Table 1 A summary of measurement site information, including the IMPROVE or STN site ID, the location of the site, the measurement network, site latitude and longitude, and the range of times in which data were analyzed in this study.

West of NYC (NJ, Sterling Forest)

 340070003

Camden, NJ

STN

39.92 N, −75.10

12 June 2001–31 December 2006

 340230006

Trenton, NJ

STN

40.47 N, −74.43

13 January 2001–31 December 2006

 340273001

Chester, NJ

STN

40.79 N, −74.68

06 June 2001–31 December 2006

 340390004

Elizabeth, NJ

STN

40.64 N, −74.21

13 May 2001–31 December 2006

 BRIG1

Brigantine NWR

IMPROVE

39.47 N, −74.45

01 January 2000–31 December 2006

 SF

Sterling Forest

IMPROVE

41.20 N, −74.26

05 September 2000–31 December 2001; 17 April 2003–2 January 2004

New York City

 360610062

Canal Street

STN

40.72 N, −74.00

15 August 2002–31 December 2006

 NEYO1

IS52, Bronx

IMPROVE

40.82 N, −73.90

01 August 2004–31 December 2006

 360050110

IS52, Bronx

STN

40.82 N, −73.90

28 January 2001–31 December 2006

 360050083

Bronx bot. gardens

STN

40.87 N, −73.88

09 February 2000–30 December 2005

 HUNT

Hunter college

NYU

40.77 N, −73.96

01 January 2001–31 December 2003

 CMS

NYU Central Monitor

NYU

40.74 N, −73.98

17 July 2000–30 January 2001

 OUT

NYU home study

NYU

Varies

17 July 2000–30 January 2001

 360810124

Queens CC

STN

40.74 N, −73.82

26 March 2001–31 December 2006

East of NYC (CT)

 90090027

New Haven (STN)

STN

41.30 N, −72.90

24 February 2004–31 December 2006

 90091123

New Haven (IMP)

STN

41.31 N, −72.92

08 June 2003–21 February 2004

 MOMO1

Mohawk Mtn.

IMPROVE

41.82 N, 73.30

13 September 2001–31 December 2006

 90019003

Westport

STN

41.12 N, −73.34

26 April 2002–05 June 2003