vvEPA
                                United States
                                Environmental Protection
                                Agency
                                Health Effects Research
                                Laboratory
                                Research Triangle Park NC 27711
                                Research and Development
                               EPA-600/S1-81-007  Feb. 1981.
Project Summary
                                Chromosome  Aberrations  in
                                Peripheral  Lymphocytes of
                                College  Students  as  a
                                Response to  Photochemical
                                Air Pollution

                                Allan R. Magie, David E. Abbey, and Willard R. Centerwall
                                 This research project confirms and
                                extends  to  a  more  homogeneous
                                group the observations of Scott and
                                Burkard in their study of chromosome
                                aberrations in the peripheral lympho-
                                cytes  of students  attending the
                                University of Southern California. This
                                study  compares whether the inci-
                                dence of chromosome aberrations in
                                students emigrating from and to an
                                area with high levels of photochemical
                                air pollutants versus an area of low
                                levels  differed  significantly  from
                                students indigenous to the respective
                                areas.
                                 The data does not support the hypo-
                                thesis that living (or attending school)
                                in the  South  Coast  Air Basin of
                                Southern  California significantly af-
                                fects the integrity of peripheral blood
                                lymphocyte  chromosomes.  Nor  is
                                there evidence that those living  in
                                areas of little or no photochemical air
                                pollution  have statistically  signifi-
                                cant fewer chromosome abnormalities.
                                 This Project Summary was devel-
                                oped by EPA's Health Effects Research
                                Laboratory, Research  Triangle Park,
                                NC, to announce key findings of the
                                research  project that  is  fully docu-
                                mented in a  separate report of the
                                same title /see Project Report order-
                                ing information at back).
                               Introduction
                                 Conflicting evidence  continues to
                               accumulate that exposure of human,
                               animal,  and  plant  tissues to the
                               constituents of  photochemical  air
                               pollution  may  result  in  increased
                               chromosome aberrations. Of particular
                               concern  is the potential danger that
                               exposure of humans to existing ambient
                               levels of photochemical smog  may
                               result in  mutagenic changes leading to
                               congenital anomalies. Although studies
                               on ozone effects on human cells have
                               been  limited,  considerable evidence
                               does exist for the induction of both point
                               and chromosome aberrations in several
                               animal species.
                                Methods
                                Two-hundred and nine (209) male
                               and female first-year students at the La
                               Sierra campus of Loma Linda University
                               (high smog) and two-hundred and six
                               (206)  male  and female  first-year
                               students at Pacific Union College (low
                               smog)  were  pre-enrolled  after
                               completing a  lifestyle questionnaire or
                               responding to  a  similar  telephone-
                               administered  questionnaire. They were
                               assigned to groups according to their
                               previous  life-time exposure  to air

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pollution and the college in which they
were matriculating. This resulted in four
groups: low  smog  to  low smog, low
smog to high smog, high smog to low
smog, and high smog to high smog.
  Blood samples  and  updated  health
histories  were  obtained  from  the
students  at  the  following   times:
September-October  1976   (410
students):   November  1976  (407
students); April 1977  (369 students);
and  September-October  1977  (317
students).  All  blood  samples  were
cultured and slides prepared  by the
Genetics Research  and Chromosome
Services,  Loma  Linda  University
Medical Center. One hundred cellsfrom
each   student   were   analyzed  for
chromosome and  chromatid  aberra-
tions   at  Utah   Biomedical  Test
Laboratory.
Conclusions
  Due to technical difficulties in blood
drawings  three and  four,  statistical
analyses of all groups for all four blood
sampling periods was not completed. It
is  felt that  this  study  is significant,
however,  in  that   four  contrasting
groups, with  respect to exposure to
photochemical air pollution in the South
Coast Air Basin of Southern California,
were  cytogenetically examined  at the
conclusion of the high pollution season
and again two and six months later.
  No statistically significant differences
in  the aberration rates for the types of
chromosome  abnormalities   studied
were   observed  between  the  four
exposure groups of students  at each of
the sampling periods or among the
same students over the duration of the
study. The   elevated rate  of  stable
changes  at the initial blood sampling
period for  males  in  the low-to-high
group was,  however, an exception of
statistical importance. This  group did
not  show  a statistically  significant
elevation  in  rate  when the   initial
criterion  of allowing students to arrive
on  campus  15 days prior  to  blood
drawing  was applied,  but  the  rate
became increasingly  elevated over the
other groups and became statistically
significant   when   two   increasingly
stringent criteria for arrival time were
applied, namely within 3 days of blood
drawing  and  then   within  1  day.
Increased differences were also noted
for females in the same group, but these
were  not as significant as they were for
the males. Moreover, these elevated
rates dropped off by the second blood
sampling 2 months later.
Recommendations
  Future studies can reduce the intra-
student  variability  by  scoring  a
minimum of 200 metaphases.
  Study group size could be reduced by
using more stringent exclusion criteria
such  as  those  used for  statistical
analyses in this study.
  An  on-going  validity study to check
accuracy   in   chromosome   scoring
should be carried out at an independent
laboratory paralleling any cytogenetic
study.
  A   carefully  controlled  laboratory
study  exposing  students  having  no
previous exposure to significant levels
of ozone could be carried out to test the
"shock effect" hypothesis.
  Allan R. Magie, David E. Abbey, and Willard R. Centerwall are with Loma Linda
     University, Loma Linda, CA 9235O.
  Dorothy C. Calafiore is the EPA Project Officer (see below).
  The complete report, entitled "Chromosome Aberrations in Peripheral Lympho-
     cytes of College Students as a Response  to Photochemical Air Pollution,"
     /Order No. PB 81-152 506; Cost: $14.00, subject to change) will be available
     only from:
          National Technical Information Service
          5285 Port Royal Road
          Springfield.  VA 22161
          Telephone: 703-487-4650
  The EPA Project Officer can be contacted at:
          Health Effects Research Laboratory
          U.S. Environmental Protection Agency
          Research Triangle Park,  NC 27711
                                                                                      : U.S. GOVERNMENT PRINTING OFFICE: 1981 -757-012/7173

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