Jekyll Island meeting report George Hi& reports on the acquisition of reliable atmospheric data
In May 1985, the 15th Annual Symposium on the Analytical Chemistry of Pollutants convened in Jekyll Island, Ga. As pan of the meeting, a series of lectures on acid deposition and the closely allied subject of acquiring valid air quality monitoring data was presented. In last month’s issue, we reported on a talk given by Courtney Riordan of EPA. This month, we report on the IecNre given by George Hidy of the Desert Research Institute (DRI) in Reno, Nev. Next month, we will conclude this series of Views with a report on the talk given by James Galloway of the University of Virginia. Hidy’s lecture covered recent progress in formalizing the process of making environmental measurements. He discussed the need for atmospheric scientists to build a framework, a data base, for monitoring programs that will generate data of a defined quality and traceability. More than 100 scientists have been involved in this field; a framework has been developed and adopted for air quality measurements and monitoring, a subject closely allied to the SNdy of acid deposition. The ultimate reasons for making such measurements are to establish historical records of atmospheric pollutants, to explore the spatial and temporal distribution of atmospheric gradients of pollutants, to test scientific and regulatory hypotheses, and to verify mechanistic and source-receptor models. Hidy illustrated the use of air quality data with application to each of these areas. Particular discussion was focused 1032
Emiron. Sci. Technol..MI. 19. No. 11. 1985
ity of the measurement, the accuracy of the measurement against a reference standard, and the validity of the measurement in relation to interferences.
On the cutting edge
George Hidy
Hidy illustrated the use of air quality data with application to each of these areas. Particular discussion was focused on the importance of traceability and consistency in measurements for trend analysis. It is important that atmospheric scientists know how and when such monitoring data are collected and whether they are reliable. Hidy discussed the difficulty encountered in interpreting observations of precipitation chemistry in light ofchanges in pollutant emissions. He also outlined the use of data to infer spatial and temporal changes in meteorology and atmospheric chemistry. Finally, he listed the data requirements for the validation of models, specifically for the determination of particulate maner source-recep tor relationships (I). Hidy defined the details of air quality measurement processes and illustrated these aspects with recent examples of significant measurements. such as “The Sulfate Regional Experiment” (2). He also related these aspects to the process of interpreting the data collected. The evaluation of monitoring activity, which has been formalized by John Watson and others (3),involves consideration of four basic factors: the datum of the ob. servation, the precision or reproducibil-
The development staNs of measurements was illustrated by three examples of current technology. First, the current established method of measuring SO2 in the atmosphere is accurate to a level of 3-5 ppb. The methodology for verifying this measurement has been described by Mueller and Hidy (2) and Mueller and Watson (3).These scientists employed the four characteristicsof measurements mentioned earlier. Second, the development of a semiestablished method for size-fractionated particulate matter measurement has resulted in a proposed new ambient air quality standard. This standard involves the < 10-pm fraction of particulate matter; new monitoring requirements are required for this standard. In the past five years, many atmospheric scientists have been involved in the development of sampling devices. Collectively, they have arrived at new standard operating procedures, compared the sampling schemes and inlet ducts of the sampling devices for the IO-pm fraction of particulate maner, resolved the efficiencies of the collection process, identified and quantified filter artifacts from gas adsorption and desorption on the collected particulate matter samples, established criteria for accepting the precision and accuracy of sample collection, and validated the collected data.
0018936~85/W141032~1.50/00 1985 American Chemical Sociely
