The U.S. Department of Health and Human Services added eight more substances to its "known human carcinogen" or "reasonably anticipated to be carcinogen" lists today, one week after a World Health Organization study concluded that cell phones may cause cancer.
Among the substances is styrene, a synthetic chemical found in Styrofoam and used in the manufacturing process for products such as pipes, fiberglass, automobile parts and other materials.
"As a pediatrician, I'm in the business of urging caution and I think this is a case where it's reasonable to urge caution even while the data are incomplete," Dr. Phillip Landrigan of Mount Sinai School of Medicine told ABC News.
John Bucher, associate director of the National Toxicology Program (NTP), emphasized that this report highlights the fact that we need to be aware of what's around us.
"This report underscores the critical connection between our nation's health and what's in our environment," he said in a prepared statement released today.
The report from the National Institute of Environmental Health Sciences (NIEHS), part of the Department of Health and Human Services, provides a list of likely and definitive carcinogens. It is released biannually has been a factor in regulatory decision making in the past, although the document is not a regulatory statement.
"Reducing exposure to cancer-causing agents is something we all want, and the Report on Carcinogens provides important information on substances that pose a cancer risk," Linda Birnbaum, director of both the NIEHS and the NTP, said in a prepared statement released today.
Two New 'Known Human Carcinogens'
Formaldehyde: Has been previously listed as a suspected human carcinogen, but has now been moved into the definitive category, "known to be a human carcinogen."
Formaldehyde can be found in salon hair treatments, tobacco smoke, paints, gas cookers and foam insulation, among other products. A review of human studies showed formaldehyde exposure can cause cancers including throat cancers and myeloid leukemia.
"We're finding based on empirical evidence that there's uncertainty of the biological basis on how the leukemia is forming. But it's conclusive to add because it fits the criteria from an epidemiological standpoint," Bucher said in the teleconference announcing the report today. "The experts that evaluated the studies associating formaldehyde and leukemia laid out a clear narrative."
Aristolochic acids: These have been added to the list because researchers believe it has been sufficiently proven by human studies to cause high rates of bladder and upper urinary tract cancers among people with kidney or renal disease who consumed botanical products containing the acids.
In 2001, the FDA recommended against using any products that include the acids, but they can still be found online and around the world, especially in "herbal medicines."
6 New Substances 'Reasonably Anticipated to Be Carcinogens'
Styrene: A synthetic chemical used around the word in the manufacturing process of many products, styrene has been added to the list based on human cancer studies, laboratory animal studies, and mechanistic scientific information. It is found in rubber, plastics and insulation, among other objects, but the general population is generally exposed to it through cigarette smoke.
The makers of Styrofoam disagree with the new classification, saying that today's announcement is "completely unjustified by the latest science."
Captafol: A fungicide used by farmers outside of the U.S. that has been shown to induce cancer in experimental animal studies, captafol has been banned in the U.S. since 1999.
Certain glass and wool fibers (inhalable): These are commonly found in home insulation products. Some of these low-cost, general-purpose fibers are typically used for insulation and premium special-purpose wool and fibers used for thermal and sound insulation.
Cobalt-tungsten carbide (in powder and hard metal form): Used in hard metal manufacturing.
Ortho-Nitrotoluene: Used in synthetic dyes such as magenta and various sulfur dyes for cotton, wool, silk, leather and paper. In addition, it is used as an intermediate in the synthesis of explosives and a variety of organic chemicals, including compounds used in agricultural chemicals, pesticides, petrochemicals, pharmaceuticals and rubber industries.
Riddelliine: Contained in some plants, they are not used for food in the United States and have no known commercial uses.
ABC News' Lara Salahi contributed to this article.