Health and the ozone layer

Ultraviolet Radiation and Cataract—A Review

Senile cataract has become a serious public health problem as the elderly population is increasing worldwide. As lens with dark iris is reported to have a higher prevalence of cataract, public health concern about cataract in Asia is a bigger issue. Among factors assumed to be involved in the pathogenesis of cataract, ultraviolet radiation (UV) has received much attention in accordance with the recent problem of ozone column depletion. It has been agreed that UV induces cataract in animal and biochemical experiments. However, in epidemiological studies, such agreement has not been reached. There are many factors that should be considered and controlled when investigating the association between cataract and UV.

In this review, we summarize major findings obtained so far on the relationship between UV and cataract, and we discuss important factors that may be the cause of disagreement in epidemiological studies. We also point out some of the research foci which should be clarified and propose protective measures against UV induced cataract.

Malignant melanoma in the 21st century, part 1: epidemiology, risk factors, screening, prevention, and diagnosis

Malignant melanoma is an aggressive, therapy-resistant malignancy of melanocytes. The incidence of melanoma has been steadily increasing worldwide, resulting in an increasing public health problem. Exposure to solar UV radiation, fair skin, dysplastic nevi syndrome, and a family history of melanoma are major risk factors for melanoma development. The interactions between genetic and environmental risk factors that promote melanomagenesis are currently the subject of ongoing research. Avoidance of UV radiation and surveillance of high-risk patients have the potential to reduce the population burden of melanoma. Biopsies of the primary tumor and sampling of draining lymph nodes are required for optimal diagnosis and staging. Several clinically relevant pathologic subtypes have been identified and need to be recognized. Therapy for early disease is predominantly surgical, with a minor benefit noted with the use of adjuvant therapy. Management of systemic melanoma is a challenge because of a paucity of active treatment modalities. In the first part of this 2-part review, we discuss epidemiology, risk factors, screening, prevention, and diagnosis of malignant melanoma. Part 2 (which will appear in the April 2007 issue) will review melanoma staging, prognosis, and treatment.