Historical exposure to inorganic mercury at the smelter works of Abbadia San Salvatore, Italy

Metallic mercury production from cinnabar ore mag result in high exposures to inorganic mercury, that are difficult to assess separately from the exposures originating from underground extraction, and previously have only been scantily described. We retrieved and analysed the air and biological mercury determinations on workers invoiced in the smelting process of the Abbadia San Salvatore mine (Monte Amiata, Italy). Native mercury was not present in the ore, and the exposure in the underground extraction,vas low. The smelter operated from 1897 to 1983, Blood and urine (24/h urine collections and concentration samples) had been sampled in 1968 to 1982, and analysed for mercury by atomic absorption spectrophotometry, and relate to all subjects. Exposure to mercury in air had been determined in a small set of personal samples in 1982, The data relate to all jobs in the smelter process, and all jobs entailed substantial exposure to mercury, The overall distribution of breathing zone air, blood and urinary levels is right-skewed and similar to the log-normal distribution (air, median 48 mu g/m(3), n = 49; blood, arithmetic mean ARI 49 mu g/L; geometric mean GM 26 mu g/L, n = 192; urinary excretion, AM 140 mu g/24 h, GM 78 mu g/24 h, n = 839; and urinary concentration, AM 160 mu g/L, GM 83 mu g/L, n = 632), Air, blood and urinary values show a high ratio of the between- and within-job variance, indicating differences in exposure by job. Cinnabar pigment production, of which the exposure has not been characterised previously, was the job with the highest air (AM 160 mu g/m(3)) and urinary levels (excretion AM 690 mu g/24 h; concentration AM 1100 mu g/L). Other jobs with high urinary levels n ere soot purification, laboratory work, and bottling, Cleaning of condensers showed the highest blood level (ARI 280 mu g/L). There is a downwards time trend in mercury concentration in blood and in urine, The corresponding trend is not seen for urinary excretion levels, the reason for this being unclear, Roasters, which is the most frequently monitored group, show however a decreasing trend in all sets of data (e.g. the mean of urinary excretion decreased from 300 mu g/24 h in 1968/69 to 50 mu g/24 h in 1980/81), The mercury exposure experienced by the smelters of Abbadia San Salvatore is in Line with the fen available data on workers from other mercury mines and smelters, and our data confirm the high exposure levels in this occupational group, in particular at cinnabar pigment production, soot purification, and condenser cleaning, (C) 1998 British Occupational Hygiene Society. Published by Elsevier Science Ltd.