Contents Search publications                                         Previous  Next

As well as long-term animal tests, a range of other tests are used to predict whether a chemical is likely to cause cancer. These are done with cell cultures, for example using mouse lymphoma cells, and micro-organisms such as the bacteria Salmonella (the Ames test) and Escherichia coli, and are known as in vitro (literally, in glass) tests. They are quicker, cheaper, and more ethically acceptable than animal tests. They test a chemical's ability to damage genetic material (genotoxicity), although as mentioned before, most but not all genotoxins cause cancer, and (more importantly) not all carcinogens act by damaging genes. These would not, therefore, be detected if only in vitro tests were used. While animal and in vitro testing might provide regulators with a lot of data, because the mechanisms leading from exposure to effect are often unknown, there is still much educated guesswork involved in risk assessment.

Some human testing of chemicals does occur, e.g. by Zeneca in the UK.

"Most animal tests and epidemiology studies are pretty much limited to high-dose-high-risk situations," J. V. Rodricks.

"Even our best scientific methods still depend heavily on extrapolations and judgements in order to infer human health risks from animal data," A. Watterson.

"Workers are often the 'canaries in the coal mine' who first demonstrate that a chemical is carcinogenic," H. Frumkin.

Contents Search publications                                         Previous  Next