Clean freaks beware: a new study carried out by the Silent Spring Institute is the first of its kind to link cleaning products with breast cancer risk. The results showed that air fresheners, products for mold and mildew control and insect repellents were most associated with the increased cancer rates.

Silent Spring Institute researchers carried out telephone interviews with more than 1,500 women, around half of whom were already diagnosed with breast cancer, and asked them about their product use and beliefs about breast cancer causes.

"Women who reported the highest combined cleaning product use had a doubled risk of breast cancer compared to those with the lowest reported use," said Julia Brody, executive director of Silent Spring Institute.

Because the report was based entirely upon telephone interviews, some subject bias did factor into the results. For instance, women who believed that chemicals and pollutants contribute "a lot" to the risk of developing breast cancer were more likely to report high product usage, indicating that their beliefs in hindsight may have influenced the accuracy of their recollection.

"When women are diagnosed with breast cancer, they often think about what happened in the past that might have contributed to the disease. As a result, it may be that women with breast cancer more accurately recall their past product use or even over-estimate it," Brody noted.

The interviews did reveal that many of the women who developed cancer claimed to be the first in their family to get the disease, a fact which, if true and statistically relevant, might strengthen the study's findings since heredity would be eliminated as a potential risk factor.

Researchers admit that a more thorough investigation needs to take place to determine the true extent of the risk, which cleaning products may carry the greatest risk, and to eliminate subject bias, but the results are nevertheless sufficient grounds for further study.