A new study has added more evidence that prenatal exposure to the ubiquitous plastic-softening chemicals known as phthalates can produce genital malformation in male children. The study was conducted by researchers from Mount Sinai Hospital in New York and published in the journal Human Reproduction on February 19.
Numerous other studies have suggested that phthalates may damage the development of the male reproductive tract. In addition to plastics, the chemicals are widely used in lotions, perfumes and other cosmetics, as well as food packaging and medical supplies. They have been conclusively established as endocrine disruptors, meaning that they disrupt the normal function of the body’s hormonal system.
Phthalates have also been linked with damage to the nervous system.
Changes linked with adult reproductive problems
The study was conducted on more than 700 pregnant women and their children, from four U.S. cities. The researchers took samples of the women’s urine during the first trimester of pregnancy — the time period when the fetal reproductive tract is starting to develop — and measured levels of 11 different phthalate metabolites. They found that newborn boys who had been exposed in utero to the highest levels of the phthalate known as diethylhexyl phthalate (DEHP) had an anogenital distance 4 percent shorter than boys exposed to the lowest DEHP levels.
Anogenital distance (the length between the anus and the genitals) is a marker of reproductive health. Because anogenital distance tends to be 50 to 100 percent longer in males than in females, researchers believe that a shorter anogenital distance in males might be a sign of incomplete masculinization — an effect consistent with phthalates’ proven ability to mimic estrogen in the body. Prior studies have also shown that phthalatesincluding DEHP may block the testes from producing male sex hormones.
No connection was found between anogenital distance and exposure to the 10 other phthalates. No connection was found in newborn girls.
It is still unknown whether the shortened anogenital distance seen in the current study could lead to other health problems, or whether it is a non-causative marker of such changes. It is also unclear whether the change was permanent or the boys’ anogenital distance would normalize as they matured.
Studies in animals have, however, connected shortened anogenital distance at birth with later reproductive problems, and human studies have linked it to eventual semen problems and testicular abnormalities.
Phthalates are everywhere, but you can still reduce exposure
Though, three phthalates, including DEHP, were banned from U.S. children’s products in 2008, the chemicals are still ubiquitous. Lead author Shanna Swan noted that, based on the new study and studies she conducted in 2000-2002, 2005 and 2008, DEHP exposure has consistently been dropping. Yet even the lesser exposure now found still seems to produce health effects.
“We are finding a significant association between male anogenital distance and phthalates at lower and lower levels, which suggests that there may be no safe level of exposure,” she said.
In addition, many other phthalates are still used in consumer and industrial products at high levels. A June 2014 study in the journal Environmental Health showed that a young child eating a typical U.S. diet is exposed to twice the phthalate levels considered safe by the Environmental Protection Agency from food and food packaging sources alone.
So what is a concerned parent or consumer to do? Swan suggests avoiding processed foods, which are more likely to come into contact with phthalates. In addition, a 2010 study found that eating a vegetarian diet for just five days led to an immediate and dramatic drop in phthalate levels in the urine.