Chemicals ‘forever’ linked to liver cancer in first human study
There is growing evidence that regular exposure to “forever” man-made chemicals, which are used in a variety of household products, is linked to increased rates of cancer.
A new study that examined the correlation between liver cancer and the presence of these chemicals in humans found that those most exposed were 350% more likely to eventually develop the disease.
The term “forever” chemicals refers to the more than 4,700 available types of perfluoroalkyl and polyfluoroalkyl substances, or PFAS, widely used in manufacturing industries – so named because the substances degrade very slowly and build up over time. , in soil, drinking water and in the body.
PFAS were first introduced in the 1930s as a revolutionary material used in the creation of non-stick cookware – hello, Teflon – and soon suitable for all kinds of products and packaging – building materials to cosmetics – which benefit from its resistance to liquids and fire. Properties, as noted centers for disease control and prevention.
Although incredibly useful, these chemicals have since been linked to the onset of cancers and other diseases. in laboratory animals. Following strong anecdotal evidence that perfluorooctane sulfonic acids (PFOS) along with another common substance called perfluorooctanoic acid (PFOA) were making consumers sick, the Environmental Protection Agency in 2006 ordered eight multinational manufacturing companies represented in the United States to phasing out the use of these chemicals. Nevertheless, as their nickname suggests, PFOS and PFOA are still detected in foreign products, in groundwater and in people.
The current study, published in JHEP Reports, is the first to show a clear association between any PFAS and nonviral hepatocellular carcinoma (the most common type of liver cancer) in humans as well.
“It builds on existing research, but goes even further,” said Jesse Goodrich, postdoctoral researcher in public health at the Keck School of Medicine, in a press release from the University of Southern California. “Liver cancer is one of the most serious endpoints of liver disease and this is the first human study to show that PFAS are associated with this disease.”
Showing an association between PFAS and cancer in humans has not been easy for scientists.
“Part of the reason there have been few human studies is because you need the right samples,” added Veronica Wendy Setiawan, a professor at the Keck School of Medicine. “When you’re looking at environmental exposure, you need samples long before a diagnosis because cancer takes time to grow.”
To make this leap, the researchers had access to the Multiethnic Cohort Study database, which includes a survey of cancer development among more than 200,000 residents of Hawaii as well as Los Angeles, California, conducted by the University of Hawaii.
Their search was narrowed down to 100 survey participants – 50 of them with liver cancer and 50 without – whose available blood and tissue samples were sufficient for analysis. The researchers were looking for traces of chemicals that were “forever” present in the body before the cancer-stricken group fell ill.
They reportedly found multiple types of PFAS among the participants, with PFOS appearing most prominently among those in the group with liver cancer. Indeed, their survey found that those who fell into the top 10% most exposed to PFOS were 4.5 times more likely to develop hepatocellular carcinoma than those who were least exposed.
The clear link between PFAS and cancer in humans is crucial for further study of how these chemicals interfere with biological processes. According to current findings, USC scientists now believe that high levels of PFOS in some subjects impaired the liver’s ability to metabolize glucose, bile acids, and branched-chain amino acids, resulting in unhealthy levels of accumulation of fat in the organ, otherwise known as non-alcoholic. fatty liver — a high risk factor for liver cancer.
That’s why many scientists agree that it’s no coincidence that the advent and widespread use of “forever” chemicals is correlated with an increase in liver disease, cancer, and other illnesses.
“We believe our work provides important insights into the long-term effects of these chemicals on human health, particularly regarding how they can damage normal liver function,” said Dr. Leda Chatzi, author of the study. “This study fills an important gap in our understanding of the true consequences of exposure to these chemicals.”