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had curious origins- Dr Fred Rose of the. Biochemistry Department at University College- Cardiff happens to live near
BP PVC plant. PVC dust often forms a
%>VC dust fells factory mice suggesting new work hazard
Guinea-pigs and rats kept in dusty areas
of PVC factories next to regular workers developed pneumoconiosis--tie - lung disease caused by asbestos, silica, and coal Just. Additional tests show- PVC cujt ro be as biologically- active as chcysotile asbestos.
This means that PVC powder--the product of polymerisation of vinyl chloride monomer (VCM)--must be treated as a health hazard potentially more widespread than VCM itself. VCM was discovered last year to be carcino genic and the chemical industry has made considerable efforts to control this gas. Efforts may now be needed to con trol PVC powder as well.
Following a report that a 31-year-old worker who bad inhaled PVC powder atwork for a year developed a new type
of pneumoconiosis. Professors N. Fron* gia, D. Casula, and R. Camba at Cag
liari (Italy) University began a long term investigation of the possible harm ful effects of PVC powder. They put rats and guinea-pigs in cages with large win dows in the bagging section of a PVC plant in Sardinia. Because PVC manufac
ture is largely automated, the bagging section is usually the dustiest. The fact that the animal* were exposed to the
same atmosphere as workers in the plant is an unusual procedure whicl^ partly overcomes- objections ter drawing con
clusions from animal experiments about the biological effects of chemicals on
man. The animals were killed after two to
- seven months of exposure to PVC dust and their lungs examined microscopic ally.
Reporting their work (Medicine- del Lavoro, Sept-Oct 1974) the three pro fessors say: "we are dealing with an authentic pneumoconiosis, or at least with a PVC pneumopathy which suggests very strongly not a few of the significant aspects of pneumoconiosis". Although
they admit that much more research
has to be done before firm conclusions can be drawn, they say their results
form a "highly consistent picture" and are "dearly correlated with the length of exposure to PVC powder".
The second piece of recent research which throws suspidon on PVC powder
fine film on the road outside the plant and also finds its way n to the roofs of
cars parked nearby and on to washing
hung out to dry. Rose's department carries out work on the biochemistry of asbestosis. Putting the two together, he'
, derided that he ought to have at least a brief look at PVC dust. Rose and Dr Roy Richards used a test that had beem found to be a good indi cator of the biological activity of other
materials such-as asbestos. The dost is
incubated with red blood cells from rab bits and the- amount of haemoglobin re
leased by the dust breaking the cell walls (haemolysis) is measured.
So far only two samples have been tested and so the results are difficult to interpret. However one of the PVC dust
samples was found to be as active in the haemolysis- test as chiysotile -asbestos. When the PVC particles were washed, this activity- surprisingly disappeared. Rose and his colleagues tentatively con cluded that the biological activity is due to a soluble. surface-associated agent.
Even more surprising is that the other PVC dust sample showed practically no activity at all.'
One possibility is that the tw samples were from different processes which pro duced different size particles, with dif ferent biological- activities. Large dust
particles do-.not reads the long, which
suggests they may be less dangerous
Will dockers black PVC powder?
than small ones. The particles in the Italian factory were very small--about
London dockers are to reconsider a
| 1 micrometre in diameter,
total ban on the handling of cargoes
j The significance of these two pieces
of PVC powder. The National Associa
j of research, if their results are confirmed
tion of Stevedores and Dockworkers
| by further experimentation, could be
(NASD) originally refused to "black"
- immense. PVC powders are bandied by a
PVC cargoes following the refusal of
} much larger number of workers than
some dockers at the Royal group of
VCM. Workers in practically every plant
docks to unload bagged PVC But
making goods from PVC powder are
armed with the new evidence that is
potentially at risk. Further, the discharge
emerging about the hazards of PVC
of PVC dust from factories Is by no
powder the issue will be raised again.
means a rare event, so communities near
Last January one gang of dockers refused to unload about 80 tonnes of
PVC plants might also be at risk.
, Lawrwnc* McGinty
bagged PVC from two bargee onto a
Romanian ship. According to one of
the dockers involved, the cargo had
French court
been lying in the barges fpr a year and many of the bags were rotten.
The refusal was prompted by publicity, especially on TV, surrounding the di> covery that vinyl chloride monomer--
from which PVC is made--causes liver cancer. But the dockers were also sus picious that the PVC powder itself might be a health hazard.
A Factory Inspector had the cargo analysed and he assured the dockers that there was no measurable vinyl
chloride monomer in the PVC and that fcvC powder . itself is harmless.
says one docker. This was the first cargo of PVC
to pass through the Royal docks, but
employer's assurances that any future cargoes would be in hessian, not paper, hags indicates the possibility of future cargoes.
Now the dockers who originally re
fused to handle the cargo are raising the question again. This time they
have the admittedly preliminary find ings of the Italian and Cardiff research to back up their claim that PVC dust could be a health hazard. Their intui
backs breeder
Two environmental groups were refused an injunction to stop El6ctririt da France from building a fast breeder . reactor at Bugey. The court ruled that there had been no infringement of property or of a fundamental right.
The environmentalists had argued tha: clean air and lack of pollution is a legs right. EUctridti de France, on the othe hand, argued that "quality of life" neither a public right nor an essentia liberty, but rather an aspiration.
Pfevidence that PVC powder could cause pneumoconiosis had been pub lished three months earlier.) Similar
tive feelings about PVC powder, which must be seen against a long history of "unscientific'' bans on dan
BOR 014911
Testing techno! gy
assurances came from Robert Murray, gerous cargoes (asbestos for example)
"The Police Department yesterday r
the TUC's medical advisor.
long belore medical evidence of ill-
mitted the following message on :
After eight days the cargo was un effects appeared, could well be a
teletype machine: 'This is a t*- ..Jit
loaded from the barges by other better guide to action than the Fac
for L.I. press only. If you (
receive
dockers. "The dust was just evory- tory Inspector's reassurances. LJVf.
this message, you need j v-pairi."
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