PFAS, Personal Care Products & Infants

Results of a study published in Environment International suggest that the use of personal care products (PCPs) increases plasma levels of per- and polyfluoroalkyl substances (PFAS) among pregnant women, as well as PFAS levels in the milk of lactating women living in Canada. The data for this study was provided by the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a prospective cohort study that enrolled over 5,000 pregnant women from 10 cities across Canada between 2008 and 2011. This analysis included data from almost 1,900 women who provided plasma samples and nearly 650 who provided milk samples post-partum. Women were also asked about their use of PCPs, such as hair dyes/relaxers, perm solutions, hair sprays or gels, nail care products, makeup, fragrances and perfumes, and lotions or moisturizers. Multiple PFAS were analyzed, with plasma sampled for levels of PFOS (perfluorooctane sulfonic acid), PFOA (perfluorooctanoic acid) and PFHxS (perfluorohexane sulfonic acid), and breastmilk sampled for two PFOS isomers (Sm-PFOS and n-PFOS), PFOA, PFHxS, as well as PFNA (perfluorononanoic acid), PFBA (perfluorobutanoic acid), and PFHxA (perfluorohexanoic acid).

Many of the types of PCPs used by pregnant women were found to increase the risk for both plasma and breastmilk PFAS levels. For example, more frequent use in the 1st trimester of hair spray or gel, nail care products, and fragrances and perfumes were all associated with higher plasma PFOS concentrations when compared to “never use” of these products. Similarly, women who dyed their hair two or more times during pregnancy had higher levels of Sm-PFOS, PFOA, and PFNA in their breast milk than women who did not, with similar increases associated with nail care products. While usage of most PCPs correlated with PFAS levels, a few did not; no PCPs were associated with human milk n-PFOS or PFHxS levels. It’s important to note that despite the large number of PFAS tested in this study, there are many other types of PFAS that were not measured and which could also have been elevated as a consequence of PCP use.

Previous studies that measure the PFAS levels within the products themselves (vs. the plasma or milk of people using them) found that they are widespread and at high levels within PCPs, yet most products do not have labels indicating the presence of fluorinated compounds. One estimate suggests that the cosmetics sold in California alone, over a one-year period, account for at least 4% of the perfluoroalkyl acids found in wastewater and as much as 56,000 kg of total PFASs.

PFAS have been associated with a wide range of harmful health outcomes, including those related to infancy and childhood. A systematic review of 46 studies concluded that PFAS are linked to an increase in risk for multiple birth outcomes, adversely affecting birth weight and length, head circumference, preterm birth risk, and risk for small-for gestational age. Another systematic review of 29 studies (with over 32,000 participants) concluded that some PFAS were linearly associated with increased preterm birth risk, as well as the risk of preeclampsia and miscarriage. Indeed, a nested case-control study within a large Danish birth cohort found that miscarriage was more than two times as likely among women in the highest quartile of plasma of PFOA compared to those in the lowest (collected around the 8th week of gestation), and nearly twice as likely for the highest PFHpS plasma levels. Data from the Shanghai Birth Cohort, including nearly 2,800 pregnant women, suggests that multiple PFAS are associated with an increased risk for gestational diabetes and high glucose levels (both fasting and post-prandial), with particularly prominent effects among women with a non-elevated pre-pregnancy BMI. Data from the Nurses' Health Study II suggests a 54-62% higher risk for type 2 diabetes among women in the highest tertiles of plasma PFOS or PFOA. Evidence is also beginning to suggest there may be metabolic dysfunction among infants as young as 6 months old, related to PFAS toxicity, potentially raising the likelihood of diabetes later in life.

PFAS have also been associated with liver injury among adults, marked by elevated liver enzyme and gamma-glutamyl transferase levels, reported in a systematic review of 24 epidemiological studies. They’ve been linked to kidney dysfunction, chronic kidney disease, and kidney cancer in an analysis of 169 studies, with multiple mechanisms for kidney toxicity. PFAS are generally lipophilic and known to accumulate in lipid-rich tissues, including the brain and central nervous system. Some PFAS have been associated with chronic obstructive pulmonary disease as well as impaired cardiovascular health among adults participating in the National Health and Nutrition Examination Survey (NHANES).

A subset of NHANES included 639 children between the ages of 3-11. Every single child had detectable levels of n-PFOA, n-PFOS, Sm-PFOS, PFHxS, and PFNA. This was true for children born after companies voluntarily discontinued production of PFOS precursors, highlighting how prevalent and persistent these compounds are. This latest study clearly shows the connection between PCPs and exposure to both mothers and their nursing infants, and should prompt both a demand for cleaner products, and avoidance of existing products if they cannot be proven safe.