The Department of Health and Human Services just released a new report adding to the current list of known cancer-causing substances. Styrene and formaldehyde both made the list along with glass wool fibers and 5 other substances.

The report states that the people most at risk from exposure to styrene are:

Workers who fabricate boats, car and truck parts, tanks, and bath tubs and shower stalls with glass fiber-reinforced polyester composite plastics, may breathe in high levels of styrene in the workplace, or may absorb it through the skin.
People breathing indoor air that has styrene vapors from building materials, photocopiers, tobacco smoke, and other products.
Smokers are exposed to styrene because it occurs in cigarette smoke.

Styrene may also leach from polystyrene containers used for food products, but the study states that these levels of styrene are very low. I've highlighted building materials and photocopiers here because many people work in buildings where the climate is controlled and the windows don't open. It's important to be aware that if you're working in a climate-controlled building that has been built or re-modeled recently, or if you're spending a lot of time around a photocopier, then you may be at greater risk. Try to get outside on your lunch break for some fresh air.

The report outlines similar concerns about formaldehyde. People with high exposure risk to formaldehyde include:

manufacturers of formaldehyde and formaldehyde-based resins, woodworking, and furniture making.
Morticians and laboratory workers
People exposed to tobacco smoke, automobile and other combustion sources, such as wood stoves, incinerators, refineries, forest fires, and fumes released from new construction or home-finishing products
People using or working with consumer goods, including some hair smoothing and straightening products used in salons, cleaning agents, glues, and adhesives

So again, if you're working in a place where there are a lot of fumes, whether it's a factory, a workshop, or a beauty salon, make sure to get as much fresh air as you can during your breaks and off-hours. What a good excuse to take a walk after lunch!