When the President's Cancer Panel released its report stating that environmental chemicals were a "grossly underestimated" cause of cancers in the U.S., the American Cancer Society (ACS) responded by saying the report put too much weight on environmental causes and not enough emphasis on known cancer risks, such as tobacco smoke and obesity.

Hoping to bring a little clarity to the field of chemicals that may trigger cancers, the ACS, three government agencies, and the International Agency for Research on Cancer published a list of 20 chemicals so far not officially linked to cancer but still in widespread use that have the strongest evidence against them that they may cause cancer.

After reviewing the existing research, the authors picked 20 chemicals that showed enough evidence of causing cancer in laboratory tests and in animals that there was a strong likelihood that they could also cause cancer in humans, said Ward.


"What we were looking for were the chemicals for which there was a lack of definitive data that they caused cancer in humans as well as evidence of widespread human exposure," she said.

And many of these chemicals, such as nanoparticles, are so new that there's very little evidence of safety or harm, yet hundreds of new products containing nanoparticles are being introduced every month.

Most of the chemicals on their list are industrial chemicals, for instance, carbon black (a substance used to make synthetic rubber) and welding fumes, but others are much more common and can crop up in everything from our sunscreen to our water supply:

Atrazine: a widely used pesticide on corn that's so hazardous it's banned in Switzerland, the home country of the company that manufactures it.

Chloroform: a water-disinfection by-product that can wind up in your tap water

Diesel engine exhaust

Diethylheyxl phthalate (DEHP): a chemical used to keep vinyl plastics, like your shower curtain, soft and pliable

Formaldehyde: already a known human carcinogen that causes pharynx and nasal cancers, this chemical (used in hundreds of building products) was added to the list because of suspicions that it might cause leukemia

Lead and lead compounds

Polychlorinated biphenyls (PCBs): banned since the 1980s, these industrial flame retardants still linger in our food supply

Styrene: used to make polystyrene foam coffee cups and takeout containers

Perchloroethylene: the commonly used dry-cleaning solvent

Titanium dioxide: used as a colorant in paints but also as an ingredient in sunscreens; the researchers were particularly concerned about nanoparticles of titanium dioxide, which are already suspected of causing brain damage

And, not a chemical, but definitely on the cancer-research radar screen:

Shift work: a growing number of studies are suggesting that workers who don't stick to regular schedules are at an increased risk of cancer.

Ward's study was meant to help researchers identify priorities for occupational cancer research, she said, because "our understanding of what causes cancer in the general population has come about in large part because of studies on occupational exposures."

But, she added, it can take anywhere from 10 to 30 years from the time a chemical is introduced to the time scientists have adequate evidence that it causes cancer in humans, which is why it's important to take the precautionary principle and protect yourself now.

Here are 11 steps you can take to protect yourself from chemicals that may cause cancer:

More on this...

1. Buy a water filter

Water filters now are pretty sophisticated and can remove a wide variety of contaminants, including atrazine, chloroform, and some of the other industrial chemicals that the ACS included on its list, such as trichloroethylene (a solvent used in auto body shops and mechanics' garages) and formaldehyde.

2. Eat organic

By switching to organic food, you're not only eliminating exposures to harmful pesticides like atrazine, you're also supporting a food system that won't pollute your water supply and keeping atrazine out of your water.

3. BYO coffee cups and food containers

Each time you drink out of a polystyrene foam coffee cup or eat takeout from a foam container, you're being exposed to styrene, which leaches out of the plastics when it comes into contact with hot food. Bring a mug or your own glass container when you anticipate that you may need a doggy bag.

4. Be anti antibacterial

Studies published in the journal Environmental Science & Technology suggest that triclosan, the main ingredient in antibacterial soaps and cleaners, can react with the chlorine in your drinking water to form chloroform. And the Centers for Disease Control and Prevention says that warm water and soap are just as effective at cleaning germy hands as antibacterial soaps, anyway. Also watch out for triclosan-treated garden hoses (they supposedly inhibit moss growth inside the hose). You don't want to be spraying chloroform on your organic garden!

5. Be anti vinyl...

The easiest way to avoid exposure to DEHP (the chemical used to keep plastics soft) is to avoid anything made with vinyl—shower curtains, floor tiles, products packaged in vinyl encasements (as curtains and bedding often are). Vinyl plastics may be marked with the number "3" in the recycling triangle, but they may not bear any indication of what type of plastic it is. In that case, use your sniffer. If a product smells plasticky, it's most likely vinyl.

6. …and wash your hands

Vinyl may be unavoidable in some cases. It's used as the external casing for computer cords and other forms of electric wiring, such as Christmas tree lights, and on that plastic wire shelving that many people have in their closets. In some cases, companies add lead to these products as a UV stabilizer; it keeps sunlight from drying the plastic out. So when you handle these types of plastic, wash your hands to prevent exposure to both DEHP (it can come off the plastics and bind to dust) and lead.

7. Test your soil and your paint

Regardless of whether it's in your plastic, lead in soil and lead-based paints remain our primary exposure to this brain-damaging heavy metal. Hopefully, you tested your soil before planting this year's garden; also be vigilant about testing for lead paint when you renovate, particularly if your home is older than 1978 (the year lead paint was banned).

8. Do your own laundry

Most delicate fabrics you'd send to the dry cleaner can easily be hand-washed at home with gentle detergents so you can avoid inhaling that sickly sweet odor of perchloroethylene, which can trigger asthma attacks and headaches.

9. Grill your cabinetmaker

Furniture and building products are by far our largest source of exposure to formaldehyde, used in pressed-wood glues, furniture stains, and a hundred other building products. When doing renovations, look for solid-wood products, or at the very least, ask companies making major installations, such as cabinetry, to use formaldehyde-free glues and finishes.

10. Learn to love white sunscreen

Sure, it's nice to spread on sunscreen and watch it disappear, but that disappearing act usually means your sunscreen contains chemicals known to interfere with hormones, or that it contains nanoparticles, microscopic particles of titanium dioxide or zinc oxide that may make it past your skin and into your bloodstream, where they may cause brain damage, colon damage, or cancer.

11. Relax!

While all this may sound ominous, says Ward, "some of these chemicals are inevitably going to be part of the human environment." Formaldehyde, for instance, exists naturally in wood. You just have to do the best you can to protect yourself from things you can control, and realize that some cancer-causers like diesel-engine exhaust are hard to avoid.

This article first appeared on Rodale Wellness.