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LETTERS It's your health
Dear Sir: Your editorial (€S&T, December 1975, p 1101) was fresh and to the point. Your admonishment to read Assistant Editor Lois Ember's special report was well taken. She did a great job of amalgamating diverse and difficult subjects into a cogent, readable article. The theme "It's your health", the importance of toxic substances, and the apparent lingering interest of Congress may suggest the desirability or need for your kind of lucid reporting to focus attention on that complicated issue. Or have you already done so and I've missed it! Industrial, commercial, and urban developments here have done much to improve economic and social conditions. The value of tourism, its impact on rnigration within the country, and developing environmental conflicts pose opportunities for societal choice. Establishing methodologies for environmental impact assessment, taking into consideration strong cultural concerns for littoral ecosystems, landscape, and historical monuments, makes fact finding for political action in this fast-developing country fun and hard work. Lois Ember's article will give us more help in assisting our Yugoslav colleagues to sort out issues and develop perspectives for environmental protection. A "message" on toxic substances would be welcome. John T. Middleton United Nations Development Programme lstarska 6-51000 Rijeka. Yugoslavia Ed: John T. Middleton was formerly the Commissioner of NAPCA, the National Air Pollution Control Administration, predecessor of the U.S. EPA.
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Environmental Science & Technology
Impact of chlorination
Dear Sir: After much thought reviewing all of the presentations at the Oak Ridge conference (€S&T, January 1976, p 20) there are two significant thoughts I would like to express. The 15-minute chlorine demand of a raw water supply (potable) should be a water quality parameter. For example, if this chlorine demand is in excess of 5 mg/l the raw water should be rejected because it is too polluted. As for the value of wastewater disinfection practices, many experts view this as a wasted effort. Not so! Several years of applying the disinfection requirement in California reveals that the value of a disinfection system as a pollution monitoring and control device is well worth the effort, in addition to the benefits from its value as a formidable barrier in the spread of waterborne disease. Any wastewater treatment plant operator, when confronted with an effluent coliform requirement, soon finds outusually to his great surprise-that the disinfection process is all but a complete
failure unless all the treatment plant unit processes are functioning properly. It is quite probable that the most important benefit of a wastewater disinfection facility is its value as a pollution monitoring device. Therefore, one of the major benefits of wastewater disinfection is the fact that its efficiency is a measure of pollution control. If we cannot achieve disinfection efficiently, we are not solving waterways pollution. Geo. Clifford White San Francisco, Calif. 941 18 Legal opinions
Dear Sir: John P. Hills has done an able job of summarizing existing legal decisions and opinions (€S&T, March 1976, pp 234-238), but has gone beyond his mandate and existing knowledge in adducing fluorocarbons as an example of infinite harm. Numerous people have tried to prove that the entire population of the Earth is at risk in this case. This is simply not so. Even if the entire hypothesis is correct, the population at risk remains essentially the small group of fair-skinned blonds. If one adds to this the recent finding of John Eddy (reported in Science 191, 1159, 19 March 1976) of several historical periods during which, if the theories to date are correct, the ozone must have been depressed to levels comparable with the forecast effects of continued fluorocarbon release for centuries, yet without any recorded biological impact, the whole matter becomes much too nebulous to warrant action at this time. Finally, it should be noted that the incremental risk of waiting until better information is available has been shown to be trivial. I submit that this is not an example of a case in which immediate actiljn is warranted, but rather of one meriting a Scottish verdict of not proven. Present talk of an enforced moratorium on fluorocarbon release is very little short of vigilante justice. James P. Lodge Consultant in Atmospheric Chemistry Boulder, Colo. 80303 The specter of cancer
Dear Sir: In the Special Report (€S&T, December 1975, p 1116) the author cannot be blamed for mentioning that NCI scientists had reported that counties having copper, lead, or zinc smelters had higher than normal lung cancer mortality and that the scientists had suggested airborne arsenic might be the cause. She should also have noted, however, that the NCI authors cited no arsenic data, either for smelters or ambient air, to support their speculation. The fact is that copper smelters account for most of the arsenic intake of the
