BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Beskæftigelsesudvalget 2021-22
BEU Alm.del Bilag 141
Offentligt

Article

Historical Asbestos Measurements in Denmark—A National

Database

Ana Sofia Fonseca

*, Amalie Kofoed Jørgensen

, Bianca Xuan Larsen

, Marina Moser-Johansen

Esben Meulengracht Flachs

, Niels Erik Ebbehøj

, Jakob Hjort Bønløkke

, Trine Olesen Østergaard

Jesper Bælum

, David Lee Sherson

, Vivi Schlünssen

1,5

, Harald William Meyer

and Keld Alstrup Jensen

National Research Centre for the Working Environment (NRCWE),DK-2100 Copenhagen, Denmark;

[email protected] (A.K.J.); [email protected] (B.X.L.); [email protected] (M.M.-J.); [email protected] (V.S.); [email protected] (K.A.J.)

Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital,

University of Copenhagen, DK-2400 Copenhagen, Denmark;

[email protected] (E.M.F.); [email protected] (N.E.E.);

[email protected] (H.W.M.)

Department of Occupational and Environmental Medicine, Danish Ramazzini Center,

Aalborg University Hospital, DK-9000 Aalborg, Denmark; [email protected] (J.H.B.);

[email protected] (T.O.Ø.)

Occupational and Environmental Medicine Clinic and Department of Pulmonary Medicine,

Odense University Hospital, DK-5000 Odense, Denmark; [email protected] (J.B.);

[email protected] (D.L.S.)

Department of public health, Work, Environment and Health, Danish Ramazzini Center,

DK-8200 Aarhus N, Denmark

Correspondence: [email protected]; Tel.: +45-20-59-45-05

Citation:

Fonseca, A.S.;

Jørgensen, A.K.; Larsen, B.X.;

Moser-Johansen, M.; Flachs, E.M.;

Ebbehøj, N.E.; Bønløkke, J.H.;

Østergaard, T.O.; Bælum, J.;

Sherson, D.L.; et al. Historical

Asbestos Measurements in

Denmark—A National Database.

Int.

J. Environ. Res. Public Health

2022,

19,

643. https://doi.org/10.3390/

ijerph19020643

Academic Editor: Luigi Vimercati

Received: 6 November 2021

Accepted: 25 December 2021

Published: 6 January 2022

Publisher’s

claims

Note:

MDPI

maps

stays

and

Abstract:

Objectives: Due to the long lag-time for health outcomes, historical asbestos exposure

measurements are valuable to support assessments of associated occupational health effects, and

also to assess time trends and effects of preventive measures. Methods: Different sources of stored

data were collated, assessed and refined to create a harmonized database on historical asbestos

fibre concentrations measured in specific work tasks and different industries. The final database

contains 9236 asbestos measurements from Danish workplaces collected from 1971 to 1997. Results:

The geometric mean of asbestos concentrations in different occupations and tasks ranged from

0.003 to 35 fibres cm

−3

. Highest concentrations were registered during handling of asbestos prod-

ucts in the construction services during the period 1981–1997. Although all the measured asbestos

exposures without the use of respiratory equipment by the worker in the period of 1971–1997

exceeded the current 8-h time-weighted average exposure limit of 0.1 fibres cm

−3

, the majority of

samples collected in the earlier period of 1971 to 1980 did not exceed the exposure limit of 2 fibres

−3

, which was in place at the time. All exposure data obtained from 1980 and onwards were

found to be one seventh of the mean fibre concentrations in the previous measurement period. The

impact of time shows a clear exponentially decreasing trend-line. Conclusions: Despite limitations

in coverage of different occupations and tasks associated with the inventoried historical asbestos

measurements, the data are helpful to identify specific work scenarios within an industry, where

relatively high asbestos exposure levels may still occur or have occurred from 1971 to 1997.

Keywords:

asbestos fibres; historical exposure measurements; occupational exposure;

personal sampling; database; phase contrast microscope

neutral with regard to jurisdictional

published

institutional affiliations.

Licensee MDPI, Basel, Switzerland.

This article is an open access article

distributed under the terms and

conditions of the Creative Commons

Attribution

(CC

BY)

license

(https://creativecommons.org/license

1. Introduction

Asbestos refer to a group of naturally occurring fibrous minerals [1] with different

compositions and physical and chemical properties [2]. The fibrous nature of the mate-

rials is their common denominator.

Int. J. Environ. Res. Public Health

2022,

19,

643. https://doi.org/10.3390/ijerph19020643

s/by/4.0/).

www.mdpi.com/journal/ijerph

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

2 of 18

Currently, around 125 million people are exposed to asbestos at the workplace

worldwide. Asbestos fibres fulfilling the “World Health Organisation (WHO)”-criteria

(WHO-criteria: length L > 5 µm, diameter D: < 3 µm, aspect ratio L:D > 3:1) are considered

hazardous if inhaled or ingested [3–7]. Epidemiologic evidence has shown that all as-

bestos fibre types cause a wide range of diseases, such as lung, larynx and ovarian cancer,

mesothelioma, and asbestosis (an interstitial lung disease) [2,8]. In most cases, more than

20 years pass from the initial asbestos exposure to the occurrence of mesothelioma and

lung cancer [9,10]. A dose-response relation is evident between asbestos exposure and

the risk of asbestosis, suggesting a 1% lifetime risk of asbestosis at 10 years of fibre ex-

posure; 10 fibre years [11,12].

Since the 19th century, asbestos were widely used in several industries due to its

extraordinary tensile strength, and resistance to heat and corrosion [13]. Asbestos can be

found worldwide in boilers and heating systems, automotive parts, electrical wires,

roofing and flooring materials, adhesives and sealants, insulation products, paints, and

other products [10].

In Denmark, the peak consumption of asbestos occurred in the early 1970s, with

annual imports of 30 000 tonnes of asbestos. Due to the first asbestos ban on insulation

materials in 1972, the import of asbestos slowly began to decrease [14] and rapidly from

1986 when the near-total national asbestos ban was decided [15]. Use of limited quantities

in brakes continued until a ban was effective from 2004 [16]. In all uses, chrysotile (CAS

number 12001-29-5) is reported to be the most commonly used type of asbestos in Den-

mark [17,18].

Prior to the bans, approximately 150 000 workers [19] are estimated to have been

exposed to asbestos in the Danish construction industry, electricity and heating plants,

shipyards, and asbestos cement manufacturing. Asbestos exposure has also occurred in

connection with a wide variety of other applications, including insulation of locomotives

and train carriages. Despite the national ban [15] and consequently significant reduction

in use [17], asbestos-containing materials can still be found in buildings, vessels and ships

constructed before 1986. Therefore, overall population can be exposed to asbestos, espe-

cially when these products are damaged, or in a state of disrepair. However, building

craftsmen and firefighters might be more prone to be exposed to significant levels of as-

bestos during fire extinguishment and during renovation, repairs, demolition activities or

deliberate removal of asbestos-containing materials. Consequently, if proper prevention

measures are not taken by the employer, asbestos may pose a health risk to them.

Considering the long latency period of asbestos-related diseases, a significant

number of cancers, mesotheliomas, and asbestosis is still expected to occur in Denmark

during the next decade due to historical asbestos exposures. In this respect, it is im-

portant to note that no threshold has been found for health effects of asbestos exposure

for any type of asbestos fibre [20,21]. The occupational exposure limit value set for 8 h

time weighted average (8h-TWA) in Denmark is currently 0.1 fibres cm

−3

[10], similar to

the limit value in European Commission Directive 2009/148/EC of 30 November 2009. In

addition, Danish policy requires that occupational exposure is assessed, prevented and

employees receive the necessary training and instruction if they work with a material

that contains asbestos [10]. Medical monitoring of workers is also required when legal

exposure limits and exposure duration are exceeded [10].

To identify whether inhalation exposure levels to asbestos have evolved over time

and to describe exposure patterns within relevant industries and occupations, it is nec-

essary to know the historical asbestos exposure concentrations and associated pertinent

descriptions of working conditions.

Previously, effort has been made to develop qualitative [22–24] and quantitative risk

matrices [25] to evaluate asbestos exposures. Subsets of data collations on asbestos ex-

posure have also been made previously, including personal measurements of asbestos

from single industries for limited time periods [17,18,26–29]. However, until now, there

has not been any attempt to compile or review the available Danish asbestos measure-

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

3 of 18

ments in order to characterize the typical range of occupational exposure concentrations

to asbestos fibres for tasks performed by different workers over time and within specific

industries.

This work aims to bring together existing knowledge, experience and data in re-

gards to past occupational exposure to asbestos in Danish workplaces. A database con-

taining 9236 historical measurements of asbestos concentrations from 1971 to 1997 was

developed and analysed. This database is considered very helpful to identify specific

work scenarios where relatively high asbestos exposure levels have occurred or may still

occur in specific industry branches, especially with building craftsmen during repair,

renovation or demolition activities. In this way, the inventoried data can help employers

and occupational hygiene professionals to estimate the potential asbestos exposure levels

for a process and from this information, support in historical health effect and epidemi-

ological assessments, provide the appropriate risk management measures to control as-

bestos exposure, and predict potential associated detrimental occupational health effects

in the next decade.

2. Methodology

2.1. Data Collection

The National Database was constructed to provide workers exposure level and as-

sociated information on the measurement, contextual information, and exposure history

when available. Data were identified and extracted from four different sources which

contained asbestos measurement documents made in the period of 1971–1997:

•

The National Research Centre for Work Environment (NRCWE) and National ar-

chives: 79 asbestos measurements from 1982 to 1986 from various industries col-

lected from [30].

Aalborg University Hospital: 3068 asbestos measurements from 1971 to 1985 in an

asbestos cement factory and in a facility which manufactured insulation materials

with and without asbestos.

Department of Public Health, Aarhus University: 132 measurements of asbestos

from 1987 to 1989 during dismantling activities in schools and hospitals.

Odense University Hospital: 5957 measurements from a facility manufacturing as-

bestos-containing materials such as transport equipment and friction materials (e.g.,

brakes) in the period of 1980–1997.

•

2.2. Asbestos Database Structure

The database was structured to provide means for harmonized data collation, and to

be suitable for grouping industries and occupations, as well as read-across. Furthermore,

it was built to be compatible with the currently available exposure assessment models

recommended for conventional chemical substances by Registration, Evaluation, Au-

thorization and Restriction of Chemicals regulations (REACH) in terms of required input

parameters [31]. Grouping and read-across rules for inhalation exposure are usually

made from mapping the source (or process) information and associated information on

exposure levels of a certain chemical substance [32]. The exposure levels and contextual

information were extracted from measurement documents by 5 different experts and

organized in nine main types of information:

(i)

Premises: Filling reference number of the archive, company sector;

(ii)

Identification of material: name and CAS number;

(iii)

Industrial sector, job and task codes according to the national classifications, as ex-

plained below;

(iv)

Purpose of the measurement: either random sampling, sampling due to disease in

an employee, sampling requested by the company, regulatory check, research pur-

poses or other;

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

4 of 18

(v)

(vi)

(vii)

(viii)

(ix)

Determinants—exposure scenario: description of working tasks, environmental

conditions such as temperature and humidity, number of people working in the

same working area (potentially exposed group of people);

Determinants—technical conditions and measures to control worker exposure: au-

tomation level, processes designed aiming to prevent release, type of local exhaust

ventilation, type of general ventilation (mechanical or natural), and personal pro-

tective measures;

Exposure metrics: worker experience in years, exposure duration, exposure fre-

quency;

Sampling characteristics: sampling position (stationary or personal), original sam-

ple track number, anonymous subject identifier, sample date and time, pump flow,

sampled volume; sampling and fibres counting method used;

Exposure data: asbestos concentration in fibres cm

−3

The final National database reports information based on the industry type, job code

and task code.

Industry codes, based on DSE77 (Statistics Denmark job coding system), were par-

tially available through the industry code (This is only the case for the measurements

coming from the ATABAS database. As the measurements in the ATABAS database are

from the years 1982–1986, DSE77 codes were used. These are based on the International

ISIC Revision2 classification. This classification has been kept in the new database) re-

ported in the original measurements. Furthermore, following the existing classification in

the ATABAS database [30], the measurements are classified according to a “job type”

code and a “task code” (The “job type” code is based on a coding system applied by the

“Arbejdstilsynets Ulykkestatistik” (translated:

The Working Environment Authority Statistics

on Accidents)

and “Arbejdstilsynets erhvervssygdomsregister” (translated:

The Working

Environment Authority Occupational Disease Register)

at the time of the ATABAS database

establishment, while the “task code”, which provide additional detail, was a coding sys-

tem only used at the Arbejdsmiljøinstituttet, (translated:

Danish Institute of Occupational

Health now National Research Centre for the Working Environment).

For measurements,

where a detailed contextual description existed, “job codes” and “task codes” were at-

tributed if information had not been recorded previously.

In total, 9236 records were registered of which 9226 data entries could be linked to 16

specific industry codes, 15 different jobs, and 53 different tasks.

The inventoried asbestos measurements were grouped into six major occupational

categories similarly as in Swuste et al. (2008) [33]: (i) manufacturing of asbestos products;

(ii) active handling of asbestos products; (iii) transport, storage, packaging of asbestos

products; (iv) maintenance jobs; (v) general supervision of work processes and inspection

tasks; and (vi) cleaning activities.

2.3. Data Analysis

Even though some of the archives and reports provided general insight about the

conditions at the workplaces, most of them lacked essential information regarding the

actual asbestos concentrations measured, corresponding work situation (job code), sam-

pled year, exposure controls (e.g., personal respiratory protection equipment (RPE), en-

capsulation of the process, ventilation systems), and the exact sampling location and

duration. Consequently, to minimize risk of erroneous data extractions and interpreta-

tions, data were only considered if they, as a minimum, included job code identification,

asbestos concentration levels (with and without sampled time), sampling year, and

measurement position). After data quality assessments, 5869 out of 9236 measurements

were available for further analysis (supplementary information Table S1 and Figure S1).

The lack of information on the asbestos concentrations was the main reason to discarding

records.

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

5 of 18

The limited number of available exposure data for specific industries and occupa-

tions may result in a risk of bias in the direct interpretation of the historical measure-

ments. However, overall, the data indicate a general trend with higher exposure concen-

trations back in time. This overall trend was described with a mathematical log-linear

gamma model based on a function of the most representative industries and year. In ad-

dition, boxplots were created to provide a visual summary of the basic statistics such as

median, the dispersion of the data, and signs of skewness. For the comparison of personal

asbestos exposure concentrations with health guideline values, basic statistics of geo-

metric mean, minimum and maximum of concentrations in each occupational category

for the period 1971–1980 or 1981–1997 were provided along with the information re-

garding the technical conditions and measures to control worker exposure.

3. Results

3.1. Measurement of Asbestos Concentrations

A complete National database may be found in the excel file available in the sup-

plementary information (Table S2). The supplementary Table S1, and Figure S1 presents

an overview of the 5869 high quality measurements of asbestos exposure in Danish

companies for each occupational category, industry and job code by the periods

1971–1980 (2189 measurements, 37%) and 1981–1997 (3680 measurements, 63%). Most

measurements were personal (5776 measurements, 98.4%), performed as part of a regu-

latory check (5722 measurements, 97.5%) and made among automotive and cement in-

dustries which manufactured asbestos products (5182 measurements, 88%). In almost all

the other occupational categories, purpose of measurement, and of sampling position, the

number of available measurements was limited to a few samples (Figures S1 and S2).

Detailed information about the type of general ventilation systems in place, control

measures, and the use of RPE was unknown in 45–60% of the cases. In 45% of the per-

sonal measurements, information lacked on whether the worker used RPE and if the

measurements were performed inside or outside the mask (Figure S2).

3.1.1. Manufacturing of Asbestos Products

The manufacturing of fibre cement plates (eternit), insulation plates, and automotive

materials (e.g., brakes) in Denmark accounts for 5190 measurements between 1971 and

1997 and involves different activities such as handling of raw materials, cutting and

shaping products/materials using manual or power tools, polishing, spraying of asbestos

insulation, weighing and mixing of asbestos (Table S1). As illustrated in Figure 1a, me-

dian fibre concentrations collected over 6–165 min at the breathing zone of the worker

without RPE during the period 1971 to 1980 were found to vary between 0.6 and 2.2 fi-

bres cm

−3

, with maximum registered concentrations levels up to 103 fibres cm

−3

. In the

consecutive period 1981–1997, the median exposure decreased considerably, resulting in

a total reduction of 79% and 84% in exposure levels during the manufacturing of cement

plates and automotive materials, respectively. The use of asbestos in cement products

ceased at the end of 1986, and therefore asbestos measurements were not performed after

1985. The reduction in exposure over time during the manufacturing of fibre cement

plates can be attributed to the use of mechanical ventilation from 1977 onwards (reported

on the original archives). Even though, there is no information regarding the use of con-

trol measures during the manufacturing of automotive materials, the reduction of ex-

posure over time can also be explained by the increased enforcement of legal standards

from 1980 onwards.

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

6 of 18

Figure 1.

Vertical box plots for the measured personal exposure asbestos concentrations (with

N ≥ 4)

without respiratory

protective equipment being used by the worker (unless specified) for each industry code for the period 1971–1980 and

1981–1997: (a) Manufacturing of asbestos products; (b) Transport, storage and package; (c) Maintenance jobs; (d) General

supervision and inspection tasks; and (e) Cleaning activities. The lower and upper limits of the box plots represent the

25th and 75th percentiles, and the line within the box marks the median. Whiskers (error bars) above and below the box

indicate the maximum and the minimum fibre concentration excluding high values (marked as *), respectively. N: total

number of measurements available; Manuf: manufacturing; Auto: Automotive.

3.1.2. Active Handling of Asbestos Products

Handling of asbestos products include 146 measurements in several industrial sec-

tors (e.g., construction, carpentry, railways, power plants, car repair services) during in-

stallation, maintenance, renovation, repair or dismantling/demolition of structures with

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

7 of 18

asbestos-containing materials (Table S1 and Figure S1). It is known that high energy tools

are often used in these tasks resulting in a high potential of asbestos release and conse-

quently worker exposure. Indeed, Figure 2 and Table S1 show relatively high asbestos

exposures levels during activities in building and construction. In 1984, samples collected

at the breathing zone of workers without RPE for 15–65 min without any personal pro-

tection equipment, fibre concentrations ranged from 0.1 to 4.7 fibres cm

−3

during building

construction and carpentry services, especially during the cutting drilling and band

sawing of eternit plates. In the same time period of 1984–1985, 15–77 min personal ex-

posure concentrations without use of RPE were <1.8 fibres cm

−3

during changing or

grinding brakes in the railways or car repair services and assembly of lamp sockets in

welfare services.

Figure 2.

Vertical box plots for the measured personal exposure asbestos concentrations (with N ≥

4) without respiratory protective equipment being used by the worker (unless specified) during

active handling of asbestos products in each industry code for the period 1981–1997. The lower and

upper limits of the box plots represent the 25th and 75th percentiles, and the line within the box

marks the median. Whiskers (error bars) above and below the box indicate the maximum and the

minimum fibre concentration, respectively. N: total number of measurements available.

In Denmark, specialized abatement workers were not common before the adoption

of a national ban on asbestos in 1986 [15]. The key tasks involved in abatement work in-

clude preparing the work area prior to demolition, and actively removing the asbes-

tos-containing materials. In 1986, the repair of a boiler in a power plant and removal of

asbestos-containing insulation materials during 36 min yielded a personal fibre concen-

tration of 4.7 fibres cm

−3

measured outside the RPE of the worker (Table S1). Similarly, in

1987, personal fibre concentrations measured outside the RPE of the worker were found

to range from about 0.24 to 4.1 fibres cm

−3

during the dismantling of a pipe insulation in a

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

8 of 18

hospital boiler room (Figure 2 and Table S1). During these asbestos measurements, con-

centrations below 0.06 fibres cm

−3

were registered inside the RPE of the worker, meaning

that the protection efficiency was relatively high and workers exposure were reduced

98.6%. However, if there were workers in the vicinity without RPE, they could have been

exposed to fibre concentrations at near field (NF) or far field (FF) in the range of 0.01–2.1

and 0.003–0.01 fibres cm

−3

, respectively (Table S1). The measurements carried out in the

decontamination facility around this working area (consisting of 3 different rooms sepa-

rated by airlocks to prevent the free passage of air or asbestos fibres) revealed that the

“clean room” was contaminated throughout the abatement project. In this particular case,

stationary concentrations up to 0.02 fibres cm

−3

were measured. Another observation is

that workers who might have spent some time in the contaminated hospital areas before

the dismantling activities, were exposed to asbestos concentrations of up to 0.5 fibres cm

−3

if they had not used RPE (Table S1).

Figure 2 also reveals that in the period of 1986 to 1989, tasks performed by abate-

ment workers during 18–140 min entailed personal exposures measured outside the RPE

to asbestos ranging from 0.2 to 4.9 fibres cm

−3

during removal of asbestos in ceilings in a

hospital and elementary school built at early 1970s by using good industrial hygiene

practices (encapsulation, use of local exhaust, dilution ventilation and personal protec-

tive equipment). These buildings seemed to contain background concentrations of

0.02–0.3 fibres cm

−3

(25th–75th percentiles) without active contact with the asbes-

tos-containing materials (Table S1). However, after the abatement activities, workers

were also exposed to asbestos concentrations ranging from 0.02 to 0.6 fibres cm

−3

in the

clean room (located in the decontamination facility adjacent to the work area).

Much higher personal fibre concentrations, measured outside the RPE, in the range

of 3.3–92 fibres cm

−3

were associated with activities involving removal and scraping of

cement floors in a hospital. Simultaneous concentrations measured outside the sanitary

area as well as in the clean area of the decontamination facility were 2 orders of magni-

tude lower (0.01–0.02 fibres cm

−3

). As also indicated in Table S1, in 1983, 1.5 fibres cm

−3

were measured over 37 min during application of heat to metal pieces (welding) in the

civil defence sector by workers who did not use RPE.

3.1.3. Transport, Storage, and Package of Asbestos Products

Warehouse workers could potentially have been exposed during the transport,

storage, and packaging of asbestos in bags such as asbestos sheets or wires. This inven-

tory accounts for a total of 363 measurements under these occupational situations. Par-

ticularly, in the period 1971–1980, exposure concentrations measured during 37–165 min

in an asbestos cement plate factory were 0.1–1.0 fibres cm

−3

(25th–75th percentiles) with a

few extremes varying from 3 to 50 fibres cm

−3

(Figure 1b and Table S1). Fibre concentra-

tions were found to decrease to 0.1–0.2 fibres cm

−3

(25th–75th percentiles) when using

improved industrial hygiene practices such as the use of mechanical ventilation from

1977 onwards (reported in the original archives). Furthermore, exposure levels found in

the automotive industry and civil defence sector for the latest period were < 1 fibre cm

−3

(Table S1).

Maintenance workers are known to install, test, maintain, and repair electrical wir-

ing, and machinery. This work often involves locating and determining electrical or

mechanical failures, testing and adjustments of equipment. Figure 1c illustrates a sum-

mary of workers exposure fibre concentrations that have been measured during tasks

performed by maintenance workers in automotive services. As indicated in Table S1, 21

measurement samples were found to contain asbestos. In particular, this inventory sug-

gests that electricians and mechanics were exposed to asbestos in 1985–1986 in the range

of 0.07 to 0.14 fibres cm

−3

. In addition, in the period of 1983–1985, personal fibre concen-

trations without use of RPE for most maintenance-related tasks in the clutch and brake

services were found to range from 0.1 to 1.5 fibres cm

−3

based on 15–110 min sampling

periods.

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

9 of 18

3.1.5. General Supervision of Work Processes and Inspection Tasks

This occupational category involves supervision and inspection of places and tasks

which can have the potential of asbestos being released to the workplace. This is the case

of quality control measurements at the automotive industry to guarantee, that manu-

facturing of metal products and casting activities are safe to perform and acceptable lev-

els of exposure are ensured. As illustrated in Figure 1d and indicated in Table S1, 6

measurement samples collected at the breathing zone of the worker in 1980–1990 for 45

min were found to contain asbestos in the range of 0.1–1 fibres cm

−3

. Furthermore, 3

samples collected with unknown sampling duration and 1 sample collected during 348

min for the period of 1983–1989 while inspection of places such as schools and regular

offices before dismantling of structures containing asbestos resulted in 0.04 to 0.53 cm

−3

airborne fibre concentrations (Table S1). After dismantling of ceiling in a school, 2 sam-

ples collected in the clean room of the decontamination facility revealed that workers

might have been exposed to geometric mean asbestos concentrations of 0.02 fibres cm

−3

3.1.6. Cleaning Activities

Historical asbestos exposure data found in Danish workplaces also confirmed that

several workers were exposed to asbestos during the cleaning of asbestos-containing

materials. However these exposure levels were not as high as the manufacturing or active

handling of asbestos products on a daily or annual basis. Table S1 and Figure 1e provides

a summary of 137 asbestos measurements during cleaning tasks performed by workers in

a variety of industries such as the asbestos cement plates manufacturing plant, automo-

tive and construction sectors. Specifically, tasks involving general clean-up at an asbestos

cement plant in the period of 1971–1980 were found to result in 0.2–0.95 fibres cm

−3

(25th–75th percentiles) fibre concentrations collected at the breathing zone of the worker

without use of RPE with few extremes reaching up to 43 fibres cm

−3

based on samples

collected for 24–68 min. Fibre concentrations were found to decrease to 0.1–0.35 fibres

−3

(25th–75th percentiles) in the subsequent period of 1981 to 1984 in the same industry

sector most likely due to the increased enforcement of legal standards and the use of

mechanical ventilation from 1977 onwards. For the time period of 1982–1985, similar

exposure levels were found in the automotive industry (0.1–0.3 fibres cm

−3

(25th–75th

percentiles) based on samples collected for 45 min). However, cleaning activities per-

formed in electromechanical workshops, construction sites, and railway services were

found to result in higher fibre personal exposure concentrations (measured without or

outside the RPE), which ranged from 0.5 to 8.7 fibres cm

−3

based on samples collected for

5–75 min in the period of 1984–1989, probably due to the confined workplaces and the

composition or type of materials being cleaned.

3.2. Time Evolution of Exposure Patterns

Prior to 1980, quantitative exposure information was scarce with only 37% of the

inventoried situations measured (Supplementary Figure S2). Most quantitative infor-

mation to describe exposure patterns among industries and jobs was available for the

primary asbestos industries which manufactured automotive and cement products cor-

responding to 96.7% of the total number of measured situations. In almost all the other

industries and jobs, the number of available measurements was limited to a few samples.

This scattered quantitative exposure information did not allow inference of time trends in

the different industries and jobs and, thus, the changes over time were derived from a

log-linear gamma model fit applied to the manufacturing industries of asbestos cement

plates and automotive components (industry codes 36993 and 39439, respectively).

The impact of time is shown in Figure 3 where concentrations are plotted against

year of measurement for these specific industries and corresponding job codes. The ob-

tained yearly exponential decline 0.75 and 0.88, equal to a yearly decrease of 0.25% and

0.12% for industry codes 36993 and 38439, respectively. A clear downwards trend, with a

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

10 of 18

somewhat exponential shape is observed with increasing age of measurement (Figure 3).

This trend over time seems to reflect the overall development in Danish industries

[27–29]. Given that the asbestos regulations did not come into force until the 1980s, it is

reasonable to assume that occupational exposures to asbestos were generally much

higher during the 1970s, as observed, and likely also earlier.

Figure 3.

Personal exposure asbestos exposure concentrations against sampled year. The grey and

blue lines stand for the log-linear gamma model fit applied for industry sector 36993 and 38439,

respectively. All the personal measurements at the asbestos cement plant correspond to exposures

without use of RPE, while at the automotive industry it is unknown if RPE was used. Horizontal

red lines show the different health guideline values over time. (For interpretation of the references

to colour in this figure legend, the reader is referred to the web version of this article).

4. Discussion

4.1. Asbestos Exposure Levels Found in Danish Industries

From the data in the established database on Danish historical asbestos exposures, it

was evident that airborne fibre concentrations were highest during active handling of

asbestos products in construction services. The highest levels stem from the period

1981–1997, but lack of measurements for this activity before 1981 does not allow us to

compare with that period. The asbestos exposure concentrations measured outside the

RPE of the worker were found to range from 3.3 to 92 fibres cm

−3

during removal and

scraping of cement floors in a hospital (Table S1 and Figure 2). The Health Effects Insti-

tute, United States has also concluded that airborne fibre concentrations during asbestos

removal tasks could have been as high as 1 fibre cm

−3

during wet removal and as high as

10 to 100 fibres cm

−3

during dry removal [34]. In our data, lower personal exposure con-

centrations in the range of 0.02 to 4.9 fibres cm

−3

were measured also outside the RPE of

the worker during removal of asbestos in ceilings and during cutting, drilling and band

sawing of eternit plates (Table S1 and Figure 2). The measurement report elaborated by

the Dutch Labour Inspectorate reported similar ranges of worker concentrations during

sawing (1.4–4.3 fibres cm

−3

) and grinding (0.1–0.2 fibres cm

−3

) of water pipes [22].

During the earliest measurement period 1971–1980, manufacturing processes were

ranked as being the occupation with the highest exposure concentrations without using

RPE (geometric mean: 1.1 to 1.9 fibres cm

−3

with a few high exposure levels of up to 103

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

11 of 18

fibres cm

−3

, especially during manufacturing of fibre cement plates, and insulation mate-

rials) followed by cleaning of asbestos-containing materials (geometric mean: 0.8 fibres

−3

, maximum: 43.1 fibres cm

−3

), and warehouse activities in the asbestos cement in-

dustry (geometric mean: 0.7 fibres cm

−3

with few high exposure levels of up to 50 fibres

−3

) (Table S1). According to Raffn et al. (1989) [17] and Raffn (1990) [28], the first

measurements of asbestos exposure at a cement manufacturer, were taken in 1949 during

asbestos milling activities. The results showed exposure concentrations varying from

85–350 and 150–800 fibres cm

−3

for 2–15 and 15–200 µm in length, respectively. Follow up

measurements in 1957 at the same factory were 10–100 fibres cm

−3

[29]. These asbestos

levels measured before 1971 were not included in the database created in this study be-

cause it is unknown how asbestos were measured or estimated in these samples. The

levels found during warehouse activities in the asbestos cement industry were slightly

higher than the levels found in the Netherlands (from 0.04 to 0.8 fibres cm

−3

) for the same

type of activities in the period of 1970–1990 [33]. Several other studies have also reported

that tasks involving general cleaning of asbestos-containing materials and debris, were

found to result in average fibre concentrations ranging from 0.005 to 4.8 fibres cm

−3

based

on short-term and longer term sampling durations collected at various industrial sites

[33,35].

The inventoried datasets from 1980 onwards were found to have seven-fold reduced

geometric mean fibre concentrations during manufacturing processes, cleaning activities,

supervision, and warehouse activities in both cement and automotive industries, com-

pared to the earlier measurement periods (Figure 4). The observed exponential decreas-

ing asbestos exposure levels over time towards 1997 are probably explained by: (i) the

revision and reduction of the occupational exposure limit set for asbestos; (ii) improved

industrial hygiene practices and engineering controls (e.g., enclosure, ventilation, and

cleaning procedures); (iii) less exposure time due to the replacement of certain asbes-

tos-containing products; and iv) increased awareness of occupational hazards, health

problems and safety measures. Lower exposure levels with time is in agreement with

results in Swuste et al. (2008) [33] who also reported a drop in exposure levels to asbestos

during manufacturing of cement products in the Netherlands ranging from 0.9–2.7 fibres

−3

during the period 1970–1979 and 0.09–0.12 fibres cm

−3

in the period 1980–1989. Sim-

ilarly, measured fibre concentrations were found to range from 0.01 to 2.4 fibres cm

−3

during production friction materials during the period of 1970 to 1984 in the Netherlands

[22,36], and varying from 1.2–12 fibres cm

−3

during production of brake linings before

1974 in Sweden [37].

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

12 of 18

Figure 4.

Personal exposure asbestos concentrations in each occupational category for the period 1971–1980 or 1981–1997 compared to the current 8-h TWA health

guideline value (horizontal dashed line). The white, grey and black dots correspond to minimum, geometric mean (GM) and maximum asbestos concentration,

respectively. Concentrations = 0 fibres cm

−3

are represented in y = 0.01 with an arrow towards down. All the personal measurements which workers used respir-

atory protective equipment were taken outside the mask unless specified; *: Mechanical ventilation used from 1977 onwards;

Measurements taken inside the

respiratory protective equipment; Manuf.: manufacturer; Const.: construction.

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

13 of 18

The lowest personal exposure concentrations without the use of RPE were observed

for maintenance workers (geometric mean <0.8 fibres cm

−3

) and workers with indirect

contact during 1980–1990, primarily involved in process general supervision and inspec-

tion tasks during manufacturing (geometric mean <1 fibres cm

−3

) or in activities that do

not require manipulation of products (e.g., office work <0.04 fibres cm

−3

) (Table S1 and

Figure 4). These exposure levels are quite well in line with the average exposure of 0.2

fibres cm

−3

found in in the Netherlands during supervision and inspection in the asbestos

cement industry for the period of 1975–1979 [33]. Other studies also reported that most

maintenance-related tasks made by electricians and mechanics resulted in arithmetic

mean fibre concentrations ranging from about <0.01 to 1 fibres cm

−3

[35,38,39]. The review

study conducted by the Health Effects Institute concluded that airborne fibre concentra-

tions during maintenance tasks in public and commercial buildings could have been kept

below 0.1 fibres cm

−3

with proper controls, but could have exceeded 10 fibres cm

−3

during

some removal and repair work without adequate controls in place [34].

Even though only 55% of the measurements reported the use of RPE and sampled

location, i.e., outside or inside the RPE, we can conclude that adoption of this control

measure increased after 1986 and it became prevalent in construction and automotive

industries in work scenarios such as removal of asbestos-containing materials and

cleaning activities which yielded the highest geometric mean personal fibre concentra-

tions measured outside the RPE of the worker in the range of 0.6–35 fibres cm

−3

(Figure 4).

Considering the protection efficiency of the RPE, it is reasonable to assume that workers

were exposed to significantly lower levels of asbestos than measured (see the demon-

strative case of plumbing services in Figure 4 showing that average exposure levels

measured inside the RPE were reduced 58 times, corresponding to 98.3% reduction)

4.2. Comparison of Asbestos Exposure Concentrations with Health Guideline Values

In the 1970s, the Danish Working Environment Authority set the first health guide-

line value (HGV) for asbestos expressed as 8h-TWA of 2 fibres cm

−3

[40]. Between 1980

and 1985, the exposure concentrations should not exceed the HGV for 8h-TWA and short

term-15 min of 1 and 5 fibres cm

−3

, respectively. From the time period 1985–1988 and

1988–2005, the HGV for 8h-TWA was reduced from 0.5 to 0.3 fibres cm

−3

[40]. Since 2005,

the Danish HGV for asbestos is 0.1 fibres cm

−3

for 8h-TWA and 1 fibre cm

−3

for short term

15 min exposure [10].

From the inventoried asbestos exposure data (Table S1), nearly all measurements

were collected during specific short duration job tasks varying from 6 to 165 min. Because

the sampling durations did not match either the 8-h TWA or the short term-15 min HGV,

it is challenging to evaluate the inventoried data regarding specific limit values. Since

most of the short-term samplings were performed as part of a regulatory check, it is very

likely that they correspond to dustiest tasks in a specific industry and would result in an

upward bias. On the other hand, it is plausible that greater care was taken to avoid excess

dust production and to work by the rules on days of regulatory measurements at the

industrial facilities investigated, resulting in an underestimation of the exposure con-

centrations. Therefore, only rough comparisons can be made by assuming that the aver-

age personal air sampling data collected for each industry code in different occupational

categories were representative of 8-h TWA measurements.

Even though geometric mean personal fibre exposure concentrations obtained in all

of the occupational situations measured without or outside the RPE from 1971 to 1997,

exceeded the current HGV of 0.1 fibres cm

−3

for 8h-TWA (Figure 4), the majority of sam-

ples collected in the period of 1971 to 1980 during manufacturing of automotive compo-

nents and general supervision and inspection tasks were below the HGV of 2 fibres cm

−3

Assuming that the use of a RPE reduce 98.3% of the airborne levels, it is likely that geo-

metric mean of workers exposure did not exceed the current HGV of 0.1 fibres cm

−3

for

8h-TWA on the exposure scenarios, during where workers used RPE, except during ac-

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

14 of 18

tivities involving removal and scraping of cement floors in a hospital which might have

exceeded 6-fold (Figure 4).

4.3. Database Limitations

The data in the Danish Asbestos Exposure Database have some limitations which

affect the ability to compare data and interpret the historical measurement data:

•

Most of the inventoried datasets did not provide comprehensive details with respect

to their study approach or design to be able to fully understand the type or duration

of exposure. Even though some of the archives and reports provided general insight

about the working conditions in the workplaces, most of them lacked essential in-

formation regarding the corresponding industry, work situation, determinants of

exposure (e.g., personal RPE, encapsulation of the process, exhaust ventilation), and

duration of measurements. From several exposure scenarios, it was unclear whether

the data was based on stationary or personal sampling and sampling year was not

reported. In case of personal sampling, it was also not stated in 44.6% of the cases

whether such measurement was with RPE and if it was measured inside or outside

the respiratory mask. Prior to 1980, exposure scenarios were scarce with only 2189

measurements, corresponding to 37% of the inventoried situations measured in

which asbestos concentrations, sampling position, industry and job codes were

available (5869 measurements). The lack of these type of descriptions and the scat-

tered quantitative exposure information over time consequently introduced uncer-

tainties in the identification and modelling of clear temporal trends in asbestos ex-

posure levels due to changes in the measurement strategy, exposure control prac-

tices and process characteristics [33,41,42].

Even though, it is very likely that majority of the inventoried asbestos exposure

concentrations were determined by using appropriate methodologies, and analysed

by using phase contrast microscope (PCM) method, 5817 (out of 5869) datasets

lacked information about sampling techniques and counting procedures. One of the

PCM method limitations is that it cannot differentiate between asbestos and

non-asbestos fibres, while scanning electron microscope (SEM) or transmission

electron microscope (TEM), which is approximately 100 times more sensitive, is ca-

pable of distinguishing different fibre types. It is therefore likely that PCM method

overestimated the asbestos fibre concentration in the air in occupational settings

where large proportions of other fibres (e.g., wool, cotton, glass) are present [43,44].

On the other hand, due to the low resolution of the PCM method, it is also probable

that most of samples did not account for thin fibres (width less than 0.25 µm) and

potentially underestimated asbestos exposures [24,45]. There have been, however,

numerous attempts to convert total fibre counts to specific fibre counts with fibre

type, length, and diameter [24].

Most quantitative information describing exposure patterns among industries and

jobs was available for the largest Danish industries which manufactured automotive

and asbestos cement products (5677 measurements, 96.7%). All the asbestos sam-

plings in these industries were conducted as part of a regulatory check. It is likely

that they correspond to the dustiest tasks and would result in an overestimation of

personal exposure concentrations if applied to the entire work force in these indus-

tries. The detailed information about tasks performed does, however, allow for es-

timation of the exposure associated with these tasks, which would most likely be

close to the typical exposure levels between 1971 and 1985. In almost all the other

occupational categories and industries, the number of available measurements was

limited to a few samples. It is probable that larger industries registered lower fibre

levels if compared to smaller workplaces or less controlled facilities where the

awareness of occupational hazards and health problems may have been lower and

where safety measures were less sophisticated or even non-existent. The measure-

•

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

15 of 18

ments on an asbestos cement factory operating in Denmark were performed quar-

terly by the factory, systematically covering relevant tasks and analysed at NRCWE

(at the time called SIFA) in agreement with the Danish Working Authorities. The

insulation materials manufacturer, by far the largest facility of its type in Denmark,

performed measurements in a similar way. In principle, these datasets should be

highly representative for these workplaces, but evidently, these companies would

have been able to affect the results by optimizing tasks, cleaning and ventilation

settings on days of measurements. However, the authors believe that if further as-

bestos exposure concentrations exist, inclusion of these would not significantly af-

fect the key findings reported here.

5. Conclusions

This work presents the first known attempt to compile available asbestos measure-

ments in Danish workplaces in order to characterize the typical airborne fibre concentra-

tion ranges associated with contextual information for specific work tasks involved in

different industries over time. The historical asbestos exposure database contained 9236

records of which 5869 data entries contained high quality measurements of asbestos

concentrations from 1971 to 1997.

The highest airborne fibre concentrations were registered during the active handling

of asbestos products in construction services during the period 1984–1989. The exposures

in the construction industry can in particular be linked to the removal of asbes-

tos-containing floors, and ceilings. For the period 1971–1980, manufacturing processes of

eternit cement plates, brake pads and insulation materials were ranked as the occupa-

tions with the highest exposure concentrations followed by cleaning of asbes-

tos-containing materials, and warehouse activities. The lowest personal exposure con-

centrations were observed in the period of 1980–1990 for maintenance workers and

workers involved in processes of general supervision and inspection tasks or in activities

that do not require manipulation of products.

All of the occupational situations measured without the use or outside the RPE in the

period of 1971–1997 exceeded the current HGV of 0.1 fibres cm

−3

for 8h-TWA (sometimes by

100-fold or more). However, the majority of samples collected for less than 8 h in the period

of 1971 to 1980 were below the contemporaneous HGV of 2 fibres cm

−3

. If a RPE with a filtra-

tion efficiency of at least 98.3% would be used in all the inventoried scenarios, the average

workers exposure would be below the HGV of 0.1 fibres cm

−3

for 8h-TWA except for activi-

ties involving removal and scraping of cement floors in a hospital.

The applied mathematical log-linear gamma model to the manufacturing industries

of asbestos cement plates and automotive components confirms a clear downwards trend

over time. Given the ban on the use of asbestos in 1986, and the regulatory enforcement

on reducing asbestos exposure in the period 1980–2005, it is reasonable to assume that

occupational asbestos exposures were generally higher during the 1970s and earlier.

Even though the database on historical asbestos measurements presented in this study

have some limitations, the data allowed the identification of specific work scenarios where

relatively high asbestos exposure levels occurred and might still occur in the construction

sector during repair, renovation or demolition activities. In this way the data can support in

historical health effect assessment and epidemiological assessments, but also provide rele-

vant information for current risk assessment, management procedures and prediction of po-

tential associated detrimental occupational health effects in the next decade.

Supplementary Materials:

Supplementary Materials to this article can be found online at

www.mdpi.com/article/10.3390/ijerph19020643/s1. Figure S1. Overview of the 5869 high quality

measurements of asbestos exposure in Danish companies distributed among: (a) all the occupa-

tional categories and each of the occupational category and industry code by the periods

1971–1980: (b) manufacturing of asbestos products; (c) active handling of asbestos products; (d)

transport, storage, packaging of asbestos products; (e) maintenance jobs; (f) general supervision of

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

16 of 18

work processes and inspection tasks; and (g) cleaning activities. N: total number of measurements

available. Figure S2. Overview of the 5869 high quality measurements of asbestos exposure in

Danish companies distributed among the following exposure determinants: (a) sampled year; (b)

purpose of the measurement; (c) sampling position; (d) type of general ventilation system; (e) con-

trol measures in place; and (f) use of respiratory protective equipment (RPE). N/A: not available

information; * unknown if RPE was used and unknown if measurement position was located inside

or outside the RPE. Table S1. Simplified structure of the Danish asbestos database containing con-

centration of asbestos fibres collected on filters during specific work shifts, date periods (1971–1980

or 1981–1997), and measurement positions. GSD: stands for the geometric standard deviation. NF:

Near field; FF: Far field; N/A: Not available data; N/R: Not recorded; -: Not applicable; RPE: res-

piratory protection equipment; LEV: Local exhaust ventilation; MV: Mechanical ventilation; Per-

sonal*: unknown if measurement position was located inside or outside the RPE; ¥: Used mechan-

ical ventilation from 1977 onwards. Table S2. Historical asbestos measurements in Den-

mark—National database.

Author Contributions:

All authors were involved in the conceptualization of the study, identifica-

tion of data sources, and collation of exposure levels and contextual information into the database.

A.S.F., E.M.F., A.K.J., B.X.L., and M.M.-J. were responsible for the formal analysis of personal ex-

posure data, data curation, and preparation of visualization of data. H.W.M., K.A.J., J.H.B., J.B. and

D.L.S. were involved in the acquisition of the financial support to conduct this study and develop a

National database. A. S. F. was responsible for the research activity planning and execution. A.S.F.

wrote the original manuscript draft. All authors have read and agreed to the published version of

the manuscript.

Funding:

This work was financially supported by the Bjørst Memorial Foundation.

Institutional Review Board Statement:

No official ethical approval for this type of study was re-

quired by the institutions involved.

Informed Consent Statement:

Not applicable.

Data Availability Statement:

The data presented in this study are available in Table S2.

Acknowledgments:

The authors also acknowledge the Danish State Archives for their technical

support in providing the measurement reports.

Conflicts of Interest:

The authors declare that they have no known competing financial interests or

personal relationships that could have appeared to influence the work reported in this paper.

References

Hendry, N.W. The geology, occurrences, and major uses of abestos.

Ann. N. Y. Acad. Sci.

1965,

132,

12–21,

doi:10.1111/j.1749-6632.1965.tb41086.x.

IARC Asbestos (chrysotile, amosite, crocidolite, tremolite, actinolite, and anthophyllite).

IARC Work. Gr. Eval. Carcinog. Risks to

Humans. Arsenic, Met. Fibres Dusts. Lyon Int. Agency Res. Cancer; 2012. (IARC Monogr. Eval. Carcinog. Risks to Humans, No. 100C.)

2012,

No. 100C. Available online: https://www.ncbi.nlm.nih.gov/books/NBK304374/ (accessed on 26 November 2020).

National Toxicology Program. NTP Toxicology and Carcinogenesis Studies of Crocidolite Asbestos (CAS No. 12001-28-4) in

F344/N Rats (Feed Studies). National Toxicology Program Technical Report Series. 1988; 280:1–178. PMID: 12748699.

Available online: https://pubmed.ncbi.nlm.nih.gov/12748699/ (accessed on 26 November 2020).

National Toxicology Program NTP Lifetime Carcinogenesis Studies of Chrysotile Asbestos (CAS No. 12001-29-5) in Syrian

Golden Hamsters (Feed Studies). National Toxicology Program Technical Report Series. 1990; 246:1-192. PMID: 12750747.

Available online: https://pubmed.ncbi.nlm.nih.gov/12750747/ (accessed on 26 November 2020).

National Toxicology Program. NTP Toxicology and Carcinogenesis Studies of Amosite Asbestos (CAS No. 12172-73-5) in

F344/N Rats (Feed Studies). National Toxicology Program Technical Report Series. 1990; 279:1-341. PMID: 12748700. Available

online: https://pubmed.ncbi.nlm.nih.gov/12748700/ (accessed on 26 November 2020).

WHO Asbestos: Elimination of Asbestos-Related Diseases. World Health Organization. Available online:

http://www.who.int/news-room/fact-sheets/detail/asbestos-elimination-of-asbestos-related-diseases (accessed on 27 July

2020).

WHO.

Determination of Airborne Fibre Number Concentrations;

WHO: Geneva, Switzerland, 1997; pp. 1–53.

Matsuzaki, H.; Maeda, M.; Lee, S.; Nishimura, Y.; Kumagai-Takei, N.; Hayashi, H.; Yamamoto, S.; Hatayama, T.; Kojima, Y.;

Tabata, R.; et al. Asbestos-induced cellular and molecular alteration of immunocompetent cells and their relationship with

chronic inflammation and carcinogenesis.

J. Biomed. Biotechnol.

2012,

492608, doi:10.1155/2012/492608.

Lanphear, B.P.; Buncher, C.R. Latent period for malignant mesothelioma of occupational origin.

J. Occup. Med.

1992,

34,

718–721.

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

17 of 18

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

AT At-Vejledning Stoffer of Materialer C.2.2-2: Asbest. Arbejdstilsynet, Denmark. July 2005–Updated June 2019. Available

online: https://at.dk/media/5675/c-2-2-2-asbest-t.pdf (accessed on 20 November 2020).

Stayner, L.; Smith, R.; Bailer, J.; Gilbert, S.; Steenland, K.; Dement, J.; Brown, D.; Lemen, R. Exposure-response analysis of risk

of respiratory disease associated with occupational exposure to chrysotile asbestos.

Occup. Environ. Med.

1997,

54,

646–652.

doi:10.1136/oem.54.9.646.

Hein, M.J.; Stayner, L.T.; Lehman, E.; Dement, J.M. Follow-up study of chrysotile textile workers: Cohort mortality and

exposure-response.

Occup. Environ. Med.

2007,

64, 616–-625, doi:10.1136/oem.2006.031005.

Gualtieri, A.F. Mineral Fibres: Crystal Chemistry, Chemical-Physical Properties, Biological Interaction and Toxicity, 2017.

Eur.

Mineral. Union Notes Mineral.

2017,

18,

7–9.

Røe, O.D. Asbest, malignt mesoteliom og lungekræft.

Ugeskr. Laeger

2018,

180,

2–5.

AT BEK nr 660 af 24/09/1986. The Ministry of Employment. Executive Order on Asbestos (Asbestos Order) [Danish].

Available online: https://www.retsinformation.dk/eli/lta/1986/660 (accessed on 20 November 2020).

AT BEK nr 1502 af 21/12/2004 The Ministry of Employment. Executive Order on Asbestos (Asbestos Order) [Danish].

Available online: https://www.retsinformation.dk/eli/lta/2004/1502 (accessed on 20 November 2020).

Raffn, E.; Lynge, E.; Juel, K.; Korsgaard, B. Incidence of cancer and mortality among employees in the asbestos cement

industry in Denmark.

Br. J. Ind. Med.

1989,

46,

90–96, doi:10.1136/oem.46.2.90.

Sherson, L. Low-dose occupational asbestos exposure and lung cancer: A Scientific reference document on behalf of the

Danish Working Environment Research Fund. Arbejds- og Miljømedicinsk Klinik. Department of occupational and

environmental medicine, Odense University Hospital, Odense, Denmark.

2013.

Brauer, C.; Baandrup, U.; Jacobsen, P.; Krasnik, M.; Olsen, J.H.; Pedersen, J.H.; Rasmussen, T.R.; Schlünssen, V.; Sherson, D.;

Svolgaard, B.; et al. Screening for asbestbetingede sygdomme?

Ugeskr. Laeger

2009,

171,

433–436.

Skammeritz, E.; Omland, L.H.; Johansen, J.P.; Omland Asbestos exposure and survival in malignant mesothelioma: A

description of 122 consecutive cases at an occupational clinic.

Int. J. Occup. Environ. Med.

2011,

224–236.

Greenberg, M.; Lloyd Davies, T.A. Mesothelioma Register 1967-68.

Br. J. Ind. Med.

1974,

doi:10.1136/oem.31.2.91.

Burdorf, A.; Swuste, P. An expert system for the evaluation of historical asbestos exposure as diagnostic criterion in

asbestos-related diseases.

Ann. Occup. Hyg.

1999,

doi:10.1016/S0003-4878(98)00074-X.

Rice, C.; Heineman, E.F. An asbestos job exposure matrix to characterize fiber type, length, and relative exposure intensity.

Appl. Occup. Environ. Hyg.

2003,

18,

506–512, doi:10.1080/10473220301459.

Nielsen, L.S.; Bælum, J.; Rasmussen, J.; Dahl, S.; Olsen, K.E.; Albin, M.; Hansen, N.C.; Sherson, D. Occupational asbestos

exposure and lung cancer - A systematic review of the literature.

Arch. Environ. Occup. Heal.

2014,

69,

191–206.

Peters, S.; Vermeulen, R.; Portengen, L.; Olsson, A.; Kendzia, B.; Vincent, R.; Savary, B.; Lavoué, J.; Cavallo, D.; Cattaneo, A.; et

al. SYN-JEM: A Quantitative Job-Exposure Matrix for Five Lung Carcinogens.

Ann. Occup. Hyg.

2016,

60,

795–811,

doi:10.1093/annhyg/mew034.

the Medical Research Council Pneumoconiosis Unit (Mrcpu) A survey of pleural thickening: Its relation to asbestos exposure

and previous pleural disease.

Environ. Res.

1972,

142–151, doi:10.1016/0013-9351(72)90029-1.

Nielsen, A. Asbestos in the indoor atmosphere and environment.

Ugeskr. Laeger

1986,

148,

3323–3328.

Raffn, E. Kræft og dødsfald i asbestcementindustrien. En kohorteundersøgelse af cancerincidensen og mortaliteten blandt

ansatte på Dansk Eternit Fabrik A/S 1928-1984. Ph.D thesis, Copenhagen University, Copenhagen, Denmark,

1990.

Brauer, C.; Jacobsen, P.

Report on Health Risks and Clinical Examiantions of DSB Employees Exposed to Asbestos (Danish);

Occupational and Environmental Department, Bispebjerg Hospital: Copenhagen, Denmark,

2007.

ATABAS Arbejdstilsynets Database for Arbejdspladsmålinger. ATABAS. Opgørelser for Perioden January 1983–December

1985 Arbejdsmiljøinstituttet January 1986. Not published.

1986.

ECHA.

Guidance on Information Requirements and Chemical Safety Assessment Chapter R. 14 : Occupational Exposure Assessment;

2016; ISBN 9789294950819. European Chemicals Agency. Helsinki, Finland.

Franken, R.; Shandilya, N.; Marquart, H.; McNally, K.; Fransman, W. Extrapolating the Applicability of Measurement Data on

Worker Inhalation Exposure to Chemical Substances.

Ann. Work Expo. Health

2020,

64,

250–269, doi:10.1093/annweh/wxz097.

Swuste, P.; Dahhan, M.; Burdorf, A. Linking Expert Judgement and Trends in Occupational Exposure into a Job-Exposure

Matrix for Historical Exposure to Asbestos in The Netherlands.

Ann. Occup. Hyg.

2008,

52,

397–403,

doi:10.1093/annhyg/men030.

Health Effects Institute.

Asbestos Research (HEI-AR) Asbestos in Public and Commercial Buildings: A Literature Review and Synthesis

of Current Knowledge;

Report Number 1991-01-01; Health Effects Institute-Asbestos Research, Cambridge, MA, USA,

1991.

Mlynarek, S.; Corn, M.; Blake, C. Asbestos exposure of building maintenance personnel.

Regul. Toxicol. Pharmacol.

1996,

doi:10.1006/rtph.1996.0045.

Akkersdijk, H.

Asbestos in Occupational Groups in The Netherlands;

Scheikundige Dienst Directoraat-Generaal van de Arbeid:

Voorburg, The Netherlands, 1984.

Boman, N.; Christensson, B.

Asbest på våra Arbetsplatser. Undersökningsrapport AMT 102/74.

Arbetarskyddsstyrelsen, Stockholm,

Sweden; 1974.

Price, B.; Crump, K.S.; Baird, E.C. Airborne asbestos levels in buildings: maintenance worker and occupant exposures.

J. Expo.

Anal. Environ. Epidemiol.

1992,

357–374.

Kinney, P.L.; Satterfield, M.H.; Shaikh, R.A. Airborne fiber levels during asbestos operations and maintenance work in a large

BEU, Alm.del - 2021-22 - Bilag 141: Orientering om artikel vedrørende historiske asbestmålinger i Danmark, fra beskæftigelsesministeren

Int. J. Environ. Res. Public Health

2022,

19,

643

18 of 18

40.

41.

42.

43.

44.

45.

office building.

Appl. Occup. Environ. Hyg.

1994,

825–835, doi:10.1080/1047322X.1994.10388417.

BAI Bygge/Anlæg & Industri (BAI) Ministry of Children and Education. Safety When Working with Asbestos-Containing

Materials [Danish]. Available online: https://materialeplatformen.dk/bookpage/99585528 (accessed on 6 December 2021).

Cherrie, J.; Addison, J.; Dodgson, J.

Comparative Studies of Airborne Asbestos in Occupational and Non-Occupational Environments

Using Optical and Electron Microscope Techniques;

IARC Scientific Publications, Lyon, France.

1989,

90,

304-309, PMID: 2663715.

Burdett, G. A comparison of historic asbestos measurements using a thermal precipitator with the membrane filter-phase

contrast microscopy method.

Ann. Occup. Hyg.

1998,

42,

21–31, doi:10.1016/S0003-4878(97)00048-3.

Moldoveanu, M. Air Pollution with Asbestos in Several Cities in Romania. In

Advanced Topics in Environmental Health and Air

Pollution Case Studies;

InTech, Rijeka, Croatia; 2011. doi: 10.5772/17775.

Harper, M.; Butler, C.; Berry, D.; Wroble, J. Where occupation and environment overlap: US forest service worker exposure to

libby amphibole fibers.

J. Occup. Environ. Hyg.

2015,

12,

D47–D53, doi:10.1080/15459624.2014.989362.

Eypert-Blaison, C.; Romero-Hariot, A.; Clerc, F.; Vincent, R. Assessment of occupational exposure to asbestos fibers:

Contribution of analytical transmission electron microscopy analysis and comparison with phase-contrast microscopy.

Occup. Environ. Hyg.

2018,

15,

263–274, doi:10.1080/15459624.2017.1412583.