The production of glass began a few thousand years B. C. but was not introduced in Sweden until the 16th century. In general, throughout history, technical development has been rapid, but considering the art of glass blowing, methods used today are much the same as when the blowpipe was invented about 2 000 years ago. The composition of glass has changed, however, as a result of production specialization and the introduction of different types of glass (e.g. lead crystal, opal and heat-resistant glass).
Workers in the Swedish art glass industry are exposed to a variety of hazardous chemicals, some of which are known carcinogens. Most of these substances are components of the glass batch (i.e. the mixture of substances used to make glass), for example, compounds of arsenic, antimony, lead, cadmium, chromium, and nickel. Furthermore, large amounts of hydrofluoric acid and sulphuric acid are used in the polishing process, and, in the past, equipment made of asbestos was used for handling hot glass. Many of these chemicals are found not only within the glassworks themselves, but have also been emitted to the environment, causing general concerns about health hazards among people living inthe vicinity of glassworks. Some glass workers are also exposed to combustion products and constant heat stress when working close to the glass furnaces.
The present studies show that Swedish art glass workers run increased risks of dying from cancer of the stomach, colon and lung and from cardiovascular diseases. In one of the studies, increased risks were also observed for prostate and pharynx cancer and for cerebrovascular diseases. The worker category showing the highest cancer risks was the glass blowers. The exposure route for this category of workers might be through both inhalation of airborne substances and ingestion of particles entering the mouth by way of the blowpipe. These possibilities are supported by hygienic measurements, including analysis of slag samples from inside the blowpipes.
The present studies were initiated due to concern about cancer risks expressed by people living close to glassworks, but the only increased risk found in this population was a cluster of brain cancers. Glass workers represent a large part of the population living in the vicinity of the glassworks, where the cluster of brain cancers occurred, and because of this, registry-based studies of Swedish glass workers seem to have spuriously indicated an occupational risk in this respect. Although the detected cluster of brain cancers might have its origin in some industrial discharge from the glassworks, the chemicals predominating in the emissions are not known to cause brain cancers, and other factors might be involved as well.
The cancer risks observed among glass workers can probably be explained by the known effects of several of the exposures occurring in glass production. The observed adverse effects on the cardiaand cerebrovascular systems may also be related to exposures at hand, first and foremost probably to lead exposure.
Linköping: Linköpings universitet , 1992. , 43 p.
1992-01-17, Administrationsbyggnadens aula, Universitetssjukhuset, Linköping, 09:00 (Swedish)
Papers, included in the Ph.D. thesis, are not registered and included in the posts from 1999 and backwards.