Managing Carbon Monoxide Pollution in Meteorological and Topographical Problem Areas (2003) / Chapter Skim
Currently Skimming:
Summary
Summary
Pages 1-15
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 1... ...
for CO were promulgated in 1971, more than 90% of ambient monitors indicated violations. Since then, motor-vehicle emissions controls have greatly reduced ambient CO concentrations.
|
From page 2... ...
These areas are typically subject to problematic meteorological and topographical conditions that produce severe atmospheric inversions in winter.3 Although CO emissions from light-duty vehicles are projectedto decrease in the future, atmospheric inversions and Tow windspeeds prevalent in some locations during winter are extremely effective in trapping the products of incomplete combustion, including CO, emitted at ground level. For example, Fairbanks, Alaska, is subject to extreme atmospheric inversions, at times experiencing inversion strengths as much as 30°C per 100 meters of altitude.
|
From page 3... ...
FINDINGS AND RECOMMENDATIONS Vulnerability to Future Violations Findings Because of a number of factors including differences in topography and temporal variability of local meteorology and emissions rates some areas are especially vulnerable to violations of the 8-hour NAAQS for CO. In geographical areas that have achieved attainment of the NAAQS, it might still be possible for ambient concentrations of CO to sporadically exceed the standard under unfavorable conditions, such as strong winter inversions.
|
From page 4... ...
In addition, given that the form of the CO standard defines a violation as the second and all subsequent exceedances in a calendar year, regions are susceptible to violating the standard due to extreme meteorological conditions, which contributes to the difficulties that meteorological and topographical problem areas have in reaching and maintaining attainment. It is also important to investigate how large-scare and local meteorological and climatological phenomena can affect the susceptibility of a location to CO buildup in ambient air.
|
From page 5... ...
Thus, reducing CO alone may or may not reduce the incidence of heart disease, childhood developmental abnormalities, and fetal loss. A significant collateral benefit from reducing CO vehicle emissions standards has been the substantial reduction in accidental deaths due to acute CO poisoning.
|
From page 6... ...
Also, there should be more toxicology studies of the automobile exhaust mixture. Management and Control of CO Management of CO Fin dings To reach attainment, communities vulnerable to exceeding the healthbased NAAQS for CO can implement various local measures to complement federal vehicle emissions standards.
|
From page 7... ...
The committee therefore recommends that EPA assess the relationship of CO to these other pollutants when the CO criteria are updated. Federal Tier 2 and Cold-Start Emissions Standards Findings Federal new-vehicle emissions standards have been effective in reducing CO emissions, including emissions from vehicles operated in cold climates.
|
From page 8... ...
along with lower standards for hydrocarbons. California, which is allowed under the Clean Air Act to adopt its own vehicle emissions standards, has already implemented a similar set of emissions limits.
|
From page 9... ...
High-Emitting Vehicles Findings A relatively small number of high-emitting vehicles contribute disproportionately to CO and other motor-vehicle emissions. The vehicle fleets operating in and around places with high local concentrations of CO (hot spots)
|
From page 10... ...
EPA's MOBILE model predicts CO emissions reductions from oxygenated fuels of 3-7% for the 20102015 fleet because of reduced emissions from pre-1994 vehicles, cold starts, and malfunctioning vehicles. There is still uncertainty about the overall effectiveness of oxygenated fuels, especially at temperatures below 20°F.
|
From page 11... ...
Public Education Findings On the basis of its review of programs in Fairbanks, Alaska, the committee is concerned that public education campaigns have not sufficiently emphasized the adverse health effects associated with exposure to high ambient concentrations of CO. Also, the public is not fully aware of the link between transportation choices and overall air quality.
|
From page 12... ...
CO can also be used to approximate the concentrations of some air tonics arising from motor-vehicle exhaust emissions, such as benzene, I,3-butadiene, and perhaps directly emitted PM2 s CO is most useful as an indicator in the microscale setting where concentrations of pollutants vary dramatically over short distances (e.g., with distance from a roadway)
|
From page 13... ...
Monitors can be deployed at temporary fixedsite locations or in mobile sampling vehicles. These studies are helpful to air pollution control agencies for evaluating their ambient air monitoring networks, characterizing pollutant concentrations over the entire saturation study area, and locating hot spots or high pollutant impact points.
|
From page 14... ...
Models are also used to demonstrate attainment of the CO NAAQS, evaluate the effects of new construction projects that greatly increase emissions, and research the causes of pollution episodes and how to predict them. However, the spatial and temporal resolution of models typically used in CO management at this time is too coarse to capture the variability in pollutant concentrations, which is necessary to identify local hot spots and accurately represent unusual meteorological conditions.
|
From page 15... ...
Ongoing research should be continued. Such models would be used for air quality planning and forecasting and for assessing human exposure to high concentrations of CO and related pollutants.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.