To accompany feature “New study raises questions about cell-phone safety” 

SCIENCE

Before Reading: 

1.   How does a signal get through the air from a cell-phone tower to your mobile phone, and then back again?

2.   When did you first use a cell phone? How many minutes a day or week do you use it now?

During Reading:

1.    What does RF stand for — and is it a type of ionizing or non-ionizing radiation? What do those terms even mean?

2.    What did the World Health Organization conclude about the safety of cell-phone use?

3.    John Bucher says that findings of the NTP cell-phone research warrant further study. What was one reason he gave for why?

4.    How many Americans own cell phones, and how many children 8 to 12 years old use such phones?

5.    Animals in the new NTP study were exposed to CDMA and GSM signals. What do the letters stand for and why were the two types of signals tested?

6.    What were the “controls” in these NTP studies?

7.    Christopher Portier says “distance is your friend.” What does he mean by that and what is his take-home message about this for people who use cell phones?

8.    According to the article, how long can it take for a carcinogen to cause cancer in people?

9.    What did the CTIA say about the results of peer-reviewed studies on cell phones?

After Reading:

1.   Do some research on animal testing. Some background materials can be available at many sites, including here and here. The NTP researchers studied the effects of RF radiation in rodents. Why do you think they used two rodent species? Why do such research centers use animals at all, instead of relying solely on human data? Many people don’t like animal testing to stand in for humans. Name some of advantages — and limitations — of investigating human risks without using animals?

MATH

1.    According to the CTIA, in the United States 51 percent of high-school students and 28 percent of middle-school students carry a smartphone (a type of cell phone) to school. If there are 8.9 million middle-school students and 17.8 million high-school students, then how many of them take a smartphone to school? Show your work.

2.   The animals were exposed over a 9-hour day for 10 minutes on and 10 minutes off, over and over again. How many hours of exposure does that add up to each week? Each year? Show your work.

3.   Track your phone use over the course of 7 days. Now graph your data to show how your phone use varies by day. Now graph it another way to show which time of day (before school, during school, after school but before dinner, after dinner) you tend to talk most on the phone?