Numerical model to quantify biogenic volatile organic compound emissions: The Pearl River Delta region as a case study

This article compiles the actual knowledge of the biogenic volatile organic compound (BVOC) emissions estimated using model methods in the Pearl River Delta (PRD) region, one of the most developed regions in China. The developed history of BVOC emission models is presented briefly and three typical emission models are introduced and compared. The results from local studies related to BVOC emissions have been summarized. Based on this analysis, it is recommended that local researchers conduct BVOC emission studies systematically, from the assessment of model inputs, to compiling regional emission inventories to quantifying the uncertainties and evaluating the model results. Beyond that, more basic researches should be conducted in the future to close the gaps in knowledge on BVOC emission mechanisms, to develop the emission models and to refine the inventory results. This paper can provide a perspective on these aspects in the broad field of research associated with BVOC emissions in the PRD region.     

Prenatal diagnosis of carbamoyl-phosphate synthetase deficiency by fetal liver biopsy

In a pregnancy at risk for carbamoyl-phosphate synthetase (CPS) deficiency, prenatal diagnosis was attempted by fetal liver biopsy, performed at 18 weeks of gestation. CPS activity was absent and the diagnosis was confirmed after termination of the pregnancy. The technique employed for fetal liver biopsy is described together with an evaluation of its possible role in prenatal diagnosis.     

Institutional controls for future land use at active installation restoration program (IRP) sites

One of the strategies now in vogue in hazardous waste cleanup is basing remedial strategies on future land use. The initial thrust of CERCLA for permanent and complete remedies has given way, pushed by concepts like “brownfields” and base closure and reuse, to strategies often based on “institutional controls” that attempt to stabilize future land uses at a site based on residual risk. The heart of this concept is that instead of removing all wastes from a site, some wastes can safely remain so long as in the future the site is not used in such a way that the residual contamination poses an unacceptable risk to human health and the environment. “Institutional controls” is a term for land use management strategies that do not rely on engineering approaches to reduce risk, but rather seek to ensure that the site is not used in an inappropriate way in the future. This article cautions that such a strategy has inherent residual risks that must be understood by those involved in implementing hazardous waste cleanups and those responsible for future uses of contaminated property. Simply put, institutional controls are only as good as the processes that are in place to ensure they are respected in the future. This presents particular problems for active duty installations because most of the protections commonly available to private sector sites are not useful at active installations. This article discusses an initiative by the Air Combat Command to develop a handbook on instituting and maintaining land restrictions. It will also discuss that effort in light of the April 21 EPA Region IV guidance on assuring Land Use Controls at Federal Facilities. This article is based on a paper and presentations given at the 1998 ACC Environmental Training Symposium.     

Method for determining minimum pool requirements to maintain and enhance salmonid fisheries in small Wyoming reservoirs

Methods for determination of minimum pool levels in reservoirs that consider sport fishery values are being sought by managers. We developed a technique for assessing the effects of incremental changes in minimum pool levels on potential salmonid abundance in small (<100 surface hectares at full pool) reservoirs in Wyoming managed for irrigation and municipal water supplies. The method has two components. One component is used to determine the minimum pool level needed to eliminate the risk of overwinter loss of salmonids due to low dissolved oxygen concentrations. The other component predicts the potential biomass of salmonids in reservoirs as a function of water depth and total dissolved solids concentration of the reservoir water. Application of the method is demonstrated for two reservoirs in Wyoming. The unit is jointly supported by the University of Wyoming, the Wyoming Game and Fish Department, and the US Fish and Wildlife Service.     

Individual changes in human EEG caused by 450 MHz microwave modulated at 40 and 70 Hz

This study was aimed to investigate the changes in the human electroencephalographic (EEG) signal caused by modulated low-level microwaves. The 450 MHz microwave exposure modulated at 40 Hz and 70 Hz frequencies was applied to a group of 15 volunteers. The field power density at the scalp was 0.16 mW/cm². Ten cycles of the exposure (1 min on and 1 min off) at both modulation frequencies were applied. Analysis of the EEG signal was performed using three different methods: nonlinear method of scaling analysis for length distribution of low variability periods (LDLVP), relative changes in EEG energy (S-parameter) and beta ratio (H-parameter). The analysis revealed significant changes caused by microwave for the whole group (H-parameter method). The exposure caused increase of the EEG beta power (S-parameter method). Statistically significant changes in EEG were detected for four subjects (26.7%) at 40 Hz modulation frequency (LDLVP method).