Hybrid Modeling Approach to Estimate Exposures of Hazardous Air Pollutants (HAPs) for the National Air Toxics Assessment (NATA)

2016 ◽  
Vol 50 (22) ◽  
pp. 12356-12364 ◽  
Author(s):  
Richard D. Scheffe ◽  
Madeleine Strum ◽  
Sharon B. Phillips ◽  
James Thurman ◽  
Alison Eyth ◽  
...  
1990 ◽  
Vol 6 (5) ◽  
pp. 245-255 ◽  
Author(s):  
Si Duk Lee

Noncriteria air pollutants are synonymous with hazardous air pollutants (HAPs), air toxics or toxic air pollutants (TAPs). The term noncriteria pollutants refers to all air pollutants except for the criteria pollutants (SOx, PM, NOx, CO, O3, and Pb). Air toxics are pervasive in our environment worldwide in varying degrees. Uses of these chemicals are varied and numerous; their emissions are ubiquitous, and they include organic compounds such as chlorinated hydrocarbons, dioxins, aldehydes, polynuclear aromatic hydrocarbons, and heavy metals such as chromium, nickel, cadmium, and mercury. There are more than 70,000 chemicals that are in use commercially in the United States, and we know relatively little about their ambient concentrations, persistence, transport and transformation as well as their effects on health and the environment, many of which take decades to emerge. The United States Environmental Protection Agency, under the authority of Section 112 of the Clean Air Act, is mandated to regulate any air pollutant which, in the Administrator's judgment, “causes, or contributes to, air pollution which may reasonably be anticipated to result in an increase in serious irreversible or incapacitating reversible illness.” For such regulatory decision-making, EPA's Office of Health and Environmental Assessment (OHEA) provides scientific assessment of health effects for potentially hazardous air pollutants. In accordance with risk assessment guidelines developed by OHEA over the years, Health Assessment Documents (HADs) containing risk assessment information were prepared and were subjected to critical review and careful revision to produce Final Draft HADs which serve as scientific databases for regulatory decision-making by the Office of Air Quality Planning and Standards (OAQPS) in its risk management process. EPA developed databases such as the Integrated Risk Information System (IRIS) and the National Air Toxics Information Clearinghouse (NATICH) and a technical assistance response system called the Air Risk Information Support Center (AIR RISC), in addition, to help in implementation of the National Air Toxics Program by state and local regulators.


Toxicology ◽  
2002 ◽  
Vol 181-182 ◽  
pp. 361-366 ◽  
Author(s):  
A.L Hinwood ◽  
P.N Di Marco

2021 ◽  
Vol 02 ◽  
Author(s):  
Pernille D. Pedersen ◽  
Nina Lock ◽  
Henrik Jensen

: The NOx gasses (NO and NO2) are among the most important air pollutants, due to the toxicity of NO2, as well as the role of NOx in the tropospheric oxidation of Volatile Organic Carbons (VOCs), contributing to the formation of other hazardous air pollutants. Air pollution is one of the biggest health threats world-wide, hence reducing NOx levels is an important objective of the UN sustainable development goals, e.g. #3, “Good health and well-being” and #11 “Sustainable cities and communities”. Photocatalysis using TiO2 and light is a promising technique for removing NOx along with other pollutants, as demonstrated on laboratory scale. Furthermore, a long range of real-life test studies of varying scales have been conducted during the past two decades. The results of these studies have been conflicting, with some studies reporting no effect on the ambient air quality and others reporting significant reductions of NOx level. However, the studies are very difficult to compare and assess due to the very different approaches used, which consequently vary in quality. In this review, we aim to develop a set of objective evaluation criteria to assess the quality of the individual studies in order to simplify the interpretation and comparison of the existing studies. Moreover, we propose some guidelines for future test-studies. Furthermore, the approaches and main conclusions from 23 studies are independently assessed and discussed herein.


2021 ◽  
Author(s):  
Anna Maria De Girolamo ◽  
Youssef Brouziyne ◽  
Lahcen Benaabidate ◽  
Aziz Aboubdillah ◽  
Ali El Bilali ◽  
...  

<p>The non-perennial streams and rivers are predominant in the Mediterranean region and play an important ecological role in the ecosystem diversity in this region. This class of streams is particularly vulnerable to climate change effects that are expected to amplify further under most climatic projections. Understanding the potential response of the hydrologic regime attributes to climatic stress helps in planning better conservation and management strategies. Bouregreg watershed (BW) in Morocco, is a strategic watershed for the region with a developed non-perennial stream network, and with typical assets and challenges of most Mediterranean watersheds. In this study, a hybrid modeling approach, based on the Soil and Water Assessment Tool (SWAT) model and Indicator of Hydrologic Alteration (IHA) program, was used to simulate the response of BW's stream network to climate change during the period: 2035-2050. Downscaled daily climate data from the global circulation model CNRM-CM5 were used to force the hybrid modeling framework over the study area. Results showed that, under the changing climate, the magnitude of the alteration will be different across the stream network; however, almost the entire flow regime attributes will be affected. Under the RCP8.5 scenario, the average number of zero-flow days will rise up from 3 to 17.5 days per year in some streams, the timing of the maximum flow was calculated to occur earlier by 17 days than in baseline, and the timing of the minimal flow should occur later by 170 days in some streams. The used modeling approach in this study contributed in identifying the most vulnerable streams in the BW to climate change for potential prioritization in conservation plans.</p>


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