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 . The calendar year to which data pertain. This is the year in which pollutant concentrations were measured. City Name of the city, town, village or other municipality in which the site is located.