نتایج جستجو برای: air quality standards
تعداد نتایج: 1019331 فیلتر نتایج به سال:
Although ambient concentrations have declined steadily over the past 30 years, Houston has recorded some of the highest levels of hazardous air pollutants in the United States. Nevertheless, federal and state regulatory efforts historically have emphasized compliance with the National Ambient Air Quality Standard for ozone, treating "air toxics" in Houston as a residual problem to be solved thr...
to teach english adequately, qualified teachers are needed. unfortunately, there are still teachers who are teaching english without an academic degree in tefl. it is necessary for teachers to have a major in english to have subject knowledge, but it is not sufficient. teachers need to have an understanding of the social, cultural, moral, ethical, and pedagogical issues of education and practic...
BACKGROUND Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. OBJECTIVES The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O(3) that exceed the U...
Surface coal mining creates more air pollution problems with respect to dust than underground mining . An investigation was conducted to evaluate the characteristics of the airborne dust created by surface coal mining in the Jharia Coalfield. Work zone air quality monitoring was conducted at six locations, and ambient air quality monitoring was conducted at five locations, for a period of 1 yea...
The National Research Council recommended both a risk- and performance-based multipollutant approach to air quality management. Specifically, management decisions should be based on minimizing the exposure to, and risk of adverse effects from, multiple sources of air pollution and that the success of these decisions should be measured by how well they achieved this objective. We briefly describ...
The aim of the study was to assess the level of air pollution by volatile organic compounds (VOCs) in a pig fattening house and in its vicinity. Air samples for chromatographic analysis were taken in the fattening house and in the vicinity of the farm. The air quality study shows that the level of organic gaseous pollutants was twice as high in the fattening house as in the atmospheric air. Alm...
Air quality is an important determinant of public health and quality of life. A secondary data analysis was carried out to investigate trends and air quality in Virginia. The analysis included an evaluation of two major air pollution source categories, emission of criteria and hazardous air pollutants, ambient concentrations of criteria pollutants, ozone standard violations and associated meteo...
background: in addition of the socio-economics costs, trauma is the 4th cause of death at all age groups, in 2000, trauma was caused more than 6 million deaths in the world. despite promising trend in improving many aspects of health care and treatment in the last decade in our country, little attention has been paid to the subject of registering trauma on an international standard. effective p...
Despite past improvements in air quality, very large parts of the population in urban areas breathe air that does not meet European standards let alone the health-based World Health Organisation Air Quality Guidelines. Over the last 10 years, there has been a substantial increase in findings that particulate matter (PM) air pollution is not only exerting a greater impact on established health e...
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