We’ve posted scores if not hundreds of items warning about the serious public health threat posed by the plastics that serve as one of the foundations of modern life.
Now comes word that not only does a plastic often used in food packaging and children’s toys and drinking vessels cause deformation in the genitals of young boys; it can also alter the genes of infants in the womb.
Exposure during early pregnancy to some phthalates—man-made chemicals commonly found in household plastics, food and personal care products—can have adverse impacts on developing fetuses, according to a new study led by Dr. Sheela Sathyanarayana, a pediatric environmental health specialist at Seattle Children’s Research Institute and associate professor at the University of Washington.
The study [ a staggering $42 to read], published in The Journal of Clinical Endocrinology & Metabolism, found that increases in exposure to certain phthalates during the first trimester of pregnancy was associated with higher estrogen concentrations and lower testosterone concentrations in the fetus, thus increasing the chance of a genital abnormality in male babies at birth.
The study reinforces that some phthalates are endocrine disrupting chemicals (EDCs) and can alter concentrations of naturally-produced hormones, which help regulate and control different cells and organs in the body. Sathyanarayana’s previous research has directly linked fetal exposure to diethylhexyl phthalate (DEHP) to the development of genital abnormalities and increased risk of future reproductive health issues in boys.
Sathyanarayana sat down with On the Pulse to discuss the key findings of the study:
Q: What are the new, significant findings from this study?
We found that increases in phthalate exposure in early pregnancy was associated with higher estrogen concentrations (MBzP, DEHP, MiBP) and lower testosterone (MCNP and DEHP) concentrations. In other words, the phthalates were associated with increases in female hormones and decreases in male hormones. We also found that having higher testosterone in pregnancy was associated with a lower chance of having a male baby with a genital abnormality, which means that anything that reduces testosterone, like the hormone DEHP, will increase chances of having a male baby with a genital abnormality.
Q: How is that different from your most recent published study on phthalates?
The study I published previously showed the link between phthalates and male genital abnormalities in the male reproductive track. This study looks at one of the possible causes of the genital abnormalities—changes in hormone concentration. One of the biggest criticisms of epidemiology, which studies the causes and effects of health issues in a specific population, is that we identify associations but we don’t really know how or why those associations occur.
Another big take-home point is that there is little evidence in humans that EDCs actually affect endocrine pathways. This is some of the strongest evidence showing that these chemicals actually do affect endocrine pathways.
Q: Why would it matter that someone’s endocrine system is affected?
Our endocrine systems control all the hormones in our body. Hormones are essential for us to live. Estrogen is vital for female reproductive function, as well as mental and cardiovascular health, which is a point that people sometimes miss. Estrogen and testosterone are not only for reproductive development. If you don’t have proper levels of estrogen or testosterone, your mood, your cardiovascular health will be affected. Our hormones keep us balanced every day.