December 2nd, 2010
Chemicals found in cleaning products may be harming the health of children and adults, new research suggests.
A study shows that young people who are over-exposed to the soap agent triclosan are more likely to suffer allergies.
The chemical bisphenol A (BPA), which is used in plastics and to line food cans, may suppress the immune system of adults.
A resin coating containing BPA allows tin cans to be heated to kill off bugs without the metal contaminating food.
The chemical will be banned from baby bottles by mid-2011 under a ruling announced last week by the European Commission.
But according to the new research, it may be most harmful to adults.
Scientists in the US carried out the study by analysing data from a major American health and nutrition survey conducted between 2003 and 2006.
Triclosan and BPA concentrations in the urine were compared with allergy prevalence and numbers of CMV (cytomegalovirus) antibodies, which act as a marker of immune system function.
Lead researcher Dr Erin Rees Clayton, from the University of Michigan, said: ‘We found that people over age 18 with higher levels of BPA exposure had higher CMV antibody levels, which suggests their cell-mediated immune system may not be functioning properly.’
The study also found that children and young people aged 18 and under who were exposed to higher levels of triclosan were more likely to have allergies and hay fever.
Co-author Dr Allison Aiello, also from the University of Michigan, said: ‘The triclosan findings in the younger age groups may support the ‘hygiene hypothesis’ which maintains that living in very clean and hygienic environments may impact our exposure to micro-organisms that are beneficial for development of the immune system.
‘It is possible that a person can be too clean for their own good.’
Triclosan is an antimicrobial agent found in many soaps and household cleaning products.
The research is published online today in the journal Environmental Health Perspectives.
Previous animal studies have already indicated that both BPA and triclosan may affect the immune system.
Next, the scientists want to study the long-term effects of the two agents in people.
At present, higher exposures to the chemicals can be seen to be associated with effects on immunity. However, the researchers want to see if there is a causal relationship.
‘It is possible, for example, that individuals who have an allergy are more hygienic because of their condition, and that the relationship we observed is, therefore, not causal or is an example of reverse causation,’ said Dr Aiello.