API Section 211(B) Tier-2 Exposure Database 

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

Data_SPME.xls, API Data_Time-integrated.xls and API Data_Reconstructed.xls) 

containing the continuous, SPME, time-integrated and reconstructed exposure data. All 

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

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

the analytical or sample collection methods. Tables explaining the meaning of each data 

field are also included with each file. The files 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 points, 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 measured 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 number 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) trailing vehicle exposure tests. 

The SPME data set is assembled in essentially the same manner as the timeintegrated data, but contains 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 included but these can be derived from the identification code 

as described in the included key. 

The fourth file contains 1-min reconstructed 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 and DNPH-carbonyl samples and 5-min canister 

samples collected over a peak exposure 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 data 

Experiment Position Type 1st Location 2nd Season 3rd + 4th 5th Mode 6th 7th 8thMEAtlanta A S-Summer W-winter ME number (01, etc) M-main P- 5 min 

B-breath 

Under score 

Replicate number 

BreathB-pea

MEChicago C S-Summer W-winter ME number M-main P- 5 min 

B-breath 

Under score 

Replicate number 

BreathB-pea

MEHouston H S-Summer W-winter ME number M-main P- 5 min 

B-breath 

Under score 

Replicate number 

BreathB-peapost; denud

trailing Vehicle 

V S-Summer 

W-winter 

Fuel (a,c,h) + vehicle (ttruck, s-sedan) 

MalFunction (F) Normal (N) 

Under score 

High (H), Low (L) vent, or coMbined (m) 

BackgA; Idle-C 

Residence w/attached garage 

R S-Summer 

W-winter 

Fuel (a,c,h) + vehicle (ttruck, s-sedan) 

MalFunction (F) Normal (N) 

Under score 

Kichen (K) or Garage(G) location 

BackgA; Ma

For example: AS02M_1 means Atlanta, summer, ME#2, first replicate. HW11B_3B means Houston, winter, Mpeak VWasN_HC means trailing vehicle, winter, Atlanta fuel, sedan, normal mode, high vent, idle. RSctF_KA m

Chicago fuel, truck, malfunction, kitchen, background