Blood Pb Levels in pregnant Nigerian women in Abakaliki, South-Eastern Nigeria

Environmental lead (Pb) exposure and toxicity have been recognised as public health problems of global importance, affecting both the developed and developing nations. In this work, blood Pb of pregnant women that were not exposed to lead by their occupation (n?=?349), with mean ± SD age of 27.0?±?4.8 years and gestational age of 21.8?±?3.1 weeks at recruitment were determined using atomic absorption spectrophotometer. The results showed that 309 (88.5 %) of the women had a mean?±?SD blood Pb of 40.0?±?16.5 μg/dl, which is higher than the current US Centre for Disease Prevention and Control action limit (>10 μg/dl). The observed high prevalence of elevated blood Pb levels may be related to maternal low socioeconomic status. Health education is, therefore, urgently needed to sensitise the general public and the policy makers of the level of Pb exposure in Abakaliki environment and the inherent health implications. In addition to mandatory environmental lead monitoring, blood Pb screening for would-be mother is recommended, and those whose blood Pb are found elevated should be appropriately treated.     

Individual-level patterns of division of labor in honeybees highlight flexibility in colony-level developmental mechanisms

Honeybee division of labor (DOL) has become a model system for exploring the genetic basis of complex traits and phenotypic plasticity. Although many highly informative behavioral studies have been conducted on this topic (both at the cohort and individual levels), most studies have focused on a few behavioral acts, such as the age of first foraging. Few studies have recorded large numbers of relatively complete individual-level patterns of DOL. Such fine-scale patterns would lay the foundation for rigorous molecular analyses of this phenomenon and allow us to differentiate between competing mechanistic models of DOL. Here, we record over 100 individual-level DOL patterns of bees living under natural conditions. We found that the transitions between castes (polyphenism states) are often gradual, with bees being in multiple castes at once. This is contrary to the traditional view that changes are abrupt. We also found that bees often skip castes, a key prediction of a recent model of DOL. We further confirm variation in the rate at which bees pass through castes and the age of first foraging. Taken together, these results greatly improve our understanding of this model system and allow for a strong revision of current models of honeybee DOL.     

Psychological drivers of risk-reducing behaviors to limit human–wildlife conflict

Conflicts between people and wild animals are increasing globally, often with serious consequences for both. Local regulations or ordinances are frequently used to promote human behaviors that minimize these conflicts (risk-reducing behaviors), but compliance with ordinances can be highly variable. While efforts to increase compliance could be improved through applications of conservation psychology, little is known about the relative influence of different factors motivating compliance. Using concepts from psychology and risk theory, we conducted a longitudinal study pairing data from mail surveys with direct observations of compliance with a wildlife ordinance requiring residents to secure residential garbage from black bears (Ursus americanus). We assessed the relative influence of beliefs and attitudes toward bears and bear proofing, perceived behavioral control, perceived risks and benefits assigned to bears, norms, trust in management, previous experience with conflicts, and demographics on compliance behavior (i.e., bear proofing). Data on previous experience were obtained through direct observation and survey reports. We found that higher compliance rates were associated with more observed conflicts on a respondent's block. Counter to expectations, however, residents were less compliant when they were more trusting of the management agency and perceived more benefits from bears. We suggest that messages have the potential to increase compliance when they empower residents by linking successful management of conflicts to individual actions and emphasize how reducing conflicts could maintain benefits provided by wildlife. Modifying existing educational materials to account for these psychological considerations and evaluating their impact on compliance behavior over time are important next steps in changing human behaviors relevant to the globally important problem of human-wildlife conflict.     

Ex situ management as insurance against extinction of mammalian megafauna in an uncertain world

The persistence of endangered species may depend on the fate of a very small number of individual animals. In situ conservation alone may sometimes be insufficient. In these instances, the International Union for Conservation of Nature provides guidelines for ex situ conservation and the Convention on Biological Diversity (CBD) indicates how ex situ management can support the CBD's objectives by providing insurance policies for species. The circumstances that justify its use are uncertain. To evaluate the current in situ extinction risk and ex situ management of 43 critically endangered species of mammalian megafauna, we used nonmetric multidimensional scaling and geopolitical variables related to governance, economics, and national policy within their extant ranges. We then fitted generalized additive models to assess the contribution of each variable to the ordination. Fifteen (almost one-third) of the world's terrestrial mammalian megafauna are not the subject of any ex situ management. Seventy-three percent of these taxa occur in areas characterized by political uncertainty, such as border zones or areas affected by armed conflicts, mainly in Africa and the Middle East. A further 23% of taxa in ex situ programs do not meet sustainability criteria for inbreeding avoidance. Strategic conservation planning, such as the One Plan approach, may improve ex situ management for these taxa. Given the escalating trend in threats afflicting megafauna, ex situ management should be considered more rigorously, particularly in politically unstable regions, to achieve CBD Target 12 (prevent extinction of threatened species).     

Pilot-scale aerated submerged biofilm reactor for organics removal and nitrification at cold temperatures.

This research describes pilot-scale experiments for efficient removal of dissolved organic and nitrogen compounds in domestic wastewater using aerated submerged biofilm (ASBF) reactors. These reactors could enhance the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. The structures are designed to encourage the growth of a nitrifying bacterial biofilm on a submerged surface. They also force the direct contact of rising air bubbles against the submerged biofilm. This direct gas-phase contact is postulated to increase the oxygen transfer rate into the biofilm and increase the microclimate mixing of water, nutrients, and waste products into and out of the biofilm. This research investigated the efficiency of dissolved organic matter and ammonia-nitrogen removals. Specifically, the effects of cold temperatures on the dissolved organic matter and ammonia-nitrogen performance of the ASBF pilot plant (see Figure 1) was investigated for the batch system. Over a period of 3.5 months, a total of 11 batch runs were performed. By the fourth run, the biofilm had matured to the point that it consumed all the ammonia in 40 hours. On the ninth run, the air supply was left off as a control run. This time, the ammonia was barely consumed, with the level dropping from 24 to 18 mg/L in 40 hours. By the middle of December, the average water temperature during the runs had dropped to approximately 6 degrees C and, at one point, was as low as 3.3 degrees C. The biofilm continued to perform even at these low temperatures, reducing ammonia levels from approximately 25 mg/L to basically zero within 40 to 48 hours.     

Antimony speciation and contamination of waters in the Xikuangshan antimony mining and smelting area,China

Water samples from Xikuangshan (China), the world largest antimony (Sb) mine with a Sb mining and smelting history of more than 200 years, were analyzed. These water samples ranged from stream water in the vicinity of the mining and smelting area that received seepage from ore residues to the underground mine-pit drainage. The concentrations of total Sb, Sb (III) and Sb (V) of the samples were determined by HPLC-ICP-MS. In addition, water pH and concentrations of major cations and anions were analyzed. All 18 samples demonstrated total Sb concentrations with ppm levels from 0.33 ppm to 11.4 ppm, which is two to three orders of magnitude higher compared to the typical concentration of dissolved Sb in unpolluted rivers (less than 1 ppb). This is probably the first time that such high Sb contents have been documented with complete environmental information. Distribution of total Sb and Sb species was investigated, taking into account the respective local environment (in the mining area or close to the smelter, etc.). Sb (V) was the predominant valence in all 18 samples. Only trace levels of Sb (III) were detected in 4 of the 18 samples. Geochemical speciation modeling showed the dominant species was Sb(OH)₆⁻. It is also probably the first time that such high Sb contents have been documented in the natural environment with Sb speciation distribution information. Several potential oxidation pathways are also discussed that might have facilitated the oxidation of Sb (III) in the natural environment. Signs of intoxication were observed among local mine workers with extensive exposure to different forms of Sb for a long period of time.     

Development and application of biotechnologies in the metal mining industry

Metal mining faces a number of significant economic and environmental challenges in the twenty-first century for which established and emerging biotechnologies may, at least in part, provide the answers. Bioprocessing of mineral ores and concentrates is already used in variously engineered formats to extract base (e.g., copper, cobalt, and nickel) and precious (gold and silver) metals in mines throughout the world, though it remains a niche technology. However, current projections of an increasing future need to use low-grade primary metal ores, to reprocess mine wastes, and to develop in situ leaching technologies to extract metals from deep-buried ore bodies, all of which are economically more amenable to bioprocessing than conventional approaches (e.g., pyrometallurgy), would suggest that biomining will become more extensively utilized in the future. Recent research has also shown that bioleaching could be used to process a far wider range of metal ores (e.g., oxidized ores) than has previously been the case. Biotechnologies are also being developed to control mine-related pollution, including securing mine wastes (rocks and tailings) by using “ecological engineering” approaches, and also to remediate and recover metals from waste waters, such as acid mine drainage. This article reviews the current status of biotechnologies within the mining sector and considers how these may be developed and applied in future years.     

Self-assembled BiVO4 mesocrystals for efficient photocatalytic decontamination of microcystin-LR

Environmental Chemistry Letters - There is a lack of efficient methods for removing microcystins produced by cyanobacterial blooms. Here, microsphere-like bismuth vanadate (BiVO4-60) mesocrystals...