Lake sediments record sensitivity of two hydrologically closed upland lakes in Mexico to human impact

We provide evidence of rapid, recent environmental change in two lakes in the highlands of central Mexico. Multiple sediment cores were obtained from Lago de Zirahuén (Michoacán) and Laguna de Juanacatlán (Jalisco). Analysis of diatom assemblages, magnetic susceptibility, and metal concentrations was carried out, with the chronology provided by 210Pb dating, 14C dating, and tephrochronology. There is evidence of catchment disturbance during the colonial period in both basins, but the most striking feature at both sites is the rapid change in diatom assemblages during the last 20 y, indicating the onset of eutrophication. Limnological data from Lago de Zirahuén support this interpretation, although none are available from Laguna de Juanacatlán. Paleolimnology is a powerful tool in tracking recent change, particularly in the absence of regular limnological monitoring programs. These lakes appear to be highly sensitive to changes in catchment exploitation, which must be considered in future drainage basin management.     

Financing remediation by delisting and selling clean portions of affected property

It is an established fact that property owners can face significant liabilities as a result of an on-site environmental contamination problem. This paper outlines a successful, innovative remedial strategy that, in conjunction with agency negotiation, afforded a property owner minimal financial expenditure and, at the same time, facilitated property cleanup and reuse. The strategy includes the delisting and sale of “clean” portions of the property to obtain the finances necessary to remediate the remaining “impacted” portion of the property. Previous investigations performed by EPA indicate the affected area to be a five to seven acre area located in the northeast portion of the property. Since a portion of the property was affected, significant restrictions for long-term use were placed on the entire property. A summary of environmental data generated for the property was prepared and submitted to the agency. This data summary communicated a strategy which was developed to delist and sell the “clean” portion of the property and to use the proceeds to clean up the affected property. To accomplish this, several tasks were outlined, including work-plan preparation and submittal, data collection, and interim remedial activities. In addition, a risk assessment is planned to identify potential threats to receptors downgradient of the impacted areas. This strategy allows the owner of an environmentally distressed property to use financial assets of the property to facilitate an acceptable solution with both regulatory agencies and the surrounding community.     

Screening for abnormal placentation and adverse pregnancy outcomes with maternal serum biomarkers in the second trimester

Second trimester biomarkers were initially introduced with the intent of screening for neural tube defects and then subsequently for Down syndrome. It was soon realized that these markers can be indirect evidence of abnormal placentation and, therefore, can be used for screening for adverse pregnancy outcomes. Several new biomarkers have subsequently been described with conflicting findings regarding their efficiency for screening for adverse pregnancy outcomes. Although a biologically feasible mechanism has been proposed for the role of these biomarkers, they still fall short of an ideal screening test to be clinically useful. © 2014 John Wiley & Sons, Ltd.