RESUMO
The radiofrequency field levels may increase in confined environments, such as underground mines, due to reflections from inner boundaries (walls and arches). This study investigated the specific absorption rate (SAR) in the head and torso of a miner wearing a wireless device in underground mine scenarios. Two high-resolution voxel models were used to analyse the effects of a tunnel structure, a metal arch and a safety helmet at 2.4 GHz and 868 MHz. The results indicated that the SAR increase is modest for all simulated underground mine scenarios and was maximum in the presence of a metal arch. At 868 MHz, some observed that the SAR was greater in deep tissues of the head and torso as compared to SAR at 2.4 GHz. Also, the torso is a better site for mounting wearable devices on the body to mitigate exposure.
Assuntos
Ondas de Rádio , Dispositivos Eletrônicos Vestíveis , Cabeça , Humanos , TroncoRESUMO
BACKGROUND: Remote sensing have been intensively used across many disciplines, however, such information was limited in spatial epidemiology. METHODS: Two years (2009 & 2010) Landsat TM satellite data was used to develop vegetation, water bodies, air temperature and humidity criterion maps to model malaria risk and its spatiotemporal seasonal variation. The criterion maps were used in weighted overlay analysis to generate final categorized malaria risk map. RESULTS: Overall, 25%, 68%, 18% and 16% of the total area of Rawalpindi region was categorized as danger zone for Jun 2009, Oct 2009, Jan 2010 and Jun 2010, respectively. The malaria risk reached at its peak during the monsoon season whereas air temperature and relative humidity were the main contributing factors in seasonal variation. CONCLUSION: Malaria risk maps could be used for prioritizing areas for malaria control measures.