Tropical limestone forest resilience during MIS-2: implications for Pleistocene foraging & modern conservation

In this paper we present a multi-proxy study of tropical limestone forest and its utilization by human groups during the major climatic and environmental upheavals of MIS-2 (29-11.7 ka BP). Our data are drawn from new field research within the Tràng An World Heritage property, on the edge of the Red River Delta, northern Vietnam. Key findings from this study include 1) that limestone forest formations were resilient to the large-scale landscape transformation and inundation of the Sunda continent at the end of the last glaciation; 2) that prehistoric human groups were probably present in this habitat through-out MIS-2; and 3) that the forested, almost insular, karst of Tràng An provided foragers with a stable resource-base in a wider changing landscape. These results have implications for our understanding of the prehistoric utilization of karst environments and resonance for conservation efforts in the face of climate and environmental change today

Development of an analytical procedure for weathered hydrocarbon contaminated soils within a UK risk-based framework.

A sequential ultrasonic extraction method for contaminated soils with weathered hydrocarbons is presented. The method covers the determination of total petroleum hydrocarbons between nC(8) and nC(40), and subranges of hydrocarbons including diesel range organic compounds, kerosene range organic compounds, and mineral oil range organic compounds in soils. Further modifications to the carbon banding may be made as requested for risk assessment. These include a series of ranges known as Texas banding (from the Texas Risk Reduction Program) as well as separation of the aliphatic and aromatic fractions. The method can be routinely used for measuring hydrocarbons down to 10 mg kg(-1) in soil. Lower limits can be achieved by employing a suitable solvent concentration step following extraction; however, this would result in increased cycle time. Detection limits may vary for individual carbon ranges calculated on the percentage of the full range they cover. With an extraction efficiency and recovery between >= 95 and 99%, this method can be easily positioned as a good alternative to Soxhlet extraction and shows a good potential for implementation as a standard method potentially providing further insight to the contaminated land sector

Contaminant Accumulation in Stormwater Retention and Detention Pond Sediments: Implications for Maintenance and Ecological Health

Stormwater retention/detention pond maintenance schedules are based on either pond age or sediment accumulation, not contaminant levels of sediments. We examined the effect of stormwater pond characteristics on sediment contaminant concentrations and resulting ecological risk. We sampled the inlet, middle, and outlet of stormwater pond sediments up to 30 cm depth at five locations in Rhode Island three times between June 2014 and June 2015 for polycyclic aromatic hydrocarbons (PAHs) and heavy metals (Pb, Zn, and Cr). The ponds were selected based on stormwater runoff origin and land uses (industrial, urban, highway). Sediment PAH concentrations ranged from 0.9-195.8 mg/kg. Heavy metal concentrations were nondetect to 864.5 mg/kg for Zn, nondetect to 502.9 mg/kg for Pb, and 5.4-320.0 mg/kg for Cr. Ponds in urban areas had the highest concentrations of contaminants, and ponds with a sediment forebay exhibited a decreasing concentration gradient of contaminants across the pond. Ecological risk assessments indicated that benthic organisms are likely to experience adverse effects due to contaminant exposure in all ponds. Here, we found that elevated contaminant concentrations were influenced by factors such as impervious cover fraction, age, and ecological risk assessments. We posit that these factors should be considered when drafting maintenance schedules instead of relying on regular time intervals since installation