Evaluation of urinary porphyrin excretion in neonates born to mothers exposed to airborne hexachlorobenzene

Abstract

The existence of a link between hexachlorobenzene (HCB) and porphyria cutanea tarda has been known for a long time. However, the epidemiologic data on effects on health caused by prenatal exposure have not provided convincing evidence that HCB alters porphyrin metabolism. Our objectives were to analyze urinary porphyrin excretion and HCB in maternal serum and fetal cord blood in neonates born in a village (Flix) near a chlorinated solvent factory, to detect possible adverse effects in urinary porphyrin excretion caused by prenatal exposure, and to assess their relationship with HCB blood levels. We conducted a cross-sectional study in the Porphyria Unit at a tertiary care facility in Barcelona, Spain, and the Pediatric Unit of the Móra d'Ebre Hospital, the reference hospital of the study area. We included in the study all neonates (n = 68) born in Móra d'Ebre Hospital 1997-1999 and their mothers. We obtained 68 urine specimens of singleton neonates on the third day after birth to test for urinary porphyrin excretion. We obtained 52 fetal cord blood and 56 maternal serum samples for HCB analysis. Total urinary porphyrins were quantified using spectrofluorometry. Porphyrin profile was determined by HPLC. Serum HCB was analyzed by gas chromatography coupled with electron capture detection. In total population, median HCB levels were 1.08 ng/mL in cord blood and 3.31 ng/mL in maternal serum. Total urinary porphyrin concentration was 37.87 micromol/mol creatinine. Coproporphyrin I and coproporphyrin III were the major porphyrins excreted. We found no positive relationship between urinary porphyrin excretion and HCB levels. However, we observed an association between maternal smoking and coproporphyrin excretion. Although high environmental levels of HCB are reported in the town of Flix, we found no alteration in urinary porphyrin excretion.