Factors driving sediment compositional change in the distal area of the Ria de Vigo (NW Spain): oceanographic processes vs. paleopollution

Environmental Science and Pollution Research - We analyze potential Late Holocene metal contamination along a sediment core collected in the distal zone of Ria de Vigo (North Spain). Statistical...     

Improving Access to Water Resources through Rainwater Harvesting as A Mitigation Measure: The Case of the Brazilian Semi-Arid Region

This paper focuses on the importance of rainwater harvesting to mitigate the scarcity of water in the semi-arid region of Brazil. It is a case study about the Million Cisterns Project, an initiative developed by NGOs with the support of Brazilian Federal Government Institutions and international funding organizations. The project is innovative in a series of ways when compared to mitigation measures previously implemented by the government. Instead of focussing on short-term, top-down, palliative measures based on the construction of dams and wells, it focuses on low cost, bottom-up, long-term measures and, most importantly, it involves an educational component. Thus, the provision of water is closely related to the empowerment of the most destitute population and this leads to the sustainability of the actions. The case study serves to illustrate the relevance of the partnership between grassroots organizations and governmental institutions in the context of mitigation.     

武汉市耕地资源非农化过程的时空变化特征分析

耕地非农化现象是实现工业化和城市化所必须付出的一种代价，已经成为经济发展和城市化，工业化进程中的一个普遍现象。根据武汉市1988-2002年来耕地资源变化的详查数据资料，分析其耕地资源非农化过程的时空变化特征。结果表明：①1988-2002年武市非农建设用地扩张占用耕地面积16394.57hm^2，占耕地资源减少面积的48.75%,耕地非农化成为耕地资源减少的一个重要的原因。②近年来城市非农建设基本上是占用质量较好的耕地，以灌溉水田和菜地为主。③随着城市化进程的加快，耕地非农化的速度在加快。④耕地非农化的区域差异明显，主要集中颁在城市主城区的新区及城郊区。⑤耕地非农人的区域指向性变化明显，主城区扩展的建设用地主要以城市、建制镇、村庄等居民点用地为主，城郊区以交通用地及工矿用地为主。     

Marine water quality assessment using transplanted oyster larvae

Active bio-monitoring in terms of biomarkers was attempted using Crassostrea gigas larvae produced in the laboratory and transplanted using special containers to two sites at the entrance (A) and inner part (P) of the harbour of Arcachon (French Atlantic Coast). The larvae were kept in the medium for 48 h. Their physiological status and their biomarker levels : acetylcholinesterase AChE, catalase CAT and glutathione S-transferase GST activities were determined together with metallothionein MT and Thiobarbituric Acid Reactive Substances TBARS concentrations. Copper and PAH (polycyclic aromatic hydrocarbon) concentrations were determined in the exposed larvae and in the sediments collected under the containers. Cadmium, lead and zinc could be also analyzed in the sediments. Toxicity tests demonstrate that the larvae are in better physiological conditions in A compared to P. Larvae transplanted in the inner harbour (P) present relatively high GST activity (869.1+/-39.3 nmol min(-1)mg protein(-1)), TBARS (2.74+/-0.19 nmol mg protein(-1)), compared to those exposed at the harbour entrance (A). Copper measured in the sediments (65+/-1 mg kg(-1) d.w.) collected under the cages at P is higher than at A. Larvae placed in A present higher total PAH concentrations compared to the inner part. The data tend to reveal a lower copper and higher PAH contamination in A than in P. Therefore larvae, developing in the natural medium, show different responses according to their immersion sites. These responses, obtained within 48 h, may be related to the chemical contamination of the environment and may be used for seawater quality assessment in future studies.     

Absorption and translocation of sulfometuron-methyl in sugarcane (Saccharum officinarum L.) at different growth stages

ABSTRACT

In Brazil, weed management in sugarcane fields is mainly done with the use of selective herbicide formulations. For many years, diuron+hexazinone was one of the main herbicide mixture formulations used in sugarcane. Later, sulfometuron-methyl was included in the same mixture, which was marketed as a new herbicide formulation for residual in-season weed control in sugarcane. The mixture diuron+hexazinone+sulfometuron-methyl has been widely used in commercial sugarcane fields in Brazil. However, recent field observations have shown that sugarcane plants at different growth stages varied in their phytotoxicity levels after treatment with diuron+hexazinone+sulfometuron-methyl. Greenhouse and laboratory studies were conducted to determine ¹⁴Csulfometuron-methyl absorption and translocation, as well as ¹⁴C distribution in sugarcane at two growth stages, 2 to 3 leaves and 5 to 6 leaves. ¹⁴Csulfometuron-methyl absorption by sugarcane did not differ between the two growth stages. Different patterns of ¹⁴C accumulation were observed, which may explain variations in sulfometuron-methyl phytotoxic responses observed in the field.     

Unexplored Diversity and Conservation Potential of Neotropical Hot Caves

The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot‐cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat‐generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism. Diversidad No Explorada y Potencial de Conservación de Cuevas Neotropicales Calientes     

Occurrence of PCBs and PAHs in an urban soil of Madrid (Spain)

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were analysed in surface soil samples collected in 2001–2002 at an open urban area of Madrid. In order to obtain representative samples, three collection points at the site were chosen. The most abundant PAHs and PCBs were phenanthrene, fluorene, pyrene, chrysene and benzo[a]pyrene and hexa- and heptachlorinated PCBs, respectively. The sum of selected PAHs (13 compounds) and PCBs (15 congeners) averaged 1 and 0.1?µg?g^?1, respectively. PCB levels in winter were 2–10 times higher than summer ones, while seasonal variation for most of PAHs were not observed. Good correlations among all PCBs were found. Five PAHs were also well correlated.