The relationship between blood lead levels and occupational exposure in a pregnant population.

BACKGROUND: Pregnant women exposed to lead are at risk of suffering reproductive damages, such as miscarriage, preeclampsia, premature delivery and low birth weight. Despite that the workplace offers the greatest potential for lead exposure, there is relatively little information about occupational exposure to lead during pregnancy. This study aims to assess the association between blood lead levels and occupational exposure in pregnant women from Durango, Mexico. METHODS: A cross-sectional study was carried out in a population of 299 pregnant women. Blood lead was measured in 31 women who worked in jobs where lead is used (exposed group) and 268 who did not work in those places (control group). Chi-square test was applied to compare exposed and control groups with regard to blood lead levels. Odds ratio (OR) and 95% confidence intervals (CI) were calculated. Multivariable regression analysis was applied to determine significant predictors of blood lead concentrations in the exposed group. RESULTS: Exposed women had higher blood lead levels than those in the control group (4.00 ± 4.08 µg/dL vs 2.65 ± 1.75 µg/dL, p = 0.002). Furthermore, women in the exposed group had 3.82 times higher probability of having blood lead levels ≥ 5 µg/dL than those in the control group. Wearing of special workwear, changing clothes after work, living near a painting store, printing office, junkyard or rubbish dump, and washing the workwear together with other clothes resulted as significant predictors of elevated blood lead levels in the exposed group. CONCLUSIONS: Pregnant working women may be at risk of lead poisoning because of occupational and environmental exposure. The risk increases if they do not improve the use of protective equipment and their personal hygiene.

Relationship between blood lead levels and hematological indices in pregnant women.

Several studies have revealed a negative association between blood lead levels and hematological impairment. In this cross-sectional study, we examined the relationship between blood lead levels and hematological indices in 292 pregnant women from Durango, Mexico. Apparently healthy pregnant women, aged 14-41 years and at 3-41 weeks of gestation, were recruited between June 2007 and May 2008. Blood lead and hematological indices were measured. The mean blood lead was 2.79 ± 2.16 µg/dL, and lead levels ≥ 5 µg/dL were detected in 25 women (8.6%). Hemoglobin, hematocrit, and red blood cells count were significantly higher in pregnant women with a blood lead concentration of ≥ 5 µg/dL than the group with lower blood lead levels (p < .05). Mean corpuscular volume and mean corpuscular hemoglobin were not significantly related to lead levels. Hemoglobin and hematocrit showed a non-significant positive correlation with blood lead, but the correlation between red blood cell count and blood lead levels was statistically significant (r = 0.185, p = .002). The findings suggest that a positive association between blood lead and some hematological indices may occur at relatively low blood lead concentration (mean < 5 µg/dL).