The scientific investigations revealed many ill effects of using cellphones for a long time especially for females. Some studies indicated infertility and impotency in females and males respectively. It may be due to the mutation of cells due to the microwave communications engaged in the cellphones. Microwave radiation which is composed of electromagnetic waves may be carcinogenic. It is advisable wherever possible to use landphones instead of cellphones and use cellphones only when it is inevitable. High energetic radiations are always dangerous.
Your vote on this answer has already been received
Any equipment which give out radiation is bad for health. various tips are available for sensible use of cell phones... try and limit the use to communicate and not converse like college kids /young girls...