GUIDELINES FOR ASBESTOS
Metoda Dodič Fikfak
Clinical Center Ljubljana, Institute of Occupational, Traffic
and Sports Medicine, Ljubljana, Slovenia
is the commercial name for a group of natural fibrous silicates,
which have no common physical or chemical properties and are for
practical reasons divided in two groups: chrysotiles and amhpiboles
(1). Chrysotile asbestos accounts for more than 90% of all asbestos
consumption in the world. Occupational exposure constitutes a serious
health risk for workers employed in mining of asbestos ore, production
and manufacturing of asbestos fibres, disposal of asbestos containing
wastes, shipyards, brake and clutch repair, and other industries
(2). Workers are only exceptionally exposed to chrysotile alone,
since chrysotile always contains at least traces of amphiboles.
Exposure to asbestos is associated with the development of certain
diseases, notably asbestosis, diffuse malignant mesothelioma and
cancers of the: lung, oral mucous, larynx, pharynx, gastro-intestinal
tract and kidney (3).
the year 1990, the so-called amphibole hypothesis stirred up a great
deal of discussion (4, 5). Its advocates maintain that chrysotile
fibres have a low carcinogenic potential, especially when compared
with amphiboles. A number of studies were carried out all over the
world in an attempt to evaluate the influence of chrysotile alone
on the development of lung cancer and mesothelioma (6, 7, 8, 9,
10, 11). The Collegium Ramazzini declared chrysotile as a cause
of mesothelioma and lung cancer. As a result of these discussions,
many countries across the world where asbestos is still used at
present have adopted different recommended values for chrysotiles
Slovenia, the use of asbestos was banned by law in 1996. At that time
the Ministry of Health was set the task to draw up national guidelines
for asbestos. As a basis for the guidelines, the Ministry sponsored
a study, which was to provide answers to the following questions:
- How much asbestos was imported into Slovenia over the past
- How many workers were either directly or potentially exposed
to asbestos during that period?
- How many asbestos products were manufactured and used in the
country, how many were exported and how many are still in use
- How many workers developed occupational asbestos disease?
- How should asbestos construction material be managed in the
future in Slovenia?
results of the study would be used by the government in drawing
up the national guidelines and regulations for work with asbestos
and for the detection and monitoring of asbestos-related occupational
Ministry appointed a group of researchers to carry out the study.
Information was gathered by the "snowball" method. For 11 companies,
data on the use of asbestos in the production process were obtained
from the Board for Asserting the Right to a Non-standardized Pension.
On the basis of this information, further potential users of asbestos
were identified in the following industries: electronic and electrical
industry, shipbuilding, construction, manufacture of household appliances,
oil refinery, car workshops where brakes and clutches were repaired,
on the import of asbestos into the country were obtained also from
the Ministry of Health, which received requests for asbestos import
from companies in 1998, the first year after use of asbestos had
been banned. Namely, Ministry of Health exceptionally allowed the
import of asbestos temporary to some companies that were not able
to replace asbestos with non-toxic material in short time. Next,
the customs authorities were asked to provide information on importers
of asbestos and asbestos-containing products for the year 1997,
the last year before the introduction of import-export licenses.
identified asbestos users were asked to complete a questionnaire
inquiring about asbestos production, workers' exposure, air monitoring
information, asbestos-containing wastes, use of protective equipment,
and possible substitution of asbestos with a less hazardous substance.
Data on the occurrence of mesothelioma and lung cancer in Slovenia
were obtained from the Cancer Registry at the Institute of Oncology
in Ljubljana. Information on occupational diseases was provided
in the Institute of Occupational, Traffic and Sports Medicine.
670,000 tons of asbestos was imported into Slovenia in the period
1946-1996. This was mostly white asbestos, chrysotile. Separate
data for white asbestos and amphiboles are available only for Salonit
Anhovo, which imported most of the above quantity, i.e. about 61,400
tons, including more than 70,000 tons of amphiboles. From the total
quantity of asbestos imported into Slovenia, it is evident that
89% of all asbestos was used by Salonit Anhovo .
shown by the figure 1, asbestos consumption in Slovenia peaked in
the mid-seventies and early eighties and started to decline rapidly
after 1982. The graph representing the total consumption closely
follows the graph illustrating the consumption by Salonit. However,
data on the second largest consumer, Donit, show that its peak consumption
was shifted slightly into the eighties, attaining the highest level
in the period 1982-1987. Izolirka, another major user of asbestos,
has no available data on asbestos consumption, but the quantities
used may be estimated from the production data, suggesting that
the peak consumption occurred in the late eighties and early nineties.
Slovenian factories manufactured a variety of asbestos products:
corrugated sheets, sheets for gaskets, asbestos millboard, pipes,
plasters, pastes, glues, etc. Asbestos was used as a construction
and insulation material, asbestos textiles, engine gaskets, industrial
gaskets, filters and insulation tapes; it was built into rail cars,
boilers and brake linings, etc. In the study, the authors also estimated
the quantity of asbestos products that have remained in Slovenia.
This information is important because, in conjunction with data
on the useful life of individual products, it forms the basis for
estimating the quantity of asbestos products that are currently
present on the territory of Slovenia. Asbestos products have a lifetime
of 1 to 45 years. Some asbestos-containing materials are permanently
installed in buildings. The expected life of products that were
manufactured in greatest quantities ranges from 35 to 45 years,
which means that most of these products are still in use at present,
although their lifetime is running out. This also means that approximately
the same quantities of asbestos will soon land on refuse dumps.
Among asbestos-manufacturing plants, train company TvT had the largest
number of workers. Salonit Anhovo was the second largest employer,
all the other companies being much smaller.
In Salonit, an estimated 300 to 600 workers, mostly employed in
cement production, were directly exposed to asbestos. In TvT, the
number of directly exposed workers is difficult to assess, as the
areas where asbestos was used were not separated from other areas.
However, TvT management estimates that about 1200 workers were exposed
to asbestos after the year 1965. In Termika, the number of directly
exposed workers was probably similar as in Salonit, but the majority
was employed outside Slovenia, in different parts of the former
combined presentation of the number of workers employed in asbestos
industry, the number of directly exposed workers and the quantity
of asbestos used shows very similar fluctuations. However, compared
to the other variables, the number of directly exposed workers is
much smaller and so the differences are more difficult to perceive.
From the companies the researchers obtained lists of all employed
workers and list of those who were directly exposed to asbestos
in the mid-eighties. In this way, they obtained a cohort of directly
exposed workers and a cohort of potentially exposed workers. The
cohorts will be followed over the coming years.
the adoption of regulations on asbestos-related occupational disease
in 1997, two interdisciplinary teams of experts evaluate all cases
of asbestos disease. In the period 1998-2002, the teams confirmed
1331 patients with occupational asbestos disease. Among them were
363 asbestosis, 932 patients with pleural plaques, 18 had occupational
lung cancer and 18 occupational mesothelioma.
Analysis of the occurrence and distribution of mesothelioma in Slovenia
in the period 1959-1994 shows that cases were clustered in the vicinity
of asbestos plants.
Discussion and conclusion
The following 14 large asbestos-manufacturing plants provided sufficient
information to be included into the analysis: Donit Laminati, Donit
Pletilnica, Donit Tesnila, Filtrauto, Fragmat, Izolirka, Kolektor,
Salonit, Sinter, Termika, TiT Tesnila, TMT Tesnila, TVT Tirna vozila
in WV Term. We are quite confident, that the analysis covered more
than 95% of all asbestos consumption in Slovenia and most probably
also a similar proportion of workers exposed to asbestos over the
past 35 years. It is true that, according to the available information,
some 30 companies in Slovenia used asbestos. However, compared to
the above-listed companies, those that were excluded form the survey
had only minimal consumption. Clearly, this does not rule out morbidity
among workers employed in smaller plants. Morbidity depends on exposure,
which does not always correlate with the quantity of asbestos used,
but is also related to the job, type of exposure, the material used
(pure or mixed asbestos) and, last but not least, the protection
of workers. The situation with environmental pollution is of course
somewhat different. Pollution is obviously most severe in environments
with the highest level of production and the greatest quantities
of asbestos wastes; it is also influenced by the method of storage
an/or disposal of wastes.
the 14 companies included in the survey, three produced gaskets
and the rest other products, ranging from pipes and sheets to asbestos
textiles, glues, filters, brake linings etc. The first asbestos-manufacturing
plants were established already in the 19th century, and ten were
founded after World War II.
was always imported into Slovenia, most frequently from Canada,
Russia, South Africa, Bosnia and Serbia. Two plants purchased asbestos
from Salonit. It is interesting to look at the safety measures used
in the workplace: seven of the 14 plants had no safety measures
whatsoever. Five companies used rotation of workers, which is a
highly unsuitable practice since more people than necessary are
exposed. Two companies used various unwritten measures, but these
were instituted only after 1970 and were probably never practiced
very consistently. Interestingly, in 11 companies internal regulations
required some form of protection (respirator or mask), but it was
apparently not obligatory, and the workers were not sufficiently
aware of the need to use protective devices, nor was non-compliance
sanctioned in any way. In one company, regular medical examinations
were performed at comparatively brief intervals already before 1960.
Apparently, periodic examinations were soon introduced also in other
plants, but it is questionable if they were sufficiently focused
and not too general. Only three companies had internal regulations
or rules referring specifically to work with asbestos.
how long asbestos has been used in Slovenia and how long we already
have and will continue to come in contact with this material, we
may expect asbestos-related diseases to be prevalent in our area
for at least another 30 years.
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NACIONALNE SMJERNICE ZA AZBEST
Slovenija je zabranila upotrebu azbesta u privredi zakonskom odredbom
Vlada je zadužila Ministarstvo zdravstva, da izradi nacionalne smjernice
za azbest, koje bi dale odgovore na pitanje o količini već upotrebljavanog
azbesta u Sloveniji u zadnjih 35 godina, o broju radnih organizacija
u kojima su radnici izloženi azbestu, o broju profesionalnih oboljenja
koje su nastale zbog ekspozicije azbestu.
Skupina istraživača, kojima je ovaj zadatak povjeren, utvrdila je:
da je Slovenija sav azbest uvozila, da je najviše azbesta koristilo
14 radnih organizacija, ali isto tako da se azbest upotrebljavao
u približno trideset radnih organizacija. Najveći korisnik azbesta
je bilo u Salonit Anhovo.
Profesionalne bolesti su se dijagnosticirale od 1998. godine i dalje.
Konačno je bila profesionalna bolest zbog izloženosti azbestu utvrđena
u 1331 bolesnika, a od toga smo imali 363 bolesnika s azbestozom,
932 s pleuralnim plakvama, 18 radnika je imalo dijagnosticiran rak
pluća i 18 mezoteliom.