Tables L - 9 ... 6 - 14

A.,. ,f '("'r;r ^{; i'J \)'0}

.¡

f

~ffN-MADE MINERAL FIBRE SURVEY

--

"'....,,,.,

AT ELKEM-ROCKWOOL AlS ~ LARVIK

BY

GRETE EDHOLM, BJØRN GYLSETH,

DAVID NICHOLSON AND EGIL M. OPHUS

HD 781/78

Ni B li D::Fü k~K.I",IN(.~iN8TITUTTENE 6IBb,IOTEKET

Gydas vei 8. .. ,

Postboks 8149 Osl" Dep. 081 fr

-INSTITUTE OF OCCUPATIONAL HEALTH, BOX 8149, DEP, OSLO I

CONTENT S : PAGE:

I,. INTRODUCTION. . . .. ' 2

II, METHODS... 3

! \':i

III RESULTS . . . .. 5

Tables L - 9 ... 6 - 14

Figures L - 4. . . .15 - iS

..':

",

k

"

'" /' ,

i

o

- 2 -

I

INTRODUCTION

The question as to whether occupational exposure to Man-

made-mineral -fibres (~~ll1F), is harmful is of current interest;

especially as these materials are being increasingly used as substi tutes for asbestos. The Joint-European Medical Research Board (JEMBR) has ini tiated an ambi tious prograrne wi th the view to establishing the consequences of sucn expo-

sures. An integral part of this prograrne consists of working out a strategy, and analytical methods, for recording

present total dust/fibre concentrations in the working atmos- pheres in anumber of European Pf~lF producing plants. The organisation responsible for this aspect of the study is the Insti tute of Occupational Medicine (IOl1), Edinburgh.

One of the countries actively participating in this

prograrne is Norway, where there are six ~rr~lF plants. Four of these were considered suitable subjects for the programre because they keep detailed medical records of workers.

Due to slightly differing methods of sampling and analysis it was considered of interest to compare the procedures used

by the two insti tu tes . Such a comparison was carried out

during the ION investigations at Elkem-Rockwool Als at Moss and Larvik. The results from the YHI~survey at Larvik are presented in this report.

:!

II

^METHODS

The dust samples were collected on 37 rnØ, O, 8 ~m Millipore

membrane fil ters using CaselIa personal air samplers wi th an adjusted flow of 21/min. The flow was checked with a

calibrated external flowmeter be fore and after

sampling . Before sèxcpling the upper part of the fil ter

moni tor was removed, thus leaving the whole fil ter area exposed to air. Then the moni tors were mounted in the workers breathing zones. The workers carried the air

samplers for 6 - 8 hours of the shift, including the lunch

period.

A new filter was used every day. Before and after use the filters were desiccated for 24 hours in a desiccator and weighed with an accuracy of + O, L mg.

After the total dust determinations a segment from each

filter was cut and placed dust-side up on to a clean standard

microscope slide. The slide was exposed to acetone vapour in order to render the fil ter transparent, a few drops of triacetine added and a cover glass placed over the

speeimen. Fibre concentrations were recorded in a Zeiss

binocular microscope with p08itive phase-contrast optics at 500x magnification. This microscope was equipped with a Ph 2 4010,75 objective with green filter and Kohler

illumination. The speeimens were surveyed by scanning inter- mi ttently across the fil ter. A random set of samples were counted twice by one person using different graticules.

Gratieule A is a 200 ~m x 200 ~m grid divided into 10 ~m

squares.

"'f__1.',;..t.

- 4 -

Gratieule B. Circular gratieule , 100 ~mØ, recornended by IOM (l). In this way one could establish potential personal as well as instrumental differences. The counting proceedures described as below.

Gratieule A. All fibres completely within the field were counted. Two adjacent field sides were defined as "counting sides" and all fibres crossing thes.e sides were included.

No other fibres were considered .

:'/~

Gratieule B. As specified by rOM (l).

For each sample 40 fields or 100 fibres were counted.

Random samples from each working place were chosen for

);.:(,;,fibre size evaluations and fibre concentration determination

in the scanning electron microscope.

The fibre size evaluations were performed by mounting a

piece of the membrane fil ter on a standard scanning electron microscope(SEM) brass stub. The filter piece was fastened

to the stub wi th carbon cement or sil ver paint and thereafter covered wi th a thin layer of carbon or gold by evaporating to make them conductive.

The fibre concentrations were recorded in the SEM at lSOOx

magnifica tion.. Hundred fields were surveyed (O, io 8 inrr,2).

Fibre size evaluations were made at lSOOx (length) and 15000x (diameter) magnification respectively. At least 50 fibres in each sample were evaluated.

(l) W. H. Walton and S.T. Beckett.

Ann. Occup. Hyg. 20 (1977) 19 - 23.

.;~

III RESULTS

Table L - 7 contains filter numbers, working places (in English/Norwegian), total dust concentrations (mg/m3), fibre concentrations as determined by optical microscopy

(fibres ~ 3~m and ? 3~m in diameter) and final

ly , the total

fibre concentration determined by SEM at 1500x magnifi-

cation.

j. ~

No statistically significant difference (p ~ 0,05) between the mean values for the two series (A and B) was observed for the two different graticules, nei ther for fibres ~ 3~m in diameter nor for the total fibre concentration.

In table 8 and 9 the fibre diameter and length from the SEM size evaluation are given. These results are further

il1ustrated in Figures L and 2. The relation between fibre concentration per unit area and magnification is demonstrated in Figure 3. Final1y the correlation between the SEM and the OM is given in Figure 4.

...i.~.. ELKEM-ROCKWOOL AlS, LARVIK TABLE IOptical microscopy fibres SEM

Iml

IOptisk mikroskop

Fil ter

Working place/PrøvestedTotal dustF ibre conc.Fibre eGne.

Total fibre

No.

conc./total

Ifiber kon-Ifiber kon-Itotal fiber støv mg/m2

sentrasjon sentrasjon kons en tr as j on

ø ~ 3 llilø ? 3 llm

fibres/ml

PRE-PRODUCTION/FØR PRODUKSJON 104Raw-ma ter ial/Rå -meteriale

-

Thor Thoresen

3,2 0,02

O, OL 78BindermaniBlanding av binde-

1,2 C 0,03 0,03

92

middel -

Harald Nordbotten2, O

0,03 0,02 0,12

88A

FurnacelOvnsmann 7,5

A

- -

94- Anton BØe

1,5 0,05 0,04 0,18

87- Bjørn Andresen

5,8

A

- -

120

1,2 0,04 0,02

A:To much dust to be counted C:

Fil ter destroyed

0\

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,.:,;¡.¡;,,: L. ELKEM-ROCKWOOL AlS, LARVIK TABLE 3

Optical microscopy fibres

SEM

Iml

IOptiske mikroskop

Fil ter

Working place/PrØvestedTotal dustFibre conc.F ibre con.

Total f ibre

No.

conc . Itota~ If iber kon-

Ifiber kon-Itotal fiber støv mg/m

sentrasjon sentrasjon konsentrasjon

ø ~ 3 pm

ø ;: 3 ~m fibres/ml

PRODUCTION/PRODUKSJON 64

Production/Produks j on

- Sverre Vollebekk

3,6 0,14

O, OS 18- Bjørn GrØnning3, S

0,14 0,13 0,80

67

0,9 0,06

O, OL 109Cavi ty wooll - S.

Halvorsen 0,9 0,09 0,09 0,42

53

shredding

- Hans J., Hansen

2,4 B 0,12 0,05

85Spinning chamberl - Tom Larsen

1,6 0,07 0,05 0,51

98

Spinnemaskin

- ø.

GrØnning

E

- -

15- R. Wirgenes

1,9

BI O, 09

0,04

105

1,8

O, 06

0,04

B:Loose dust on fil ter surface I E:Same marking as 86

I:

Larqe difference between

co pump time and real time.

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Fil ter

NOe 66 108 106 56 103 93 72 57 98 70 Working place/Prøvested SECONDARY PROCESSI ETTERBEHANDLING

Lamella m/clOperatør

lamella - Gerd T. Hansen

(Leca piper etter kl. 9) - Ber i t Lunde Cavi ty wool, packing

- So Halvorsen MAINTENANCE/VEDLIKEHOLD

ForemaniFormann

- Kjell Thorsen

Electr ician/Elek tr iker

- Willy Hansen Spinner mechanicl - BjØrn Thorsen mekaniker, spinnemaskin Total dust

conc./total

støv mg/m3

3,8 1,5

2, l

1,3

l, L

1,2 1,2

^{l, O}

2,2

;,~,:~" . Optical microscopy fibres

Iml

IOptiske mikroskop F ibre conc. Ifiber kon-

sentrasjon

ø ~ 3 ~m

A - 0,07 0,07 0,12 0,03 0,02 0,03 0,05

E

0,21

F ibre conc. Ifiber kon-

sentrasjon

ø ? 3 ~m

0,06 0,08 0,07 0,05 0,03 0,02 0,02 0,08

SEM

Total fibre ¡total fiber kons en tr as j on fibres/ml 0,55 ;-

I-

o 0,19 0,28 1,00

,;, ELKEM~ROCKWOOL AlS, LARVIK T ABLE 6

Fil ter

No. 118 112 99 SO 115 101 91 60 62 IL 7 95 51 Working place/Prøvested MAINTENANCE/VEDLIKEHOLD

GreaserlSmører

- Gunnar Jacobsen

Mechanic/Mekaniker

- Thor Tinnseth - Einar Andersen QUALITY CONTROLIKVALITETS- KONTROLL Labo ass ./Laboratorie assi stent - Widar Baarnes DISTRIBUTION/LAGER Warehouseman Il Lagerarbei der I - Olav Nilsen - Ivar Skjærvø - Hans Andersen - Leif Holteberg Total dust conc ./to'tal støv mg/m3

1,2

3, O

3,5

2, O l, L

1,2

l, S

2,4

3, L l, O 2, O 2, L

,,;!~.. Optical microscopy fibres

Iml

IOptiske mikroskop F ibre conc. Ifiber kon-

sentrasjon

ø ~3 ~m

Fibre conc. Ifiber kon-

sentrasjon

ø ?3 ~m

0,06 0,05 0,06 0,04 0,06 0,04

0,04 0,04

^{O, 05}

0,03 0,03 0,03

c 0,06 0,05 0,13 0,11

DO, io

0,05 0,06 0,06 0,04 0,07 0,06 0,04

SEM

Total fibre

Itotal fiber

konsentrasjon fibres/ml 0,47

0,35 c

0,33 0,77

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