Danish girls develop breasts before the age of eight according to Professor Anders Juul and his colleagues at Rikshospitalet, Copenhagen. Juuls’s study includes 2000 Danish schoolgirls over a 15-year period between 1991 and 2006. The study evaluates the evolution of sex hormones in blood samples and phthalates in urine samples. Phthalates are hormone disrupting chemicals used as softeners in plastics and found in shampoos, shower creams, nail polish, perfumes, plastic mats and laundry detergents. Traces of phthalates existed in the urine of all girls tested. Animal tests show that phthalates interfere with animal reproduction.
Puberty onset has been found to occur earlier and earlier – especially among girls. This has been observed, first in the US in the mid-1990s and now also in Europe. The development of breast tissue in girls occurs at a much younger age and the incidence of precocious puberty (PP) is increasing. Genetic factors and increasing prevalence of adiposity may contribute, but environmental factors are also likely to be involved. In particular the widespread presence of endocrine-disrupting chemicals (EDCs) is suspected to contribute to the trend of earlier pubertal onset.