Childhood jabs are 'less effective' in youngsters exposed to food packaging chemicals
Children with PFCs in their blood stream were less likely to respond to vaccines for tetanus and diptheria
Jabs: Children with PFCs in their blood stream were less likely to respond to two vaccines
Food packaging chemicals can weaken the ability of vaccination jabs to protect young children, research suggests.
A study founds children exposed to perfluorinated compounds (PFCs) in the womb or in the first years of life had lower immunity to tetanus and diphtheria.
The chemicals are widely used in manufacturing and food packaging. They are found in everything from teflon cookware, to microwave popcorn bags and stain-resistant carpets.
Scientists analysed data on 587 children born in the Faroe Islands between 1999 and 2001.
The children were tested for immune responses to tetanus and diphtheria vaccinations at the ages of five and seven years.
Researchers also measured PFC levels in the blood of mothers and five-year-olds.
The findings, published today in the Journal of the American Medical Association, showed that PFC exposure was associated with fewer numbers of antibodies, an essential part of the immune system.
It also increased the chances of children having antibody levels insufficient to provide long-term protection.
Doubling the concentrations of three major PFCs led to a halving of antibody levels in children at age seven.
Study leader Dr Philippe Grandjean,
from the Harvard School of Public Health in Boston, US, said: 'Routine
childhood immunisations 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.'
PFCs are found in microwave bags of popcorn
Exposure to two common PFCs before birth had a negative impact on diphtheria vaccinations.
A two-fold increase in levels of one, perfluorooctane sulfonic acid (PFOS), reduced antibody counts by 39 per cent in five-year-olds.
'If the associations are causal, the clinical importance of our findings is therefore that PFC exposure may increase a child's risk for not being protected against diphtheria and tetanus, despite a full schedule of vaccinations,' the authors wrote.
The trend may reflect a more general impact on the immune system's ability to fight infection, said the scientists.
'PFC-associated decreases in antibody concentrations may indicate the potential existence of immune system deficits beyond the protection against the two specific bacteria examined in this study,' they added.
Chemical risk Some stain-resistant carpets contain PFC, which has been found to reduce a baby's immunity
The fishing community of the Faroe Islands, which lie between Scotland and Iceland, was chosen for the study because frequent consumption of marine food is associated with increased PFC exposure.
However, the PFC levels seen in the research were similar or slightly lower than those previously reported in US women, said the researchers.
Most PFC blood concentrations in five-year-old Faroese children were lower than those in US children aged three to five.
British expert Alastair Hay, Professor of Environmental Toxicology at the University of Leeds, said the research “must be an alert for all health and environment authorities”.
He added: '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.
'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.'
Dr Tony Fletcher, senior lecturer in environmental epidemiology at the London School of Hygiene and Tropical Medicine, said: 'Most of the results would suggest that vaccine protection is being reduced by these exposures, either exposures during childhood or their earlier exposures prenatally passed on from their mothers.
'But the picture is not so clear in that for one of the vaccines, tetanus, the opposite effect appears where antibody levels at age seven go up, not down, with exposure to PFOS. So maybe chance is playing a part here in some of the results.
'This is the first such study so it will be important to see if other studies of exposed populations show consistent findings either on infection disease risk or immune function.'