The case for integrating low dose, beneficial responses into US EPA risk assessments

2006 ◽  
Vol 25 (1) ◽  
pp. 7-10 ◽  
Author(s):  
J M DeSesso ◽  
R E Watson
Keyword(s):  
Environmental Protection Agency ◽  
Low Dose ◽  
Risk Assessments ◽  
Protection Agency ◽  
Beneficial Effects ◽  
The Us ◽  
Adverse Effect Level ◽  
Us Epa ◽  
Effect Level ◽  
Epa Methods

When conducting risk assessments, the US Environmental Protection Agency (EPA) does not currently consider the beneficial effects from exposure to concentrations of agents below the no observed adverse effect level (NOAEL). If such benefits were observed, and if the beneficial and toxicological mechanisms of action were identical, this would probably be represented as a ‘j–shaped’ hormetic dose–response curve. If such data are available, they should be considered when assigning uncertainty factors for safe exposure calculations. However, when such data are not readily available, as is likely the case when the mechanism of action of the benefit differs from that of toxicity, current US EPA methods appear adequate.

An evaluation of the US Environmental Protection Agency definition of a risk assessment

2006 ◽  
Vol 25 (1) ◽  
pp. 3-5 ◽  
Author(s):  
B D Beck
Keyword(s):  
Risk Assessment ◽  
Environmental Protection Agency ◽  
Relevant Information ◽  
American Thoracic Society ◽  
Risk Assessments ◽  
Protection Agency ◽  
Beneficial Effects ◽  
The Us ◽  
Definition Of ◽  
Risk Managers

A full presentation of relevant information, including both non–adverse and beneficial effects, of chemicals is important to developing sound and balanced risk assessments. Such considerations are not new. For example, the American Thoracic Society has developed criteria for defining adverse and non–adverse pulmonary effects. Failing to allow risk assessors to even consider non–adverse and beneficial effects will discourage the use of information from developing technologies, such as genomics, and from new understandings of dose–response relationships, as reflected in the hormetic model. Failing to provide such information to risk managers potentially provides a biased perspective on risk

scholarly journals Simulation of a biogas cleaning process using different amines

2018 ◽  
Vol 27 (47) ◽  
Author(s):  
Guillermo Sepúlveda ◽  
Luis Eduardo Jaimes ◽  
Leonardo Pacheco ◽  
Carlos Alirio Díaz
Keyword(s):  
Environmental Protection Agency ◽  
Landfill Gas ◽  
Cleaning Process ◽  
Fuel Gas ◽  
Combustion Properties ◽  
The Us ◽  
Us Epa ◽  
Combustible Gases ◽  
Combustion Processes ◽  
Landfill Gas Emissions

The use of biogas generated in landfills has gained importance in developing countries like Colombia. Taking into account that this biogas presents poor combustion properties that make interchangeability with other combustible gases difficult, the elimination of gases and vapors, such as CO2 and H2O, through a cleaning process, in which the biogas is converted to biomethane, improves the biogas properties as a fuel gas for general use. In this work, we simulated the generation of biogas at El Carrasco sanitary landfill in Bucaramanga, using the US EPA (United States Environmental Protection Agency) landfill gas emissions model. Additionally, we simulated the biogas cleaning process to extract the remaining moisture using the ProMax software; for this, we used three different amines (MDEA, MEA, and DEA), followed by a glycol dehydration process. The results showed that the amine MEA produced the largest increase in the concentration of CH4 (90.37 %) for the biogas generated in the landfill. Furthermore, dehydration with glycol was an efficient process to obtain a gas with a high percentage of methane (91.47 %) and low water presence (1.27 %); this would allow the use of biomethane in conventional industrial combustion processes and power generation.

scholarly journals Comparative Analysis of Microcystin Prevalence in Michigan Lakes by Online Concentration LC/MS/MS and ELISA

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 13 ◽  
Author(s):  
Johnna A. Birbeck ◽  
Judy A. Westrick ◽  
Grace M. O’Neill ◽  
Brian Spies ◽  
David C. Szlag
Keyword(s):  
Environmental Protection Agency ◽  
Degradation Products ◽  
Tandem Mass ◽  
Protection Agency ◽  
Chromatography Tandem Mass Spectrometry ◽  
Drinking Waters ◽  
Liquid Chromatography Tandem Mass ◽  
Us Epa ◽  
The Impact ◽  
Elisa Data

Fast and reliable workflows are needed to quantitate microcystins (MCs), a ubiquitous class of hepatotoxic cyanotoxins, so that the impact of human and environmental exposure is assessed quickly and minimized. Our goal was to develop a high-throughput online concentration liquid chromatography tandem mass spectrometry (LC/MS/MS) workflow to quantitate the 12 commercially available MCs and nodularin in surface and drinking waters. The method run time was 8.5 min with detection limits in the low ng/L range and minimum reporting levels between 5 and 10 ng/L. This workflow was benchmarked by determining the prevalence of MCs and comparing the Adda-ELISA quantitation to our new workflow from 122 samples representing 31 waterbodies throughout Michigan. The frequency of MC occurrence was MC-LA > LR > RR > D-Asp3-LR > YR > HilR > WR > D-Asp3-RR > HtyR > LY = LW = LF, while MC-RR had the highest concentrations. MCs were detected in 33 samples and 13 of these samples had more than 20% of their total MC concentration from MCs not present in US Environmental Protection Agency (US EPA) Method 544. Furthermore, seasonal deviations between the LC/MS/MS and Adda-ELISA data suggest Adda-ELISA cross-reacts with MC degradation products. This workflow provides less than 24-h turnaround for quantification and also identified key differences between LC/MS/MS and ELISA quantitation that should be investigated further.

scholarly journals Benefits of Electrified Powertrains in Medium- and Heavy-Duty Vehicles

2020 ◽  
Vol 11 (1) ◽  
pp. 12
Author(s):  
Ram Vijayagopal ◽  
Aymeric Rousseau
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Fuel Saving ◽  
Heavy Duty ◽  
Protection Agency ◽  
Light Duty ◽  
Design Choice ◽  
The Us ◽  
Light Duty Vehicles ◽  
Heavy Duty Vehicles

The benefits of electrified powertrains for light-duty vehicles are well understood, however sufficient published information is not available on the benefits of advanced powertrains on the various types of medium and heavy duty vehicles. Quantifying the benefits of powertrain electrification will help fleet operators understand the advantages or limitations in adopting electrified powertrains in their truck fleets. Trucks vary in size and shape, as they are designed for specific applications. It is necessary to model each kind of truck separately to understand what kind of powertrain architecture will be feasible for their daily operations. This paper examines 11 types of vehicles and 5 powertrain technology choices to quantify the fuel saving potential of each design choice. This study uses the regulatory cycles proposed by the US Environmental Protection Agency (EPA) for measuring fuel consumption.

scholarly journals Geochemical Behavior of Uranium and Radon in Groundwater of Jurassic Granite Area, Icheon, Middle Korea

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1278 ◽  
Author(s):  
Byong Wook Cho ◽  
Chang Oh Choo
Keyword(s):  
Standard Deviation ◽  
Environmental Protection Agency ◽  
Maximum Contaminant Level ◽  
Contaminant Level ◽  
Low Concentrations ◽  
Wide Range ◽  
The Us ◽  
Us Epa ◽  
Independent Behavior ◽  
Radon Concentrations

Uranium concentrations (a total of 82 samples) in groundwater in Icheon, middle Korea, showed a wide range from 0.02 to 1640 μg/L with a mean of 56.77 μg/L, a median of 3.03 μg/L, and a standard deviation of 228.63 μg/L. Most groundwater samples had quite low concentrations: 32.9% were below 1 μg/L, while 15.9% exceeded 30 μg/L, the maximum contaminant level (MCL) of the US EPA (Environmental Protection Agency). Radon concentrations also ranged widely from 1.48 to 865.8 Bq/L. Although the standard deviation of radon was large (151.8 Bq/L), the mean was 211.29 Bq/L and the median was 176.86 Bq/L. Overall, 64.6% of the samples exceeded the alternative maximum contaminant level (AMCL) of the US EPA (148 Bq/L). According to statistical analyses, there was no close correlations between uranium and radon, but there were correlations between uranium and redox potential (Eh) (−0.54), dissolved oxygen (DO) (−0.50), HCO3− (0.45), Sr (0.65), and SiO2 (−0.44). Radon showed independent behavior with respect to most components in groundwater. Uranium concentrations in groundwater increased with increasing water–rock interactions. Anomalously high uranium and radon concentrations in groundwater are preferentially localized in granite areas and spatial distributions are remarkably heterogeneous.

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