The potential for endocrine system disruption is of great concern, especially in early life, when developmental programming of organ systems is susceptible to permanent and lifelong disruption. The international medical and scientific communities have called attention to these issues in several recent landmark reports, including a scientific statement from the Endocrine Society in 2009,42 which was updated in 2015 to reflect rapidly accumulating knowledge3; a joint report from the World Health Organization and United Nations Environment Program in 201343; and a statement from the International Federation of Gynecology and Obstetrics in 2015.44 Chemicals of increasing concern include the following:
bisphenols, which are used in the lining of metal cans to prevent corrosion45;
phthalates, which are esters of diphthalic acid that are often used in adhesives, lubricants, and plasticizers during the manufacturing process17;
nonpersistent pesticides, which have been addressed in a previous policy statement from the American Academy of Pediatrics and, thus, will not be discussed in this statement46;
perfluoroalkyl chemicals (PFCs), which are used in grease-proof paper and packaging47; and
perchlorate, an antistatic agent used for plastic packaging in contact with dry foods with surfaces that do not contain free fat or oil and also present as a degradation product of bleach used to clean food manufacturing equipment.48
Additional compounds of concern discussed in the accompanying technical report include artificial food colors, nitrates, and nitrites.
Environmentally relevant doses (ie, low nanomolar concentrations that people are likely to encounter in daily life) of bisphenol A (BPA)4 trigger the conversion of cells to adipocytes,9 disrupt pancreatic β-cell function in vivo,49 and affect glucose transport in adipocytes.9–11 Phthalates are metabolized to chemicals that influence the expression of master regulators of lipid and carbohydrate metabolism, the peroxisome proliferator-activated receptors,21 with specific effects that produce insulin resistance in nonhuman laboratory studies. Some studies have documented similar metabolic effects in human populations.22 Some phthalates are well known to be antiandrogenic and can affect fetal reproductive development.18,19,50 Authors of recent studies have linked perfluoroalkyl chemicals with reduced immune response to vaccine27,28 and thyroid hormone alterations,29,51,52 among other adverse health end points. Perchlorate is known to disrupt thyroid hormone34 and, along with exposures to other food contaminants, such as polybrominated diphenyl ethers,53–55 may be contributing to the increase in neonatal hypothyroidism that has been documented in the United States.56 Artificial food colors may be associated with exacerbation of attention-deficit/hyperactivity disorder symptoms.57 Nitrates and nitrites can interfere with thyroid hormone production40 and, under specific endogenous conditions, may result in the increased production of carcinogenic N-nitroso compounds.37,38