Background pollution

Such sources constitute background pollution and that portion of the pollution problem over which control activities can have little, if any, effect. 

We have chosen four molecules that are either simulants or pre-cursors of CWA s in order to characterize the capabilities of the CP-FTMW spectrometer for the detection of airborne CWA s. The rotational spectrum of each compound serves as a basis for molecular recognition allowing positive identification of the species of interest. The resulting spectrum contains both frequency and intensity iirformation that can be used to discriminate against other CWA or background pollutants. 

Trichloroethane has been identified in urban, rural, and indoor air throughout the United States at concentrations shown in Table 5-3. Due to the nature of 1,1,1-trichloroethane s use, volatilization to the atmosphere is a predictable outcome, and thus its widespread detection is not unexpected. It is the only chlorinated ethane regularly seen as a background pollutant in the troposphere (Spence and Hanst 1978). For the year 1980, an estimated global atmospheric quantity of... 

Air quality monitoring carried out at the international level is concentrated in background pollution stations as part of BAPMoN and EMEP networks. Also the local trans-boundary pollution along the Danube River is monitored in several stations. At the local level, common pollutants (SO2, NO2, NH3, suspended powders) are measured at all stations and specific... 

The concentration of a toxic substance is critical however, it is necessary to compare it with a reference "background pollution." The background pollution is specific to a zone free of toxic substances. It is then possible to make a diffusion map of toxic substances. 

Background Pollutant Levels Overall pollution levels in Region... 

Rovinsky F, Pastukhov B, Bouyvolov L, Burtseva L (1995) Present day state of background pollution of the natural environment in the Russian Arctic in the region of the Ust-Lena Reserve. Sci Total Environ 160/161 193-199... 

Mean tropospheric background for is given. Value can be much higher in polluted areas. 

Empirical—statistical models ate based on estabUshing a relationship between historically observed air quaUty and the corresponding emissions. The linear rollback model is simple to use and requites few data, and for these reasons has been widely appHed (3,4). Linear rollback models assume that the highest measured pollutant concentration is proportional to the basinwide emission rate, plus the background value that is,... 

The global geochemical background and enormous industrial environmental pollution have increased, thus, there are all the bases to speak about the beginning of biogeochemical formation development which has a direct influence on the ecological system condition in general as well as on the population health. 

As background, Garrod and Whitmarsh describe market failure with respect to protecting the marine environment. Particular difficulties arise because of the diverse and perhaps conflicting exploitation of the sea and its resources. Thus, pollutants may be released into the marine environment by one sector or industry... 

At least three types of problems contribute to air pollution problems on the regional scale. One is the carryover of urban oxidant problems to the regional scale. With the existence of major metropolitan areas in close proximity, the air from one metropolitan area, containing both secondary pollutants formed through reactions and primary pollutants, flows on to the adjacent metropolitan area. The pollutants from the second area are then added on top of the "background" from the first. 

Under low-dose conditions, forest ecosystems act as sinks for atmospheric pollutants and in some instances as sources. As indicated in Chapter 7, the atmosphere, lithosphere, and oceans are involved in cycling carbon, nitrogen, oxygen, sulfur, and other elements through each subsystem with different time scales. Under low-dose conditions, forest and other biomass systems have been utilizing chemical compounds present in the atmosphere and releasing others to the atmosphere for thousands of years. Industrialization has increased the concentrations of NO2, SO2, and CO2 in the "clean background" atmosphere, and certain types of interactions with forest systems can be defined. 

Pollution Prevention and Abatement Pesticides Manufacturing." Draft Technical Background Document. Environment Department, Washington, D.C. 

Background level The concentration of a particular substance present in the air without any local source of the pollutant, or the concentration of the pollutant at some distance from its source. 

Two key parameters have been found to determine the ultimate eapabili-ties of the MOEMS-based MOS contrast and spectral photometric variation (SPV). Contrast is dehned as the total amount of non-selected flux of light passing through the multi-slit device a contrast requirement of 2000 has been established in order to avoid pollution of the spectra by strong sources (spoilers) and sky background. The SPV is the unpredictable photometric variation due to the random position of the sources on the PMSM grid SPV requirement has been fixed to <10%. 

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