"Map" of Chemicals Could Help Reduce Animal Testing
Excerpted from The Washington Post
What can the chemicals we know are hazardous tell us about chemicals we know nothing about? Quite a lot — and an unprecedented new project to map the world’s chemical landscape could help scientists figure out which compounds are dangerous without spending billions on testing.
In 2007, the European Union began to require that substances manufactured or imported in quantities of a ton per year or more be registered and described. REACH, or Registration, Evaluation, Authorization and Restriction of Chemicals, requires companies to collect information on chemicals’ properties and uses and describe their hazards.
The result was an enormous amount of chemical data — descriptions of tens of thousands of chemicals and their properties. But those chemicals are just the tip of the iceberg: For every chemical that has been tested, there are tens of thousands that haven’t. Thomas Hartung, a public health toxicologist at Johns Hopkins who directs the Center for Alternatives to Animal Testing, estimates that there are 100,000 chemicals in everyday products alone, 90 percent of which have never been tested.
But therein lies the beauty of chemistry. When it comes to toxicology, it turns out that chemically similar substances usually have similar effects on humans. Consider the case of bisphenol-S. The chemical came into wide use when its relative, bisphenol-A, was found to mimic estrogen and linked to a host of diseases and disorders. Bisphenol-S, which is chemically similar to bisphenol-A, was touted as an alternative for baby bottles and plastic cups — but earlier this year, scientists announced that it appears to affect animal embryos in similar ways.
Since similar chemicals have similar effects, reasoned Hartung, why not map their relationships? His team embarked on a dizzying data project, sorting out REACH data for 10,000 chemicals and adding info from over 800,000 research studies conducted on those chemicals alone. They created a computer model that shows which chemicals are similar to other chemicals with the click of a button. The results were published last month in the journal ALTEX.