ភាពខុសគ្នារវាងកំណែនានារបស់ "ផ្លាយ អាស់"

 
===ភ្នាក់​ងារ​ចំលង===
Fly ash contains trace concentrations of [[heavy metals]] and other substances that are known to be detrimental to health in sufficient quantities. Potentially toxic trace elements in coal include [[arsenic]], [[beryllium]], [[cadmium]], [[barium]], [[chromium]], [[copper]], [[lead]], [[mercury (element)|mercury]], [[molybdenum]], [[nickel]], [[radium]], [[selenium]], [[thorium]], [[uranium]], [[vanadium]], and [[zinc]]. Approximately 10 percent of the mass of coals burned in the United States consists of unburnable mineral material that becomes ash, so the concentration of most trace elements in coal ash is approximately 10 times the concentration in the original coal.<ref name="USGS" >{{cite web
|author = U.S. Geological Survey | authorlink = USGS
|title = Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance
|date = October 1997
|url = http://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.pdf
|work = U.S. Geological Survey Fact Sheet FS-163-97
|format=PDF
}}</ref> A 1997 analysis by the [[U.S. Geological Survey]] (USGS) found that fly ash typically contained 10 to 30 ppm of uranium, comparable to the levels found in some [[granite|granit]]ic rocks, [[phosphate]] rock, and black [[shale]].<ref name="USGS" />
 
In 2000, the [[United States Environmental Protection Agency‎]] (EPA) said that coal fly ash did not need to be regulated as a hazardous waste.<ref>{{cite web
|author = Environmental Protection Agency | authorlink = Environmental Protection Agency
|title = Notice of Regulatory Determination on Wastes From the Combustion of Fossil Fuels
| url = http://frwebgate.access.gpo.gov/cgi-bin/getpage.cgi?dbname=2000_register&position=all&page=32214
| work=Federal Register Vol. 65, No. 99
| page=32214
|date = May 22, 2000
}}</ref> Studies by the [[USGS|U.S. Geological Survey]] and others of radioactive elements in coal ash have concluded that fly ash compares with common soils or rocks and should not be the source of alarm.<ref name="USGS" /> However, community and environmental organizations have documented numerous environmental contamination and damage concerns.<ref name="McCabe, 2008, Chesapeake" >{{cite news
|first=Robert |last=McCabe | coauthors=Mike Saewitz
|title=Chesapeake takes steps toward Superfund designation of site.
|url=http://www.norfolk.com/2008/07/chesapeake-takes-steps-toward-superfund-designation-site?page=1
|publisher =''The Virginian-Pilot'' |date=2008-07-19
}}</ref><ref name="McCabe, 2008, Golf" >McCabe, Robert.[http://hamptonroads.com/2008/03/above-ground-golf-course-just-beneath-it-potential-health-risks "Above ground golf course, Just beneath if potential health risks"], ''[[The Virginian-Pilot]]'', 2008-03-30</ref><ref name="CCC, 2000" >Citizens Coal Council, Hoosier Environmental Council, Clean Air Task Force (March 2000), [http://www.catf.us/publications/reports/Laid_to_Waste.pdf "Laid to Waste: The Dirty Secret of Combustion Waste from America's Power Plants"]</ref>
 
A revised risk assessment approach may change the way coal combustion wastes (CCW) are regulated, according to an August 2007 EPA notice in the [[Federal Register]].<ref>{{cite web
|author = Environmental Protection Agency | authorlink = United States Environmental Protection Agency
|title= Notice of Data Availability on the Disposal of Coal Combustion Wastes in Landfills and Surface Impoundments
|date=August 29, 2007
|work=72 [[Federal Register]] 49714
|url = http://edocket.access.gpo.gov/2007/pdf/E7-17138.pdf
|format=PDF
}}</ref> In June 2008, the U.S. House of Representatives held an oversight hearing on the Federal government's role in addressing health and environmental risks of fly ash.<ref name="HCNR, 2008, Risks" >{{cite web
| author = House Committee on Natural Resources, Subcommittee on Energy and Mineral Resources
|title =Oversight Hearing: How Should the Federal Government Address the Health and Environmental Risks of Coal Combustion Wastes?
|date=June 10, 2008
|url = http://resourcescommittee.house.gov/index.php?option=com_jcalpro&Itemid=65&extmode=view&extid=184
}}</ref>
 
===ការ​ព្រួយ​បារម្ភ​នឹង​​ការ​ប៉ះ​ពាល់===
[[ស៊ីលីស​|គ្រីស្តាល់​ស៊ីលីស​]](Crystalline silica) និង​ [[កំបោរ​(រ៉ែ)|កំបោរ​]](lime) រួម​ជា​មួយ​នឹង​សារធាតុ​ពុល​ផ្សេង​ទៀត​ អាច​បង្ក​ជា​បញ្ហា​ដល់​សុខភាព​។ ថ្វី​បើ​ខាង​ឧស្សាហកម្ម​បាន​អះអាង​ថា​ ផ្លាយអាស់​ មិន​មែន​ជា​សារធាតុ​ពុល​និង​គ្មាន​សារធាតុ​ពុល​ក៏​ដោយ ក៏​ការ​ដក​ដង្ហើម​យក​សារធាតុ​អស់នេះ ការ​ប៉ះ​ពាល់​ដោយ​ផ្ទាល់​ជា​មួយ​នឹង​ស្បែក និង​ការ​ផឹក​ទឹក​ដែល​មាន​សារធាតុ​អស់​នេះ​ ប្រហែល​ជា​អាច​បង្ក​គ្រោះ​ថ្នាក់​ដល់​សុខភាព<ref>Managing Coal Combustion Residues in Mines, Committee on Mine Placement of Coal Combustion Wastes, National Research Council of the National Academies, 2006</ref> ។
៥៥៣

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