Excretion kinetics and variability of urinary mercury in workers exposed to mercury vapour

Abstract

Summary Determinations of mercury in urine were made in samples collected from workers that were: (a) exposed prior to sampling urine has been sampled over 3 weeks'post-exposure period; (b) currently exposed sampling on consecutive days of the working week; (c) currently exposedurine sampled over 24 hrs, during working shift (morning or afternoon) and off work. Regardless of exposure time pattern in all groups studied, a diurnal variation of urinary concentrations of mercury was observed with a maximum at night and morning hours, and minimal values in the afternoon The great variability in Hgconcentrations could have been related to the time of day at which the sampling took place, and partly to variation of urine excretion rate, the 2 factors being interrelated Only a moderate variability in urinary concentrations of mercury was found when the sampling was instituted at a constant time of day, and when the results were standardized for specific gravity of urine.

Individual mercury exposure of chloralkali workers and its relation to blood and urinary mercury levels.

“…Piotrowsky et al (13) found that urinary mercury levels are generally high at night and in the morning and low in the afternoon, independent of the diurnal rhythm of exposure. This variation may explain the lowness of the ratio of urinary mercury to blood mercury in our investigations when compared to others (table 4).…”

Intoxicación ocupacional por mercurio

“…Entre otros, la ACGIH (Conferencia Gubernamental Americana de Higienistas Industriales) establece el valor de los indicadores biológicos de exposición (BEIs, por sus siglas inglesas) en trabajadores expuestos: 1) mercurio inorgánico total en muestra de orina tomada antes de la jornada laboral: 35 μg/g creatinina; y, 2) mercurio inorgánico total en muestra de sangre tomada al final de la jornada diaria o al fin de semana laboral: 15 μg/L (21,22) . En exposición ocupacional, se recomienda dosar mercurio en orina de 24 horas; y, en exposición aguda accidental, preferir su dosaje en sangre (23,24) . En todos los casos, un programa de gestión de salud ocupacional para el riesgo mercurio debe iniciarse con su valoración en el ambiente de labor.…”

“…-Mercurio inorgánico total en sangre: menor a 15µg/L, en muestra tomada al final de la jornada diaria o al fin de semana laboral (21,22) . -En exposición ocupacional, se recomienda medir mercurio en orina de 24 horas, mientras que en exposición aguda o accidental se debe preferir su dosaje en sangre (23,24) . -Para valoración de la función renal, la vigilancia médica debe hacerse con indicadores precoces de daño renal, como la excreción de ß 2 microglobulina, N-acetil-D-glucosaminidasa (NAG) o ß galactosidasa (5,25,29,30) .…”

Occupational and Environmental Toxicology of Mercury and Its Compounds.

“…Moreover, little dietary methylmercury is excreted in the urine, rendering the contribution of ingested methylmercury less significant. Although good correlation has been observed between urinary mercury levels and air levels of mercury vapor, such correlation was obtained after adjusting data for creatinine or specific gravity and after standardizing the amount of time elapsed after exposure 77) , as considerable intra-and inter-individual variability has been observed in the urinary excretion rate 81,82) .…”