Document ymXQb0e7OJeGGLD55Ex94BnN2
lower now than in 1871
Concentrations of lead in the atmos phere have risen steadily since 1940, says the National Academy of Sciences. Even so, human absorption of environ mental lead may have decreased signicantly in the past 50 years, according to a report in the Oct. 6 Sc ie n c e. The research is based on comparisons of the lead content of antique and contenfporary samples of human hair. The presence of lead in the hair reflects the prior presence of lead in the blood because during growth the emerging hair accumulates and retains heavy metals such as lead.
Advertisements for samples of old hair produced 130 specimens (from mu seums and private individuals) dated be tween 1871 and 1923 (the year tetra ethyl lead was introduced into gaso line). Contemporary hair samples were collected from rural and urban barber shops. Donald Weiss of Newton, Pa., and Bert Whitten and David Leddy of Michigan Technological University in Houghton, Mich., used atomic absorp tion spectrophotometry to analyze the lead content of the hair. They found the amount of lead in antique hair to be as much as 10 times the amount in 1971 samples--'both rural and urban. Whitten admits that the technique may not be sensitive enough to detect small differences (significant differences were not found between urban and rural sampies), but the difference between preand post-1923 samples was obvious.
These results may seem surprising; in recent years much of the emphasis on lead pollution has focused bn getting the lead out of gasoline and thus out of the air. But, in fact, the amount of lead absorbed through the lungs by breathing polluted air is minor com pared with the amount of lead ingested through the stomach by eating leadbased paint. The use of lead in in terior paints was largely discontinued by 1950. Similarly, water is no longer collected from lead roofing nor stored in leaded jugs as it was in the early part of the century. Lead-contaminated stills, lead-glazed pottery, lead tooth paste tubes and lead in food and cos metics are all sources of lead poisoning much more closely monitored than they were 50 years ago. "Thus," say the re searchers, "the lower lead content in human hair in our contemporary popu lation is probably a result of greater precautions in the use of lead in spite of a general increase in atmospheric concentrations."
Still, lead pollution and lead poison ing are problems. In 1971, a Gov ernor's Task Force in Connecticut dis covered that seven percent of a sam ple of inner city children in that state
,October 14 1972
poisoning, usually associated with ex posure to lead-based paints, can cause mental retardation, behavioral difficul ties, perceptual disabilities, emotional instability and distractibilty.
But similar information is not avail able on the effects of low exposure to
stitute of Mental Health suggest that
low chronic exposure levels may have
subtle effects on behavior Without prior
acute exposure; the nearly universal ex
posure to low levels of lead makes re
search into the problem an urgent con
cern.
'Pay as you launch' plan for foreign satellites
President Nixon announced this week a formal "launch assistance" policy for satellite projects of other nations or in ternational organizations. The policy provides for a "pay as you launch" plan for any nation that wants to orbit spacecraft for peaceful purposes, n as a has launched satellites for other coun tries in the past. But `there has been some confusion about the U.S. posi tion toward n as a's launching corhmuncations satellites for the Europeans if those satellites would be in direct com petition with Intelsat, an international communications consortium of which the United States is a member.
The new policy says in effect that the United States will consider launch-
ing communications satellites such as
the French-German Symphonie (SN:
8/29/70, p. 165) and the French re
gional system for communication with
North Africa. One n as a official noted
that the recent domestic communica
tions system decision opened up the
market for competition in the United
States and that Nixon's policy state
ment followed the same spirit on the
international scene.
The policy would also eliminate un
necessary duplications in world space
communities; the need of a nation to
develop its own booster when it could
buy a booster from the United States
and launch it from either U.S. facilities
or foreign launch sites.
Interstellar particles 'seen' in solar system
The sun is traveling through the
galaxy toward Hercules at about 20
kilometers per second relative to the
near stars. So it is reasonable to as
sume that the observed du&t particles in
the galaxy and from other stars would
pass through the solar system at times.
But until now, no one has detected
them.
.
Now, micrometeorite detectors aboard
Pioneer 8 have detected at least two
particles, mass IQ-*13 grams, from out
side the solar system---and possibly
many more. The instruments provide
data for scientists to calculate not only
the direction of particles hitting the
Pioneer spacecraft but also their speed.
Pioneer 8 detected two particles moving
in the direction opposite that which the
sun is traveling. Their velocity was
around 100 kilometers per second
Some 400 other events have been de
tected, and Otto Berg of the Goddard
Space Flight Center estimates that a
significant number of these may also
be passing through the solar system.
Since such particles are most likely
primordial material, the next step is
for scientists to calculate their com
position. That chance may come later
in this decade. Berg has proposed an
instrument on the possible Jupiter-Sat-
urn mission in 1977 (SN; 3/4/72, p.
152) that can detect not only the size,
speed and direction of the particles, but
also their composition.
Aiding mass transif via highway fund: Hopes dim
Hopes by urban mass transit sup porters that this year's federal highway bill would include a provision for di version of some Highway Trust Fund monies to urban transit were dimmed in House action last week.
Claiming "betrayal," House sponsors of diversion amendments charged that last minute parliamentary maneuvering by Krifsc Speaker Carl Albert (DOkla.X nnd Parliamentarian Lewis Deschler had thwarted their efforts to in troduce their amendments. In this case, the environmentalist legislators and the Administration were on the same side, with Transportation Secretary John A. Volpe also supporting diversion of the funds.
But the Senate version of the bill in
cludes diversion amendments, and sup
porters said there is some hope these
can be incorporated into a conference
committee version.
Advisory committee act
With no fanfare and no public state ment, President Nixon late last week signed the Federal Advisory Committee Act. The act (SN: 10/7/72, p, 234) goes further than an earlier executive order in opening the operations of many Federal advisory committees, in cluding many involving scientific mat ters, to press and public scrutiny. Whether the President would sign or veto the bill was in doubt until the final day left for Presidential action. Q
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