# API Section 211(B) Tier-2 Exposure Database

The data have been organized into four data files (API Da ta_Continuous.xls, API

Data_SPME.xls, API Data_Time-integrat ed.xls and API Data_Reconstructed.xls)

containing the continuous, SPM E, time-integrated and reco nstructed exposure data. All

files include data fields describing the sample collection conditions (e.g.;

microenvironment, fuel type, test mode) as well as data flags i ndicating problems with

the analytical or sample coll ection methods. Tables explaini ng the meaning of each data

field are also included with each file. The fi les are supplied in Excel workbook format for

convenience, but have been formatted to be compatible with common database software

(the value -99 is used for missing data poi nts, and time is in hhmm text format)

The time-integrated data contains speciation results from canister, DNPH

cartridge, and TENAX adsorbent tubes, plus time-averaged values of pollutants and

environmental parameters that were meas ured continuously during the batch sample

collection periods. Within the time-integrated data file there are 4 sub-categories that are

presented separately due to the differing numbe r of experimental variables for each type:

1) microenvironment exposure measurements from the three cities, 2) breath samples

collected from subjects participating in 4 of the microenvironments, 3) residence with

attached garage, and 4) trai ling vehicle exposure tests.

The SPME data set is assembled in essentially the same manner as the timeintegrated data, but contai ns only the BTEX hydrocarbon compounds and uses some

different sample descriptors where necessary to identify which portion of each test the

sample was collected. The same sample IDs are used to facilitate comparison of the two

sampling methods.

The third data file contains 1-minute averages of the pollutants and environmental

parameters that were measured continuously during the microenvironment exposure tests

in the 3 cities. Data were typically logged every 10 seconds during testing, but to reduce

measurement noise, make the data set more manageable, and reduce the effect of minor

timing discrepancies between instruments due to imperfect clock synchronization or

differences in sample line residence time, the data was time averaged by minute. Each

data record in this file has both a time/date stamp and an identification code that relates it

to the corresponding time-integrated sample. Data flags are given to identify any missing

or invalid data for each minute. Due to the large size of this file, the various sample

descriptors have not been incl uded but these can be derived from the identification code

as described in the included key.

The fourth file contains 1-min reconstr ucted data for benzene, 1,3-butadiane and

formaldehyde based on PID and NDIR CO continuous data, as described in Chapter 1 of

this report. Both full time canister a nd DNPH-carbonyl samples and 5-min canister

samples collected over a peak expos ure in selected MEs are included.

Table G-1 contains the key to the name of the samples collected during this study.Table G-1. Naming convention for the API dataExperimentPositionType1stLocation2ndSeason3rd+ 4th5thMode6th7th8thMEAtlantaAS-SummerW-winterME number(01, etc)M-mainP- 5 minB-breathUnderscoreReplicatenumberBreath: A-pre;B-peak, C-postMEChicagoCS-SummerW-winterME numberM-mainP- 5 minB-breathUnderscoreReplicatenumberBreath: A-pre;B-peak, C-postMEHoustonHS-SummerW-winterME numberM-mainP- 5 minB-breathUnderscoreReplicatenumberBreath: A-pre;B-peak, Cpost; NOxdenuder: DtrailingVehicleVS-SummerW-winterFuel (a,c,h) +vehicle (ttruck, s-sedan)MalFunction(F)Normal (N)UnderscoreHigh (H), Low(L) vent, orcoMbined (m)Background –A; Main-B;Idle-CResidencew/attachedgarageRS-SummerW-winterFuel (a,c,h) +vehicle (ttruck, s-sedan)MalFunction(F)Normal (N)UnderscoreKichen (K) orGarage(G)locationBackground:A; Main - BFor example: AS02M_1 means Atlanta, summer, ME#2, first replicate. HW11B_3B means Houston, winter, ME#11, breath sample,peakVWasN_HC means trailing vehicle,winter, Atlanta fuel, sedan, normal mode, high vent, idle. RSctF_KA means garage, summer,Chicago fuel, truck, malfunction, kitchen, background