Blood lead at currently acceptable levels may cause preterm labour.

OBJECTIVES: Although occupational and environmental exposures to lead have been dramatically reduced in recent decades, adverse pregnancy outcomes have been observed at 'acceptable' levels of blood lead concentrations (≤ 10 µg/dl). METHODOLOGY: Blood samples were collected from 348 singleton pregnant women, aged 16-35 years, during the first trimester of pregnancy (8-12 weeks) for lead measurement by inductively coupled plasma-mass spectrometry. Subjects were followed up and divided into two groups (preterm and full-term deliveries) according to duration of gestation. RESULTS: The average (range) and geometric means of blood lead levels were 3.8 (1.0-20.5) and 3.5 µg/dl, respectively. Blood lead level was significantly (p<0.05) higher in mothers who delivered preterm babies than in those who delivered full-term babies (mean±SD: 4.46±1.86 and 3.43±1.22 µg/dl, respectively). Logistic regression analysis demonstrated that a 1 unit increase in blood lead levels led to an increased risk of preterm birth (OR 1.41, 95% CI 1.08 to 1.84). CONCLUSION: Adverse pregnancy outcomes may occur at blood lead concentrations below the current acceptable level.

Status of occupational health and safety in Iran.

In recent decades, Iran has had a steadily growing economy with an annual rate of 6% on average. The country's economy is dominantly influenced by oil and natural gas production and related industries like petrochemicals and fertilizers. There are two million job units and sixteen million employees. The occupational health and safety (OHS) system is mainly regulated by two bodies: the Ministry of Health and Medical Education, responsible for occupational health services and legislations; and the Ministry of Labour and Social Affairs, which undertakes the enactment and enforcement of occupational safety legal issues. Inspectorates in each ministry carry out regular health and safety monitoring according to the OHS legislations. The most common occupational health disorders are musculoskeletal problems, respiratory diseases, noise induced hearing loss, and occupational injuries. Because the OHS is a complex system with overlapping responsibilities among the co-responders, its improvement needs well-organized collaboration among Iranian universities, industries, and governmental agencies, and reliable basic data. The present study takes a glance at the situation and activities of the Iranian OHS system.

Blood manganese concentrations and intrauterine growth restriction.

To assess the relationship between blood concentrations of manganese (Mn) and intrauterine growth restriction (IUGR), Mn levels in the umbilical cord blood (UCB) and the mother whole blood (MWB) samples were measured in apparently healthy mothers and their newborns. Measurement was conducted by an inductively coupled plasma mass spectrometry. Manganese concentrations in MWB were significantly lower (p<0.01) in IUGR cases than in appropriate for gestational age (AGA) cases (mean+/-S.D.; 16.7+/-4.8 and 19.1+/-5.9 microg/l, respectively). Conversely, UCB concentrations of Mn were significantly higher (p<0.05) in IUGR newborns than AGA newborns (44.7+/-19.1 and 38.2+/-13.1 microg/l, respectively). Logistic regression analysis demonstrated significant relationships of the mother whole blood and the umbilical cord blood concentrations of Mn in IUGR cases (OR=0.868, 1.044, respectively). The study suggests that manganese concentrations in MWB and UCB might induce different effects on birth weight in healthy mothers. Because intrauterine growth restriction is a multi-factorial problem, further epidemiological and clinical studies on larger numbers of subjects are needed to confirm the findings in the present study.