundings with contiguous 10 or 20 m sided loops along the survey lines in a granitic terrain affected by deep (> 50 m) weathering in northeast Brazil. A somewhat layered structure consisting of resistive hardpan/leached zone, conductive saprolite, and resistive basement is identifiable in the typical TEM depth sounding data. We obtained coincident HLEM and TEM anomalies at all the sites, enabling a relatively straightforward selection of potential drilling positions. Simple resistivity-depth transformation of the TEM data was done for each site, yielding an approximate section from which drilling depths were estimated. All of the boreholes located were successful. Although our results appear to indicate that the single-loop TEM method could be used independently for borehole sitting in deeply weathered granitic terrains and that the weathering profile over granite can be mapped using TEM depth soundings of appropriate observational bandwidth, we recommend a joint electromagnetic approach for optimal well sitting.

Electric Conductivity↗
PubMed2006

Some topics on geochemistry of weathering: a review.

Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importance of complexes. Weathering is not only a destructive process. It can concentrate chemical species and form mineral deposits (kaolin, bauxite, Fe, Mn, P, Nb, Au). Weathering studies are important in pedology, engineering geology, hydrogeology, paleoclimatology and ecology. The use of stonemeal is based upon the study of rock weathering.

Journal Article↗
PubMed2005

Weathering and aging of 2,4,6-trinitrotoluene in soil increases toxicity to potworm Enchytraeus crypticus.

Energetic materials are employed in a wide range of commercial and military activities and often are released into the environment. Scientifically based ecological soil-screening levels (Eco-SSLs) are needed to identify contaminant explosive levels in soil that present an acceptable ecological risk. Insufficient information for 2,4,6-trinitrotoluene (TNT) to generate Eco-SSLs for soil invertebrates necessitated toxicity testing. We adapted the standardized Enchytraeid Reproduction Test and selected Enchytraeus crypticus for these studies. Tests were conducted in Sassafras sandy loam soil, which supports relatively high bioavailability of TNT. Weathering and aging procedures for TNT amended to test soil were incorporated into the study design to produce toxicity data that better reflect the soil exposure conditions in the field compared with toxicity in freshly amended soils. This included exposing hydrated TNT-amended soils in open glass containers in the greenhouse to alternating wetting and drying cycles. Definitive tests showed that toxicity for E. crypticus adult survival and juvenile production was increased significantly in weathered and aged soil treatments compared with toxicity in freshly amended soil based on 95% confidence intervals. The median effect concentration and 20% effective concentration for reproduction were 98 and 77 mg/kg, respectively, for TNT freshly amended into soil and 48 and 37 mg/kg, respectively, for weathered and aged TNT soil treatments. These findings of increased toxicity to E. crypticus in weathered and aged TNT soil treatments compared with exposures in freshly amended soils show that future investigations should include a weathering and aging component to generate toxicity data that provide more complete information on ecotoxicological effects of energetic contaminants in soil.

Animals↗
PubMed2006

Toxicity of weathered Exxon Valdez crude oil to pink salmon embryos.

Research was conducted at the University of Idaho (Moscow, ID, USA) on the toxicity of weathered Exxon Valdez crude oil to embryos of pink salmon from 2001 to 2003 for the purpose of comparing these data with those from the National Oceanic and Atmospheric Administration Fisheries Laboratory at Auke Bay (AK, USA). Mortality reported at Auke Bay for embryos chronically exposed to very low concentrations of aqueous solutions of weathered oil, measured as dissolved polycyclic aromatic hydrocarbons (PAHs), was inconsistent with that in other published research. Using the Auke Bay experimental design, we found that toxicity is not evident in pink salmon embryos until chronic exposure to laboratory weathered and naturally weathered oil concentrations exceeding 1,500 and 2,250 ppm, respectively, representing a total PAH tissue burden in excess of 7,100 ppb. Effluent hydrocarbons also drop well below concentrations sufficient to cause harm over the time frame of a few weeks, regardless of oiling level. Resolution of differences with Auke Bay involved the source of contributing hydrocarbons. The experimental design did not exclude dispersed oil droplets from the aqueous solution; thus, toxicity was not limited to the dissolved hydrocarbon fraction. The implications of the present results are discussed regarding the toxic risk of weathered oil to pink salmon embryos in streams of Prince William Sound (AK, USA).

Alaska↗
PubMedDate not supplied

Effects of spent mushroom substrate weathering on the chemistry of underlying soils.

Passive weathering of heaped material in the field is a popular method for treating spent mushroom substrate (SMS) before its reuse. During the weathering process, leachate containing high concentrations of dissolved organic matter and inorganic salts is released into the underlying soils, but effects on soil and ground water quality remain uncertain. We conducted a field study to measure the effects of SMS weathering on chemical and morphological properties of underlying soils. Two SMS piles, 20 m long, 6 m wide, and either 90 or 150 cm high, were placed in a fallow agricultural field dominated by grasses and weathered for 24 mo. Soil samples were taken from each genetic horizon under the SMS piles following their removal and analyzed for pH, total organic carbon (TOC), electrical conductivity (EC), water-soluble organic carbon (WSOC), water-soluble inorganic cations and anions, and exchangeable inorganic cations. Compared with an unaffected control, SMS weathering did not raise soil TOC, but did alter soil pH, and significantly increased EC, WSOC, and water-soluble and exchangeable inorganic ions. At 200 cm below the soil surface, the EC, WSOC, and water-soluble Cl-, NO3-, Ca2+, Mg2+, Na+, and K+ under SMS piles were 4 to 20 times higher than in unaffected soils. Water-soluble NO3- was minimal in the surface soil but peaked in the C horizon (120-180 cm) under the 90-cm SMS pile, indicating that these soils may have little capacity for retaining NO3-. Concentration profiles of the different solutes reflect their relative mobilities in the soil environment and indicate the potential for effects on subsurface water supplies.

Agaricales↗
PubMed2006

Distribution of uranium contamination in weathered fractured saprolite/shale and ground water.

The objective of this study was to determine how structure, stratigraphy, and weathering influence fate and transport of contaminants (particularly U) in the ground water and geologic material at the Department of Energy (DOE) Environmental Remediation Sciences Department (ERSD) Field Research Center (FRC). Several cores were collected near four former unlined adjoining waste disposal ponds. The cores were collected, described, analyzed for U, and compared with ground water geochemistry from surrounding multilevel wells. At some locations, acidic U-contaminated ground water was found to preferentially flow in small remnant fractures weathering the surrounding shale (nitric acid extractable U [U(NA)] usually < 50 mg kg(-1)) into thin (<25 cm) Fe oxide-rich clayey seams that retain U (U(NA) 239 to 375 mg kg(-1)). However, greatest contaminant transport occurs in a 2 to 3 m thick more permeable stratigraphic transition zone located between two less permeable, and generally less contaminated zones consisting of (i) overlying unconsolidated saprolite (U(NA) < 0.01 to 200 mg kg(-1)) and (ii) underlying less-weathered bedrock (U(NA) generally < 0.01 to 7 mg kg(-1)). In this transition zone, acidic (pH < 4) U-enriched ground water (U of 38 mg L(-1)) has weathered away calcite veins resulting in greater porosity, higher hydraulic conductivity, and higher U contamination (U(NA) 106 to 745 mg kg(-1)) of the weathered interbedded shale and sandstone. These characteristics of the transition zone produce an interval with a high flux of contaminants that could be targeted for remediation.

Environmental Monitoring↗
PubMed1996

Use of weather data and remote sensing to predict the geographic and seasonal distribution of Phlebotomus papatasi in southwest Asia.

Sandfly fever and leishmaniasis were major causes of infectious disease morbidity among military personnel deployed to the Middle East during World War II. Recently, leishmaniasis has been reported in the United Nations Multinational Forces and Observers in the Sinai. Despite these indications of endemicity, no cases of sandfly fever and only 31 cases of leishmaniasis have been identified among U.S. veterans of the Persian Gulf War. The distribution in the Persian Gulf of the vector, Phlebotomus papatasi, is thought to be highly dependent on environmental conditions, especially temperature and relative humidity. A computer model was developed using the occurrence of P. papatasi as the dependent variable and weather data as the independent variables. The results of this model indicated that the greatest sand fly activity and thus the highest risk of sandfly fever and leishmania infections occurred during the spring/summer months before U.S. troops were deployed to the Persian Gulf. Because the weather model produced probability of occurrence information for locations of the weather stations only, normalized difference vegetation index (NDVI) levels from remotely sensed Advanced Very High Resolution Radiometer satellites were determined for each weather station. From the results of the frequency of NDVI levels by probability of occurrence, the range of NDVI levels for presence of the vector was determined. The computer then identified all pixels within the NDVI range indicated and produced a computer-generated map of the probable distribution of P. papatasi. The resulting map expanded the analysis to areas where there were no weather stations and from which no information was reported in the literature, identifying these areas as having either a high or low probability of vector occurrence.

Animals↗
PubMed2001

Municipal hotlines and automated weather stations as a tool for monitoring bad odour dispersion: the northern Negev case.

Bad odours are often dispersed from chemical industries, waste dumps, sewer plants, and other facilities. They are indicative of pollution emissions from these sites and cause discomfort, apprehension, and sometimes signal the presence of health hazards. Monitoring the pollution by direct means, such as chemical analysis of ambient air, is obviously the most reliable mechanism to acquire data regarding pollution. However, this is not always possible. In this paper we report on the value of local government hotlines that record information provided by the public regarding bad odours. These data can alert the authorities to the existence of pollution and should be regarded as potentially useful when collected in conjunction with information from automated weather stations. An analysis of data from the Be'er Sheva municipality and the Ramat Negev regional council hotlines is provided. Complaints recorded by these systems were correlated with weather data from local automatic weather stations to indicate the sources of the bad odours. Wind direction was found to be highly correlated with bad odour and pollution sources, revealing consistent patterns in terms of the time of day and weather conditions.

Chemical Industry↗