Arsenic accumulation and metabolism in rice (Oryza sativa L.)

The use of arsenic (As) contaminated groundwater for irrigation of crops has resulted in elevated concentrations of arsenic in agricultural soils in Bangladesh, West Bengal (India), and elsewhere. Paddy rice (Oryza sativa L.) is the main agricultural crop grown in the arsenic-affected areas of Bangladesh. There is, therefore, concern regarding accumulation of arsenic in rice grown those soils. A greenhouse study was conducted to examine the effects of arsenic-contaminated irrigation water on the growth of rice and uptake and speciation of arsenic. Treatments of the greenhouse experiment consisted of two phosphate doses and seven different arsenate concentrations ranging from 0 to 8 mg of As L(-1) applied regularly throughout the 170-day post-transplantation growing period until plants were ready for harvesting. Increasing the concentration of arsenate in irrigation water significantly decreased plant height, grain yield, the number of filled grains, grain weight, and root biomass, while the arsenic concentrations in root, straw, and rice husk increased significantly. Concentrations of arsenic in rice grain did not exceed the food hygiene concentration limit (1.0 mg of As kg(-1) dry weight). The concentrations of arsenic in rice straw (up to 91.8 mg kg(-1) for the highest As treatment) were of the same order of magnitude as root arsenic concentrations (up to 107.5 mg kg(-1)), suggesting that arsenic can be readily translocated to the shoot. While not covered by food hygiene regulations, rice straw is used as cattle feed in many countries including Bangladesh. The high arsenic concentrations may have the potential for adverse health effects on the cattle and an increase of arsenic exposure in humans via the plant-animal-human pathway. Arsenic concentrations in rice plant parts except husk were not affected by application of phosphate. As the concentration of arsenic in the rice grain was low, arsenic speciation was performed only on rice straw to predict the risk associated with feeding contaminated straw to the cattle. Speciation of arsenic in tissues (using HPLC-ICP-MS) revealed that the predominant species present in straw was arsenate followed by arsenite and dimethylarsinic acid (DMAA). As DMAA is only present at low concentrations, it is unlikely this will greatly alter the toxicity of arsenic present in rice.

Trading off dietary choices, physical exercise and cardiovascular disease risks

Despite several decades of decline, cardiovascular diseases are still the most common causes of death in Western societies. Sedentary living and high fat diets contribute to the prevalence of cardiovascular diseases. This paper analyses the trade-offs between lifestyle choices defined in terms of diet, physical activity, cost, and risk of cardiovascular disease that a representative sample of the population of Northern Ireland aged 40-65 are willing to make. Using computer assisted personal interviews, we survey 493 individuals at their homes using a Discrete Choice Experiment (DCE) questionnaire administered between February and July 2011 in Northern Ireland. Unlike most DCE studies for valuing public health programs, this questionnaire uses a tailored exercise, based on the individuals’ baseline choices. A “fat screener” module in the questionnaire links personal cardiovascular disease risk to each specific choice set in terms of dietary constituents. Individuals are informed about their real status quo risk of a fatal cardiovascular event, based on an initial set of health questions. Thus, actual risks, real diet and exercise choices are the elements that constitute the choice task. Our results show that our respondents are willing to pay for reducing mortality risk and, more importantly, are willing to change physical exercise and dietary behaviours. In particular, we find that to improve their lifestyles, overweight and obese people would be more likely to do more physical activity than to change their diets. Therefore, public policies aimed to target obesity and its related illnesses in Northern Ireland should invest public money in promoting physical activity rather than healthier diets.

Arsenic uptake and metabolism in arsenic resistant and nonresistant plant species

Elevation of arsenic levels in soils causes considerable concern with respect to plant uptake and subsequent entry into wildlife and human food chains, Arsenic speciation in the environment is complex, existing in both inorganic and organic forms, with interconversion between species regulated by biotic and abiotic processes. To understand and manage the risks posed by soil arsenic it is essential to know how arsenic is taken up by the roots and metabolized within plants. Some plant species exhibit phenotypic variation in response to arsenic species, which helps us to understand the toxicity of arsenic and the way in which plants have evolved arsenic resistances. This knowledge, for example, could be used produce plant cultivars that are more arsenic resistant or that have reduced arsenic uptake. This review synthesizes current knowledge on arsenic uptake, metabolism and toxicity for arsenic resistant and nonresistant plants, including the recently discovered phenomenon of arsenic hyperaccumulation in certain fern species. The reasons why plants accumulate and metabolize arsenic are considered in an evolutionary context. © New Phytologist.

Musculoskeletal (MSK) and Sport and Exercise Medicine (SEM) in General Practice (GP): A Novel GP-based clinic

The problem-Musculoskeletal (MSK) symptoms are common within primary care but some GPs are not comfortable managing these; waiting times for hospital appointments are a major cause of patients’ complaints. Current UK healthcare policies emphasise a need for more community-based management. We aimed to pilot an innovative general practice-based clinic to improve the management of MSK and Sport and Exercise Medicine (SEM) symptoms within general practice.

The approach-This project was conducted in an inner-city practice of approximately 9,000 patients and 5 GP partners. The practice commissioned a novel monthly 4-hour clinic staffed by one GP with a specialist interest in MSK and SEM conditions. Each patient was allocated a 20-minute appointment. All primary care staff within the practice could refer any patient for whom they considered hospital referral appropriate, with no specific exclusion criteria. Management plans included injection therapy, exercise prescription and onward referral. After three months (August-October 2014) numbers of consultations, sources of referral, reasons for referral and management outcomes were described; patient satisfaction was assessed by questionnaire, offered to 10 randomly selected patients by reception staff and self-completed by patients. Costs of the clinic were compared to current options.

Findings- All patients (14 males; 21 females; aged 35-77 years), were seen within four weeks of referral (one third of orthopaedic referrals in 2013 waited over 9 weeks for appointment). Most were referred from other GPs; some came from physiotherapy and podiatry. Shoulder problems were the most frequent reason for referral. The commonest management option was steroid injection, with most patients being given advice regarding exercise and analgesia; there were 3 onward referrals (2 physiotherapy; 1 rheumatology).

Comparing August-October data in 2014 and 2013, total, orthopaedic and rheumatology referrals were reduced by 147, 2 and 3, respectively; within the practice MSK presentations and physiotherapy and x-ray referrals were 60, 47 and 90 fewer, respectively.

The cost per attendance at the clinic was £61; initial orthopaedic-ICAT assessments cost £82 and a consultant appointment £213.

Satisfaction questionnaires were returned by all 10 selected participants and provided positive feedback, expressing preference for community-based, rather than hospital, management.

Consequence- Our pilot study indicates that this novel service model has potential for efficient and effective management of MSK and SEM complaints in primary care, reducing the need for hospital referral and the clinical burden on general practices. The innovation deserves further evaluation in a full-scale trial to determine its generalisability to other practice settings and populations.