Some aspects of heavy metals contamination remediation and role of biosurfactants

Contamination by heavy metals is the result of different industrial activities. The presence of heavy metals in soil and water causes serious problems, as these materials are not biodegradable and do contaminate both biological systems and the subsoil. Biological surface-active compounds otherwise known as biosurfactants in general and rhamnolipids biosurfactants in particular have been successfully employed in the remediation of environments contaminated with heavy metal ions. The aim of the present review is to highlight potential applications of these tensioactive compounds for use in environmental heavy metals removal and bioremediation and processes involved.     

Gastroenteric Viruses Detection in a Drinking Water Distribution-to-Consumption System in a Low-Income Community in Rio de Janeiro

Food and Environmental Virology - The availability of drinking water is one of the main determinants of quality of life, disease prevention and the promotion of health. Viruses are important agents...     

Occurrence of endocrine disruptor compounds in the estuary of the Iberian Douro River and nearby Porto Coast (NW Portugal)

Previous studies in the Douro River estuary, based on occasional sampling, showed the presence of several estrogenic disrupting chemicals (EDCs). In sequence, we hypothesized that such type of pollution was more likely an enduring issue than an occasional phenomenon, and that it may even affect recreational beaches in each side of the estuarine mouth. Thus to conclude about the continuous influx of EDCs, water samples were taken twice a day, once per a week, from March to May of 2009, at four sites within the estuary and at two sites in the coastline. After solid-phase extraction, the extracts were prepared for GC-MS analysis of 11 reference EDCs. These embraced natural and pharmaceutical estrogens (17β-estradiol, estrone and 17α-ethynylestradiol) and xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol, and their mono and diethoxylates and bisphenol A). Data showed the ubiquitous presence of potentially hazardous amounts of natural estrogens (particularly of estradiol, ca 5.5?ng?L^?1) and persistent organic pollutants such as nonylphenol mono (up to 550?ng?L^?1) and diethoxylate (up to 2000?ng?L^?1). It was concluded that the targeted area is continuously polluted by the assayed EDCs, and as a consequence, conditions exist for endocrine disturbance in the biota by chronic exposure to EDCs.     

Mapping and evaluating sugarcane expansion in Brazil’s savanna using MODIS and intensity analysis: a case-study from the state of Tocantins

In Brazil, the main biofuel crop is sugarcane, and with its rapid expansion, there is much debate about what land uses and land covers it is replacing, and what are the associated environmental and social impacts. Some argue sugarcane is mainly replacing cattle pasture, thus having minimal impacts on native vegetation and small-scale family farming. In contrast, others claim sugarcane is replacing cropland traditionally under soybeans, rice, beans, and corn. Thus, food security is negatively affected and small-scale family farming livelihoods and culture are threatened. This is a proof-of-concept paper illustrating methods contributing toward the resolution of such debates. First we map land use and cover change in areas undergoing sugarcane expansion using satellite data from MODIS (Moderate Resolution Imaging Spectroradiometer); second, we test the hypothesis that sugarcane is replacing traditional annual crops using intensity analysis, via a case study of land change in the municipality of Pedro Afonso, Tocantins in northern Brazil between the 2008–2013 crop years. Maps matched reference data with overall agreements between 87–91%. Intensity analysis confirmed sugarcane is replacing annual crops much more than cattle pasture and other land uses and covers, pointing to particular economic and social processes driving land change.     

Distribution of endocrine disruptors in the Mondego River estuary, Portugal

Recent studies in the Mondego River estuary demonstrated signs of pollution in the area, but the nature of the contamination remains unexplored. Because there seems to be any studies in that zone checking for the simultaneous presence of xenoestrogenic endocrine disrupting compounds, either of animal (estradiol and estrone), vegetal (daidzein, genistein and biochanin A), pharmaceutical (17alpha-ethynylestradiol) or industrial (bisphenol A, 4-octylphenol, 4-nonylphenol) origins, the main objective of this study was to investigate their presence, in every year season and at eight points along the estuarine gradient. For this propose, water samples (2 L) were collected in high and low tides, preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by HPLC-DAD and GC-MS. The current data showed the absence of contamination by animal or pharmaceutical estrogens and by alkylphenols, but demonstrated the presence of high levels of phytoestrogens (up to 1.1 mug/L) and of bisphenol A (up to 880.0 ng/L). Because these two chemicals existed in high environmental concentrations in the most upstream sampling station, and taking in account that these pollutants may additively contribute to endocrine disruption, namely on fish, it was concluded that at least this particularly area of the Mondego estuary deserves continuous monitoring programmes.     

Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1?±?4.3 % to 264.7?±?3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3?±?1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5?±?2.0 % to 118.8?±?1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect.     

Antiviral Activity of Ctn[15-34], A Cathelicidin-Derived Eicosapeptide,Against Infectious Myonecrosis Virus in <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis> Primary Hemocyte Cultures

The shrimp farming has been converted into a mature aquaculture industry dealing with over millions of metric tonnes of processed commodities. Nevertheless, the global shrimp productions are constantly threatened by disease outbreaks, mainly triggered by rapidly disseminating viruses. Infectious myonecrosis virus (IMNV) is one of these epizootic agents affecting shrimp production in Brazil, of which no treatment exists. Herein, the antiviral activity against IMNV of an eicosapeptide, named Ctn[15-34], derived from a member of the cathelicidin family of antimicrobial peptides, was demonstrated. Cultures of hemocytes from Litopenaeus vannamei were established that support IMNV replication and infectivity titration. The cytotoxic effect of IMNV in culture and the in vitro anti-IMNV activity of Ctn[15-34] were assessed using a high-sensitive fluorescent-based method in combination with quantitative PCR. The Ctn[15-34] (<12.5 µM) neutralized the toxic effects of IMNV at loads sufficient to kill 50% of shrimp hemocytes. This study reported for the first time the replication of IMNV in vitro and the employment of a straightforward methodology to assess cell viability and viral/antiviral activities. In addition, it provided the basis for the development of the anti-infective multi-effector Ctn[15-34] eicosapeptide and analogs as components of antiviral formulations against shrimp viral diseases.     

A qualitative examination of factors shaping high and low exposures to hazardous air pollutants among Hispanic households in Miami

Hispanic residents suffer disproportionately from exposure to toxic pollution hazards, but little is known about why some Hispanic residents live in high-risk neighbourhoods while others are protected from similar risks. This study uses comparative interview-based methods to further understanding of Hispanic people’s residential decision-making and their associated exposures to hazardous air pollutants (HAPs) in the Miami Metropolitan Statistical Area (Florida), which is home to one of the most diverse Hispanic populations in the U.S. We use 22 in-depth interviews conducted with Hispanic householders living at high and low risk to HAPs, selected from a larger representative phone survey of 650 local residents. For Hispanic households at high risk, economic constraints, family ties, desiring a central location, a sense of community, and comfort in a shared culture contributed to their residences in high risk locations. In contrast, protective factors for Hispanic households living at low risk included the desire to live in an ethnically diverse setting, the ease of finding service work, and preferring environmental amenities and exclusivity. Findings demonstrate that there are considerable differences in factors shaping residential decision-making of low- and high-risk Hispanic residents, but that all were influenced by economic, socio-cultural, and environmental considerations to varying degrees.     

Heterogeneous alternative catalysts: A bibliometric and systematic evaluation of their application in solar photocatalytic processes

The present study sought to objectively demonstrate how a researcher can, in a structured way, select relevant articles about alternative heterogeneous catalysts in photocatalytic processes. Therefore, the ProKnow-C (Knowledge Development Process – Constructivist) method was used to systematize the results found, with the application bibliometric and systematic analysis techniques for the evaluation of the results. The search string adopted as criteria was: solar photocatalysis AND heterogeneous catalysts OR alternative catalysts AND effluents. The databases were Web of Science, Science Direct and Scopus. The final bibliographic portfolio obtained for the research theme was made up of 19 articles. It was possible to verify advances in the number of publications on the theme over the evaluated period, with the Journal of Photochemistry and Photobiology A: Chemistry standing out in the final portfolio. Evaluating each article in the portfolio individually, it was possible to verify that most studies use combinations of catalysts already reported to create an alternative material to those already investigated in the literature. Those that use waste as catalysts chose to source this material from treatment plants and the steel industry. Around 58% of the papers used hydrogen peroxide in their processes, while 42% chose not to use it. Finally, approximately 63% of the papers in the portfolio used synthetic effluent in their processes, while the rest (37% of the research) chose to use real effluent. The results obtained in this research by applying the method can contribute to studies related to heterogeneous photocatalysis by alternative means over the years.