Pollutants potential mobilization in Santos bay/Brazil: subsidies for the environmental management of a highly anthropized estuary: Potencial de mobilização de poluentes na baía de Santos/Brasil: subsídios para a gestão ambiental de um estuário altamente antropizado

Understanding the dynamics and spatial variation of subaquatic sediment contamination in the Santos Estuarine System has been of interest to the scientific community and environmental managers; the hazardous contaminant compounds, either individually or synergistically, can affect the health of the local community. In the present study, water column salinity and sediment geochemical properties (calcium and organic matter content, grain size) of the Santos Estuarine System were correlated with heavy metal concentrations (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and Fe) in order to elucidate the relationship between the toxic elements and the dynamics of water mixing. To assess the potential relationships, Spearman’s correlation test and Principal Component Analysis (PCA) between were applied. The heavy metal concentrations were also evaluated by calculating Contamination Factor, Geoaccumulation index and Enrichment Factor. Results revealed extremely heterogeneous particle sizes within the sampling stations. Most of the heavy metal concentrations were not at critical levels. The only exception was arsenic, which reached levels above the threshold effect. The statistical analysis allowed the influence of organic matter and grain size on the dynamics of heavy metal accumulation to be demonstrated. The values between these binding matrices and metals were mostly significant. Bottom water salinity, on the other hand, showed no apparent influence on the distribution of metals. However, the various pollution indices used were contradictory, with certain cases presenting critical results. The Geoaccumulation Index presented the Mn as highly polluting at all sampling stations and classified the environment as moderately polluted by Zn. The same pollution pattern was not found by the other contamination indexes

Influence of Environment on Microbial Colonization of Historic Stone Buildings with Emphasis on Cyanobacteria

Microbial cells that produce biofilms, or patinas, on historic buildings are affected by climatic changes, mainly temperature, rainfall and air pollution, all of which will alter over future decades. This review considers the colonization of stone buildings by microorganisms and the effects that the resultant biofilms have on the degradation of the structure. Conservation scientists require a knowledge of the potential effects of microorganisms, and the subsequent growth of higher organisms such as vascular plants, in order to formulate effective control strategies. The vulnerability of various structural materials (“bioreceptivity”) and the ways in which the environmental factors of temperature, precipitation, wind-driven rain and air pollution influence microbial colonization are discussed. The photosynthetic microorganisms, algae and cyanobacteria, are acknowledged to be the primary colonizers of stone surfaces and many cyanobacterial species are able to survive climate extremes; hence special attention is paid to this group of organisms. Since cyanobacteria require only light and water to grow, can live endolithically and are able to survive most types of stress, they may become even more important as agents of stone cultural property degradation in the future

The Importance of Biofilms on Microplastic Particles in Their Sinking Behavior and the Transfer of Invasive Organisms between Ecosystems

Although plastic is ubiquitous in marine systems, our current knowledge of its transport is limited. Recent studies suggest size-selective removal of small plastic particles (<5 mm) from the ocean surface as a result of the formation of a biofilm (the “plastisphere”) on the microplastic particle (MP) surface. This localized microenvironment can isolate the microcosm from the adjacent aqueous medium, and thus protect component alien species from the surrounding physico-chemical conditions. Apart from resulting in specific conditions for the transfer of alien species through the environment, the plastisphere can impact MP hydrodynamics and cause MPs to move through the water column, initially sinking. The importance of this phenomenon has not been previously considered for these particles. The size-dependent vertical movement of MPs through the water column determines their distribution, which will vary with time of exposure and colonization. Some plastisphere organisms have plastic-degrading activities, which could be harnessed in marine depollution strategies. This article seeks to increase our understanding of the role of biofilms in the biological dynamics and diffusion of plastic microparticles