New research shows that perfluorinated compounds (PFCs), widely used in manufactured products such as non-stick cookware, waterproof clothing, and fast-food packaging, are associated with lowered immune response to vaccinations in children.
Danish and American researchers analysed data from 587 children tested for immune response to tetanus and diphtheria vaccinations at ages 5 and 7 years. PFCs were measured in maternal pregnancy serum and in the serum of children at age 5 to determine prenatal and postnatal exposure.
The results of the study, published today in the Journal of the American Medical Association (JAMA), showed that PFC exposure was associated with lower antibody responses to immunisations and an increased risk of antibody levels in children lower than those needed to provide long-term protection. (Antibody concentrations in serum are a good indicator of overall immune functions in children.) A two-fold greater concentration of three major PFCs was associated with a 49% lower level of serum antibodies in children at age 7 years.
“Routine childhood immunizations are a mainstay of modern disease prevention. The negative impact on childhood vaccinations from PFCs should be viewed as a potential threat to public health,” said study lead author Philippe Grandjean, adjunct professor of environmental health at Harvard School of Public Health.
PFCs have thousands of industrial and manufacturing uses. Most Americans have the chemical compounds in their bodies. Prior studies have shown that PFC concentrations in mice similar to those found in people suppressed immune response, but the adverse effects on people had been poorly documented.
The UK Science Media Centre collected the following expert commentary:
Prof Alastair Hay, Professor of Environmental Toxicology at the University of Leeds, said:
“The work was well conducted. It suggests that perfluorocarbons (PFCs, chemicals comprised of carbon and fluorine) concentrations have an adverse effect on antibody levels for tetanus and diphtheria toxins, two antibodies chosen for investigation. A single birth cohort was followed and PFCs were measured in the mothers before birth and in the children when they were 5 and 7 years of age and before and after antibody booster vaccination.
“Twofold increases in PFC concentrations were associated with significant falls in antibody levels. In other words children with higher PFC concentrations had lower antibody levels. The study authors were careful to assess whether the type of vaccine, be it combination or single, played any role in their observations and this was taken account of in the analysis by the team.
“So what does this mean? Firstly, it must be an alert for all health and environment authorities. The chemicals, although present in low amounts in our bodies, have very long residence times before they are excreted.
“Grandjean and his co-authors say that the effect they observed occurs at PFC levels which also affect immune function in animals. This is even more concerning because it indicates that the effect occurs across species and at levels of the chemicals which are present in our blood. How the chemicals operate on the immune system is not understood.
“Grandjean and his team’s work will have to be replicated in other human studies. In parallel, work should be done to investigate possible mechanisms by which the PFCs may affect cells in the immune system. We also need to know if there is safe exposure to these chemicals and what it might be. Does the effect change as we get older and well past the stage when there are booster vaccinations?
“The implication of this work is that everyday exposure to these chemicals makes us more vulnerable to infections. We cannot afford to ignore the research, but equally we should not panic. What we need is a measured response to test the findings in a robust way and assess their implications for our health and particularly that of our children.”
Prof Anthony Dayan, independent toxicologist, said:
“Exposure of mothers and children is proven as an analytical methodology so this looks OK. But the association between PFC levels in maternal serum taken late pre-birth, and antibody levels to two standard antigens taken in children aged 5 and after a ‘booster’ using a different vaccine (they admit this complicates interpretation), is not strong.”
“The statement that the antibody levels were below the level accepted for adequate immunity is not properly referenced. The measured level related to immunity (following immunisation or boosting) falls, and the level taken as ‘protective’ must be justified.
“More to the point there is ample information that polyunsaturated fatty acids (PUFAs) are found in marine organisms and they suppress many immune responses. This paper uses neither a control nor even any mention of that well proven fact. So, as eating is claimed to be the source of PFCs and it is the source of the immunosuppressive PUFAs, the study proves nothing.”