Variability of hazardous air pollutants in an urban area

Spatial and Temporal Variability of Ambient Air Toxics Data

“…As illustrated by Figure 2 and shown by several authors, [12][13][14] there can be large differences in city concentrations for certain pollutants. Carbon Tetrachloride has the lowest between-city CV, indicating similar concentrations in MSAs across the country, whereas, air toxics with high between-city variability include chloroform, tetrachloroethylene, methylene chloride, and most of the total suspended particulate (TSP) metals.…”

“…This pattern is consistent with carbon tetrachloride's long atmospheric lifetime 15 and has been reported in previous studies. 14,16 The second, named the "cool season" pattern, is characterized by higher concentrations in the cooler seasons. Benzene, methylene chloride, and lead are examples of pollutants with this pattern.…”

Assessment of air quality in Viana do Castelo, Portugal, in the scope of the polis programme

“…It is curious to note that operations with these products, presumably xylene emitters, occur at the end of the afternoon. Figure 7 compares the benzene levels registered at Viana do Castelo and other cities all over the world [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] . Slightly higher benzene levels were registered during the nineties in Europe (2-36 µg/m 3 ) and Asia (7-31 µg/m 3 , excepting Calcutta), whereas concentrations in North America and Oceania were the smallest (≤8 µg/m 3 ).…”

Toxicological Profile for Zinc

“…In 1990, the median concentration of zinc in air samples collected across Minnesota was 0.012 µg/m 3 (maximum, 0.187 µg/m 3 ) (Pratt et al 2000). At six measurement sites in Columbus, Ohio, the mean atmospheric particulate concentration of zinc for samples collected in 1989 was 0.01±0.01 µg/m 3 (Spicer et al 1996). Data on zinc concentrations ; n=108 samples) (Injuk et al 1992).…”

“…Zinc has been detected in air (Barrie and Hoff 1985;Duce et al 1975;EPA 1980d;Evans et al 1984;John et al 1973;Lioy et al 1978;Lloyd and Showak 1984;Patterson et al 1977;Pratt et al 2000;Ragaini et al 1977;Saltzman et al 1985;Spicer et al 1996;Zoller et al 1974), water (Bruce and McMahon 1996;Coale and Flegal 1989;Cole et al 1984;EPA 1980d;Hale 1977;HazDat 2005;Heit et al 1989;Maessen et al 1985;Minear et al 1981;NAS 1977;Nriagu et al 1996;Ohanian 1986;Sañudo-Wilhelmy and Gill 1999;Schock and Neff 1988;Scudlark et al 1994;Shiller and Boyle 1985;Taylor et al 2001;Windom et al 1991), soil (Beavington 1975;Chen et al 1999;Connor and Shacklette 1975;EPA 1980d;Haines 1984;HazDat 2005;Mayer and Manning 1990;Mielke et al 1999Mielke et al , 2000Mumma et al 1984Mumma et al , 1990…”