Can cosmetics cause cancer? Which pesticides are safe? The aim of scientific research is to answer questions like these, but what happens when two or more studies produce conflicting results?
Since the 1990s, medical science has relied on ‘systematic review’ as a means of weighing up the available evidence and coming up with a reliable answer. It saves time, resources and avoids unnecessary research.
Approach will be fundamental in resolving chemical controversies like triclosan
Arguing for new approach to risk assessment
In Environment International, guest edited by Lancaster University, a team of international scientists is now arguing for this approach to be taken up in chemical risk assessment to help give clearer answers to chemical concerns.
“When it comes to determining the risk which chemicals pose to human health and the planet, scientists sometimes struggle to come up with a clear answer because there is no universally accepted system for weighing up the available evidence,” said Paul Whaley at the Lancaster University Environment Centre.
This used to be a problem in medicine until they began to introduce a new system for sifting through existing studies to come to a scientifically reliable answer to a particular question.
According to Dr Crispin Halsall, fellow guest editor; “Scientists working in the field of chemical research believe this approach will be fundamental in the future to resolving some of the biggest controversies in chemical risk assessment.”
One such controversy is whether the chemical triclosan, which has been banned in soaps in the EU but is still commonly used in cosmetics, is toxic to humans.
First systematic review showing triclosan maybe toxic
One of the articles in the publication’s special issue is the first systematic review in environmental health to show that triclosan is ‘possibly toxic’ based on its adverse impacts on thyroid hormones.
Dr Paula Johnson, the lead author of the paper and leader of the California Safe Cosmetics Program at the California Department of Public Health, said: “Products may contain ingredients with very limited safety testing or, for example, no data on reproductive effects from prenatal exposure.”
“Agencies should adopt systematic review methods to evaluate the toxicity of chemicals. The public could greatly benefit from this, in terms of health and simply from a consumer right-to-know perspective.”