Table 1.

Comparison between low- and high-media exposures respondents (those below vs. above the 50th percentile for all panelists participating at T1; 8 separate media use indexes combined; all risk perception data reported on 5-point scale from 1 = “not important” to 5 = “very important” in response to question: “How risky do you believe nanotechnology will be for society over the next 20 years with respect to each of the following areas?”)

	Perceived 20-year risk (5-point scale) of nanotechnology for respondents characterized by:
	Low-media exposure		High-media exposure		“Risk gap”
In the area of	T1	T2	T1	T2	T2
Human health	3.04	3.25	3.18	3.75a	+0.50
Animal health	3.08	2.96	2.96	3.21	+0.25
Environmental pollution	2.56	2.88	2.89	3.14	+0.26
Expenses	2.92	3.20	2.96	3.57b	+0.37
Rich/poor country divide	2.80	3.00	3.50	3.89	+0.89
Privacy issues	2.88	3.68c	3.39	3.93d	+0.25
Access issues	2.76	2.92	3.39	3.32	+0.40
Economic insecurity	2.36	2.72	2.93	2.82	+0.10

The “risk gap” represents the degree to which high media exposure respondents continue to perceive more risk than low-media exposure respondents at T2. Significance levels of p = 0.100 or below based on 2-tailed t-tests between T1 and T2 values for perceived risk by type of risk separately for each exposure group are indicated in footnotes a–d. Includes only respondents who remained active in study at T2 (N = 57)

^ap = 0.080

^bp = 0.027

^cp = 0.041

^dp = 0.037