Almost all cancers can be attributed to known carcinogens and carcinogenic lifestyles, such as tobacco, alcohol, sun, excessive red and processed meats, lack of fruit and vegetables, obesity, bacteria, viruses and lack of exercise.
Yet with so many people getting cancer these days, not to mention the apparent increase in fertility problems, allergies, attention deficit hyperactivity disorder, chronic fatigue syndrome and other modern-day maladies, it's not surprising people worry about man-made chemicals in our food, homes and the environment.
Given the ubiquity of their use, it's easy to blame ingredients in beauty products. Many substances haven't been well studied, and there are vested interests on both sides ensuring the message about the safety or danger of chemicals gets maximum – and credible – airplay.
On the upside, we found many of the products from major international brands no longer contain any of the more dubious ingredients. In the globalised marketplace, there's little sense in producing different formulations for different countries – some with a banned or restricted chemical and others without.
As a result, the once-common dibutyl phthalate, toluene, butylated hydroxyanisole (BHA) and petroleum distillates have all but disappeared from big brand nail polishes, lipsticks and mascaras.
However, beyond these international brands, the findings were less reassuring. As well as supermarkets, department stores and chemists, we looked in ethnic grocers and two-dollar shops and found examples of cosmetics made in Australia, Asia and the Middle East that contain chemicals banned or restricted elsewhere.
Of concern, too, was the number of products without ingredients listed, particularly skin whiteners, henna for tattoos and certain eye make-up products that are sometimes found to contain heavy metals (lead and mercury) or other problem chemicals.
The US-based health and environment advocacy coalition, Campaign for Safe Cosmetics, is lobbying to get the personal care products industry to phase out use of chemicals linked to cancer, birth defects and other serious health concerns, and replace them with safer alternatives – already with some successes.
Should you be worried?
Many chemicals used in personal care products are dangerous in high concentrations, high dose (when administered to laboratory animals) and industrial quantities. Some people may also suffer an allergic reaction to the smaller quantities, such as you'd find in personal care products, and some endocrine disrupting chemicals have an effect at very low doses.