Search results
Results From The WOW.Com Content Network
Nitrogen dioxide is a reddish-brown gas with a pungent, acrid odor above 21.2 °C (70.2 °F; 294.3 K) and becomes a yellowish-brown liquid below 21.2 °C (70.2 °F; 294.3 K). It forms an equilibrium with its dimer , dinitrogen tetroxide ( N 2 O 4 ), and converts almost entirely to N 2 O 4 below −11.2 °C (11.8 °F; 261.9 K).
Nitrogen dioxide 2011 tropospheric column density. The EPA have some regulations and guidelines for monitoring nitrogen dioxide levels. Historically, some states in the US including Chicago, Northeast corridor and Los Angeles have had high levels of nitrogen dioxide.
For nitrogen dioxide (NO 2), the guidelines set 10 μg/m 3 for the annual mean or 25 μg/m 3 for a 24-hours mean. [2] For sulfur dioxide (SO 2), the guidelines stipulate concentrations not exceeding 40 μg/m 3 24-hour mean. [2] For carbon monoxide concentrations not exceeding 4 mg/m 3 24-hour mean. [2]
The AQI level is based on the level of six atmospheric pollutants, namely sulfur dioxide (SO 2), nitrogen dioxide (NO 2), suspended particulates smaller than 10 μm in aerodynamic diameter (PM 10), [19] suspended particulates smaller than 2.5 μm in aerodynamic diameter (PM 2.5), [19] carbon monoxide (CO), and ozone (O 3) measured at the ...
Criteria pollutants that are due 18 months after an area has been designated include sulfur dioxide (SO 2), nitrogen dioxide (NO 2), coarse particle pollution (PM 10), fine particle pollution (PM 2.5), and lead (Pb). [9] Ozone (O 3) and carbon monoxide (CO) are due 24 months after designation. [9]
The API was based on the level of six atmospheric pollutants, namely sulphur dioxide (SO 2), nitrogen dioxide (NO 2), respirable suspended particulates, carbon monoxide (CO), ozone (O 3), and lead (Pb), measured at all the monitoring stations throughout the territory. [5] It was replaced by the Air Quality Health Index on 30 December 2013.
Among these are nitric oxide (NO), nitrous oxide (N 2 O), and nitrogen dioxide (NO 2), all of which are covered in the NAAQS. NO 2 is the oxide measured and used as the indicator for the entire NO x family as it is of the most concern due to its quick formation and contribution to the formation of harmful ground level ozone. [18]
Unlike low-cost monitors, which are carried from place to place, static monitors continuously sample and measure the air quality in a particular, urban location. Public places such as busy railroad stations sometimes have active air quality monitors permanently fixed alongside platforms to measure levels of nitrogen dioxide and other pollutants ...