Hầu như tất cả mọi người sử dụng một điện thoại di động, và hầu như không ai nghĩ rằng nó là nguy hiểm. Điện thoại di động đã chuyển đổi hoạt động kinh doanh và xã hội theo những cách mà ít người có thể dự đoán cách đây 15 hoặc 20 năm. Công nghệ này hoàn toàn được nhúng trong cấu xã hội của chúng tôi. Tuy nhiên, như với bất kỳ công nghệ mới, mối quan tâm an toàn đã được nâng lên. Mặc dù bằng chứng khoa học rõ ràng nguy cơ ung thư là thiếu,. | 9 Hold the Phone Almost everyone uses a cell phone and almost no one thinks it is dangerous. Cell phones have transformed business and social activities in ways that few people could have predicted 15 or 20 years ago. The technology is now completely embedded in our social fabric. But as with any new technology safety concerns have been raised. Although clear scientific evidence of cancer risk is lacking some governments have issued directives to control cell phone use. Such policies have only served to heighten public fears but not to the point that cell phone use has diminished. The public health impact of cell phones serves as a powerful case study to illustrate themes in this book related to risk assessment and risk management. What constitutes a public health threat How well can we measure small risks when experiences and direct observations are limited Should a precautionary approach to risk management be adopted when evidence of risk is lacking The government of the United Kingdom . has issued a directive that children up to the age of about 16 should avoid using cell phones as a precautionary measure. Invoking the precautionary principle in this way has created serious questions about management of essentially phantom risks. Cell phone use has grown exponentially in the . since 1985 use of cell phones has grown at the rate of about 15 per year. This means that the number of cell phones doubles approximately every 5 years assuming an exponential growth The rate of growth is likely to slow in the near future as population use becomes saturated. In 2005 there were more than 180 million cell phone users in the . Cell phones are nothing more than two-way radios that use electromagnetic radiation in the radiofrequency RF range to transmit and receive signals. What distinguishes RF from visible light and other kinds of electromagnetic radiation is the radiation frequency Figure . Cell phones and other personal communications systems operate in
