Correlación de protoporfirina zinc y plomo en sangre en trabajadores de fábricas de baterías, de Bogotá, Colombia

Objective. To determine the usefulness of zinc protoporphyrin in blood (PPz) as an indicator of lead exposure in workers of the homemade car battery industry. Material and methods. A cross-sectional study was performed in 116 workers of the car battery industry in Bogotá, Colombia. Data on general, occupational, and health variables were collected by interview. Two categories of PPz values were established: Those below the cutoff value (70 μg/dL) and those above it. A linear regression analysis was performed to measure the correlation between logarithm values of PPz (>70 μg/dL) and lead in blood (PbB) (>38 μg/dL). Results. A semi-logarithmic correlation coefficient of r=0.54 was found, and statistically significant associations between high levels of PPz and direct exposure to lead were observed (OR:3.35, 95% IC 1.02-11.91; p:0.02); for workers who often use lead as a raw material (OR:7.80, 95% IC 2.96-21.03; p<0.01), as well as for workers who do not change work clothes often (OR:3.55, 95% IC 1.17-11.01; p<0.01). Conclusions. PPz may be a useful diagnostic indicator for lead poisoning; it may also be used as a screening test for surveillance programs in the biological monitoring of workers exposed to lead.