Search results
Results From The WOW.Com Content Network
Air pollution can occur naturally or be caused by human activities. [4] Air pollution causes around 7 or 8 million deaths each year. [5] [6] It is a significant risk factor for a number of pollution-related diseases, including heart disease, stroke, chronic obstructive pulmonary disease (COPD), asthma and lung cancer.
The EPA elected to not modify the Pb NAAQS further, but decided to instead focus on the 1991 U.S. EPA Strategy for Reducing Lead Exposure. The EPA concentrated on regulatory and remedial clean-up efforts to minimize Pb exposure from numerous non-air sources that caused more severe public health risks, and undertook actions to reduce air emissions.
A 2020 paper reported that about half of air pollution and half of the resulting deaths are caused by emissions from outside a given state's boundaries, typically from prevailing winds moving west to east. [9] Regulation of air pollution is a shared responsibility between federal, state, and local governments.
The decrease in air pollution without a significant drop in CO2 seems to support the idea that policies aimed at reducing local pollutants don’t necessarily reduce CO2 emissions. This aligns with other studies showing that U.S. air pollution policies haven’t significantly impacted greenhouse gas emissions. [37]
The technical literature on air pollution dispersion is quite extensive and dates back to the 1930s and earlier. One of the early air pollutant plume dispersion equations was derived by Bosanquet and Pearson. [2] Their equation did not assume Gaussian distribution nor did it include the effect of ground reflection of the pollutant plume.
The Pollutant Standards Index (PSI) is a type of air quality index used in Singapore, which is a number used to indicate the level of pollutants in air.Initially PSI was based on five air pollutants, but since 1 April 2014 it has also included fine particulate matter (PM 2.5).
In heating, ventilation, and air conditioning in winter months, large commercial buildings interior spaces may need cooling, even while perimeter spaces may need heating. [2] Free cooling is the production of chilled water without the use of a chiller, and can be used generally in the late fall, winter and early spring, in temperate zones. [3]
Air is separated causing a cooler air stream coming out the exhaust hoping to chill as a refrigerator. [22] In 1988 R. T. Balmer applied liquid water as the working medium. It was found that when the inlet pressure is high, for instance 20-50 bar, the heat energy separation process exists in incompressible (liquids) vortex flow as well.