The method of calculation compensates for scheduled sampling that did not occur. If non-zero, report row is red . If non-zero, report row is red . This level may not be exceeded in any quarter of a year. Lead is captured with particulate matter and extracted from it for analysis.
Some sites take measurements every day.
Qtr 1, Qtr 2, Qtr 3, Qtr 4 Arithmetic average of all 24-hour values for a calendar quarter. If non-zero, report row is red . Monitor Type A code identifying the administrative classification of the monitor. This column is included for each pollutant. The calendar year to which the data pertain.