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PubMed1989

Weathering of 134/137Cs following leaf contamination of grass cultures in an outdoor experiment.

After spraying grass cultures with rainwater collected after the Chernobyl reactor accident, the time-dependence of the weathering of leaf contamination of 134/137Cs was determined. Hereby the influence of rain and of biomass increase due to growth was considered. Two effective half-lives were found of 6 d and more than 60 d in rain-protected grass for the activity per area (corresponding to 8 d and more than 60 d when related to the activity per dry weight) and 2 d and 30 d in rain-exposed grass for the activity per area (3 d and 23 d when activity per dry weight is considered). These half-lives represent the initially rapid (for about 90% of the activity) and later slow (for the residual about 10%) decrease of the Cesium content in grass. They might be due to different weathering mechanisms whereby the translocation of the radionuclides from the leaf surface into the plant interior and the loss of wax particles might be of importance.

Accidents↗

PubMed1994

Falls, hip fractures and the weather.

The time of fall for 429 patients with a hip fracture was correlated with the prevailing weather conditions. Results show that other than for ground frost, there was no significant association between the prevailing weather conditions and no seasonal variance in the incidence of hip fractures.

Accidental Falls↗

PubMed2004

Prevalence of exercise-induced bronchospasm in long distance runners trained in cold weather.

We investigated whether regular training in cold weather has an effect on the development of exercise-induced bronchospasm. Nineteen sedentary males and 20 male long distance runners who were regularly training in Erzurum participated in this study. They had no history of asthma, atopy or allergic rhinitis. Pre- and post-exercise spirometry was performed in the participants in room temperature. EIB was defined as at least a > or =10% fall in FEV1 or a > or =15% fall in FEF(25-75%) or a > or =25% fall in PEFR. EIB was established in 7 of 20 athletes and in 1 of 19 sedentaries. Prevalence of EIB will be higher even if it is established in room temperature when training for the sports like long distance running which is not a cold weather sport. We conclude that it will be more convenient to establish EIB in room temperature and in the laboratory since the exercise test and spirometry can be performed more accurately under more standard conditions.

Adolescent↗

PubMed2004

Panic anxiety, under the weather?

The relationship between weather conditions and psychiatric disorders has been a continuous subject of speculation due to contradictory findings. This study attempts to further clarify this relationship by focussing on specific conditions such as panic attacks and non-panic anxiety in relation to specific meteorological variables. All psychiatric emergencies attended at a general hospital in Barcelona (Spain) during 2002 with anxiety as main complaint were classified as panic or non-panic anxiety according to strict independent and retrospective criteria. Both groups were assessed and compared with meteorological data (wind speed and direction, daily rainfall, temperature, humidity and solar radiation). Seasons and weekend days were also included as independent variables. Non-parametric statistics were used throughout since most variables do not follow a normal distribution. Logistic regression models were applied to predict days with and without the clinical condition. Episodes of panic were three times more common with the poniente wind (hot wind), twice less often with rainfall, and one and a half times more common in autumn than in other seasons. These three trends (hot wind, rainfall and autumn) were accumulative for panic episodes in a logistic regression formula. Significant reduction of episodes on weekends was found only for non-panic episodes. Panic attacks, unlike other anxiety episodes, in a psychiatric emergency department in Barcelona seem to show significant meteorotropism. Assessing specific disorders instead of overall emergencies or other variables of a more general quality could shed new light on the relationship between weather conditions and behaviour.

Adult↗

PubMed2006

Plant development scores from fixed-date photographs: the influence of weather variables and recorder experience.

In 1944, John Willis produced a summary of his meticulous record keeping of weather and plants over the 30 years 1913-1942. This publication contains fixed-date, fixed-subject photography taken on the 1st of each month from January to May, using as subjects snowdrop Galanthus nivalis, daffodil Narcissus pseudo-narcissus, horse chestnut Aesculus hippocastanum and beech Fagus sylvatica. We asked 38 colleagues to assess rapidly the plant development in each of these photographs according to a supplied five-point score. The mean scores from this exercise were assessed in relation to mean monthly weather variables preceding the date of the photograph and the consistency of scoring was examined according to the experience of the recorders. Plant development was more strongly correlated with mean temperature than with minimum or maximum temperatures or sunshine. No significant correlations with rainfall were detected. Whilst mean scores were very similar, botanists were more consistent in their scoring of developmental stages than non-botanists. However, there was no overall pattern for senior staff to be more consistent in scoring than junior staff. These results suggest that scoring of plant development stages on fixed dates could be a viable method of assessing the progress of the season. We discuss whether such recording could be more efficient than traditional phenology, especially in those sites that are not visited regularly and hence are less amenable to frequent or continuous observation to assess when a plant reaches a particular growth stage.

Climate↗

PubMed2006

Weather impacts on respiratory infections in Athens, Greece.

In this study the contribution of meteorological parameters to the total variability of respiratory infections (RI) is analysed. For this purpose, data on the daily numbers of general practitioner (GP) consultations for RI during the year 2002 were used. This dataset has been compiled by the Local Health Service in the surroundings of Athens, Greece (Acharnes city). The meteorological data obtained by the Meteorological Station of the National Observatory of Athens comprise daily values of mean, maximum, and minimum air temperature, air temperature range, relative humidity, absolute humidity, sunshine, surface atmospheric pressure, wind speed, as well as day-to-day changes of these parameters. Furthermore, the following biometeorological parameters and thermal indices were also evaluated: mean radiant temperature (T (mrt)), predicted mean vote (PMV), physiologically equivalent temperature (PET) and standard effective temperature (SET*) as well as their day-to-day changes. First, the relationship between every meteorological-biometeorological parameter and consultations for RI was examined by applying the Pearson Chi-Square Test (chi (2)) to the data of the 25 compiled contingency tables. In the second stage, the application of generalised linear models (GLM) with Poisson distribution to the data revealed how much the weather variability leads to statistically important changes in consultations for RI. The results of this study contribute to the evidence that there is an association between weather conditions and the number of GP consultations for RI. More specifically, the influence of air temperature and absolute humidity on consultations on the same day is weaker than the lag effect ( approximately 2 weeks) related to cold existence and absolute humidity, while a strong wind during the preceding 3 days drives a peak in GP consultations.

Greece↗

PubMed1997

The time factor in mortality: weather associations in a subtropical environment.

Mortality rates for a decade in Brisbane are analysed for dependence upon atmospheric factors. Time filters are applied to both the dependent and independent variables, and several models are developed to enable prediction, especially for weekly intervals. Statistically, deaths are observed to increase with colder and less humid weather with winds from a westerly, direction. Overall, taking account of both synoptic and seasonal influences, > 90% of cumulative deviations from mean death rates are explained. Some differences are also noted in the association of death with the weather between sexes, age groups and causes of death.

Adolescent↗

PubMed2004

Cold weather and GP consultations for respiratory conditions by elderly people in 16 locations in the UK.

BACKGROUND: Cold weather is associated with increases in mortality and demands on hospital services in the UK, particularly by the elderly. Less is known about the relationship with patterns of consultation in primary care. We wished to determine the magnitude and consistency of associations between cold temperature and consultations for respiratory conditions in primary care settings at different sites in the UK. METHODS: Time series analysis of any short-term effects of temperature on daily general practitioner (GP) consultations made by elderly people (65+ years) for lower and upper respiratory tract infections (LRTI, URTI) over a 10-year period, 1992--2001. Practices were situated in 16 urban locations across the UK where a Met Office monitoring station was in operation. RESULTS: An association between low temperatures and an increase in LRTI consultations was observed in all 16 locations studied. The biggest increase was estimated for the Norwich practices for which a 19.0% increase in LRTI consultations (95% CI 13.6, 24.7) was associated with every 1 degrees C drop in mean temperature below 5 degrees C observed 0-20 days before the day of consultation. Slightly weaker relationships were observed in the case of URTI consultations. A north/south gradient, with larger temperature effects in the north, was in evidence for both LRTI and URTI consultations. CONCLUSIONS: An effect that was consistent and generally strongest in populations in the north was observed between cold temperature and respiratory consultations. Better understanding of the mechanisms by which cold weather is associated with increases in consultations for respiratory infections could lead to improved strategies for prevention and reduced burdens for health services.

Aged↗

PubMed2005

North Atlantic weather oscillation and human infectious diseases in the Czech Republic, 1951-2003.

Longitudinal correlation between the North Atlantic Oscillation large-scale weather system (NAO) and the annual incidence rate of 14 viral, bacterial and protozoan national notifiable human diseases in the Czech Republic was examined. In simple correlation, cases of salmonellosis, erysipelas, infectious mononucleosis and toxoplasmosis were positively correlated with the winter NAO index, while hepatitis A and shigellosis were negatively correlated, and the other diseases tested (rubella, mumps, chickenpox, tick-borne encephalitis, Lyme borreliosis, leptospirosis, tularemia and scarlet fever) were uncorrelated with NAO. However, 8 of the 14 diseases also revealed a significant time trend, either increasing (infectious mononucleosis, salmonellosis, erysipelas, toxoplasmosis) or decreasing (hepatitis A, scarlet fever, leptospirosis, shigellosis) during the period. When the effect of NAO on incidence of the diseases was then controlled for calendar year using partial correlation analysis and detrended regression, only toxoplasmosis and infectious mononucleosis were found significantly positively correlated with the NAO when the index was lagged 1 or 2 years, and leptospirosis was correlated negatively with a lag of 2 years. Large-scale weather changes as described by NAO therefore do not seem to be a crucial factor in the fluctuation of annual incidence rate of the majority of tested infectious diseases in the Czech Republic, while other factors, especially social and public health circumstances, are obviously more important.

Atlantic Ocean↗

PubMed2006

Variations in epilimnion thickness in small boreal shield lakes: relationships with transparency, weather and acidification.

We used multiple linear regression analysis to investigate relationships between late-summer epilimnion thickness, transparency, lake area, acidity and summer weather conditions in a large ($n = 116$) multi-year data set for 9 small Boreal Shield lakes. Dissolved organic carbon (DOC) was the best individual predictor of late summer epilimnion thickness ($r;{2} = 0.69$). Total chlorophyll~$a$, the number of days between ice-out and late-summer stratification, and lake area collectively explained an additional 14% of the variation in epilimnion thickness. The three attributes of summer weather that we examined, mean daily temperature, mean daily wind speed, and mean daily hours of bright sunshine, did not add to the predictive ability of our regression model. Lake acidity also did not add directly to the predictive ability of the model, likely because DOC concentrations already reflected the effects of pH. Our study supports an increasing body of evidence indicating that the dominant effects of climate change on lake thermal structure in small lakes will be through effects on processes that affect lake transparency.

Acids↗

PubMed1988

Risk of a road accident in rainy weather.

A number of methods have been proposed for measuring the added risk of a road accident during rainy weather. These methods are reviewed here, and two of them are applied, with adjustments, to data from Israel and the United States. Their accuracy, however, is limited because surrogates have to be used for traffic exposure to rain. Nevertheless, results to indicate that the added risk of an injury accident in rainy conditions can be substantial: two to three times greater than in dry weather. And when a rain follows a dry spell the hazard could be even greater.

Accidents, Traffic↗

PubMed1982

Weather and infradian rhythms in self-reports of health, sleep and mood measures.

Some individuals exhibit significant and sustained periodicities in their self-reports of physical well-being, mood, hours of sleep, anxiety and cognition. These infradian rhythms may be related to weather variables such as solar flux, barometric pressure, temperature and humidity. The time of year, or season, during which self-reporting is performed may predicate the infradian rhythms and their relationship to weather.

Affect↗

PubMed2005

The association of rainfall and other weather variables with road traffic volume in Melbourne, Australia.

An investigation into the effect of weather variables on traffic flow at a site in Melbourne, Australia, for the period 1989-1996 was performed. Rainfall was the strongest correlated weather parameter and it had the greatest impact in winter and spring, when traffic volume is reduced on wet days. There are statistically significant decreases of 1.35 and 2.11% in traffic volume on wet days in winter and spring. The reduction increases to 2-3% over the 2-10mm range, the largest being 3.43% for the 2-5mm class in spring. For the first time, our study considers separately daytime and nighttime periods. We found a reduction of 1.86% in winter and 2.16% in spring during daytime rainfall. The reduction at nighttime is significant over all seasons, ranging from 0.87% in winter to 2.91% in spring. We have explored an application where the traffic volume was used to normalise the road accident count and found the rain effect to increase by 2.4, 1.9 and 5.2% relative to the daily, daytime and nighttime dry mean accident count. Generally, the normalised count is greater than the raw count, with a larger increase for the higher rainfall classes.

Accidents, Traffic↗

PubMed2005

Phytotoxicity of nitroaromatic energetic compounds freshly amended or weathered and aged in sandy loam soil.

The toxicities of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), and 2,6-dinitrotoluene (2,6-DNT) to terrestrial plants alfalfa (Medicago sativa L.), Japanese millet (Echinochloa crusgalli L.), and perennial ryegrass (Lolium perenne L.) were determined in Sassafras sandy loam soil using seedling emergence, fresh shoot, and dry mass measurement endpoints. A 13-week weathering and aging of energetic materials in soils, which included wetting and drying cycles, and exposure to sunlight of individual soil treatments, was incorporated into the study design to better reflect the soil exposure conditions in the field than toxicity determinations in freshly amended soils. Definitive toxicity tests showed that dinitrotoluenes were more phytotoxic for all plant species in freshly amended treatments based on EC20 values for dry shoot ranging from 3 to 24mgkg(-1) compared with values for TNB or TNT ranging from 43 to 62mgkg(-1). Weathering and aging of energetic materials (EMs) in soil significantly decreased the toxicity of TNT, TNB or 2,6-DNT to Japanese millet or ryegrass based on seedling emergence, but significantly increased the toxicity of all four EMs to all three plant species based on shoot growth. Exposure of the three plant species to relatively low concentrations of the four compounds initially stimulated plant growth before the onset of inhibition at greater concentrations (hormesis).

Benzene Derivatives↗

PubMed2005

Effects of oil sands tailings compounds and harsh weather on mortality rates, growth and detoxification efforts in nestling tree swallows (Tachycineta bicolor).

Oil sands mining companies in Alberta, Canada, are evaluating the feasibility of using wetlands to detoxify oil sands process material (OSPM) as a reclamation strategy. Reproductive success, nestling growth, survival and ethoxyresorufin-o-deethylase (EROD) activity were measured in tree swallows (Tachycineta bicolor) on experimental wetlands. In 2003, harsh weather triggered a widespread nestling die-off. Mortality rates on the control site reached 48% while they ranged from 59% to 100% on reclaimed wetlands. The odds of dying on the most process-affected sites were more than ten times higher than those on the control site. In 2004, weather was less challenging. Mortality rates were low, but nestlings on reclaimed wetlands weighed less than those on the control site, and had higher EROD activity. These results indicate that compared with reference birds, nestlings from OSPM-impacted wetlands may be less able to withstand additional stressors, which could decrease their chances of survival after fledging.

Animals↗

PubMed2005

Relationships between weather and myocardial infarction: a biometeorological approach.

OBJECTIVES: To calculate threshold values of weather discomfort which increase the risk of hospital admissions for myocardial infarction in winter and summer. BACKGROUND: Notwithstanding heat waves were reported to acutely increase hospital admissions for cardiovascular diseases, large surveys failed to reveal any increase of event rates with increasing air temperature. However, the assessment of air temperature does not allow evaluation of the actual discomfort perception caused by the combination of different meteorological parameters. METHODS: Hospital admissions for myocardial infarction for the period 1998-2002 in Florence, Italy, were considered. The percentages of variation of daily event rates according to daily mean air temperature variations were preliminary derived by using a regression analysis. An alternative biometeorological approach, considering the Apparent Temperature Index (ATI) in summer, and the New U.S./Canada Wind Chill Temperature Index (NWCTI) in winter, which combine air temperature, relative humidity and wind velocity, was then used. RESULTS: The traditional approach showed that daily event rates significantly increased with daily mean air temperature decrease (10 degrees C decrease were associated with 19% increase in daily event rates for people older than 65 years), but failed to show any negative effect caused by hot climatic conditions. Conversely the biometeorological approach allowed to show that at least 9 h per day of severe discomfort caused by hot conditions significantly increased the rate of admission (P<0.01). CONCLUSIONS: This approach might be useful for the development of an operative weather watch/warning system for population and for hospital professional care.

Aged↗

PubMed2005

The influence of weather and environment on pulmonary embolism: pollutants and fossil fuels.

Previous publications have highlighted seasonal variations in the incidence of thrombosis and pulmonary embolism, and that weather patterns can influence these. While medical risk factors for pulmonary thrombo-embolism such as age, obesity, hypercoagulable states, cancer, previous thrombo-embolism, immobility, limb paralysis, surgery, major illness, trauma, hypotension, tachypnoea and right ventricular hypokinesis are not directly implicated regarding environmental factors such as weather, they could be influenced indirectly by these. This would be especially relevant in polluted areas that are associated with a higher pulmonary embolism risk. Routine nuclear medicine lung ventilation/perfusion studies (V/Q scans) of 2071 adult patients referred to the nuclear medicine department of the Royal Surrey County Hospital in Guildford, UK, between January 1998 and October 2002 were reviewed and 316 of these patients were classified as positive for pulmonary embolism with high probability scan on PIOPED criteria. The occurrence of positive scans was compared to environmental factors such as temperature, humidity, vapour pressure, air pressure and rainfall. Multiple linear regression was used to establish the significance of these relations. The incidence of pulmonary embolism was positively related to vapour pressure and rainfall. The most significant relation was to vapour pressure (p=0.010) while rainfall was less significant (p=0.017). There was no significant relation between pulmonary embolism and air pressure, humidity or temperature. It is postulated that rainfall and water vapour may be contributary factors in thrombosis and pulmonary embolism by way of pollutants that are carried as condensation nuclei in micro-droplets of water. In particular, fossil fuel pollutants are implicated as these condensation nuclei. Pollutants may be inhaled by populations exposed to windborne vapour droplets in cities or airports. Polluted vapour droplets may be absorbed by the lung to hasten coagulation cascades in the blood. This may lead to thrombosis and increased pulmonary embolism under high vapour pressure conditions. With combined factors such as pre-existing ill health or immobility on long flights, the risk of thrombosis and consequent embolism might increase substantially.

Adult↗

PubMed1988

Modeling mortality fluctuations in Los Angeles as functions of pollution and weather effects.

Linear and nonlinear models are used to investigate possible associations between mortality and pollution and weather effects in Los Angeles County. State-space modeling and time and frequency domain regressions are used to modify the data base and to isolate significant weather factors and pollutants associated with increased daily mortality. Nonparametric and parametric regression methods are used to develop nonlinear dose-response profiles relating mortality to temperature and to the statistically significant pollutants. A parametric nonlinear time series model involving linear and squared terms in temperature and the logarithm of pollution provides a reasonable predictive model.

Air Pollutants↗