Prenatal lead exposure animal studies

In contrast to the animal studies for prenatal exposure, animal studies for postnatal exposure report effects at blood lead levels similar to those associated with effects in humans. 

Animal studies support he human evidence of neurobehavioral toxicity from prenatal exposure to low levels of lead. In an extensive review of the literature, Davis et al. (1990) discussed similarities between human effects and those in animals. The authors concluded that qualitatively "... the greatest similarities between human and animal effects involve cognitive and relatively complex behavioral processes such as learning." They further reported that quantitative relationships for PbB levels across species that cause developmental neurobehavioral effects are 10-15 pg/dL in children, <15 pg/dL in primates, and <20 pg/dL in rodents. 

There is some evidence from animal studies that cannabis can lead to reduced sperm production and impaired ovulation (Bloch, 1983). Furthermore, it has been reported that prenatal exposure to cannabis leads to significant impairment of... 

Reproductive effects from lead exposure have been documented in animals and human beings of both sexes. High occupational exposure levels in pregnant women have been associated with increased incidences of spontaneous abortions, miscarriages, and stillbirths. Some studies also seem to indicate that prenatal exposure to lower levels of lead may increase the risk of preterm delivery and reduced birth weight. Lead penetrates the placental barrier and has caused congenital abnormalities in animals. There is no conclusive evidence, however, that low-level lead exposure leads to an increased incidence of... 

As to other prenatal effects, lead certainly appears toxic to the fetus, although intrauterine exposure is generally believed to be at a low level. In a study by Barltrop (1969) only about 300/tg of lead was found in the fetus at term. Measurements of lead in amniotic fluid show a concentration of less than 20 ng/100 ml, i.e. below the limits of detection for the analytical method used (Kubasik and Volosin, 1972). However, lead is shown to be present in the fetus at all stages of development, and this may be of greater importance than the presence of a given load at term. The distribution of radiolabelled lead in embryonic animals indicates that all major organ systems are exposed (Carpenter, 1974). 

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