A new study conducted by iFixit and HealthyStuff.org was designed to determine if the smartphones use materials that contain toxic chemicals or not and if they are dangerous to humans.
The study was done on 36 smartphones which were studied using X-ray fluorescence spectrometry to determine the chemical composition.
Out of the 36, only 6 were classified as having a low risk for humans, 24 a medium risk degree and another 6 have a high degree of risk.
All handsets that present a high risk were produced before 2010, with the iPhone 2G bearing the highest.
In the picture above you have the results of the study. The Motorola Citrus has less toxic chemicals, followed by the iPhone 4S, Remrq LG, Samsung Captivate, iPhone 5 and Samsung Evergreen.