Cancer affects millions of lives all over the world, with 1.7 million cases predicted to be diagnosed in 2015. Malignant tumors grow rapidly and can spread to other parts of the body (called “metastasis”) while benign tumors are usually localized to one area. As tumors grow in size, they can destroy the function of different body organs and systems. 
The risks from personal exposure to carcinogens are constantly being studied in cancer research.Radon and cigarette smoke are only two of the substances typically linked to the development of certain cancers. You already knew about those: Here are six more important ones to be aware of.
Formaldehyde, also known as methanal, is used in a vast number of industrial applications and is found in an enormous number of industrial products. Formaldehyde is a volatile organic compound (VOC) and is “off-gassed” from a variety of construction materials, furnishings, and consumer products. The three products that emit the highest concentrations are medium density fiberboard, hardwood plywood, and particle board.  Carpets and memory foam also emit formaldehyde. In 2011, the US National Toxicology Program described formaldehyde as “known to be a human carcinogen”. Owing to its widespread use, you might have a difficult time removing formaldehyde-emitting products from your home entirely, and this is a bigger problem ever before now that modern homes are much more “air sealed” than ever before – for insulation purposes. However the USA and Europe have now limited the allowable emission of formaldehyde in products such as plywood. One thing that is advised is to maintain a supply of fresh air in the home. It’s also possible to obtain VOC-removing air purifiers.