Blood lead levels (BLLs) and delta-aminolevulinic acid dehydratase (ALAD) activity are considered biomarkers of lead exposure and lead toxicity, respectively. The present study was designed to investigate the association between BLLs and ALAD activity in pregnant women from Durango, Mexico. A total of 633 pregnant women aged 13–43 years participated in this study. Blood lead was measured by a graphite furnace atomic absorption spectrometer. ALAD activity was measured spectrophotometrically. Mean blood lead was 2.09 ± 2.34 µg/dL; and 26 women (4.1%) crossed the Centers for Disease Control (CDC) recommended level of 5 µg/dL. ALAD activity was significantly lower in women with levels of lead ≥5 µg/dL compared to those with BLLs < 5 µg/dL (p = 0.002). To reduce the influence of extreme values on the statistical analysis, BLLs were analyzed by quartiles. A significant negative correlation between blood lead and ALAD activity was observed in the fourth quartile of BLLs (r = −0.113; p < 0.01). Among women with blood lead concentrations ≥2.2 µg/dL ALAD activity was negatively correlated with BLLs (r = −0.413; p < 0.01). Multiple linear regression demonstrated that inhibition of ALAD in pregnant women may occur at levels of lead in blood above 2.2 µg/dL.

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. 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. 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. 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.

This study was to evaluate whether selenium and vitamin-E counteract the toxic effects of arsenic on reproductive aspects and physiological conditions of male goats. Male goats [Criollo, n = 20, 4–5 yr-old, 72 kg live weight (LW)] were distributed in homogeneous groups (n = 5), and received during 12 weeks: (1) Sodium arsenite 2 mg/kg of LW/day (AG, LW = 69 kg); (2) Sodium selenite 6 mg + vitamin-E 420 I.U. every 14 days during the 12 weeks (SG, LW = 68 kg); (3) Both AG and SG treatments (ASG, LW = 77 kg); and (4) 1 mL of physiological solution every 14 days during the 12 weeks (CG, LW = 72 kg). The animals had access to water from a well with a concentration of 35 μg/L of arsenic. The SG had the highest percentage of sperm viability (80.6%) followed by the CG, ASG (74.7; p > 0.05), and AG (64.3; p ≤ 0.05). The ASG and SG had a lower heart rate as compared to the CG and AG (58.8, 58 vs. 65.4, 63.5; respectively, p ≤ 0.05). The CG and SG showed a lower respiratory rate than the AG and ASG (19.2, 18.7 vs. 22.1, 21.0, respectively; p ≤ 0.05). Selenium and vitamin-E were efficient in reducing the damage caused by sodium arsenite in sperm quality and maintaining heart and respiratory rates and increases in odor in male goats.