Phthalates, chemicals that make plastics and vinyls more flexible, have been linked to many adverse health events. So much so, that stringent phthalate levels have been imposed as part of the Consumer Product Safety Improvement Act (CPSIA). Now, an emerging report found a link between phthalate concentrations in urine to attention-deficit/hyperactivity disorder (ADHD), reports Science Daily.

The new study, out of Korea and published by Elsevier in the November 15th issue of Biological Psychiatry, used computerized testing that measured attention and impulsivity levels and teacher-reported symptoms, said Science Daily. The team found a noteworthy link between phthalate metabolite levels in urine to ADHD test results and symptoms, with increased symptoms connected to increased levels, said Science Daily.

According to senior study author Yun-Chul Hong, MD, PhD, "these data represent the first documented association between phthalate exposure and ADHD symptoms in school-aged children." Also, the Editor of Biological Psychiatry, John Krystal, MD, said, "This emerging link between phthalates and symptoms of ADHD raises the concern that accidental environmental exposure to phthalates may be contributing to behavioral and cognitive problems in children. This concern calls for more definitive research."

The U.S. Centers for Disease Control and Prevention (CDC), in the Summary of its 2005 Third National Report on Human Exposure to Environmental Chemicals, stated that "very limited scientific information is available on potential human health effects of phthalates at levels" found in the U.S. population, said Science Daily. The study, conducted on a Korean population, is likely "comparable" to that in the U.S., Science Daily reported, noting that the Korean study findings, while not proving ADHD symptoms are caused by phthalate exposure, the study offers compelling evidence for more research.

The National Institute of Mental Health (NIMH) describes ADHD as involving difficulty staying focused, paying attention, and controlling behavior, and hyper- or over-activity.

Phthalates - phthalate ester and alcohol - is an organic compound mixed with synthetic rubber. Ubiquitous in a wide array of consumer products and industry, phthalates are found in cosmetics, personal care products, pharmaceuticals and medical devices, food packaging, and cleaning and building materials, noted the National Academy of Sciences previously. Phthalates can be found in pacifiers and rubber ducks, and foods. The compound is also found in, said Science Daily previously, flooring, cables, and packaging materials and, because of its broad use, can be introduced quite easily into the food chain and the human body. Another study found that even when adopting a healthy eating lifestyle, phthalates are difficult to avoid, reported Science Daily.

High phthalate levels during pregnancy were linked to the birth of boys who express less typically masculine behaviors; another study of pregnant women found some phthalates may contribute to this country's increase in premature births. Phthalates have been found to exacerbate dermatitis in tests with mammals. Some studies linked phthalate exposure in lab animals produced 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.