Evidence suggests that dietary-intakes of the essential element selenium have fallen in Scotland in recent years, due to changing sources of bread-making wheat. The Scottish environment is thought to ...be Se-poor due to the geology and climate. This initial study assessed whether geological parent-materials could be used to predict relatively high and low soil-Se areas in Scotland and whether differences in soil-Se were reflected in foodstuff-Se produced on them. Samples (n
=
8 per farm) of wheat, calabrese (broccoli), potato, beef-steak, milk, cattle pasture (grass) and soil were collected from pairs of farms (one in each high/low predicted Se area (PSA)). Potatoes and soils were collected from a further 34 farms in high/low PSAs to assess a greater geographical zone. Total soil-Se ranged from 0.115 to 0.877
mg
kg
-1 but most samples (90%) could be classed as Se-deficient (<
0.6
mg
kg
−1), irrespective of PSA. Total soil-Se was significantly higher (p
<
0.05) in the high than in the low PSAs as expected; however, the difference between the two was small (mean 0.48 and 0.37
mg
kg
−1, respectively). Water-soluble soil-Se (6.69 to 26.78
μg
kg
−1) concentrations were not significantly different between the two PSAs (p
=
0.71). Soil loss-on-ignition (indicating organic matter content) correlated significantly with total and water-soluble soil-Se (p
<
0.001) and exerted a greater control than parent-material on soil-Se. Significant differences between the PSAs for beef-Se (p
<
0.001), wheat-Se (p
<
0.001), calabrese-Se (p
<
0.01) and beef-farm grass-Se (p
<
0.05) indicated partial success of the parent-material soil-Se prediction. However, only wheat-Se (p
<
0.001) and potato-Se (p
<
0.001) correlated significantly with total soil-Se. The results suggest that soil-Se concentrations in the main agricultural areas of Scotland are generally low. Given the low Se concentrations also reported in the food commodities; further investigations may be warranted to fully characterise the Se-status of Scottish produce and dietary-Se intakes in Scotland.
There is growing interest in links between poor health and socio-environmental inequalities (e.g. inferior housing, crime and industrial emissions) under the environmental justice agenda. The current ...project assessed associations between soil metal content, air pollution (NO₂/PM₁₀) and deprivation and health (respiratory case incidence) across Glasgow. This is the first time that both chemical land quality and air pollution have been assessed citywide in the context of deprivation and health for a major UK conurbation. Based on the dataset ‘averages’ for intermediate geography areas, generalised linear modelling of respiratory cases showed significant associations with overall soil metal concentration (p = 0.0367) and with deprivation (p < 0.0448). Of the individual soil metals, only nickel showed a significant relationship with respiratory cases (p = 0.0056). Whilst these associations could simply represent concordant lower soil metal concentrations and fewer respiratory cases in the rural versus the urban environment, they are interesting given (1) possible contributions from soil to air particulate loading and (2) known associations between airborne metals like nickel and health. This study also demonstrated a statistically significant correlation (−0.213; p < 0.05) between soil metal concentration and deprivation across Glasgow. This highlights the fact that despite numerous regeneration programmes, the legacy of environmental pollution remains in post-industrial areas of Glasgow many decades after heavy industry has declined. Further epidemiological investigations would be required to determine whether there are any causal links between soil quality and population health/well-being. However, the results of this study suggest that poor soil quality warrants greater consideration in future health and socio-environmental inequality assessments.
Like many elements, fluorine (which generally occurs in nature as fluoride) is beneficial to human health in trace amounts, but can be toxic in excess. The links between low intakes of fluoride and ...dental protection are well known; however, fluoride is a powerful calcium-seeking element and can interfere with the calcified structure of bones and teeth in the human body at higher concentrations causing dental or skeletal fluorosis. One of the main exposure routes is via drinking water and the World Health Organisation currently sets water quality guidelines for the element. In Central Europe, groundwater resources that exceed the guideline value of 1.5 mg l-¹ are widespread and effects on health of high fluoride in water have been reported. The aim of the current project was to develop a geographic information system (GIS) to aid the identification of areas where high-fluoride waters and fluorosis may be a problem; hence, where water treatment technologies should be targeted. The development of the GIS was based upon the collation and digitisation of existing information relevant to fluoride risk in Ukraine, Moldova, Hungary and Slovakia assembled for the first time in a readily accessible form. In addition, geochemistry and health studies to examine in more detail the relationships between high-fluoride drinking waters and health effects in the population were carried out in Moldova and Ukraine demonstrating dental fluorosis prevalence rates of 60-90% in adolescents consuming water containing 2-7 mg l-¹ fluoride.
Selenium deficiency (Keshan Disease) and toxicity diseases in humans occur within 20 km of each other in Enshi District in China and have been linked to environmental levels of Se. Low concentrations ...of Se are associated with Jurassic siltstones and sandstones, whereas high concentrations occur in areas underlain by Permian carbonaceous strata. Although these broad relationships between Se in the environment and the human population have been established previously, not all villages underlain by the carbonaceous strata suffer Se toxicity problems and the precise controls on Se distribution and availability have not been quantified. In the present study, soil, grain, drinking water and human hair samples are examined to determine the controls on Se availability in 3 Se environments in Enshi District. Five low-Se and Keshan Disease villages, 5 high-Se and no toxicity villages and 5 high-Se and toxicity villages were selected for the study. Results show that the majority of samples in the low-Se villages are deficient or marginal in Se, and that Se availability to plants is inhibited by adsorption onto organic matter and Fe oxyhydroxides in soil. Therefore, remediation strategies involving the application of Se fertiliser direct to the soil may not increase plant Se levels as expected. In the high-Se villages, localised lithological variations result in considerable ranges in Se concentrations in all sample types. Deficient and excessive levels of Se are recorded in samples from the same village. Selenium bioavailability in the high-Se toxicity villages is controlled by the total soil Se concentration and pH. A greater proportion of the Se is plant available in villages where the carbonaceous strata are interbedded with limestone. Villagers should be advised to avoid planting crops in these areas if possible.
Summary
Reasons for performing study
We hypothesised that the apparent geographical distribution of equine grass sickness (EGS) is partly attributable to suboptimal levels of soil macro‐ and trace ...elements in fields where EGS occurs. If proven, altering levels of particular elements could be used to reduce the risk of EGS.
Objectives
To determine whether the geographical distribution of EGS cases in eastern Scotland is associated with the presence or absence of particular environmental chemical elements.
Study design
Retrospective time‐matched case‐control study.
Methods
This study used data for 455 geo‐referenced EGS cases and 910 time‐matched controls in eastern Scotland, and geo‐referenced environmental geochemical data from the British Geological Survey Geochemical Baseline Survey of the Environment stream sediment (G‐BASE) and the James Hutton Institute, National Soil Inventory of Scotland (NSIS) datasets.
Results
Multivariable statistical analyses identified clusters of three main elements associated with cases from (i) the G‐BASE dataset ‐ higher environmental Ti and lower Zn, and (ii) the NSIS dataset ‐ higher environmental Ti and lower Cr. There was also some evidence from univariable analyses for lower Al, Cd, Cu, Ni and Pb and higher Ca, K, Mo, Na and Se environmental concentrations being associated with a case. Results were complicated by a high degree of correlation between most geochemical elements.
Conclusions
The work presented here would appear to reflect soil‐ not horse‐level risk factors for EGS, but due to the complexity of the correlations between elements, further work is required to determine whether these associations reflect causality, and consequently whether interventions to alter concentrations of particular elements in soil, or in grazing horses, could potentially reduce the risk of EGS. The effect of chemical elements on the growth of those soil microorganisms implicated in EGS aetiology also warrants further study.
REASONS FOR PERFORMING STUDY: Equine grass sickness (EGS) remains a frequently fatal disease of equids in Britain. Since previous investigations of signalment‐ and meteorology‐related risk factors ...for EGS have yielded some conflicting data, further investigation is warranted. OBJECTIVES: To identify signalment‐ and meteorology‐related risk factors for EGS in Scotland. STUDY DESIGN: Retrospective time‐matched case–control study. METHODS: This study was undertaken using data for 455 EGS cases and 910 time‐matched controls that were referred to the Royal (Dick) School of Veterinary Studies, and average UK Meteorological Office weather station meteorological values from the month of admission of the animal, from the 3, 6 and 12 months prior to admission, and for the entire 1990–2006 period. RESULTS AND CONCLUSION: Signalment‐related risk factors associated with an increased risk of EGS were native Scottish pure breeds compared with crossbreeds (odds ratio OR = 3.56, 95% confidence interval CI 2.43–5.43) and animals living on premises located further north within the study region (OR = 1.08, 95% CI 1.06–1.10). There was a decreased risk of EGS in animals aged 11–20 years compared with animals 2–10 years (OR = 0.32, 95% CI 0.22–0.45), non‐native Scottish pure breeds compared with crossbreeds (OR = 0.71, 95% CI 0.54–0.94), and stallions compared with mares (OR = 0.43, 95% CI 0.22–0.86). Meteorology‐related risk factors associated with an increased risk of EGS were (if Ordnance Survey northing is excluded) more sun hours (OR>1.43) and more frost days (OR>1.13), while there was a decreased risk of EGS with higher average maximum temperature (OR<0.83). POTENTIAL RELEVANCE: The signalment‐related risk factors will help owners identify high‐risk animals, thereby allowing them to prioritise management strategies. The identification of meteorological risk factors may assist studies on the aetiology of EGS.
Induced defenses are widespread in nature, and in amphibian larvae they are often expressed as altered behavior and changes in tail shape, color, and size. Theory predicts that induced defenses ...should be costly in the absence of a predator threat. No costs have been found for these defenses after metamorphosis. In this study, we tested for induced defenses in western toads, Bufo boreas, and measured larval and postmetamorphic consequences of these responses. Larvae were raised in either the presence or absence of nonlethal predator cues. Defense responses to these larval treatments were measured during the larval stage and shortly after metamorphosis using both predator bioassays and quantification of the putative chemical defense common in toads, bufadienolides. We found no differences in larval morphology, growth rate, or development rate between the predator and control treatments. In the larval bioassays, some types of invertebrate predators consumed significantly fewer of the B. boreas larvae that were reared with predator cues compared to the control treatments. Bufadienolides were not present in B. boreas larvae. In the postmetamorphic bioassays, tiger salamanders (Ambystoma tigrinum) had longer handling times when consuming B. boreas that had developed in larval environments without predator cues compared to predator-treatment B. boreas. However, postmetamorphic B. boreas from predator cue larval environments had significantly higher concentrations of bufadienolides than did those from larval environments without predators, suggesting that these defenses are ineffective against tiger salamanders. Our results demonstrate that there is plasticity in the chemical defenses of toads and suggest that induced larval defenses may incur costs that are only apparent after metamorphosis.
A strategy of administering a transfusion only when the hemoglobin level falls below 7 or 8 g per deciliter has been widely adopted. However, patients with acute myocardial infarction may benefit ...from a higher hemoglobin level.
In this phase 3, interventional trial, we randomly assigned patients with myocardial infarction and a hemoglobin level of less than 10 g per deciliter to a restrictive transfusion strategy (hemoglobin cutoff for transfusion, 7 or 8 g per deciliter) or a liberal transfusion strategy (hemoglobin cutoff, <10 g per deciliter). The primary outcome was a composite of myocardial infarction or death at 30 days.
A total of 3504 patients were included in the primary analysis. The mean (±SD) number of red-cell units that were transfused was 0.7±1.6 in the restrictive-strategy group and 2.5±2.3 in the liberal-strategy group. The mean hemoglobin level was 1.3 to 1.6 g per deciliter lower in the restrictive-strategy group than in the liberal-strategy group on days 1 to 3 after randomization. A primary-outcome event occurred in 295 of 1749 patients (16.9%) in the restrictive-strategy group and in 255 of 1755 patients (14.5%) in the liberal-strategy group (risk ratio modeled with multiple imputation for incomplete follow-up, 1.15; 95% confidence interval CI, 0.99 to 1.34; P = 0.07). Death occurred in 9.9% of the patients with the restrictive strategy and in 8.3% of the patients with the liberal strategy (risk ratio, 1.19; 95% CI, 0.96 to 1.47); myocardial infarction occurred in 8.5% and 7.2% of the patients, respectively (risk ratio, 1.19; 95% CI, 0.94 to 1.49).
In patients with acute myocardial infarction and anemia, a liberal transfusion strategy did not significantly reduce the risk of recurrent myocardial infarction or death at 30 days. However, potential harms of a restrictive transfusion strategy cannot be excluded. (Funded by the National Heart, Lung, and Blood Institute and others; MINT ClinicalTrials.gov number, NCT02981407.).
Endemic goitre has been reported in the climatic wet zone of south-west Sri Lanka for the past 50 years, but rarely occurs in the northern dry zone. Despite government-sponsored iodised salt ...programmes, endemic goitre is still prevalent. In recent years, it has been suggested that Se deficiency may be an important factor in the onset of goitre and other iodine deficiency disorders (IDD). Prior to the present study, environmental concentrations of Se in Sri Lanka and the possible relationships between Se deficiency and endemic goitre had not been investigated. During the present study, chemical differences in the environment (measured in soil, rice and drinking water) and the Se-status of the human population (demonstrated by hair samples from women) were determined for 15 villages. The villages were characterised by low (<10%), moderate (10–25%) and high (>25%) goitre incidence (NIDD, MIDD and HIDD, respectively). Results show that concentrations of soil total Se and iodine are highest in the HIDD villages, however, the soil clay and organic matter content appear to inhibit the bioavailability of these elements. Concentrations of iodine in rice are low (≤58 ng/g) and rice does not provide a significant source of iodine in the Sri Lankan diet. High concentrations of iodine (up to 84 μg/l) in drinking water in the dry zone may, in part, explain why goitre is uncommon in this area. This study has shown for the first time that significant proportions of the Sri Lankan female population may be Se deficient (24, 24 and 40% in the NIDD, MIDD and HIDD villages, respectively). Although Se deficiency is not restricted to areas where goitre is prevalent, a combination of iodine and Se deficiency could be involved in the pathogenesis of goitre in Sri Lanka. The distribution of red rice cultivation in Sri Lanka is coincident with the HIDD villages. Varieties of red rice grown in other countries contain anthocyanins and procyanidins, compounds which in other foodstuffs are known goitrogens. The potential goitrogenic properties of red rice in Sri Lanka are presently unknown and require further investigation. It is likely that the incidence of goitre in Sri Lanka is multi-factorial, involving trace element deficiencies and other factors such as poor nutrition and goitrogens in foodstuffs.
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