Scientists at the University of Ulster are investigating a possible link between sunscreens and Alzheimer's disease. Some man-made nanoparticles in the sunscreen could be the problem.
Professor Vyvyan Howard, a pathologist and toxicologist and Dr Christian Holscher, an expert in Alzheimer's disease are leading this groundbreaking research into whether human engineered nanoparticles can induce neurodegenerative disease, according to a university press release.
A nanoparticle measures between 1 and 100 nanometres. A nanometre is one millionth of a millimetre.
Their research is part of a worldwide project call NeuroNano which includes European academic partners at the universities of Dublin, Cork, Edinburgh and Munich. In America, the universities of California, Rochester and Rice and in Japan the National Institute of Materials Science.
"The overall science and technology objective of this programme is to determine if engineered nanoparticles could constitute a significant neuro-toxicological risk to humans for two diseases - Alzheimer's and Parkinson's," said Professor Howard.
The University of Ulster experts will be specifically looking at nanoparticles present in chemicals found in sunscreens and an additive in some diesel fuels - titanium dioxide and cerium oxide - and their connection to Alzheimer's and Parkinson's diseases.
"There is now firm evidence that some engineered nanoparticles entering intravenously or via lungs can reach the brains of small animals. Indeed they lodge in almost all parts of the brain and there are no efficient clearance mechanisms to remove them once there," said Professor Howard.
"There are also suggestions that nanoscale particles arising from urban pollution have reached the brains of animals and children living in Mexico City.
"It has recently been discovered that nanoparticles can have highly significant impacts on the rate of misfolding of key proteins associated with neurodegenerative diseases like Alzheimer's and Parkinson's disease.
"The brain itself is a very special organ. It cannot repair by replacing nerve cells, the ones you get at birth have to last all your life, which makes them peculiarly vulnerable to long term low dose toxicity.
"The brain has built up some protective mechanisms, such as the blood brain barrier. A major worry is that nanoparticles seem to be able to circumvent this. All this adds up to a new field of investigation.
"This research programme is deeply challenging and entails the gathering of entirely new knowledge in a field - neuronanotoxicology.
"It requires the marshalling of unique expertise, methodologies, techniques and materials, many themselves completely new and never before brought together in the required combination.
"The latest figures show that neurodegenerative diseases currently affect over 1.6% of the European population, with dramatically rising incidence likely in part to the increase of the average age of the population. This is a major concern for all industrialized societies.
"There is also some epidemiological evidence that Parkinson's disease is connected to environmental pollutants and it is often noted that historically, reports of Parkinson's symptoms only began to appear after widespread industrialization.
"There is some general agreement that pesticides are significant risk factors. There are persistent claims, based on the epidemiology, that pollution may be a co-factor in Alzheimer's disease, but here the evidence is controversial.
"The risk that engineered nanoparticles could introduce unforeseen hazards to human health is now also a matter of growing concern in many regulatory bodies, governments and industry."
The NeuroNano Programme builds on some striking published findings as well as preliminary data from most significant circumstantial evidence that nanoscale particles could impact on such diseases.