Chapter 14, Problem 1DAA

Summary Introduction

To determine: The country that receives the most UV radiation.

Introduction: The reflectance index is a measure of the amount of light energy especially UV radiations absorbed by the body per unit area. The variation of color in human skin shows the amount of melanin synthesized in melanosomes. More melanin pigments provide protection against UV radiations and reflect less light.

Answer to Problem 1DAA

Correct answer: Country K receives the most UV radiations.

Explanation of Solution

As given in the problem statement, researchers in the year 2000 measured the average amount of received UV radiation in more than fifty regions of the world. These data correlated with average skin reflectance of people native to those regions. Skin reflectance is measured as the amount of light at 685nm wavelength is reflected from the skin. It is a way to measure the amount of melanin in skin as more melanin reflects less light. Refer Fig. 14.1, “Average skin reflectance of people native to ten countries correlated with regional incident UV radiation”, in the textbook. It shows skin reflectance in people native to ten countries and UVMED for each country, that is, the amount of annual average UV radiation received at the earth’s surface. As per the data given in the figure, Country K with the highest UVMED (354.21) receives the most UV radiation.