Laserfiche WebLink
<br />EPA has concluded that the following groups may be particularly sensitive <br />...... to co: angina patients, individuals with other types of cardiovascular <br />~J disease, persons with chronic obstructive pulmonary disease, anemic <br />CJ) individuals, fetuses, and pregnant women. 'Concern also exists-for healthy <br />CJ children because of the increased oxygen requirements associated with <br />their higher metabolic rates. The Denver metropolitan, Colorado Springs, <br />Fort Collins and Greeley areas are considered nonattainment areas for <br />carbon monoxide. <br /> <br />B. Particulate Matter <br /> <br />Particulate matter includes a broad class of chemically and physically <br />diverse substances. Particulate matter exists in the liquid or solid <br />phase as discrete particles ranging in size from molecular clusters of <br />0.005 micrometers (um) to coarse particles on the order of 100 um in <br />diameter (1 urn ~ 1/1,000,000 meter). The major chemical and physical <br />properties of particulate matter vary greatly with time, region, <br />meteorology and source category. For the purpose of assessing health and <br />welfare, particulate matter is divided into three categories. <br /> <br />The range of most concern is from 0-15 um. Particles in the size range <br />0-2.5um are referred to as "respirable" particles, indicating that they <br />are taken into the deepest region of the lung. 2.5-15 um particles are <br />considered "inhalable", meaning that they are taken into the respiratory <br />tract but not as deeply as respirable particles. Most of the remaining <br />particles, in the range 15-100 um, are filtered out by cilia cells in the <br />nose or upper thorax. <br /> <br />Pollutants of concern from diesel engines include NOX, Sulfurous <br />compounds, and carbonaceous particulates. Diesel particulates are in the <br />respirable size (0-2.5 um) range and contain known and suspected <br />carcinogens. Diesel particulates contribute significantly to Denver's <br />visibility problem. They also contribute more to urban soiling problems <br />than typical airborne particulates. <br /> <br />Windblown materials, road dust propelled bY,moving vehicles, sulfates <br />formed from sulfur oxides, residential wood combustion, products of oil <br />and coal combustion, and industrial emissions contribute most of the <br />particulate matter in urban areas. Fine particles are usually produced by <br />industrial emissions, combustion processes, or atmospheric transformation <br />of gases to particles. Mechanical processes provide most of the coarse <br />particles. <br /> <br />Both fine and coarse particles are deposited in the tracheobronchial <br />region. They can cause constriction of the bronchia, reduced mucocilliary <br />clearance, and aggravation of chronic respiratory diseases such as asthma, <br />bronchitis, emphysema, and possibly cancer. <br /> <br />Fine and coarse particles can be absorbed by the alveolar region of the <br />lung. Deposition in this area can be of special concern because the body <br />may take weeks or years to remove these particles. They can affect the <br />lung in several ways. They may aggravate chronic lung disease by <br />disturbing normal ventilation and causing a reflex constriction of blood <br />vessels that supply part of the lung. They may also be associated with <br />inflammation, fibrosis, and other conditions of the lung. <br /> <br />-3- <br /> <br />I <br /> <br />.. <br /> <br />J. <br />, ',- "~-~"-;; <br />",. ~ -.:.. -~ . --;;.~ <br />