Gypsum support fungal growth as it is hygroscopic. Paper and glue used in indoor surfaces are very good growth substrates for most of the indoor fungi. Fiber glass insulation and ceiling tiles support the growth of a number of fungi, among them frequently isolated were A. Polyurethanes used in composites for insulation are attacked by Paecilomyces variotii, Trichoderma harzianum and Penicillium species Yazicioglu et al.
Toxic air pollutants, also referred to as air toxics or hazardous air pollutants HAPsare chemicals that, at sufficient concentrations and exposures, are known or suspected to cause cancer. HAPs can also cause other serious health effects or cause adverse environmental effects.
Air toxic pollutants of greatest concern are those that are released to the air in amounts large enough to create a risk to human health and in which many people may be exposed. Air toxic pollutants may exist as particles or gases.
Air toxics that exist as particles can include heavy metals, such as cadmium, mercury, chromium, and lead compounds, as well as organic compounds, such as polycyclic aromatic hydrocarbons PAHswhich are emitted during the combustion of fossil fuels and wastes.
Gaseous air toxic pollutants include benzene, toluene, and xylenes, found in gasoline; perchloroethylene, used in dry cleaning; and methylchloride used as a solvent by various industries.
What are the sources of air toxics? Air toxics can be produced from both stationary sources, either point or area sources, and mobile sources.
Point sources include facilities that report emissions, including power plants, manufacturers, refineries, large office buildings, landfills, hospitals, incinerators, and government facilities. Smaller stationary sources or area sources include dry cleaners, printers, and automobile paint shops.
Mobile sources include both on- and off-road motor vehicles, as well as boats and aircraft. Some air toxics are released from natural sources, including volcanoes, radon gas, and emissions from forests.
Although natural sources of air toxics exist, most toxics originate from man-made sources.
DATAS determined that 68 percent of the mass of emissions come from mobile sources, 23 percent come from area sources, while 9 percent are contributed by point sources. The study has been updated with air toxics data fromwhich will be released to states in NATA identified certain air toxics that pose the greatest risk on a national or regional level.
However, in many cases, EPA was unable to develop local estimates of air toxics emissions and relied on national default values to generate much of the emissions data that went into the NATA analysis.
For the air quality monitoring component, the five sites were selected based upon the following criteria: Location of the site relative to industrial facilities. Location of the site relative to major roadways. Ability of existing infrastructure at the site to support additional toxics instrumentation.
Incorporation of sites already equipped with air toxics instrumentation. From where do the pollutants originate that were observed at the monitoring sites? Sources contributing to the ambient concentrations of air toxics observed at the monitoring sites can include point sources, area sources, and on-road and off-road mobile sources.
These sources can be located in Delaware, near the monitors, as well as located upwind of Delaware in another state. Certain pollutants, in part, form in the atmosphere from other pollutants in a process called photochemistry.
The monitors do not readily tell us from where the pollutants originate. In general, the emission inventory matches what the monitors found. As an example, some volatile organic compounds were not observed at the monitors, and sources for these same pollutants were not found in Delaware when the inventory was developed.
The modeling effort of Phase II will account for the transport of emissions from sources inside and outside of Delaware. The modeling results can be analyzed to associate sources contributing to a particular ambient concentration.13 days ago · The report, Air pollution in Asia and the Pacific: Science-based Solutions, is the first comprehensive scientific assessment of the air pollution outlook in the region and is meant to help 1 billion people breathe cleaner air by in Asia.
Nov 05, · Air pollution affects people’s health in a variety of ways. These health effects can be seen in the young and old as well as the healthy and infirm. With both outdoor and indoor sources, air pollution is a health issue with global consequences.
There is an urgent need to address the effects of air pollution on the global climate as well as on human health, particularly among vulnerable populations such as . Identification of key missing by-product of prioritization efforts as documentation of knowledge gaps can inform future prioritization efforts.
CHAPTER 8. HAZARDOUS AIR POLLUTANTS: APPROACHES AND CHALLENGES IN IDENTIFYING ASSESSMENT PRIORITIES the primary focus of air quality management programmes. These pollutants accumulate in. Toxic air pollutants are poisonous substances in the air that come from natural sources (for example, radon gas coming up from the ground) or from manmade sources (for example, chemical compounds given off by factory smokestacks) and can harm the environment or your health.
Jun 08, · California Air Toxics Program. This page last reviewed June 8, The California Air Toxics Program establishes the process for the identification and control of toxic air contaminants and includes provisions to make the public aware of significant toxic exposures and for reducing risk.