Urinary nickel as bioindicator of workers' Ni exposure in a galvanizing plant in Brazil.
OBJECTIVE
We measured urinary nickel (U-Ni) in ten workers (97 samples) from a galvanizing plant that uses nickel sulfate, and in ten control subjects (55 samples) to examine the association between occupational exposure to airborne Ni and Ni absorption.


METHODS
Samples from the exposed group were taken before and after the work shift on 5 successive workdays. At the same time airborne Ni (A-Ni) was measured using personal samplers. Ni levels in biological material and in the airborne were determined by a graphite furnace atomic absorption spectrometry validated method. In the control group the urine samples were collected twice a day, in the before and after the work shift, on 3 successive days.


RESULTS
Ni exposure low to moderate was detected in all the examined places in the plant, the airborne levels varying between 2.8 and 116.7 micrograms/m3 and the urine levels, from samples taken postshift, between 4.5 and 43.2 micrograms/g creatinine (mean 14.7 micrograms/g creatinine). Significant differences in U-Ni creatinine were seen between the exposed and control groups (Student's t test, P < or = 0.01). A significant correlation between U-Ni and A-Ni (r = 0.96; P < or = 0.001) was detected. No statistical difference was observed in U-Ni collected from exposed workers in the 5 successive days, but significant difference was observed between pre- and postshift samples.


CONCLUSIONS
Urinary nickel may be used as a reliable internal dose bioindicator in biological monitoring of workers exposed to Ni sulfate in galvanizing plants regardless of the day of the workweek on which the samples are collected.
Oliveira
J P
JP
Escola de Farmacia e Odontologia de Alfenas, Departamento de Análises Clínicas, Alfenas, Brazil. marelisa@int.efoa.br
de Siqueira
M E
ME
da Silva
C S
CS
D000395:Air Pollutants, Occupational / Q000633:toxicity / Q000652:urine*; D001938:Brazil; D006801:Humans; D009532:Nickel / Q000633:toxicity* / Q000652:urine*
D000395:Air Pollutants, Occupational; C029938:nickel sulfate; D009532:Nickel