But that is not how it works.. According to Spencer, an SPF 15 product blocks about 94% of UVB rays; an SPF 30 product blocks 97% of UVB rays; and an SPF 45 product blocks about 98% of rays. After that, it just gets silly, he says.Sunscreens with higher SPF ratings block slightly more UVB rays, but none offers 100% protection.he SPF rating is a measure of the time it would take you to sunburn if you were not wearing sunscreen as opposed to the time it would take with sunscreen on. SPF is not a consumer-friendly number, says Florida dermatologist James M. Spencer, MD.
Definition of cancer - a disease caused by an uncontrolled division of abnormal cells in a part of the body Definition of cancer - a disease caused by an uncontrolled division of abnormal cells in a part of the body
The term oncology literally means a branch of science that deals with tumours and cancers. The word âoncoâ means bulk, mass, or tumor while â-logyâ means study. Each of the cells of the body have a tightly regulated system that controls their growth, maturity, reproduction and eventual death. Cancer begins when cells in a part of the body start to grow out of control. There are many kinds of cancer, but they all start because of out-of-control growth of abnormal cells.