Perfluoroalkyl substances (PFASs) such as perfluorocarboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs) have been widely used in high-tech industries and consumer products in which need their water-proof and oil-resistant properties. Because of their environmental persistency, they have been found ubiquitous in wild animals and can bioaccumulate in the food chain. PFASs could disrupt reproductive and immune functions.
Although there are some reports on concentrations of PFASs in food, most of them focus on seafood and meat rather than staples. In addition, people in East and Southeast Asia may consume less meat and wheat but more rice and seafood comparing to the Western countries. A team led by Dr. Chia-Yang Chen at the National Taiwan University College of Public Health, surveyed eight PFASs in 14 types of food in Taiwan using ultra-performance liquid chromatography/tandem mass spectrometry between September 2010 and April 2011, in the total of 140 samples. PFCAs were detected in 90-100 percent of the food items, with the highest geometric means (GM) of perfluorooctanoic acid (PFOA) ranging from 5.73 ng/g (eggs, n = 10) to 12.1 ng/g (beef, n = 10). Long-chain PFCAs tended to accumulate more in eggs, pork liver, and seafood than in cereals andnmeat.
Taiwanese consume a comparable amount of meat to those in European Union and North America, but eat much more rice. The estimated total ingestion of PFASs for the general population were mainly from rice (2.4 mg/day, 20.1 percent), pork (1.8 mg/day, 15.0 percent), and eggs (1.6 mg/day, 14 percent).
Taiwanese are exposed to much higher PFCAs (4.5-85.1 ng/kg b.w./day) than people in western countries (0.34-70.0 ng/kg b.w./day). Perfluorohexanoic acid (PFHxA) and PFOA in rice (GM 1.10 and 8.90 ng/g, respectively) and in flour (GM 1.33 and 8.84 ng/g, respectively) observed in this study were two to three orders of magnitude higher than those reported for cereals in Sweden (0.004-0.062 ng/g). PFOA in meats (GM 8.78-12.1 ng/g) in this study were also two orders of magnitude higher than those in Spain, Italy, and Norway (not detectable to 0.1 ng/g).
Pregnant women at the 95 percent upper limit exposed to total PFASs from pork liver (740 ng/person/day) were at least two orders of magnitude higher than that of the general population (4.17 ng/person/day); especially, their intake of perfluorooctane sulfonate (PFOS) (1.33 ng/kg b.w./day) is about 320-fold higher the general population. This study noted that pork liver tends to accumulate C10-C12 PFCAs and PFOS. Pork liver is a specialty food commonly consumed by pregnant and postnatal women in Taiwan; The high amount of PFASs in pork liver may pose health risks to pregnant women, and these compounds could be transmitted to their offspring.
July 2018. “Concentrations of perfluoroalkyl substances in foods and exposure through ingestion among the general population and pregnant women in Taiwan“. Journal of Food and Drug Analysis, 26 (3): 994-1004.