Globally Pervasive Class of Chemicals Linked to Cancer and Liver Damage

 A study published last week in the Journal of Hepatology found that high levels of perfluorooctane sulfonic acid (PFOS) were associated with an increased risk of hepatocellular carcinoma. The research conducted by the Keck School of Medicine and funded by the NIH looked at tissue and blood samples from more than 200,000 people living in Hawaii and California and identified 50 cases of hepatocellular cancer — the most common form of liver cancer — that were linked to high polyfluoroalkyl substances (PFAS) exposure.  

Researchers used the human samples previously collected in a large epidemiological study to identify 50 people who had developed liver cancer. They then compared the PFAS concentrations in their tissue and blood samples with those of 50 people who did not develop cancer. Blood samples yielded several types of PFAS for the individuals who developed cancer. Researchers concluded that subjects in the top 10% of PFAS exposure were 4.5 times as likely to develop liver cancer than those with the lowest levels of PFAS exposure. 

The team also assessed the mechanisms by which PFAS class chemicals disrupt normal liver function in humans. Using the same samples in the large epidemiological study, they found evidence showing that PFAS alters normal glucose metabolism, bile acid metabolism, and amino acid metabolism. These findings build on another USC study earlier this year that linked PFAS to liver problems and found that fatty liver disease was associated with high PFAS exposures.  

PFAS are included in various consumer products and are still used by manufacturers for industrial and commercial purposes. Their pervasive and long-lasting nature has led to them ending up in the blood of virtually all adults in the United States. It’s estimated that PFAS can last up to eight years inside the human body. 

One recent study revealed that PFAS are so prevalent they can be found at unsafe levels in rainwater across the globe. The study conducted in Sweden exposed that Environmental Protection Agency (EPA) lifetime drinking advisories based on human epidemiology studies have now been exceeded in rainwater analyses, indicating that PFAS have infiltrated the global water cycle and will become more prevalent in freshwater overtime.  

Despite regulation from federal and state authorities, PFAS-contaminated drinking water is rampant in the US and throughout the world. Leaders are now focusing on strengthening environmental protections for citizens and funding environmental justice projects, but it will be challenging to reverse much of the damage already done.