Spring 2015 Closure

Q. In module 1C you mentioned that the scientific basis for experimental data is weak and that most “scare” chemicals may have never harmed anyone.  Since environmental exposure of a given chemical may have never harmed anyone (although we may never know if that means the regulations helped protect us or if there wasn’t really a significant hazard to begin with) the current process of assessing the risk of various chemicals appears to over protect people.  Do you think the methods or standards should be changed to improve the data used for assessing the risks of various chemicals? 
A. To really get data you would have to expose people, which you can’t do on purpose.  There are data from accidental and workplace exposure, although the exposure dose is usually uncertain.  So, one could spend a lot more money on animal studies, but not get much better results.  The current process is to state the conservative values, then explain that they are probably conservative (although we don’t know how conservative) and then let the decision makers decide. 

Q. Revisiting a question in the closure that didn’t quite answer a question I had:  I understand that the length of time required may be subjective, but… are reversible effects only those which correct themselves on their own, or do they include effects which require medical treatment?
A. They would include medical treatment. 

Question/Comment on an item in one of the closure modules
Q. Often, industry and environmental advocates differ in opinion and may use similar studies to emphasize opposing points. A current example may be Pebble mine.  Let’s say the Cheech beer example applies to fish affected by water contaminants due to a future mine.  Would two opposing groups agree on values such as NOEL, LD50, ED10, etc.? Who is correct?
A. They would agree on the laboratory data.  However that data is just that, “laboratory.” The relevance of the lab data to the environment is what they would argue about.  Also, the likely hood (risk) of its release into the environment. 
Comment:  They do not always agree on the laboratory data- given that a good portion of the arguments are over the laboratory protocols- as an example- under the DWH case- which weathered oil most likely represents what exposure to then use for the tests; which species are most appropriate to use; what constitutes an effect- ie what are the endpoint measurements [only death, reproduction and growth- or many other sublethal potential effects]; do you stir or not, temp., dose and exposure duration.  Unfortunately, unless there is agreement on the laboratory protocols- there will rarely be agreement on the results.
Response. At the litigation – expert witness- level, of course you are right.  At the somewhat-expert level, the question often gets back to what people are trying to prove.  In ecological risk assessment, which we really do not do too much with in this class, the concern is the population, not individuals.  So what does a 10% mortality in an indicator species mean to fishermen?