ES&T LETTERS
Correction In the "Destroying hazardous wastes" article (ES&T, Vol. 15, No. 11, 1981, p. 1268) David Wimert of the ACS Department of Public Affairs assisted with the survey. His name was misspelled in the article.
Acid precipitation Dear Sir: In reference to the article "Acid precipitation" (ES&T, Vol. 15, No. 10, p. 1119), I find it incomprehensible that basic (high pH) air pollutants aren't considered. Since the 1960s and 1970s, when the EPA forced cement manufacturing companies to install dust collectors, the air has been "cleaned" of 10 million
tons/y of pollutants that formerly neutralized acidic substances in the air, on the ground, or in our lakes. The fact that the lowest pH regions in the country are just east of the locations of highest concentration of cement plants suggests an immediate remedy, especially since no one has ever shown cement plant emissions to be anything but a nuisance. William G. Hime Vice President Erlin, Hime Associates, Inc. 811 Skokie Boulevard Northbrook, Ill. 60062
Raymond C. Loehr Liberty Hyde Bailey Professor of Engineering
FOR THE 13 th CONSECUTIVE YEAR...
1982 STACK
SAMPLING SEMINARS
Conducted by Walter S. Smith, P.E., President, Entropy Environmentalists, Inc., Research Triangle Park, North Carolina. Mr. Smith was formerly employed by the United States EPA where he co-developed and coauthored EPA Test Methods 1-8, the basis for all stationary emissions sampling. For complete information, including registration fees, contact Mr. Rob Ford, National Sales Manager, at the address or phone number listed.
Call Toll Free 800-638-9566
1 9 8 2 S E M I N A R SCHEDULE
Two Day Technical Seminars The RAC 2 day technical seminars provide a basic understanding of the necessary procedures involved in the complicated art of sampling. Month February April June August October December
Date 4-5 1-2 3-4 5-6 7-8 2-3
Location Orlando, FL New Orleans, LA Las Vegas, NV San Francisco, CA Denver, CO Pittsburgh, PA
Five Day "Hands-on " Seminars The RAC 5 day seminars offer a broad overview of sampling with "hands-on" experiences. Month February May
Date 22-26 17-21
Location Raleigh, NC Raleigh, NC
Sponsored by
RAC
RESEARCH APPLIANCE C O M P A N Y P.O. Box 265, M o o s e Lodge Road C a m b r i d g e , M D . 21613 - 301 -228-9505
® CIRCLE 11 ON READER SERVICE CARD Environ. Sci. Technol., Vol. 16, No. 1, 1982
Lewis M. Naylor, Ph.D. Research Associate Cornell University Ithaca, N.Y. 14853
Dietary cadmium Dear Sir: We wish to acknowledge and clarify the following items related
COMPLIMENTARY SLIDE RULE NOMOGRAPH
6A
to our article titled "Increase in dietary cadmium as a result of application of sewage sludge to agricultural land" ( E S & T , Vol. 15, No. 8, 1981, pp. 881-886). 1. Reference 9 was an important key document used in preparing the summary review presented in the article. 2. Table 1 in the article was taken from reference 9 and should have been so noted.
