The effect of natural terrestrial gamma radiation emissions and environmental radon levels on the incidence of cutaneous squamous cell carcinoma of the head and neck.

The effects of ionising radiation on the development of cutaneous squamous cell carcinoma have been previously studied in environments in which the levels of ionising radiation have been increased by artificial sources. The purpose of this study is to determine the role that environmental radon concentration and natural gamma radiation emissions may play in the development of head and neck cutaneous squamous cell carcinoma in a geographical area which is known to have high levels of radon and natural terrestrial gamma radiation emissions. A total of 284 patients diagnosed with cutaneous squamous cell carcinoma during the 26-month observation period were included in the study. The overall incidence was 37.33 cases/100,000 people-year. The mean of environmental radon concentration according to their council of residence was 116.69 Bq/m3 (40.05) and the mean of natural terrestrial gamma radiation emitted according to their council of residence was 14.25 Rad/hour (3.86). The multiple linear regression analysis revealed that only mean natural terrestrial gamma radiation emissions in the council of residence (P < 0.05), carrying out an outdoor profession (P < 0.05) and the mean number of hours of sunlight per year in the council of residence (P = 0.03) were found to have statistical significance on the incidence of head and neck cutaneous squamous cell carcinoma. Emissions of natural terrestrial gamma radiation have never been proposed as a factor having an influence on the development of cutaneous neoplasms. The implications that this could have in areas with naturally high terrestrial gamma radiation emissions should be more exhaustively studied to assess the true weight of this factor.