“…The concentrations of total extractable organic matter (EOM = CX + DCM + ACE) in Rio were similar to those reported for a mixed industrial/ residential site in Newark, N.J. during winter, but were 70 percent higher than summer levels at this site, 10 The distribution of the mass among the three EOM fractions differed considerably from those observed for wintertime samples collected in the two U.S. cities, as shown in Table VI and -- 7 For the Rio samples, approximately half of the mass was in the nonpolar fraction, with only 40 percent in the ACE fraction. The distribution for the Rio samples is similar to that observed for samples collected in the Caldecott Tunnel 28 and is consistent with greater contributions from motor vehicle emissions.…”