tailieunhanh - Children’s Environmental Health Units

A phenomenon called “mercury sunrise” was discovered in 1995 by Canadian atmospheric researcher Bill Schroeder working in the Arctic. The phenomenon occurs when the sun first returns after the long dark winter, producing high levels of one form of mercury, called reactive gaseous mercury. In fact the highest levels of this form of mercury ever recorded were found in the Canadian Arctic. At the same time, levels of elemental mercury drop dramatically. When he first saw the mercury readings on his instruments fluctuate wildly, Dr. Schroeder assumed the instruments were not working properly. Scientists are just beginning to understand what is causing this phenomenon and why it is seen in the Arctic (and recently in the. | Children s World Health Organization Children s Environmental Health Units ỂỂỀÌÌS World Health Organization WHO Library Cataloguing-in-Publication Data Children s environmental health units. welfare. exposure - prevention and control. personnel - education. health services. Health Organization. ISBN 978 92 4 150042 5 NLM classification WA 320 World Health Organization 2010 All rights reserved. Publications of the World Health Organization can be obtained from WHO Press World Health Organization 20 Avenue Appia 1211 Geneva 27 Switzerland tel. 41 22 791 3264 fax 41 22 791 4857 e-mail bookorders@ . Requests for permission to reproduce or translate WHO publications - whether for sale or for noncommercial distribution - should be addressed to WHO Press at the above address fax 41 22 791 4806 e-mail permissions@ . The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country territory city or area or of its authorities or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted the names of proprietary products are distinguished by initial capital letters. All reasonable precautions have been taken by the World Health Organization to verify the information contained in this publication. However the published material is being distributed without warranty of any kind either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event .