Second-highest eight-hour average carbon monoxide (CO) concentration in ppm for sites in Massachusetts. The eight-hour CO standard is 9 ppm.
| MAX 1-HR | MAX 8-HR | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Site ID | P O C | M T | City | County | Address | YR | REP ORG | # OBS | 1ST | 2ND | OBS > 35 | 1ST | 2ND | OBS > 9 | METH |
| 25-013-0016 | 1 | 1 | Springfield | Hampden | Liberty Street Parking Lot | 97 | 001 | 8546 | 6.8 | 6.5 | 0 | 6.1 | 5.3 | 0 | 67 |
| 25-013-2007 | 1 | 1 | Springfield | Hampden | East Columbus Avenue | 97 | 001 | 8536 | 7.9 | 7 | 0 | 5.3 | 4.9 | 0 | 67 |
| 25-017-0007 | 1 | 2 | Lowell | Middlesex | Old City Hall, Merrimack Street | 97 | 001 | 7962 | 6 | 5.7 | 0 | 4.1 | 3.6 | 0 | 67 |
| 25-025-0002 | 1 | 2 | Boston | Suffolk | Kenmore Square, 590 Commonwealth Avenue | 97 | 001 | 8503 | 6.6 | 5.7 | 0 | 4.5 | 2.9 | 0 | 67 |
| 25-025-0016 | 1 | 2 | Boston | Suffolk | Visconti Street, East Boston | 97 | 001 | 8650 | 5.9 | 5.4 | 0 | 4.4 | 3.8 | 0 | 67 |
| 25-025-0021 | 1 | 1 | Boston | Suffolk | 340 Breman Street, East Boston | 97 | 001 | 8661 | 6.6 | 5.1 | 0 | 4.6 | 3.7 | 0 | 67 |
| 25-025-0038 | 1 | 1 | Boston | Suffolk | Federal Post Office Bldg, Milk & Congress | 97 | 001 | 8439 | 6.7 | 6.6 | 0 | 4.9 | 4.7 | 0 | 67 |
| 25-027-0020 | 1 | 2 | Worcester | Worcester | Central Street Fire Station | 97 | 001 | 8398 | 6.2 | 5.5 | 0 | 3.7 | 3.4 | 0 | 67 |
| 25-027-0022 | 1 | 2 | Worcester | Worcester | Franklin Street Parking Lot | 97 | 001 | 8449 | 7.5 | 5.8 | 0 | 3.4 | 3.3 | 0 | 67 |