Arsenic behaviour from groundwater and soil to crops:impacts on agriculture and food safety

High levels of As in groundwater commonly found in Bangladesh and other parts of Asia not only pose a risk via drinking water consumption but also a risk in agricultural sustainability and food safety. This review attempts to provide an overview of current knowledge and gaps related to the assessment and management of these risks, including the behaviour of As in the soil-plant system, uptake, phytotoxicity, As speciation in foods, dietary habits, and human health risks. Special emphasis has been given to the situation in Bangladesh, where groundwater via shallow tube wells is the most important source of irrigation water in the dry season. Within the soil-plant system, there is a distinct difference in behaviour of As under flooded conditions, where arsenite (AsIII) predominates, and under nonflooded conditions, where arsenate (AsV) predominates. The former is regarded as most toxic to humans and plants. Limited data indicate that As-contaminated irrigation water can result in a slow buildup of As in the topsoil. In some cases the buildup is reflected by the As levels in crops, in others not. It is not yet possible to predict As uptake and toxicity in plants based on soil parameters. It is unknown under what conditions and in what time frame As is building up in the soil. Representative phytotoxicity data necessary to evaluate current and future soil concentrations are not yet available. Although there are no indications that crop production is currently inhibited by As, long-term risks are clearly present. Therefore, with concurrent assessments of the risks, management options to further prevent As accumulation in the topsoil should already have been explored. With regard to human health, data on As speciation in foods in combination with food consumption data are needed to assess dietary exposure, and these data should include spatial and seasonal variability. It is important to control confounding factors in assessing the risks. In a country where malnutrition is prevalent, levels of inorganic As in foods should be balanced against the nutritional value of the foods. Regarding agriculture, As is only one of the many factors that may pose a risk to the sustainability of crop production. Other risk factors such as nutrient depletion and loss of organic matter also must be taken into account to set priorities in terms of research, management, and overall strategy.

From 'Good as Gold' to 'Gold Diggers': Farming Women and the Survival of British Family Farming

The survival of family farming in British agriculture has long been a topic of interest for rural researchers and is undergoing something of a current renewal of interest. However, insights from feminist approaches remain underutilised despite the crucial role farming women continue to play in family farming. This paper addresses the unity of farm, family and business by interpreting it as a patriarchal â??way of lifeâ??. An ethnographic-informed repeated life history methodology is employed to study in detail the family members of seven farms in rural mid-Wales. Findings show that the recent survival of the family farms investigated has been heavily dependent upon compliance with a patriarchal ideology that demands women be â??as good as goldâ??. However, it is discovered that a new view of women is emerging in the world of British family farming, that of â??gold diggerâ??. Women entering relationships with farming men are increasingly being considered a threat to farm survival by virtue of their entitlements if the relationship breaks down. The necessity to study the intricacies of personal relationships in family farming has important implications for most future research into this form of agricultural business arrangement.

Microbial analysis of soil and groundwater from a gasworks site and comparison to a sequenced biological reactive barrier remediation process (SEREBAR)

Aims: To investigate the distribution of a polymicrobial community of biodegradative bacteria in (i) soil and groundwater at a former manufactured gas plant (FMGP) site and (ii) in a novel SEquential REactive BARrier (SEREBAR) bioremediation process designed to bioremediate the contaminated groundwater. Methods and Results: Culture-dependent and culture-independent analyses using denaturing gradient gel electrophoresis (DGGE) and polymerase chain reaction (PCR) for the detection of 16S ribosomal RNA gene and naphthalene dioxygenase (NDO) genes of free-living (planktonic groundwater) and attached (soil biofilm) samples from across the site and from the SEREBAR process was applied. Naphthalene arising from groundwater was effectively degraded early in the process and the microbiological analysis indicated a dominant role for Pseudomonas and Comamonas in its degradation. The microbial communities appeared highly complex and diverse across both the sites and in the SEREBAR process. An increased population of naphthalene degraders was associated with naphthalene removal. Conclusion: The distribution of micro-organisms in general and naphthalene degraders across the site was highly heterogeneous. Comparisons made between areas contaminated with polycyclic aromatic hydrocarbons (PAH) and those not contaminated, revealed differences in the microbial community profile. The likelihood of noncultured bacteria being dominant in mediating naphthalene removal was evident. Significance and Impact of the Study: This work further emphasizes the importance of both traditional and molecular-based tools in determining the microbial ecology of contaminated sites and highlights the role of noncultured bacteria in the process.

Mature DC from skin and skin-draining LN retain the ability to acquire and efficiently present targeted antigen.

Skin-draining LN contain several phenotypically distinguishable DC populations, which may be immature or mature. Mature DC are generally considered to have lost the capacity to acquire and present newly encountered Ag. Using antibody-opsonized liposomes as Ag carriers, we show that mature DC purified from skin explants are able to efficiently capture liposomes, process Ag encapsulated within them and activate Ag-specific CD4(+) T cells. Explant DC from mice with Langerhans cells (LC) expressing the primate diphtheria toxin receptor that were exposed to diphtheria toxin in vivo presented Ag as well as explant DC from wild-type mice, indicating that LC are not required and dermal DC are probably responsible for this presentation. We further show that all DC subtypes from LN that capture opsonized Ag are capable of cross-presenting it to CD8(+) T cells. Induction of additional maturation in vivo by LPS or treatment with double-stranded RNA did not alter the Ag presentation capacity of the skin or LN DC subtypes. These results suggest that mature DC present in skin-draining LN may play an important role in the induction of primary and/or secondary immune responses against Ag delivered to the LN that they take up by receptor-mediated endocytosis.

PVT Property Measurements for Some Aliphatic Esters from (298 to 393) K and up to 35 MPa

The results of PVT measurements of the liquid phase within the temperature range of (298 to 393) K and up to 35 MPa are presented for some aliphatic esters. Measurements were made by means of a vibrating-tube densimeter, model DMA 512P from Anton Parr. The calibration of the densimeter was performed with water and n-heptane as reference fluids. The experimental PVT data have been correlated by a Tait equation. This equation gives excellent results when used to predict the density of the esters using the method proposed by Thomson et al. (AIChE J. 1982, 28, 671-676). Isothermal compressibilities, isobaric expansivities, thermal pressure coefficients, and changes in the isobaric heat capacity have been calculated from the volumetric data.

Safety and Pharmacokinetics of Dapivirine Delivery From Matrix and Reservoir Intravaginal Rings to HIV-Negative Women

Vaginal microbicides for the prevention of HIV transmission may be an important option for protecting women from infection. Incorporation of dapivirine, a lead candidate nonnucleoside reverse transcriptase inhibitor, into intravaginal rings (IVRs) for sustained mucosal delivery may increase microbicide product adherence and efficacy compared with conventional vaginal formulations. Twentyfour
healthy HIV-negative women 18–35 years of age were randomly assigned (1:1:1) to dapivirine matrix IVR, dapivirine reservoir IVR, or placebo IVR. Dapivirine concentrations were measured in plasma
and vaginal fluid samples collected at sequential time points over the 33-day study period (28 days of IVR use, 5 days of follow-up). Safety was assessed by pelvic/colposcopic examinations, clinical laboratory tests, and adverse events. Both IVR types were safe and well tolerated with similar adverse events observed in the placebo and dapivirine groups. Dapivirine from both IVR types was successfully distributed throughout the lower genital tract at concentrations over 4 logs greater than the EC50 against wild-type HIV-1 (LAI) in MT4 cells. Maximum concentration (Cmax) and area under the concentration–time curve (AUC) values were significantly higher with the matrix than reservoir IVR. Mean plasma concentrations of dapivirine were ,2 ng/mL. These findings suggest that IVR delivery of microbicides is a viable option meriting further study.

Non-shivering thermogenesis in common spiny mice Acomys cahirinus from adjacent habitats: response to seasonal acclimatization and salinity acclimation

1. We compared resting metabolic rate (RMR) and non-shivering thermogenesis (NST) values between founder and F1-populations of winter-acclimatized Acomys cahirinus that originated from north- and south-facing slopes (NFS and SFS) of the same valley, representing mesic and xeric habitats. 2. NST was measured by the increase in oxygen consumption (VO2) and body temperature (T-b) after a noradrenaline (NA) injection (VO2 NA, TbNA). 3. Body mass and TbNA values were higher in SFS F1-mice, while RMR and VO2 NA values were higher in NFS F1-mice. Differences were not apparent in founders. 4. Results are consistent with NFS and SFS mice being considered as

Presence of arsenic in agricultural products from arsenic-endemic areas and strategies to reduce arsenic intake in rural villages

About 100 million rural people in Asia are exposed to arsenic (As)-polluted drinking water and agricultural products. Total and inorganic arsenic (t-As and i-As) intake mainly depend on the quality of drinking and cooking waters, and amounts of seafood and rice consumed. The main problems occur in countries with poor water quality where the population depends on rice for their diet, and their t-As and i-As intake is high as a result of growing and cooking rice in contaminated water. Workable solutions to remove As from water and breeding rice cultivars with low As accumulation are being sought. In the meantime, simple recommendations for processing and cooking foods will help to reduce As intake. For instance, cooking using high volumes of As-free water may be a cheap way of reducing As exposure in rural populations. It is necessary to consider the effects of cooking and processing on t-As and i-As to obtain a realistic view of the risks associated with intake of As in Asendemic areas.

Identifying families with multiple problems: Possible responses from child and family social work to current policy developments

In the development of family policy under New Labour there has been a growing tendency to identify groups who are likely to be high in lifetime costs to the state. Investment in such groups is seen as crucial. Whilst the economic case for current investment is compelling, idenitiying one of these groups, ‘families with multiple problems’ raises complex research problems and ethical issues. Reseach indicates that families with multiple problems may be identified on the caseloads of child and family social worker and there are claims that key events such as the registration of a child on the child protection register may indicate such multiple problems. This offers new opportunities for child and family social work to embrace less incident based ways of working in favour of longer term provision of services to address longer term risks.