RESEARCH PROGRESS ON ECOTOXICOLOGY 



PART 2 



LABORATORY MICROCOSM TESTS 



James W. Giliett 



INTRODUCTION 



Understanding the role that pollution plays in irretrievable losses of resources is 

 critical to the ecological and economic survival of man. It has long been 

 acknowledged that fisheries, forests, agricultural lands, game, and other wild species 

 of plants and animals are at risk from increased environmental pollution. Yet, only as 

 man came to rely more heavily on chemicals derived in laboratories was the empirical 

 knowledge from studies in the field, lake, and stream also addressed in the 

 laboratory. Attempts to quantify biological measurements of impact were under- 

 taken in earnest during the decades of the 1950s and 1960s. These measurements 

 became critical in the evolution of an assessment logic and control approach that has 

 seen increasing reliance on laboratory testing. 



Laboratory testing is now the backbone of such evaluations as pesticide and drug 

 registration processes, pre-manufacturing review of toxic substances, worker and 

 consumer safety studies, and practically every other aspect of chemical regulation. It 

 encompasses not only biological effects, but, just as importantly, the fate and 

 movement of the chemical pollutants. Because of sensitivity, specificity, and cost, 

 biological testing has again come to be used in evaluation of complex effluents (such 

 as waste streams from coal gasification plants). Increased attention to precise 

 physiochemical measurements, structure-activity relationships, and comparative 

 toxicologic relationships now has become part of an approach to protecting the 

 environment that is easily taken for granted. We only have to recall how much of a 

 struggle it has been to reach our current state of "knowledgeable ignorance." 



A decade ago biologists were literally swamped with needs created by the growing 

 awareness of the impact of pollutants. Increasingly sophisticated chemical analysis 

 revealed the presence of ubiquitous and persistent toxicants such as l,l-(p-chloro- 

 phenyl)-2,2,2-trichloroethane (DDT) and polychlorinated biphenyls (PCB). Argu- 

 ments over which pollutant was most significantly involved in major ecological 

 problems — loss of certain fisheries, failure of bird reproduction, increasing eutro- 

 phication of lakes, etc. — led to acrimonious finger-pointing as to which polluter was 

 going to have to bear the burden of cleaning up. The potent awakening of 

 environmental concerns in the mid-1960s engendered more questions and rhetoric 

 than solutions. 



By 1970, certain scientific tools were beginning to be recognized and accepted. 

 These tools consisted of various laboratory tests which depended upon standardized 

 conditions for production of data which, if they did not represent exactly what went 



The Author: Dr. Giliett is Leader of the U.S. Environmental Protection Agency's Chemical Biodegrada- 

 tion/Soil Microbiology Team at the Environmental Research Laboratory at Corvallis. Oregon. Prior to 

 joining the U.S. EPA in 1 974, Dr. Giliett was Associate Professor of Agricultural Chemistry at Oregon State 

 University. His research interests include pesticide toxicology and physical and mathematical modeling of the 

 environment. 



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