A study carried out in rural Bangladesh found that higher prenatal exposure to cadmium was significantly associated with IQ at age of five. Children in the 95th percentile of cadmium exposure before birth scored 2.7 IQ-points less than children in the lowest 5 percent. The cadmium exposure was at levels found in many countries, but two to three times lower than in the U.S. (0.63µg/l compared to 0.21µg/l).
Cadmium is known to be a neurotoxin and can cross the placenta. The researchers assume that in Bangladesh the main source of exposure is the rice-based diet. The study had examined 1305 women in Bangladesh in their eighth week of gestation. The babies were all born between 2002 and 2003.
The heavy metal cadmium is present naturally in soils and water in some regions but can also be found in a number of applications and processes. As such glass food packaging material may be contaminated with cadmium and it may be used as a stabilizer in plastic food contact materials.
Maria Kippler, et al. (2012). Early-Life Cadmium Exposure and Child Development in 5-Year-Old Girls and Boys: A Cohort Study in Rural Bangladesh. Environmental Health Perspectives 120(10): 1462–1468. Published online 2012 July 3. doi: 10.1289/ehp.1104431