Approximately 80-90 glassworks have been located in southeast Sweden since the 1600s. When glass was manufactured raw materials such as sand, soda, lime, potash and red lead were used in different proportions depending on the type of glass to be produced. A number of heavy metals were used to colour the glass; cadmium, molybdenum, chromium and even uranium.
Until the 1970s, environmental considerations were limited and therefore the glasswork areas are heavily polluted. For example, concentrations of Pb in soil have been found at levels about 1300 times the Swedish EPA generic guidelines. There are currently a number of studies examining how people who live or lived near the contaminated glassworks are affected by emissions and pollution; through drinking water, consumption of home-grown vegetables, wild-picked mushrooms and berries as well as self-caught fish and shellfish. However, beside the deposition of waste materials on the glassworks properties, extensive Pb emissions to air occurred in the past and a significant fraction (about 10% in 1977/1978) of the total Swedish Pb emissions to air occurred from the glass factories in the Swedish glassworks region. Hence, the historical exposure may have been largely associated with the inhalation of flue gas particles. In this context, exposure through inhalation of air-born particles is an area that is difficult to assess because there are no measurements of the air emission that extends further back than the 1980s. This study uses a new methodological approach to assess metal exposure through this exposure route for the time period 1900-2016 at 10different glassworks sites.
In a first step, archival studies (Swedish National Archives) revealed historical glassworks raw material purchases and production levels. These data were used to estimate the historical emissions based on the measured emissions available from the 1990s - before the glassworks installed filters.
In a second step, wind direction data from the Swedish Meteorological and Hydrological Institute was combined with deposition studies (mosses), giving the local distribution of air borne pollutants around each facility.
In the third step, time series were created where exposure to air borne heavy metals for the inhabitants of each glasswork site was estimated.
For the 10 glassworks in the study, total and continuous air emissions have been estimated over time and an estimate has been made of the exposure to heavy metals through inhalation of air-borne flue gas particles (lead, chromium and arsenic) at the ten glassworks facilities.