PFAS concentrations continued to increase in pups after weaning<\/a>\u00a0(Environ. Health 2026, DOI: 10.1021\/envhealth.5c00782).<\/p>\nThis \u201ccontamination in animals that are foraging way out in the middle of the ocean reflects a level of background contamination that\u2019s frankly terrifying,\u201d says Jane Khudyakov, a comparative physiologist at the University of the Pacific.<\/p>\n
In 2022, Khudyakov\u2019s team collected blood from 14 pairs of mothers and pups and milk from 9 of the mothers. The researchers searched these samples for specific PFAS molecules and identified 17 compounds in blood and 12 in milk. They also screened for other potential PFAS compounds, which turned up another 10 PFAS in both.<\/p>\n
Average total PFAS concentrations in nursing pups\u2019 blood were three times that of mothers, while weaned pups had nearly 90 ng\/mL of PFAS in their blood on average, around five times as high as that of mothers. \u201cWe think that\u2019s because mom is concentrating all of the PFAS in her milk and giving it to the pup during that relatively short period of lactation,\u201d says Kara Joseph, an analytical chemist working on the study with Erin Baker at University of North Carolina at Chapel Hill. After pups are weaned, they redistribute nutrients, which may push more PFAS into young animals\u2019 blood.<\/p>\n
The types of PFAS found in blood and milk varied, with one long-chain PFAS molecule found only in milk. \u201cIt\u2019s giving us a really interesting picture of exposure that we didn’t know just from the blood,\u201d Baker says. Concentrations in milk were 5.88 ng\/mL on average. Nursing could transfer over 1 mg of PFAS for pups whose mothers are exposed to a lot of pollution, the authors estimate.<\/p>\n
Concentrations in all the seals exceeded 2 ng\/mL, the level of PFAS below which health effects are not expected in people, and often surpassed the 20 ng\/mL threshold for increased health risks.<\/p>\n
It\u2019s not clear what health effects the high levels of PFAS have on seals, either adults or developing youngsters. The molecules can affect the immune system, so PFAS may hamper the pinnipeds\u2019 ability to withstand disease outbreaks, says Rainer Lohmann, an environmental chemist at the University of Rhode Island who was not involved in the study.<\/p>\n
In humans, PFAS also affect reproduction and kidney and liver function, and they dysregulate lipid metabolism, Joseph says. If the molecules mess with seals\u2019 lipids, this interference could cause major impacts. \u201cBeing able to effectively store and then release the fats from storage for energy is just critical,\u201d Khudyakov says. Females forage for much of the year, building up fat reserves, and they fast while they nurse, losing 60% of their body weight.<\/p>\n
The seal pups\u2019 early dependence on their mother\u2019s milk provides a way to study the maternal transfer of forever chemicals without the confounding effects of other foods. The findings could provide hints about what happens in humans, which Joseph and her colleagues are already starting to study.<\/p>\n
\u201cEverything that is being studied here is also relevant for human beings,\u201d says Carrie McDonough, an environmental chemist at Carnegie Mellon University who wasn\u2019t part of the work. \u201cWe do maternal offloading. Our babies, before they\u2019re even born, have PFAS in them. Our breast milk has PFAS accumulated in it as well.\u201d<\/p>\n
Taking milk samples is less invasive than drawing blood. But analyzing milk can be tricky. \u201cMost people tend to stay away from it because it is very complicated,\u201d Joseph says. She based her method for extracting PFAS on a US Department of Agriculture protocol developed for food and optimized it so she could measure PFAS in just 1 mL of these precious samples.<\/p>\n
\u201cIt\u2019s really good work,\u201d McDonough says. But she cautions against the authors\u2019 suggestion that PFAS accumulate in these animals because the molecules are lipophilic like many legacy persistent organic pollutants, or POPs. \u201cPFAS are such different molecules than a lot of those more well-studied molecules,\u201d she says. \u201cWe don\u2019t usually see a lot of them in fat.\u201d PFAS compounds act like surfactants and tend to accumulate in places where they have favorable hydrogen bonding, she says, and it\u2019s not clear what mechanism is behind the increase in blood levels of PFAS in pups after they fast. \u201cThere might be more-complex pathways, or maybe they are stored in fat and we just don\u2019t know.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"\u00a0 Northern elephant seal females and pups go through intense cycles of fueling and fasting. Thanks to extremely…\n","protected":false},"author":2,"featured_media":543971,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[273],"tags":[18,19,17,233348,50752,27826,38295,233347,233346,7400,167698,133,20324,461],"class_list":["post-543970","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-eire","tag-ie","tag-ireland","tag-lactation","tag-mammals","tag-marine","tag-milk","tag-persistant","tag-persistent-pollutants","tag-pfas","tag-pollutants","tag-science","tag-seal","tag-wildlife"],"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/543970","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=543970"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/543970\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/543971"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=543970"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=543970"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=543970"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}