The chemicals that make plastic and vinyl more flexible - phthalates - have long been linked to adverse health events and are part of a group of endocrine disruptors, which interfere with the body's hormone system. Phthalates can be found in nail polishes, cosmetics, perfumes, lotions, car interiors, floor tiles, raincoats, synthetic leathers, food packaging, and shampoos and are used to carry fragrance, increase product flexibility and durability, coat time-release medications or supplements, and are used as solvents.

A new study has found that the ubiquitous chemical might harm children's mental and behavioral development as well as their muscular coordination, said WebMD, citing a study published in the journal, Environmental Health Perspectives. How phthalates adversely affect development is unclear; however, emerging evidence suggests phthalates affect thyroid hormone levels, which are important to prenatal and newborn brain development.

We recently wrote that phthalates were linked in a first-of-its-kind, large-scale study to impacts to thyroid function in humans. The research revealed that larger urinary phthalate metabolite levels were linked with increased impacts on serum thyroid measures and that there exists an "inverse" relationship between urine exposure markers and thyroid hormone levels. The most significant thyroid disruption link was with the plasticizer phthalate, DEHP, which is typically received through food.

The recent study, said WebMD, suggests that phthalates might reduce testosterone produced in the body, according to study researcher Robin M. Whyatt, DrPH, deputy director of the Columbia Center for Children's Environmental Health at Columbia University. Whyatt explained that being an important component in male sexual development, testosterone is important to the brain development in both boys and girls.

This study was the first to look at how phthalates affect preschoolers and Whyatt and her team looked at 319 children born between 1999 and 2006, said WebMD. Four phthalates were measured during pregnancy and children were evaluated at age three. Two phthalates - Mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP) - were significantly linked to muscular coordination development delays that increased with increased phthalate concentrations.

In girls, there was a link between MnBP and mental development delays; boys showed a link to withdrawn behavior and increased mood changes, panic, whining, and worrying, wrote WebMD. Mono-benzyl phthalate (MBzP) was linked to anxious and depressed behavior and, in girls, to headaches and stomachaches. "I was surprised and pretty depressed, particularly by the behavioral problems," Whyatt said. "We didn't expect to see that at all, but it was a consistent pattern and highly significant.... These are really consistent findings right down the line," she noted, wrote WebMD. She also noted that "17.6% of children in our study evidenced risk of motor [muscular coordination] delay; 27.9% evidenced risk of mental delay and 12.9% were in the clinical range for internalizing behaviors," in an email to WebMD.
"No matter how you characterize it, these proportions are concerning."
Research has also revealed that exposure to phthalates in young girls can result in disruption in pubertal development, which can lead to later complications; can cause negative behaviors in young children; have been linked to breast enlargement in boys; have been linked to ADHD; and, in pregnancy, to the birth of boys who express less typically masculine behaviors and to an increase in premature births. Phthalates have also been found to exacerbate dermatitis in tests with mammals. Some studies linked phthalate exposure to effects on the development of the male reproductive system: Infertility, undescended testes, and testicular development; penis and other reproductive tract malformations, such as hypospadias; and reduced testosterone levels. Some phthalates have been associated with liver cancer and problems with the developing fetus and are known to interfere with androgens.