The terms gender dysphoria and gender identity disorder were not used until the 1970s, when Laub and Fisk published several works on transsexualism using these terms. "Transsexualism" was replaced in the DSM-IV by "gender identity disorder in adolescents and adults". Male-to-female transsexualism has sometimes been called "Harry Benjamins syndrome" after the endocrinologist who pioneered the study of dysphoria. As the present-day medical study of gender variance is much broader than Benjamins early description, there is greater understanding of its aspects, and use of the term Harry Benjamins syndrome has been criticized for delegitimizing gender-variant people with different experiences. Sexual orientation
Since the middle of the 20th century, homosexual transsexual and related terms were used to label individuals sexual orientation based on their birth sex. Many sources criticize this choice of wording as confusing, "heterosexist", "archaic", and demeaning because it labels people by sex assigned at birth instead of their gender identity. Sexologist John Bancroft also recently expressed regret for having used this terminology, which was standard when he used it, to refer to transsexual women. He says that he now tries to choose his words more sensitively. Sexologist Charles Allen Moser is likewise critical of the terminology. Sociomedical scientist Rebecca Jordan-Young challenges researchers like Simon LeVay, J. Michael Bailey, and Martin Lalumiere, who she says "have completely failed to appreciate the implications of alternative ways of framing sexual orientation. "The terms androphilia and gynephilia to describe a persons sexual orientation without reference to their gender identity were proposed and popularized by psychologist Ron Langevin in the 1980s.
The International Agency for Research on Cancer finds that tanning beds are "carcinogenic to humans" and that people who begin using tanning devices before the age of thirty years are 75% more likely to develop melanoma.Those who work in airplanes also appear to have an increased risk, believed to be due to greater exposure to UV.UVB light (wavelengths between 315 and 280 nm) from the sun is absorbed by skin cell DNA and results in a type of direct DNA damage called cyclobutane pyrimidine dimers. Thymine, cytosine, or cytosine-thymine dimers are formed by the joining of two adjacent pyrimidine bases within a DNA strand. Somewhat similarly to UVB, UVA light (longer wavelengths between 400 and 315 nm) from the sun or from tanning beds can also be directly absorbed by skin DNA (at about 1/100 to 1/1000 of the efficiency of UVB).Exposure to radiation (UVA and UVB) is one of the major contributors to the development of melanoma. Occasional extreme sun exposure (resulting in "sunburn") is causally related to melanoma. Melanoma is most common on the back in men and on legs in women (areas of intermittent sun exposure). The risk appears to be strongly influenced by socioeconomic conditions rather than indoor versus outdoor occupations; it is more common in professional and administrative workers than unskilled workers. Other factors are mutations in or total loss of tumor suppressor genes.