Urinary excretion of homovanillic acid in workers exposed to manganese

Abstract

Homovanillic acid, an end product of dopamine catabolism, and manganese (Mn) were measured in the urine of 68 male workers exposed to Mn-containing dust in a dry alkaline battery plant or an Mn oxide and salt producing plant, and in 35 control male subjects. The geometric mean of the airborne concentration of inhalable (total) dust amounted to 0.95 and 1.37 mg/m3 in the dry alkaline battery plant and the Mn oxide and salt producing plant, respectively. In the latter, a higher prevalence of increased values of urinary homovanillic acid concentration was found. In the total population, there was a low but statistically significant positive correlation between the concentration of homovanillic acid and Mn in urine (r = 0.20, P = 0.04) but there was no significant correlation between the level of homovanillic acid in urine and Mn in airborne dust or duration of exposure. This observation might be compatible with the stimulation of dopamine turnover in the brain, which has been observed in the early phase of Mn intoxication in animals. However, the large variability in urinary homovanillic acid excretion in control subjects precludes the use of this biological indicator to detect early interference of Mn with the dopaminergic system.

Biomonitoring of manganese in blood, urine and axillary hair following low-dose exposure during the manufacture of dry cell batteries

“…Most of these studies were focused on work areas in manganese re®ning, steel production and welding processes whereas low-exposure situations such as dry cell manufacturing have been surveyed less frequently (i.e. Emara et al 1971;Roels et al 1992;Buchet et al 1993). …”

Manganese exposure among smelting workers: blood manganese–iron ratio as a novel tool for manganese exposure assessment

“…Ellingsen et al (2003a,b) further suggested that the Mn-induced elevation of prolactin is generally within the reference limits and therefore is not suitable for use as a biomarker of Mn exposure. HVA, a catcholamine metabolite, is significantly increased in the urine of Mn-exposed welders (Ai et al 1998, Buchet et al 1993), yet a large fluctuation within control populations limits the use of HVA as an indicator of Mn exposure (Buchet et al 1993). …”

Autonomic Function in Manganese Alloy Workers

“…Biomarkers of autonomic dysfunction reported for manganism include assays of serum dopamine hydroxylase and platelet monoamine oxidase (Smargiassi et al, 1995), urine homovanillic acid (Buchet, 1993), and serum prolactin (Mutti et al, 1996). Hyperhidrosis is a common autonomic symptom in manganism but the quantitation of the sweat response has not yet been evaluated in lesser exposures.…”