Liver copper concentrations in cull cattle in the UK: are cattle being copper loaded?

With the release of the Department for the Environment, Food and Rural Affairs/Advisory Committee on Animal Feed Guidance Note for Supplementing Copper to Bovines it was noted that the current copper status of the national herd was not known. Liver samples were recovered from 510 cull cattle at a single abattoir across a period of three days. The samples were wet-ashed and liver copper concentrations determined by inductively coupled plasma mass spectrometry analysis. Breed, age and previous location information were obtained from the British Cattle Movement Service. Dairy breeds had higher liver copper concentrations than beef breeds. Holstein-Friesian and ‘other’ dairy breeds had 38.3 per cent and 40 per cent of cattle above the Animal Health and Veterinary Laboratories Agency (AHVLA) reference range (8000 µmol/kg dry matter), respectively, whereas only 16.9 per cent of animals in the combined beef breeds exceeded this value. It was found that underlying topsoil copper concentration was not related to liver copper content and that age of the animal also had little effect on liver concentration. In conclusion, over 50 per cent of the liver samples tested had greater-than-normal concentrations of copper with almost 40 per cent of the female dairy cattle having liver copper concentrations above the AHVLA reference range, indicating that a significant proportion of the UK herd is at risk of chronic copper toxicity

Lability of Pb in soil: effects of soil properties and contaminant source

Environmental Context: There is growing concern that lead (Pb) in the environment may cause adverse health effects in human populations. We investigated the combined use of isotopic abundance and isotopic dilution to show how the origins of soil Pb and soil characteristics affect lability. Soil pH and soil Pb content are the dominant controls on Pb lability; the lability of recent petrol-derived Pb is similar to that of other sources in urban soils but greater than geogenic Pb in rural roadside topsoils. Lability of lead (Pb) in soils is influenced by both soil properties and source(s) of contamination. We investigated factors controlling Pb lability in soils from (i) land adjacent to a major rural road, (ii) a sewage processing farm and (iii) an archive of the geochemical survey of London. We measured isotopically exchangeable Pb (E-values; PbE), phase fractionation of Pb by a sequential extraction procedure (SEP) and inferred source apportionment from measured Pb isotopic ratios. Isotopic ratios (206Pb/207Pb and 208Pb/207Pb) of total soil Pb fell on a mixing line between those of petrol and UK coal or Pb ore. The main determinant of the isotopically exchangeable Pb fraction (%E-value) was soil pH: %E-values decreased with increasing pH. In rural roadside topsoils and there was also evidence that, petrol-derived Pb remained more labile (35%) than Pb from soil parent material (27%). However, in biosolid-amended and London soils %E-values were low (c. 25%), covered a restricted range, and showed no clear evidence of source-dependent lability

Zinc-enriched fertilisers as a potential public health intervention in Africa

Background In this review, we examine the potential of Zn-enriched fertilisers to alleviate human dietary Zn deficiency. The focus is on ten African countries where dietary Zn supply is low and where fertiliser subsidies are routinely deployed on cereal crops. Scope Dietary Zn supply and deficiency prevalence were quantified from food supply and composition data. Typical effects of soil (granular) and foliar Zn applications on Zn concentrations in maize (Zea mays L.), rice (Oryza sativa L.) and wheat (Triticum aestivum L.) grains were based on a systematic literature review. Reductions in disease burdens attributable to Zn deficiency and cost-effectiveness were estimated using a disability-adjusted life years (DALYs) approach. Conclusions Baseline Zn supply in 2009 ranged from 7.1 (Zambia) to 11.9 (Mali) mg capita−1 day−1; prevalence of Zn deficiency ranged from 24 (Nigeria) to 66 % (Zambia). In reviewed studies, soil Zn application led to an increase in median Zn concentration in maize, rice and wheat grains of 23, 7 and 19 %; foliar application led to increases of 30, 25 and 63 %. Enriching granular fertilisers within current subsidy schemes would be most effective in Malawi, reducing DALYs lost due to Zn deficiency by 10 %. The cost per DALY saved ranged from US$624 to 5893 via granular fertilisers and from US$ 46 to 347 via foliar fertilisers. Foliar applications are likely to be more cost effective than soil applications due to fixation of Zn in the soil but may be more difficult to deploy. Zinc fertilisation is likely to be less cost-effective than breeding in the longer term although other micronutrients such as selenium could be incorporated

Optimisation of a current generation ICP-QMS and benchmarking against MC-ICP-MS spectrometry for the determination of lead isotope ratios in environmental samples

© 2018 The Royal Society of Chemistry. Novel ANOVA methodology was used to benchmark ICP-QMS against MC-ICP-MS for Pb isotope ratios, demonstrating "fitness-for-purpose" in environmental source apportionment. The precision and accuracy of lead (Pb) isotope measurements obtained from quadrupole-based mass spectrometers (ICP-QMS) are considered to be limited by a number of factors originating in different components of the instruments. In this study, experimental and instrumental protocols were optimised for determining lead isotope ratios in urban soil digests. Experimental measures included individual dilution of all samples and isotopic standards (SRM-981, NIST) to a single Pb concentration intended to produce an intensity which was high enough to negate blanks and interferences but low enough to ensure the detector operated only in pulse counting mode. Instrumental protocols included batch dead time correction, optimisation of dwell time and the number of scans employed and correction of mass discrimination by sequential application of both internal ( 203 Tl/ 205 Tl ratio) and external (SRM-981, NIST) standards. This optimised methodology was benchmarked against multi-collector mass spectrometer (MC-ICP-MS) measurements of Pb isotope ratios using replicate digest solutions of the same soil; but after these had been subjected to Pb separation using an ion-exchange procedure. On the assumption that MC-ICP-MS measurements are more accurate, small additive and multiplicative differences were observed in only the 4 th decimal place. ANOVA was used to compare the precisions of the two techniques demonstrating equal precisions c. 0.08% for 207 Pb/ 206 Pb, suggesting a sample heterogeneity limitation. By contrast, for 207 Pb/ 204 Pb, the worst-case ratio, ICP-QMS had a 10-fold poorer precision, despite negligible interference from 204 Hg, implying an instrumental limitation. The study concludes that ICP-QMS can provide valuable source apportionment information for most Pb isotope ratios but further efforts should focus on improving assay of the 207 Pb/ 204 Pb ratio

A reconnaissance survey of farmers’ awareness of hypomagnesaemic tetany in UK cattle and sheep farms

Hypomagnesaemic tetany (HypoMgT) in ruminants is a physiological disorder caused by inadequate intake or impaired absorption of magnesium (Mg) in the gut. If it is not detected and treated in time, HypoMgT can cause the death of the affected animal. A semi-structured questionnaire survey was conducted from July 2016–2017 to assess farmers’ awareness of HypoMgT in cattle and sheep in the UK. The questionnaire was distributed to farmers at farm business events and agricultural shows, and through a collaborative group of independent veterinary practices to their clients. Farmers were asked about (i) the incidence of presumed HypoMgT (PHT); (ii) their strategies to treat or prevent HypoMgT; (iii) mineral tests on animals, forage and soil, and (iv) farm enterprise type. A total of 285 responses were received from 82 cattle, 157 mixed cattle and sheep, and 46 sheep farmers, of whom 39% reported HypoMgT in their livestock, affecting 1–30 animals. Treatment and/or prevention against HypoMgT was reported by 96% respondents with PHT and 79% of those without. Mineral tests on animal, forage, and soil was conducted by 24%, 53%, and 66% of the respondents, respectively, regardless of PHT. There was a highly significant association between the use of interventions to tackle HypoMgT and the incidence of PHT (p < 0.01). The top three treatment/prevention strategies used were reported as being free access supplementation (149), in feed supplementation (59) and direct to animal treatments (drenches, boluses and injections) (45) although these did vary by farm type. Although some (9) reported using Mg-lime, no other pasture management interventions were reported (e.g., Mg-fertilisation or sward composition). Generally, the results indicate that UK farmers are aware of the risks of HypoMgT. A more integrated soil-forage-animal assessment may improve the effectiveness of tackling HypoMgT and help highlight the root causes of the problem

Valuing increased zinc (Zn) fertiliser-use in Pakistan

Use of zinc (Zn) fertilisers may be cost-effective in increasing crop yields and in alleviating dietary Zn deficiency. However, Zn fertilisers are underutilised in many countries despite the widespread occurrence of Zn-deficient soils. Here, increased Zn fertiliser-use scenarios were simulated for wheat production in Punjab and Sindh Provinces, Pakistan. Inputs and outputs were valued in terms of both potential yield gains as well as health gains in the population. Methods The current dietary Zn deficiency risk of 23.9 % in Pakistan was based on food supply and wheat grain surveys. “Disability-adjusted life years (DALYs) lost” are a common metric of disease burden; an estimated 245,000 DALYs y−1 are lost in Punjab and Sindh due to Zn deficiency. Baseline Zn fertiliser-use of 7.3 kt y−1 ZnSO4.H2O was obtained from published and industry sources. The wheat area currently receiving Zn fertilisers, and grain yield responses of 8 and 14 % in Punjab and Sindh, respectively, were based on a recent survey of >2500 farmers. Increased grain Zn concentrations under Zn fertilisation were estimated from literature data and converted to improved Zn intake in humans and ultimately a reduction in DALYs lost

Selenium deficiency is widespread and spatially dependent in Ethiopia

Selenium (Se) is an essential element for human health and livestock productivity. Globally, human Se status is highly variable, mainly due to the influence of soil types on the Se content of crops, suggesting the need to identify areas of deficiency to design targeted interventions. In sub-Saharan Africa, including Ethiopia, data on population Se status are largely unavailable, although previous studies indicated the potential for widespread Se deficiency. Serum Se concentration of a nationally representative sample of the Ethiopian population was determined, and these observed values were combined with a spatial statistical model to predict and map the Se status of populations across the country. The study used archived serum samples (n = 3269) from the 2015 Ethiopian National Micronutrient Survey (ENMS). The ENMS was a cross-sectional survey of young and school-age children, women and men. Serum Se concentration was measured using inductively coupled plasma mass spectrometry (ICPMS). The national median (Q1, Q3) serum Se concentration was 87.7 (56.7, 123.0) μg L−1. Serum Se concentration differed between regions, ranging from a median (Q1, Q3) of 54.6 (43.1, 66.3) µg L−1 in the Benishangul-Gumuz Region to 122.0 (105, 141) µg L−1 in the Southern Nations, Nationalities, and Peoples’ Region and the Afar Region. Overall, 35.5% of the population were Se deficient, defined as serum Se < 70 µg L−1. A geostatistical analysis showed that there was marked spatial dependence in Se status, with serum concentrations greatest among those living in North-East and Eastern Ethiopia and along the Rift Valley, while serum Se concentrations were lower among those living in North-West and Western Ethiopia. Selenium deficiency in Ethiopia is widespread, but the risk of Se deficiency is highly spatially dependent. Policies to enhance Se nutrition should target populations in North-West and Western Ethiopi

Hazard ranking method for populations exposed to arsenic in private water supplies: relation to bedrock geology

Approximately one million people in the UK are served by private water supplies (PWS) where main municipal water supply system connection is not practical or where PWS is the preferred option. Chronic exposure to contaminants in PWS may have adverse effects on health. South West England is an area with elevated arsenic concentrations in groundwater and over 9000 domestic dwellings here are supplied by PWS. There remains uncertainty as to the extent of the population exposed to arsenic (As), and the factors predicting such exposure. We describe a hazard assessment model based on simplified geology with the potential to predict exposure to As in PWS. Households with a recorded PWS in Cornwall were recruited to take part in a water sampling programme from 2011 to 2013. Bedrock geologies were aggregated and classified into nine Simplified Bedrock Geological Categories (SBGC), plus a cross-cutting “mineralized” area. PWS were sampled by random selection within SBGCs and some 508 households volunteered for the study. Transformations of the data were explored to estimate the distribution of As concentrations for PWS by SBGC. Using the distribution per SBGC, we predict the proportion of dwellings that would be affected by high concentrations and rank the geologies according to hazard. Within most SBGCs, As concentrations were found to have log-normal distributions. Across these areas, the proportion of dwellings predicted to have drinking water over the prescribed concentration value (PCV) for As ranged from 0% to 20%. From these results, a pilot predictive model was developed calculating the proportion of PWS above the PCV for As and hazard ranking supports local decision making and prioritization. With further development and testing, this can help local authorities predict the number of dwellings that might fail the PCV for As, based on bedrock geology. The model presented here for Cornwall could be applied in areas with similar geologies. Application of the method requires independent validation and further groundwater-derived PWS sampling on other geological formation

The availability and geographic location of open-source food composition data used to estimate micronutrient intakes in sub-Saharan Africa: A scoping review

BACKGROUND: Estimates of dietary micronutrient intakes rely on food composition data. The nutrient composition of foods varies spatially with potentially large effects on dietary micronutrient intakes. This review assessed the availability and geographic origin of five minerals (calcium, iron, iodine, selenium and zinc) in publicly available food composition tables/databases (FCTs) for use in sub-Saharan Africa (SSA). METHODS: A scoping review was conducted following PRISMA guidelines, in which four databases (MEDLINE, Embase, Global Health and Africa Wide Information) and four online resources were searched to identify published FCTs for use in SSA. Metadata were reviewed to identify the geographic origin of composition values for selected foods. RESULTS: Nineteen publicly available FCTs were identified, with the highest geographic coverage in Eastern Africa (45% of countries) and lowest coverage in Central Africa (12% of countries). Iodine and selenium were reported in four and six FCTs, respectively, while iron and calcium were included in ≥ 18 FCTs. More than 60% of nutrient values were borrowed from other FCTs. The geographic origin of 22% of mineral values were documented. CONCLUSIONS: Limited local food composition analytical data is available, for estimating mineral intakes of SSA populations, with poor documentation of the data sources and the geographic origins of samples. New data structures and improved metadata are required to capture and report geographic information in publicly available FCTs, and to accommodate a new generation of spatially-resolved food composition data

Short-term iodine dynamics in soil solution

Assessing the reactions of iodine (I) in soil is critical to evaluate radioiodine exposure and understand soil-to-crop transfer rates. Our mechanistic understanding has been constrained by method limitations in assessing the dynamic interactions of iodine between soil solution and soil solid phase over short periods (hours). We use microdialysis to passively extract soil solution spiked with radioiodine (129I– and 129IO3–) to monitor short-term (≤40 h) in situ fixation and speciation changes. We observed greater instantaneous adsorption of 129IO3– compared to 129I– in all soils and the complete reduction of 129IO3– to 129I– within 5 h of addition. Loss of 129I from solution was extremely rapid; the average half-lives of 129I– and 129IO3– in soil solution were 4.06 and 10.03 h, respectively. We detected the presence of soluble organically bound iodine (org-129I) with a low molecular weight (MW) range (0.5–5 kDa) in all soils and a slower (20–40 h) time-dependent formation of larger MW org-I compounds (12–18 kDa) in some samples. This study highlights the very short window of immediate availability in which I from rainfall or irrigation remains in soil solution and available to crops, thus presenting significant challenges to phytofortification strategies in soil-based production systems